Search results for: CO2 removal
1000 Sorption Properties of Biological Waste for Lead Ions from Aqueous Solutions
Authors: Lucia Rozumová, Ivo Šafařík, Jana Seidlerová, Pavel Kůs
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Biosorption by biological waste materials from agriculture industry could be a cost-effective technique for removing metal ions from wastewater. The performance of new biosorbent systems, consisting of the waste matrixes which were magnetically modified by iron oxide nanoparticles, for the removal of lead ions from an aqueous solution was tested. The use of low-cost and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods. This article deals with the removal of metal ions from aqueous solutions by modified waste products - orange peels, sawdust, peanuts husks, used tea leaves and ground coffee sediment. Magnetically modified waste materials were suspended in methanol and then was added ferrofluid (magnetic iron oxide nanoparticles). This modification process gives the predictions for the formation of the smart materials with new properties. Prepared material was characterized by using scanning electron microscopy, specific surface area and pore size analyzer. Studies were focused on the sorption and desorption properties. The changes of iron content in magnetically modified materials after treatment were observed as well. Adsorption process has been modelled by adsorption isotherms. The results show that magnetically modified materials during the dynamic sorption and desorption are stable at the high adsorbed amount of lead ions. The results of this study indicate that the biological waste materials as sorbent with new properties are highly effective for the treatment of wastewater.Keywords: biological waste, sorption, metal ions, ferrofluid
Procedia PDF Downloads 136999 Effectiveness of Catalysis in Ozonation for the Removal of Herbizide 2,4 Dichlorophenoxyacetic Acid from Contaminated Water
Authors: S. Shanthi
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Catalyzed oxidation processes show extraordinary guarantee for application in numerous wastewater treatment ranges. Advanced oxidation processes are emerging innovation that might be utilized for particular objectives in wastewater treatment. This research work provides a solution for removal a refractory organic compound 2,4-dichlorophenoxyaceticacid a common water pollutant. All studies were done in batch mode in a constantly stirred reactor. Alternative ozonation processes catalysed by transition metals or granular activated carbon have been investigated for degradation of organics. Catalytic ozonation under study are homogeneous catalytic ozonation, which is based on ozone activation by transition metal ions present in aqueous solution, and secondly as heterogeneous catalytic ozonation in the presence of Granular Activated Carbon (GAC). The present studies reveal that heterogeneous catalytic ozonation using GAC favour the ozonation of 2,4-dichlorophenoxyaceticacid by increasing the rate of ozonation and a much higher degradation of substrates were obtained in a given time. Be that it may, Fe2+and Fe3+ ions decreased the rate of degradation of 2,4-dichlorophenoxyaceticacid indicating that it acts as a negative catalyst. In case of heterogeneous catalytic ozonation using GAC catalyst it was found that during the initial 5 minutes of contact solution concentration decreased significantly as the pollutants were adsorbed initially. Thereafter the substrate started getting oxidized and ozonation became a dominates the treatment process. The exhausted GAC was found to be regenerated in situ. The percentage reduction of the substrate was maximum achieved in minimum possible time when GAC catalyst is employed.Keywords: ozonation, homogeneous catalysis, heterogeneous catalysis, granular activated carbon
Procedia PDF Downloads 243998 Removal of Nickel and Vanadium from Crude Oil by Using Solvent Extraction and Electrochemical Process
Authors: Aliya Kurbanova, Nurlan Akhmetov, Abilmansur Yeshmuratov, Yerzhigit Sugurbekov, Ramiz Zulkharnay, Gulzat Demeuova, Murat Baisariyev, Gulnar Sugurbekova
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Last decades crude oils have tended to become more challenge to process due to increasing amounts of sour and heavy crude oils. Some crude oils contain high vanadium and nickel content, for example Pavlodar LLP crude oil, which contains more than 23.09 g/t nickel and 58.59 g/t vanadium. In this study, we used two types of metal removing methods such as solvent extraction and electrochemical. The present research is conducted for comparative analysis of the deasphalting with organic solvents (cyclohexane, carbon tetrachloride, chloroform) and electrochemical method. Applying the cyclic voltametric analysis (CVA) and Inductively coupled plasma mass spectrometry (ICP MS), these mentioned types of metal extraction methods were compared in this paper. Maximum efficiency of deasphalting, with cyclohexane as the solvent, in Soxhlet extractor was 66.4% for nickel and 51.2% for vanadium content from crude oil. Percentage of Ni extraction reached maximum of approximately 55% by using the electrochemical method in electrolysis cell, which was developed for this research and consists of three sections: oil and protonating agent (EtOH) solution between two conducting membranes which divides it from two capsules of 10% sulfuric acid and two graphite electrodes which cover all three parts in electrical circuit. Ions of metals pass through membranes and remain in acid solutions. The best result was obtained in 60 minutes with ethanol to oil ratio 25% to 75% respectively, current fits into the range from 0.3A to 0.4A, voltage changed from 12.8V to 17.3V.Keywords: demetallization, deasphalting, electrochemical removal, heavy metals, petroleum engineering, solvent extraction
Procedia PDF Downloads 302997 Radiographic Predictors of Mandibular Third Molar Extraction Difficulties under General Anaesthetic
Authors: Carolyn Whyte, Tina Halai, Sonita Koshal
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Aim: There are many methods available to assess the potential difficulty of third molar surgery. This study investigated various factors to assess whether they had a bearing on the difficulties encountered. Study design: A retrospective study was completed of 62 single mandibular third molar teeth removed under day case general anaesthesia between May 2016 and August 2016 by 3 consultant oral surgeons. Method: Data collection was by examining the OPG radiographs of each tooth and recording the necessary data. This was depth of impaction, angulation, bony impaction, point of application in relation to second molar, root morphology, Pell and Gregory classification and Winters Lines. This was completed by one assessor and verified by another. Information on medical history, anxiety, ethnicity and age were recorded. Case notes and surgical entries were examined for any difficulties encountered. Results: There were 5 cases which encountered surgical difficulties which included fracture of root apices (3) which were left in situ, prolonged bleeding (1) and post-operative numbness >6 months(1). Four of the 5 cases had Pell and Gregory classification as (B) where the occlusal plane of the impacted tooth is between the occlusal plane and the cervical line of the adjacent tooth. 80% of cases had the point of application as either coronal or apical one third (1/3) in relation to the second molar. However, there was variability in all other aspects of assessment in predicting difficulty of removal. Conclusions: Of the cases which encountered difficulties they all had at least one predictor of potential complexity but these varied case by case.Keywords: impaction, mandibular third molar, radiographic assessment, surgical removal
Procedia PDF Downloads 178996 The Role of Phycoremediation in the Sustainable Management of Aquatic Pollution
