Electrocoagulation in Wastewater Treatment

A review of the literature published in from 2008 to 2010 on topics related to electrochemical treatment within wastewater was presented. The review included several sections such as optimization, modeling, various wastewater treatment techniques, analytical and instrumentation, and comparison with other treatment methods

Electrocoagulation Technology in Wastewater Treatment: A Review of Methods and Applications

The purpose of this paper is to review the relevant literature that published from 2010 to 2013 on topics related to electrocoagulation technology within the wastewater. The review describes and discussing issues surrounding electrocoagulation treatment within wastewater, including its concept, the background and various wastewater treatment techniques applications in the industry such as, optimization, modelling, combination composition and ,comparison with other treatment methods. Keywords: coagulation,electrochemical treatment , electrocoagulation, electrode, wastewater treatment

Electrochemical/Electroflotation Process for Dye Wastewater Treatment

The use of dyes has become very significant across various industries such as textiles, paper, and clothing. The organic chemical composition of dyes is a major concern when discharging wastewater not only into the environment, but also within wastewater treatment plants. Dye effluent consists of high chemical oxygen demand (COD) and also color, components that require treatment before discharge. As a result, federal legislation has required industries that discharge high components in wastewater to undergo treatment within the plants. Within literature, authors have considered various biological, physical, and chemical methods of treating dye wastewater. Recently, electrocoagulation/electroflotation (ECF) has been an additional method of treatment that has been considered for the treatment of dye wastewater. Two separate studies are considered. First, Acid Yellow 11 (AY11) at a concentration of 25 mg/L (by weight) underwent treatment from three different coagulants (Alum, Ferric Sulfate, and Ferric Chloride) , under three different strengths (5 mg/L, 10 mg/L, and 15 mg/L), and two different initial pH considerations (4 and 7) for the purpose of analyzing color removal. Following the study, the results were collaborating into a response surface methodology, developing an equation for the three different coagulants. In addition, a Box-Behnken design has been setup for the purpose of considering the effects of pH, dye concentration, dye type, coagulant type and strength on the efficiency of electrocoagulation. These values will be analyzed using statistical analysis, along with toxicity study done on the effectiveness of removing toxic contaminants from the wastewater. Finally, a photo-oxidation study was completed on Acid Orange 7 (AO7) synthetic dye wastewater for the purpose of determining the effects of photo-oxidation based on dye concentration, catalyst type and dose. Langmuir-Hinshelwood coefficients were developed based on the results of this experimen

Electrochemical/Electroflotation Process for Dye Wastewater Treatment

The use of dyes has become very significant across various industries such as textiles, paper, and clothing. The organic chemical composition of dyes is a major concern when discharging wastewater not only into the environment, but also within wastewater treatment plants. Dye effluent consists of high chemical oxygen demand (COD) and also color, components that require treatment before discharge. As a result, federal legislation has required industries that discharge high components in wastewater to undergo treatment within the plants. Within literature, authors have considered various biological, physical, and chemical methods of treating dye wastewater. Recently, electrocoagulation/electroflotation (ECF) has been an additional method of treatment that has been considered for the treatment of dye wastewater. Two separate studies are considered. First, Acid Yellow 11 (AY11) at a concentration of 25 mg/L (by weight) underwent treatment from three different coagulants (Alum, Ferric Sulfate, and Ferric Chloride) , under three different strengths (5 mg/L, 10 mg/L, and 15 mg/L), and two different initial pH considerations (4 and 7) for the purpose of analyzing color removal. Following the study, the results were collaborating into a response surface methodology, developing an equation for the three different coagulants. In addition, a Box-Behnken design has been setup for the purpose of considering the effects of pH, dye concentration, dye type, coagulant type and strength on the efficiency of electrocoagulation. These values will be analyzed using statistical analysis, along with toxicity study done on the effectiveness of removing toxic contaminants from the wastewater. Finally, a photo-oxidation study was completed on Acid Orange 7 (AO7) synthetic dye wastewater for the purpose of determining the effects of photo-oxidation based on dye concentration, catalyst type and dose. Langmuir-Hinshelwood coefficients were developed based on the results of this experimen

Characterization and optimization of the performance of an integrated ultrasonic membrane anaerobic (IUMAS) in treating pome as substrate