Authors: Raymond Ezenweani, Jeffrey Ogbebor
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The menace of aquatic pollution has become increasingly of great concern and the effects of this pollution as a result of anthropogenic activities cannot be over emphasized. Phycoremediation is the application of algal remediation technology in the removal of harmful products from the environment. Harmful products also known as pollutants are usually introduced into the environment through variety of processes such as industrial discharge, agricultural runoff, flooding, and acid rain. This work has to do with the capability of algae in the efficient removal of different pollutants, ranging from hydrocarbons, eutrophication, agricultural chemicals and wastes, heavy metals, foul smell from septic tanks or dumps through different processes such as bioconversion, biosorption, bioabsorption and biodecomposition. Algae are capable of bioconversion of environmentally persistent compounds to degradable compounds and also capable of putting harmful bacteria growth into check in waste water remediation. Numerous algal organisms such as Nannochloropsis spp, Chlorella spp, Tetraselmis spp, Shpaerocystics spp, cyanobacteria and different macroalgae have been tested by different researchers in laboratory scale and shown to have 100% efficiency in environmental remediation. Algae as a result of their photosynthetic capacity are also efficient in air cleansing and management of global warming by sequestering carbon iv oxide in air and converting it into organic carbon, thereby making food available for the other organisms in the higher trophic level of the aquatic food chain. Algae play major role in the sustenance of the aquatic ecosystem by their virtue of being photosynthetic. They are the primary producers and their role in environmental sustainability is remarkable.Keywords: Algae , Pollutant, ., Phycoremediation, Aquatic, Sustainability
Procedia PDF Downloads 115995 Synthesis, Characterization, and Application of Novel Trihexyltetradecyl Phosphonium Chloride for Extractive Desulfurization of Liquid Fuel
Authors: Swapnil A. Dharaskar, Kailas L. Wasewar, Mahesh N. Varma, Diwakar Z. Shende
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Owing to the stringent environmental regulations in many countries for production of ultra low sulfur petroleum fractions intending to reduce sulfur emissions results in enormous interest in this area among the scientific community. The requirement of zero sulfur emissions enhances the prominence for more advanced techniques in desulfurization. Desulfurization by extraction is a promising approach having several advantages over conventional hydrodesulphurization. Present work is dealt with various new approaches for desulfurization of ultra clean gasoline, diesel and other liquid fuels by extraction with ionic liquids. In present paper experimental data on extractive desulfurization of liquid fuel using trihexyl tetradecyl phosphonium chloride has been presented. The FTIR, 1H-NMR, and 13C-NMR have been discussed for the molecular confirmation of synthesized ionic liquid. Further, conductivity, solubility, and viscosity analysis of ionic liquids were carried out. The effects of reaction time, reaction temperature, sulfur compounds, ultrasonication, and recycling of ionic liquid without regeneration on removal of dibenzothiphene from liquid fuel were also investigated. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 84.5% for mass ratio of 1:1 in 30 min at 30OC under the mild reaction conditions. Phosphonium ionic liquids could be reused five times without a significant decrease in activity. Also, the desulfurization of real fuels, multistage extraction was examined. The data and results provided in present paper explore the significant insights of phosphonium based ionic liquids as novel extractant for extractive desulfurization of liquid fuels.Keywords: ionic liquid, PPIL, desulfurization, liquid fuel, extraction
Procedia PDF Downloads 601994 The Production of Collagen and Collagen Peptides from Nile Tilapia Skin Using Membrane Technology
Authors: M. Thuanthong, W. Youravong, N. Sirinupong
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Nile tilapia (Oreochromis niloticus) is one of fish species cultured in Thailand with a high production volume. A lot of skin is generated during fish processing. In addition, there are many research reported that fish skin contains abundant of collagen. Thus, the use of Nile tilapia skin as collagen source can increase the benefit of industrial waste. In this study, Acid soluble collagen (ASC) was extracted at 5, 15 or 25 ˚C with 0.5 M acetic acid then the acid was removed out and collagen was concentrated by ultrafiltration-diafiltration (UFDF). The triple helix collagen from UFDF process was used as substrate to produce collagen peptides by alcalase hydrolysis in an enzymatic membrane reactor (EMR) coupling with 1 kDa molecular weight cut off (MWCO) polysulfone hollow fiber membrane. The results showed that ASC extracted at high temperature (25 ˚C) with 0.5 M acetic acid for 5 h still preserved triple helix structure. In the UFDF process, the acid removal was higher than 90 % without any effect on ASC properties, particularly triple helix structure as indicated by circular dichroism spectrum. Moreover, Collagen from UFDF was used to produce collagen peptides by EMR. In EMR, collagen was pre-hydrolyzed by alcalase for 60 min before introduced to membrane separation. The EMR operation was operated for 10 h and provided a good of protein conversion stability. The results suggested that there is a successfulness of UF in application for acid removal to produce ASC with desirable preservation of its quality. In addition, the EMR was proven to be an effective process to produce low molecular weight peptides with ACE-inhibitory activity properties.Keywords: acid soluble collagen, ultrafiltration-diafiltration, enzymatic membrane reactor, ace-inhibitory activity
Procedia PDF Downloads 474993 Biodegradation of Direct Red 23 by Bacterial Consortium Isolated from Dye Contaminated Soil Using Sequential Air-lift Bioreactor
Authors: Lata Kumari Dhanesh Tiwary, Pradeep Kumar Mishra
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The effluent coming from various industries such as textile, carpet, food, pharmaceutical and many other industries is big challenge due to its recalcitrant and xenobiotiocs in nature. Recently, biodegradation of dye wastewater through biological means was widely used due to eco-friendly and cost effective with the higher percentage of removal of dye from wastewater. The present study deals with the biodegradation and decolourization of Direct Red 23 dye using indigenously isolated bacterial consortium. The bacterial consortium was isolated from soil sample from dye contaminated site near a cluster of Carpet industries of Bhadohi, Uttar Pradesh, India. The bacterial strain formed consortia were identified and characterized by morphological, biochemical and 16S rRNA gene sequence analysis. The bacterial strain mainly Staphylococcus saprophyticus strain BHUSS X3 (KJ439576), Microbacterium sp. BHUMSp X4 (KJ740222) and Staphylococcus saprophyticus strain BHUSS X5 (KJ439576) were used as consortia for further studies of dye decolorization. Experimental investigations were made in a Sequencing Air- lift bioreactor using the synthetic solution of Direct Red 23 dye by optimizing various parameters for efficient degradation of dye. The effect of several operating parameters such as flow rate, pH, temperature, initial dye concentration and inoculums size on removal of dye was investigated. The efficiency of isolated bacterial consortia from dye contaminated area in Sequencing Air- lift Bioreactor with different concentration of dye between 100-1200 mg/l at different hydraulic rate (HRTs) 26h and 10h. The maximum percentage of dye decolourization 98% was achieved when operated at HRT of 26h. The percentage of decolourization of dye was confirmed by using UV-Vis spectrophotometer and HPLC.Keywords: carpet industry, bacterial consortia, sequencing air-lift bioreactor
Procedia PDF Downloads 331992 Removal of Metal Ions (II) Using a Synthetic Bis(2-Pyridylmethyl)Amino-Chloroacetyl Chloride- Ethylenediamine-Grafted Graphene Oxide Sheets
Authors: Laroussi Chaabane, Emmanuel Beyou, Amel El Ghali, Mohammed Hassen V. Baouab
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The functionalization of graphene oxide sheets by ethylenediamine (EDA) was accomplished followed by the grafting of bis(2-pyridylmethyl)amino group (BPED) onto the activated graphene oxide sheets in the presence of chloroacetylchloride (CAC) produced the martial [(Go-EDA-CAC)-BPED]. The physic-chemical properties of [(Go-EDA-CAC)-BPED] composites were investigated by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPs), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA). Moreover, [(Go-EDA-CAC)-BPED] was used for removing M(II) (where M=Cu, Ni and Co) ions from aqueous solutions using a batch process. The effect of pH, contact time and temperature were investigated. More importantly, the [(Go-EDA-CAC)-BPED] adsorbent exhibited remarkable performance in capturing heavy metal ions from water. The maximum adsorption capacity values of Cu(II), Ni(II) and Co(II) on the [(GO-EDA-CAC)-BPED] at the pH of 7 is 3.05 mmol.g⁻¹, 3.25 mmol.g⁻¹ and 3.05 mmol.g⁻¹ respectively. To examine the underlying mechanism of the adsorption process, pseudo-first, pseudo-second-order, and intraparticle diffusion models were fitted to experimental kinetic data. Results showed that the pseudo-second-order equation was appropriate to describe the three metal ions adsorption by [(Go-EDA-CAC)-BPED]. Adsorption data were further analyzed by the Langmuir, Freundlich, and Jossensadsorption approaches. Additionally, the adsorption properties of the [(Go-EDA-CAC)-BPED], their reusability (more than 10 cycles) and durability in the aqueous solutions open the path to removal of metal ions (Cu(II), Ni(II) and Co(II) from water solution. Based on the results obtained, we conclude that [(Go-EDA-CAC)-BPED] can be an effective and potential adsorbent for removing metal ions from an aqueous solution.Keywords: graphene oxide, bis(2-pyridylmethyl)amino, adsorption kinetics, isotherms
Procedia PDF Downloads 129991 Devulcanization of Waste Rubber Tyre Utilizing Deep Eutectic Solvents and Ultrasonic Energy
Authors: Ricky Saputra, Rashmi Walvekar, Mohammad Khalid, Kaveh Shahbaz, Suganti Ramarad
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This particular study of interest aims to study the effect of coupling ultrasonic treatment with eutectic solvents in devulcanization process of waste rubber tyre. Specifically, three different types of Deep Eutectic Solvents (DES) were utilized, namely ChCl:Urea (1:2), ChCl:ZnCl₂ (1:2) and ZnCl₂:urea (2:7) in which their physicochemical properties were analysed and proven to have permissible water content that is less than 3.0 wt%, degradation temperature below 200ᵒC and freezing point below 60ᵒC. The mass ratio of rubber to DES was varied from 1:20-1:40, sonicated for 1 hour at 37 kHz and heated at variable time of 5-30 min at 180ᵒC. Energy dispersive x-rays (EDX) results revealed that the first two DESs give the highest degree of sulphur removal at 74.44 and 76.69% respectively with optimum heating time at 15 minutes whereby if prolonged, reformation of crosslink network would be experienced. Such is supported by the evidence shown by both FTIR and FESEM results where di-sulfide peak reappears at 30 minutes and morphological structures from 15 to 30 minutes change from smooth with high voidage to rigid with low voidage respectively. Furthermore, TGA curve reveals similar phenomena whereby at 15 minutes thermal decomposition temperature is at the lowest due to the decrease of molecular weight as a result of sulphur removal but increases back at 30 minutes. Type of bond change was also analysed whereby it was found that only di-sulphide bond was cleaved and which indicates partial-devulcanization. Overall, the results show that DES has a great potential to be used as devulcanizing solvent.Keywords: crosslink network, devulcanization, eutectic solvents, reformation, ultrasonic
Procedia PDF Downloads 169990 Removal of Na₂SO₄ by Electro-Confinement on Nanoporous Carbon Membrane
Authors: Jing Ma, Guotong Qin
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We reported electro-confinement desalination (ECMD), a desalination method combining electric field effects and confinement effects using nanoporous carbon membranes as electrode. A carbon membrane with average pore size of 8.3 nm was prepared by organic sol-gel method. The precursor of support was prepared by curing porous phenol resin tube. Resorcinol-formaldehyde sol was coated on porous tubular resin support. The membrane was obtained by carbonisation of coated support. A well-combined top layer with the thickness of 35 μm was supported by macroporous support. Measurements of molecular weight cut-off using polyethylene glycol showed the average pore size of 8.3 nm. High salt rejection can be achieved because the water molecules need not overcome high energy barriers in confined space, while huge inherent dehydration energy was required for hydrated ions to enter the nanochannels. Additionally, carbon membrane with additional electric field can be used as an integrated membrane electrode combining the effects of confinement and electric potential gradient. Such membrane electrode can repel co-ions and attract counter-ions using pressure as the driving force for mass transport. When the carbon membrane was set as cathode, the rejection of SO₄²⁻ was 94.89%, while the removal of Na⁺ was less than 20%. We set carbon membrane as anode chamber to treat the effluent water from the cathode chamber. The rejection of SO₄²⁻ and Na⁺ reached to 100% and 88.86%, respectively. ECMD will be a promising energy efficient method for salt rejection.Keywords: nanoporous carbon membrane, confined effect, electric field, desalination, membrane reactor
Procedia PDF Downloads 120989 Evaluating Cyanide Biodegradation by Bacteria Isolated from Gold Mine Effluents in Bulawayo, Zimbabwe
Authors: Ngonidzashe Mangoma, Caroline Marigold Sebata
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The release of cyanide-rich effluents from gold mines, and other industries, into the environment, is a global concern considering the well-known metabolic effects of cyanide in all forms of life. Such effluents need to be treated to remove cyanide, among other pollutants, before their disposal. This study aimed at investigating the possible use of bacteria in the biological removal of cyanide from cyanide-rich effluents. Firstly, cyanide-degrading bacteria were isolated from gold mine effluents and characterised. The isolates were then tested for their ability to grow in the presence of cyanide and their tolerance to increasing levels of the compound. To evaluate each isolate’s cyanide-degrading activities, isolates were grown in the simulated and actual effluent, and a titrimetric method was used to quantify residual cyanide over a number of days. Cyanide degradation efficiency (DE) was then calculated for each isolate. Identification of positive isolates involved 16S rRNA gene amplification and sequence analysis through BLAST. Six cyanide-utilising bacterial strains were isolated. Two of the isolates were identified as Klebsiella spp. while the other two were shown to be different strains of Clostridium bifermentans. All isolates showed normal growth in the presence of cyanide, with growth being inhibited at 700 mg/L cyanide and beyond. Cyanide degradation efficiency for all isolates in the simulated effluent ranged from 79% to 97%. All isolates were able to remove cyanide from actual gold mine effluent with very high DE values (90 – 94%) being recorded. Isolates obtained in this study were able to efficiently remove cyanide from both simulated and actual effluent. This observation clearly demonstrates the feasibility of the biological removal of cyanide from cyanide-rich gold mine effluents and should, therefore, motivate research towards the possible large-scale application of this technology.Keywords: cyanide effluent, bioremediation, Clostridium bifermentans, Klebsiella spp, environment
Procedia PDF Downloads 169988 Suicide Prevention through Spiritual Practice
Authors: Jayant Balaji Athavale, Sean Clarke
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Background: According to the WHO, every year, more than 700,000 people die by suicide, which is one person around every 45 seconds. Suicide is the fourth leading cause of death among 15 to 29-year-olds globally. The most common situations or life events that might cause suicidal thoughts are financial problems/unemployment, rejections, relationship breakups, sexual/substance abuse and mental illnesses. Mental/psychological weakness caused due to defects in one’s personality is one of the main reasons why people feel they cannot cope in such situations and contemplate suicide. A WHO Mental Health Action Plan 2013–2020 lists a 4-point strategy to enhance mental health by ‘implementing strategies for promotion and prevention in mental health.’ Methodology: With 40 years of spiritual research background, the team at the Maharshi University of Spirituality has studied the spiritual root causes that can significantly affect one’s mental health and the solutions to improve it. Results/Findings: According to spiritual science, the time and nature of death are mostly due to spiritual reasons. A person would mostly contemplate and attempt suicide when he is spiritually most vulnerable. Spiritual practice, as per universal principles, helps in protecting a person spiritually and prevents him from getting such thoughts of self-harm or acting upon them by controlling such impulses. The University has had much success in helping people to overcome the defects in their personalities, including those with suicidal thoughts, through spiritual practices such as chanting the Name of God and the Personality Defect Removal (PDR) process developed by the Author. Conclusion: If such techniques were taught in educational institutions, they could be simple yet effective self-help tools to prevent thoughts of suicide and enhance mental health and well-being.Keywords: suicide, mental health, abuse, suicide prevention, personality defect removal
Procedia PDF Downloads 189987 Adsorption of Heavy Metals Using Chemically-Modified Tea Leaves
Authors: Phillip Ahn, Bryan Kim
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Copper is perhaps the most prevalent heavy metal used in the manufacturing industries, from food additives to metal-mechanic factories. Common methodologies to remove copper are expensive and produce undesired by-products. A good decontaminating candidate should be environment-friendly, inexpensive, and capable of eliminating low concentrations of the metal. This work suggests chemically modified spent tea leaves of chamomile, peppermint and green tea in their thiolated, sulfonated and carboxylated forms as candidates for the removal of copper from solutions. Batch experiments were conducted to maximize the adsorption of copper (II) ions. Effects such as acidity, salinity, adsorbent dose, metal concentration, and presence of surfactant were explored. Experimental data show that maximum adsorption is reached at neutral pH. The results indicate that Cu(II) can be removed up to 53%, 22% and 19% with the thiolated, carboxylated and sulfonated adsorbents, respectively. Maximum adsorption of copper on TPM (53%) is achieved with 150 mg and decreases with the presence of salts and surfactants. Conversely, sulfonated and carboxylated adsorbents show better adsorption in the presence of surfactants. Time-dependent experiments show that adsorption is reached in less than 25 min for TCM and 5 min for SCM. Instrumental analyses determined the presence of active functional groups, thermal resistance, and scanning electron microscopy, indicating that both adsorbents are promising materials for the selective recovery and treatment of metal ions from wastewaters. Finally, columns were prepared with these adsorbents to explore their application in scaled-up processes, with very positive results. A long-term goal involves the recycling of the exhausted adsorbent and/or their use in the preparation of biofuels due to changes in materials’ structures.Keywords: heavy metal removal, adsorption, wastewaters, water remediation
Procedia PDF Downloads 285986 Review of Sulfur Unit Capacity Expansion Options
Authors: Avinashkumar Karre
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Sulfur recovery unit, most commonly called as Claus process, is very significant gas desulfurization process unit in refinery and gas industries. Explorations of new natural gas fields, refining of high-sulfur crude oils, and recent crude expansion projects are needing capacity expansion of Claus unit for many companies around the world. In refineries, the sulphur recovery units take acid gas from amine regeneration units and sour water strippers, converting hydrogen sulfide to elemental sulfur using the Claus process. The Claus process is hydraulically limited by mass flow rate. Reducing the pressure drop across control valves, flow meters, lines, knock-out drums, and packing improves the capacity. Oxygen enrichment helps improve the capacity by removing nitrogen, this is more commonly done on all capacity expansion projects. Typical upgrades required due to oxygen enrichment are new burners, new refractory in thermal reactor, resizing of 1st condenser, instrumentation changes, and steam/condensate heat integration. Some other capacity expansion options typically considered are tail gas compressor, replacing air blower with higher head, hydrocarbon minimization in the feed, water removal, and ammonia removal. Increased capacity related upgrades in sulfur recovery unit also need changes in the tail gas treatment unit, typical changes include improvement to quench tower duty, packing area upgrades in quench and absorber towers and increased amine circulation flow rates.Keywords: Claus process, oxygen enrichment, sulfur recovery unit, tail gas treatment unit
Procedia PDF Downloads 118985 Geometric Model to Study the Mechanism of Machining and Predict the Damage Occurring During Milling of Unidirectional CFRP
Authors: Faisal Islam, J. Ramkumar
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The applications of composite materials in aerospace, sporting and automotive industries need high quality machined surfaces and dimensional accuracy. Some studies have been done to understand the fiber failure mechanisms encountered during milling machining of CFRP composites but none are capable of explaining the exact nature of the orientation-based fiber failure mechanisms encountered in the milling machining process. The objective of this work is to gain a better understanding of the orientation-based fiber failure mechanisms occurring on the slot edges during CFRP milling machining processes. The occurrence of damage is predicted by a schematic explanation based on the mechanisms of material removal which in turn depends upon fiber cutting angles. A geometric model based on fiber cutting angle and fiber orientation angle is proposed that defines the critical and safe zone during machining and predicts the occurrence of delamination. Milling machining experiments were performed on composite samples of varying fiber orientations to verify the proposed theory. Mean fiber pulled out length was measured from the microscopic images of the damaged area to quantify the amount of damage produced. By observing the damage occurring for different fiber orientation angles and fiber cutting angles for up-milling and down-milling edges and correlating it with the material removal mechanisms as described earlier, it can be concluded that the damage/delamination mainly depends on the portion of the fiber cutting angles that lies within the critical cutting angle zone.Keywords: unidirectional composites, milling, machining damage, delamination, carbon fiber reinforced plastics (CFRPs)
Procedia PDF Downloads 525984 Low Temperature Biological Treatment of Chemical Oxygen Demand for Agricultural Water Reuse Application Using Robust Biocatalysts
Authors: Vedansh Gupta, Allyson Lutz, Ameen Razavi, Fatemeh Shirazi
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The agriculture industry is especially vulnerable to forecasted water shortages. In the fresh and fresh-cut produce sector, conventional flume-based washing with recirculation exhibits high water demand. This leads to a large water footprint and possible cross-contamination of pathogens. These can be alleviated through advanced water reuse processes, such as membrane technologies including reverse osmosis (RO). Water reuse technologies effectively remove dissolved constituents but can easily foul without pre-treatment. Biological treatment is effective for the removal of organic compounds responsible for fouling, but not at the low temperatures encountered at most produce processing facilities. This study showed that the Microvi MicroNiche Engineering (MNE) technology effectively removes organic compounds (> 80%) at low temperatures (6-8 °C) from wash water. The MNE technology uses synthetic microorganism-material composites with negligible solids production, making it advantageously situated as an effective bio-pretreatment for RO. A preliminary technoeconomic analysis showed 60-80% savings in operation and maintenance costs (OPEX) when using the Microvi MNE technology for organics removal. This study and the accompanying economic analysis indicated that the proposed technology process will substantially reduce the cost barrier for adopting water reuse practices, thereby contributing to increased food safety and furthering sustainable water reuse processes across the agricultural industry.Keywords: biological pre-treatment, innovative technology, vegetable processing, water reuse, agriculture, reverse osmosis, MNE biocatalysts
Procedia PDF Downloads 124983 Finding Optimal Operation Condition in a Biological Nutrient Removal Process with Balancing Effluent Quality, Economic Cost and GHG Emissions
Authors: Seungchul Lee, Minjeong Kim, Iman Janghorban Esfahani, Jeong Tai Kim, ChangKyoo Yoo
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It is hard to maintain the effluent quality of the wastewater treatment plants (WWTPs) under with fixed types of operational control because of continuously changed influent flow rate and pollutant load. The aims of this study is development of multi-loop multi-objective control (ML-MOC) strategy in plant-wide scope targeting four objectives: 1) maximization of nutrient removal efficiency, 2) minimization of operational cost, 3) maximization of CH4 production in anaerobic digestion (AD) for CH4 reuse as a heat source and energy source, and 4) minimization of N2O gas emission to cope with global warming. First, benchmark simulation mode is modified to describe N2O dynamic in biological process, namely benchmark simulation model for greenhouse gases (BSM2G). Then, three types of single-loop proportional-integral (PI) controllers for DO controller, NO3 controller, and CH4 controller are implemented. Their optimal set-points of the controllers are found by using multi-objective genetic algorithm (MOGA). Finally, multi loop-MOC in BSM2G is implemented and evaluated in BSM2G. Compared with the reference case, the ML-MOC with the optimal set-points showed best control performances than references with improved performances of 34%, 5% and 79% of effluent quality, CH4 productivity, and N2O emission respectively, with the decrease of 65% in operational cost.Keywords: Benchmark simulation model for greenhouse gas, multi-loop multi-objective controller, multi-objective genetic algorithm, wastewater treatment plant
Procedia PDF Downloads 497982 Design and Synthesis of Copper-Zeolite Composite for Antimicrobial Activity and Heavy Metal Removal From Waste Water
Authors: Feleke Terefe Fanta
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Background: The existence of heavy metals and coliform bacteria contaminants in aquatic system of Akaki river basin, a sub city of Addis Ababa, Ethiopia has become a public concern as human population increases and land development continues. Hence, it is the right time to design treatment technologies that can handle multiple pollutants. Results: In this study, we prepared a synthetic zeolites and copper doped zeolite composite adsorbents as cost effective and simple approach to simultaneously remove heavy metals and total coliforms from wastewater of Akaki river. The synthesized copper–zeolite X composite was obtained by ion exchange method of copper ions into zeolites frameworks. Iodine test, XRD, FTIR and autosorb IQ automated gas sorption analyzer were used to characterize the adsorbents. The mean concentrations of Cd, Cr, and Pb in untreated sample were 0.795, 0.654 and 0.7025 mg/L respectively. These concentrations decreased to Cd (0.005 mg/L), Cr (0.052 mg/L) and Pb (bellow detection limit, BDL) for sample treated with bare zeolite X while a further decrease in concentration of Cd (0.005 mg/L), Cr (BDL) and Pb (BDL) was observed for the sample treated with copper–zeolite composite. Zeolite X and copper-modified zeolite X showed complete elimination of total coliforms after 90 and 50 min contact time respectively. Conclusion: The results obtained in this study showed high antimicrobial disinfection and heavy metal removal efficiencies of the synthesized adsorbents. Furthermore, these sorbents are efficient in significantly reducing physical parameters such as electrical conductivity, turbidity, BOD and COD.Keywords: WASTE WATER, COPPER DOPED ZEOITE X, ADSORPITION, HEAVY METAL, DISINFECTION, AKAKI RIVER
Procedia PDF Downloads 57981 [Keynote Talk]: Uptake of Co(II) Ions from Aqueous Solutions by Low-Cost Biopolymers and Their Hybrid
Authors: Kateryna Zhdanova, Evelyn Szeinbaum, Michelle Lo, Yeonjae Jo, Abel E. Navarro
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Alginate hydrogel beads (AB), spent peppermint leaf (PM), and a hybrid adsorbent of these two materials (ABPM) were studied as potential biosorbents of Cobalt (II) ions from aqueous solutions. Cobalt ion is a commonly underestimated pollutant that is responsible for several health problems. Discontinuous batch experiments were conducted at room temperature to evaluate the effect of solution acidity, mass of adsorbent on the adsorption of Co(II) ions. The interfering effect of salinity, the presence of surfactants, an organic dye, and Pb(II) ions were also studied to resemble the application of these adsorbents in real wastewater. Equilibrium results indicate that Co(II) uptake is maximized at pH values higher than 5, with adsorbent doses of 200 mg, 200 mg, and 120 mg for AB, PM, and ABPM, respectively. Co(II) adsorption followed the trend AB > ABPM > PM with Adsorption percentages of 77%, 71% and 64%, respectively. Salts had a strong negative effect on the adsorption due to the increase of the ionic strength and the competition for adsorption sites. The presence of Pb(II) ions, surfactant, and dye BY57 had a slightly negative effect on the adsorption, apparently due to their interaction with different adsorption sites that do not interfere with the removal of Co(II). A polar-electrostatic adsorption mechanism is proposed based on the experimental results. Scanning electron microscopy indicates that adsorbent has appropriate morphological and textural properties, and also that ABPM encapsulated most of the PM inside of the hydrogel beads. These experimental results revealed that AB, PM, and ABPM are promising adsorbents for the elimination of Co(II) ions from aqueous solutions under different experimental conditions. These biopolymers are proposed as eco-friendly alternatives for the removal of heavy metal ions at lower costs than the conventional techniques.Keywords: adsorption, Co(II) ions, alginate hydrogel beads, spent peppermint leaf, pH
Procedia PDF Downloads 124980 StockTwits Sentiment Analysis on Stock Price Prediction
Authors: Min Chen, Rubi Gupta
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Understanding and predicting stock market movements is a challenging problem. It is believed stock markets are partially driven by public sentiments, which leads to numerous research efforts to predict stock market trend using public sentiments expressed on social media such as Twitter but with limited success. Recently a microblogging website StockTwits is becoming increasingly popular for users to share their discussions and sentiments about stocks and financial market. In this project, we analyze the text content of StockTwits tweets and extract financial sentiment using text featurization and machine learning algorithms. StockTwits tweets are first pre-processed using techniques including stopword removal, special character removal, and case normalization to remove noise. Features are extracted from these preprocessed tweets through text featurization process using bags of words, N-gram models, TF-IDF (term frequency-inverse document frequency), and latent semantic analysis. Machine learning models are then trained to classify the tweets' sentiment as positive (bullish) or negative (bearish). The correlation between the aggregated daily sentiment and daily stock price movement is then investigated using Pearson’s correlation coefficient. Finally, the sentiment information is applied together with time series stock data to predict stock price movement. The experiments on five companies (Apple, Amazon, General Electric, Microsoft, and Target) in a duration of nine months demonstrate the effectiveness of our study in improving the prediction accuracy.Keywords: machine learning, sentiment analysis, stock price prediction, tweet processing
Procedia PDF Downloads 146979 Modeling of the Biodegradation Performance of a Membrane Bioreactor to Enhance Water Reuse in Agri-food Industry - Poultry Slaughterhouse as an Example
Authors: masmoudi Jabri Khaoula, Zitouni Hana, Bousselmi Latifa, Akrout Hanen
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Mathematical modeling has become an essential tool for sustainable wastewater management, particularly for the simulation and the optimization of complex processes involved in activated sludge systems. In this context, the activated sludge model (ASM3h) was used for the simulation of a Biological Membrane Reactor (MBR) as it includes the integration of biological wastewater treatment and physical separation by membrane filtration. In this study, the MBR with a useful volume of 12.5 L was fed continuously with poultry slaughterhouse wastewater (PSWW) for 50 days at a feed rate of 2 L/h and for a hydraulic retention time (HRT) of 6.25h. Throughout its operation, High removal efficiency was observed for the removal of organic pollutants in terms of COD with 84% of efficiency. Moreover, the MBR has generated a treated effluent which fits with the limits of discharge into the public sewer according to the Tunisian standards which were set in March 2018. In fact, for the nitrogenous compounds, average concentrations of nitrate and nitrite in the permeat reached 0.26±0.3 mg. L-1 and 2.2±2.53 mg. L-1, respectively. The simulation of the MBR process was performed using SIMBA software v 5.0. The state variables employed in the steady state calibration of the ASM3h were determined using physical and respirometric methods. The model calibration was performed using experimental data obtained during the first 20 days of the MBR operation. Afterwards, kinetic parameters of the model were adjusted and the simulated values of COD, N-NH4+and N- NOx were compared with those reported from the experiment. A good prediction was observed for the COD, N-NH4+and N- NOx concentrations with 467 g COD/m³, 110.2 g N/m³, 3.2 g N/m³ compared to the experimental data which were 436.4 g COD/m³, 114.7 g N/m³ and 3 g N/m³, respectively. For the validation of the model under dynamic simulation, the results of the experiments obtained during the second treatment phase of 30 days were used. It was demonstrated that the model simulated the conditions accurately by yielding a similar pattern on the variation of the COD concentration. On the other hand, an underestimation of the N-NH4+ concentration was observed during the simulation compared to the experimental results and the measured N-NO3 concentrations were lower than the predicted ones, this difference could be explained by the fact that the ASM models were mainly designed for the simulation of biological processes in the activated sludge systems. In addition, more treatment time could be required by the autotrophic bacteria to achieve a complete and stable nitrification. Overall, this study demonstrated the effectiveness of mathematical modeling in the prediction of the performance of the MBR systems with respect to organic pollution, the model can be further improved for the simulation of nutrients removal for a longer treatment period.Keywords: activated sludge model (ASM3h), membrane bioreactor (MBR), poultry slaughter wastewater (PSWW), reuse
Procedia PDF Downloads 51978 Biochar - A Multi-Beneficial and Cost-Effective Amendment to Clay Soil for Stormwater Runoff Treatment
Authors: Mohammad Khalid, Mariya Munir, Jacelyn Rice Boyaue
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Highways are considered a major source of pollution to storm-water, and its runoff can introduce various contaminants, including nutrients, Indicator bacteria, heavy metals, chloride, and phosphorus compounds, which can have negative impacts on receiving waters. This study assessed the ability of biochar for contaminants removal and to improve the water holding capacity of soil biochar mixture. For this, ten commercially available biochar has been strategically selected. Lab scale batch testing was done at 3% and 6% by the weight of the soil to find the preliminary estimate of contaminants removal along with hydraulic conductivity and water retention capacity. Furthermore, from the above-conducted studies, six best performing candidate and an application rate of 6% has been selected for the column studies. Soil biochar mixture was filled in 7.62 cm assembled columns up to a fixed height of 76.2 cm based on hydraulic conductivity. A total of eight column experiments have been conducted for nutrient, heavy metal, and indicator bacteria analysis over a period of one year, which includes a drying as well as a deicing period. The saturated hydraulic conductivity was greatly improved, which is attributed to the high porosity of the biochar soil mixture. Initial data from the column testing shows that biochar may have the ability to significantly remove nutrients, indicator bacteria, and heavy metals. The overall study demonstrates that biochar could be efficiently applied with clay soil to improve the soil's hydraulic characteristics as well as remove the pollutants from the stormwater runoff.Keywords: biochar, nutrients, indicator bacteria, storm-water treatment, sustainability
Procedia PDF Downloads 113977 Removal of Diesel by Soil Washing Technologies Using a Non-Ionic Surfactant
Authors: Carolina Guatemala, Josefina Barrera
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A large number of soils highly polluted with recalcitrant hydrocarbons and the limitation of the current bioremediation methods continue being the drawback for an efficient recuperation of these under safe conditions. In this regard, soil washing by degradable surfactants is an alternative option knowing the capacity of surfactants to desorb oily organic compounds. The aim of this study was the establishment of the washing conditions of a soil polluted with diesel, using a nonionic surfactant. A soil polluted with diesel was used. This was collected near to a polluted railway station zone. The soil was dried at room temperature and sieved to a mesh size 10 for its physicochemical and biological characterization. Washing of the polluted soil was performed with surfactant solutions in a 1:5 ratio (5g of soil per 25 mL of the surfactant solution). This was carried out at 28±1 °C and 150 rpm for 72 hours. The factors tested were the Tween 80 surfactant concentration (1, 2, 5 and 10%) and the treatment time. Residual diesel concentration was determined every 24 h. The soil was of a sandy loam texture with a low concentration of organic matter (3.68%) and conductivity (0.016 dS.m- 1). The soil had a pH of 7.63 which was slightly alkaline and a Total Petroleum Hydrocarbon content (TPH) of 11,600 ± 1058.38 mg/kg. The high TPH content could explain the low microbial count of 1.1105 determined as UFC per gram of dried soil. Within the range of the surfactant concentration tested for washing the polluted soil under study, TPH removal increased proportionally with the surfactant concentration. 5080.8 ± 422.2 ppm (43.8 ± 3.64 %) was the maximal concentration of TPH removed after 72 h of contact with surfactant pollution at 10%. Despite the high percentage of hydrocarbons removed, it is assumed that a higher concentration of these could be removed if the washing process is extended or is carried out by stages. Soil washing through the use of surfactants as a desorbing agent was found to be a viable and effective technology for the rapid recovery of soils highly polluted with recalcitrant hydrocarbons.Keywords: diesel, hydrocarbons, soil washing, tween 80
Procedia PDF Downloads 135976 Comparison of Adsorbents for Ammonia Removal from Mining Wastewater
Authors: F. Al-Sheikh, C. Moralejo, M. Pritzker, W. A. Anderson, A. Elkamel
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Ammonia in mining wastewater is a significant problem, and treatment can be especially difficult in cold climates where biological treatment is not feasible. An adsorption process is one of the alternative processes that can be used to reduce ammonia concentrations to acceptable limits, and therefore a LEWATIT resin strongly acidic H+ form ion exchange resin and a Bowie Chabazite Na form AZLB-Na zeolite were tested to assess their effectiveness. For these adsorption tests, two packed bed columns (a mini-column constructed from a 32-cm long x 1-cm diameter piece of glass tubing, and a 60-cm long x 2.5-cm diameter Ace Glass chromatography column) were used containing varying quantities of the adsorbents. A mining wastewater with ammonia concentrations of 22.7 mg/L was fed through the columns at controlled flowrates. In the experimental work, maximum capacities of the LEWATIT ion exchange resin were 0.438, 0.448, and 1.472 mg/g for 3, 6, and 9 g respectively in a mini column and 1.739 mg/g for 141.5 g in a larger Ace column while the capacities for the AZLB-Na zeolite were 0.424, and 0.784 mg/g for 3, and 6 g respectively in the mini column and 1.1636 mg/g for 38.5 g in the Ace column. In the theoretical work, Thomas, Adams-Bohart, and Yoon-Nelson models were constructed to describe a breakthrough curve of the adsorption process and find the constants of the above-mentioned models. In the regeneration tests, 5% hydrochloric acid, HCl (v/v) and 10% sodium hydroxide, NaOH (w/v) were used to regenerate the LEWATIT resin and AZLB-Na zeolite with 44 and 63.8% recovery, respectively. In conclusion, continuous flow adsorption using a LEWATIT ion exchange resin and an AZLB-Na zeolite is efficient when using a co-flow technique for removal of the ammonia from wastewater. Thomas, Adams-Bohart, and Yoon-Nelson models satisfactorily fit the data with R2 closer to 1 in all cases.Keywords: AZLB-Na zeolite, continuous adsorption, Lewatit resin, models, regeneration
Procedia PDF Downloads 378975 Microalgae Bacteria Granules, an Alternative Technology to the Conventional Wastewater Treatment: Structural and Metabolic Characterization
Authors: M. Nita-Lazar, E. Manea, C. Bumbac, A. Banciu, C. Stoica
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The population and economic growth have generated a significant new number of pollutant compounds which have to be degraded before reaching the environment. The wastewater treatment plants (WWTPs) have been the last barrier between the domestic and/or industrial wastewaters and the environment. At present, the conventional WWTPs have very high operational costs, most of them linked to the aeration process (60-65% from total energy costs related to wastewater treatment). In addition, they have had a low efficiency in pollutants removal such as pharmaceutical and other resilient anthropogenic compounds. In our study, we have been focused on new wastewater treatment strategies to enhance the efficiency of pollutants removal and decrease the wastewater treatment operational costs. The usage of mixed microalgae-bacteria granules technology generated high efficiency and low costs by a better harvesting and less expensive aeration. The intertrophic relationships between microalgae and bacteria have been characterized by the structure of the population community to their metabolic relationships. The results, obtained by microscopic studies, showed well-organized and stratified microalgae-bacteria granules where bacteria have been enveloped in the microalgal structures. Moreover, their population community structure has been modulated as well as their nitrification, denitrification processes (analysis based on qPCR genes expression) by the type of the pollutant compounds and amounts. In conclusion, the understanding and modulation of intertrophic relationships between microalgae and bacteria could be an economical and technological viable alternative to the conventional wastewater treatment. Acknowledgements: This research was supported by grant PN-III-P4-ID-PCE-2016-0865 from the Romanian National Authority for Scientific Research and Innovation CNCS/CCCDI-UEFISCDI.Keywords: activated sludge, bacteria, granules, microalgae
Procedia PDF Downloads 109974 High-Pressure CO₂ Adsorption Capacity of Selected Unusual Porous Materials and Rocks
Authors: Daniela Rimnacova, Maryna Vorokhta, Martina Svabova
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CO₂ adsorption capacity of several materials - waste (power fly ash, slag, carbonized sewage sludge), rocks (Czech Silurian shale, black coal), and carbon (synthesized carbon, activated carbon as a reference material) - were measured on dry samples using a unique hand-made manometric sorption apparatus at a temperature of 45 °C and pressures of up to 7 MPa. The main aim was finding utilization of the waste materials and rocks for removal of the air or water pollutants caused by anthropogenic activities, as well as for the carbon dioxide storage. The equilibrium amount of the adsorbate depends on temperature, gas saturation pressure, porosity, surface area and volume of pores, and last but not least, on the composition of the adsorbents. Given experimental conditions can simulate in-situ situations in the rock bed and can be achieved just by a high-pressure apparatus. The CO₂ excess adsorption capacities ranged from 0.018 mmol/g (ash) to 13.55 mmol/g (synthesized carbon). The synthetized carbon had the highest adsorption capacity among all studied materials as well as the highest price. This material is usually used for the adsorption of specific pollutants. The excess adsorption capacity of activated carbon was 9.19 mmol/g. It is used for water and air cleaning. Ash can be used for chemisorption onto ash particle surfaces or capture of special pollutants. Shale is a potential material for enhanced gas recovery or CO₂ sequestration in-situ. Slag is a potential material for capture of gases with a possibility of the underground gas storage after the adsorption process. The carbonized sewage sludge is quite a good adsorbent for the removal and capture of pollutants, as well as shales or black coal which show an interesting relationship between the price and adsorption capacity.Keywords: adsorption, CO₂, high pressure, porous materials
Procedia PDF Downloads 155973 Uptake of Copper by Dead Biomass of Burkholderia cenocepacia Isolated from a Metal Mine in Pará, Brazil
Authors: Ingrid R. Avanzi, Marcela dos P. G. Baltazar, Louise H. Gracioso, Luciana J. Gimenes, Bruno Karolski, Elen A. Perpetuo, Claudio Auguto Oller do Nascimento
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In this study was developed a natural process using a biological system for the uptake of Copper and possible removal of copper from wastewater by dead biomass of the strain Burkholderia cenocepacia. Dead and live biomass of Burkholderia cenocepacia was used to analyze the equilibrium and kinetics of copper biosorption by this strain in function of the pH. Living biomass exhibited the highest biosorption capacity of copper, 50 mg g−1, which was achieved within 5 hours of contact, at pH 7.0, temperature of 30°C, and agitation speed of 150 rpm. The dead biomass of Burkholderia cenocepacia may be considered an efficiently bioprocess, being fast and low-cost to production of copper and also a probably nano-adsorbent of this metal ion in wastewater in bioremediation process. In this study was developed a natural process using a biological system for the uptake of Copper and possible removal of copper from wastewater by dead biomass of the strain Burkholderia cenocepacia. Dead and live biomass of Burkholderia cenocepacia was used to analyze the equilibrium and kinetics of copper biosorption by this strain in function of the pH. Living biomass exhibited the highest biosorption capacity of copper, 50 mg g−1, which was achieved within 5 hours of contact, at pH 7.0, temperature of 30°C, and agitation speed of 150 rpm. The dead biomass of Burkholderia cenocepacia may be considered an efficiently bioprocess, being fast and low-cost to production of copper and also a probably nano-adsorbent of this metal ion in wastewater in bioremediation process.Keywords: biosorption, dead biomass, biotechnology, copper recovery
Procedia PDF Downloads 333972 Evaluation of Iron Application Method to Remediate Coastal Marine Sediment
Authors: Ahmad Seiar Yasser
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Sediment is an important habitat for organisms and act as a store house for nutrients in aquatic ecosystems. Hydrogen sulfide is produced by microorganisms in the water columns and sediments, which is highly toxic and fatal to benthic organisms. However, the irons have the capacity to regulate the formation of sulfide by poising the redox sequence and to form insoluble iron sulfide and pyrite compounds. Therefore, we conducted two experiments aimed to evaluate the remediation efficiency of iron application to organically enrich and improve sediments environment. Experiments carried out in the laboratory using intact sediment cores taken from Mikawa Bay, Japan at every month from June to September 2017 and October 2018. In Experiment 1, after cores were collected, the iron powder or iron hydroxide were applied to the surface sediment with 5 g/ m2 or 5.6 g/ m2, respectively. In Experiment 2, we experimentally investigated the removal of hydrogen sulfide using (2mm or less and 2 to 5mm) of the steelmaking slag. Experiments are conducted both in the laboratory with the same boundary conditions. The overlying water were replaced with deoxygenated filtered seawater, and cores were sealed a top cap to keep anoxic condition with a stirrer to circulate the overlying water gently. The incubation experiments have been set in three treatments included the control, and each treatment replicated and were conducted with the same temperature of the in-situ conditions. Water samples were collected to measure the dissolved sulfide concentrations in the overlying water at appropriate time intervals by the methylene blue method. Sediment quality was also analyzed after the completion of the experiment. After the 21 days incubation, experimental results using iron powder and ferric hydroxide revealed that application of these iron containing materials significantly reduced sulfide release flux from the sediment into the overlying water. The average dissolved sulfides concentration in the overlying water of the treatment group was significantly decrease (p = .0001). While no significant difference was observed between the control group after 21 day incubation. Therefore, the application of iron to the sediment is a promising method to remediate contaminated sediments in a eutrophic water body, although ferric hydroxide has better hydrogen sulfide removal effects. Experiments using the steelmaking slag also clarified the fact that capping with (2mm or less and 2 to 5mm) of slag steelmaking is an effective technique for remediation of bottom sediments enriched organic containing hydrogen sulfide because it leads to the induction of chemical reaction between Fe and sulfides occur in sediments which did not occur in conditions naturally. Although (2mm or less) of slag steelmaking has better hydrogen sulfide removal effects. Because of economic reasons, the application of steelmaking slag to the sediment is a promising method to remediate contaminated sediments in the eutrophic water body.Keywords: sedimentary, H2S, iron, iron hydroxide
Procedia PDF Downloads 157971 Synthesis and Characterization of CNPs Coated Carbon Nanorods for Cd2+ Ion Adsorption from Industrial Waste Water and Reusable for Latent Fingerprint Detection
Authors: Bienvenu Gael Fouda Mbanga
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This study reports a new approach of preparation of carbon nanoparticles coated cerium oxide nanorods (CNPs/CeONRs) nanocomposite and reusing the spent adsorbent of Cd2+- CNPs/CeONRs nanocomposite for latent fingerprint detection (LFP) after removing Cd2+ ions from aqueous solution. CNPs/CeONRs nanocomposite was prepared by using CNPs and CeONRs with adsorption processes. The prepared nanocomposite was then characterized by using UV-visible spectroscopy (UV-visible), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential, X-ray photoelectron spectroscopy (XPS). The average size of the CNPs was 7.84nm. The synthesized CNPs/CeONRs nanocomposite has proven to be a good adsorbent for Cd2+ removal from water with optimum pH 8, dosage 0. 5 g / L. The results were best described by the Langmuir model, which indicated a linear fit (R2 = 0.8539-0.9969). The adsorption capacity of CNPs/CeONRs nanocomposite showed the best removal of Cd2+ ions with qm = (32.28-59.92 mg/g), when compared to previous reports. This adsorption followed pseudo-second order kinetics and intra particle diffusion processes. ∆G and ∆H values indicated spontaneity at high temperature (40oC) and the endothermic nature of the adsorption process. CNPs/CeONRs nanocomposite therefore showed potential as an effective adsorbent. Furthermore, the metal loaded on the adsorbent Cd2+- CNPs/CeONRs has proven to be sensitive and selective for LFP detection on various porous substrates. Hence Cd2+-CNPs/CeONRs nanocomposite can be reused as a good fingerprint labelling agent in LFP detection so as to avoid secondary environmental pollution by disposal of the spent adsorbent.Keywords: Cd2+-CNPs/CeONRs nanocomposite, cadmium adsorption, isotherm, kinetics, thermodynamics, reusable for latent fingerprint detection
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