Palm oil mill effluent (POME) is a highly polluting wastewater with high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). These causes severe pollution to the environment, and water resources. Traditional ways of treating POME are disadvantageous from both economic and environmental perspectives. In this Thesis, the potential of an integrated ultrasonic membrane anaerobic system (IUMAS) for the treatment of POME was investigated. The work began with some characterization studies to provide understandings of fundamental issues for wastewater treatment. This research used different organic loading rates from 0.5 to 13 kg/COD/m3/d as a fed to the system, which operated as semi-continuously at mesophilic temperature from 25-35 °C and pressure ranges of 1.5-2 bars. The IUMAS overall efficiency has been evaluated under six steady states and the influent COD varied between 70,000 to 80,000 mg/L. IUMAS depicted better performance as compared to membrane anaerobic system MAS results in treating the palm oil mill effluent, POME as it achieved higher percentage removal efficiencies for COD, BOD, Turbidity and total suspended solids, TSS which are 97%, 80%, 96% and 98.6% respectively. The highest methane gas percentage, CH4 was 84.5%. The POME characterized qualitatively using SEM, EDX and FTIR. IUMAS performed better compared to MAS. Monod, Contois, Chen and Hashimoto kinetics models were used to estimate the performance of IUMAS for POME sludge treatment and the system has shown good prediction and Chen and Hashimoto model has shown the best fittings of 90%. An optimization study for the preparation conditions of the selected optimum parameters for maximum methane gas production was investigated using Response Surface Methodology, RSM. The determining factors such as pH, organic loading rates, OLR, COD, and Hydraulic retention time, HRT were initially screened using 2 level factorial approach. The screening revealed that the effect of screened parameters was significant. Furthermore, the impact of these four operating parameters were investigated using the faced central design techniques. The results presented the optimum conditions for highest methane yield is 88.7% from POME were pH, 6.9; OLR, 6.5kg COD/m3/day, COD, 74,000 mg/L, and HRT, 5 days. The results obtained in this study have exposed the capability of integrated ultrasonic membrane anaerobic system, IUMAS, in treating POME wastewater

Treatment of Dairy Wastewater by Electrocoagulation using Iron Filings Electrodes

This study investigated the treatment of dairy wastewater using the electrocoagulation method with iron filings as electrodes. The study dealt with real samples collected from local factory for dairy products in Baghdad. The Response Surface Methodology (RSM) was used to optimize five experimental variables at six levels for each variable, for estimating chemical oxygen demand (COD) removal efficiency. These variables were the distance between electrodes, detention time, dosage of NaCl as electrolyte, initial COD concentration, and current density. RSM was investigated the direct and complex interaction effects between parameters to estimate the optimum values. The respective optimum value was 1 cm for the distance between electrodes, (60 – 120) min for detention time, 250 mg NaCl/L added, C0/6 = 5,775 mg COD/L as initial COD concentration, and  7.884 - 8.077  mA/cm2 as current provided. At the optimum parameter values, the optimum COD removal efficiency was 73.4%. Meanwhile, the study also performed removal efficiency for nitrogen (N) and phosphate (P) due to their effects on the aquatic life and systems. The optimum removal efficiency for phosphorus and nitrogen was 98.0% and 80.3%, respectively. Due to its effects on the environment and to comply with local legislations, treating these wastewaters using eco-friendly processes was highly recommended taking in consideration the economic feasibility, flexibility and easiness to operate. In addition, the study proved that the high surface area for iron filings played a crucial role in removing process

Wastewater Treatment: Current and Future Techniques

This book examines the state-of-the-art water and wastewater treatment methods that can be applied to develop a sustainable treatment technique in the future. Of the several high-quality articles submitted, twelve were published after the peer-review process, with an acceptance rate of 59 percent. In the first section of this book, the articles include the occurrence and removal of emerging contaminants in water bodies. Moreover, the presence of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in water sources is discussed in detail. Subsequently, the removal of polycyclic aromatic hydrocarbons (PAHs), pharmaceuticals and personal care products (PPCPs), and dye with different physicochemical methods is investigated. In another section of this book, the removal of ammonia with anaerobic ammonium oxidation (anammox) is studied. Additionally, the elimination of heavy metals using the adsorption process, as an effective method, is discussed. Moreover, the performance of membrane bioreactors in the elimination of pollutants from landfill leachate is investigated in another article in this book. In addition to this, green and sustainable wastewater technologies (GSWTs) have recently attracted the attention of researchers. Therefore, nanoremediation and microalgae-based systems are discussed as the GSWTs

The performance of integrated ultrasonic membrane anaerobic system (IUMAS) in treating sugar cane wastewater

Sugarcane mill effluent (SCME) causes severe environmental pollution due to its high concentration in term of pollutants. Conventional methods of treating SCME have disadvantages from both environmental and economic perspectives. Most of the treatment methods used the membrane as a solution to wastewater pollution problems but suffering from membrane fouling. In this study, the potentials of Integrated Ultrasonic Assisted Membrane Anaerobic System (IUMAS) in treating sugarcane mill effluent was investigated. In this research different organic loading rates were used as a fed to the system, which operated semi-continuously at mesophilic temperature 30°C to 35°C and pressure ranges of 1.5–2 bars. Seven steady states were accomplished as a part of a kinetic study that considered concentration ranges of 2500 mg/L to 6000 mg/L for mixed liquor suspended solids (MLSS). The aim was to obtain optimum operating conditions and maximum methane production as well as the performance of IUMAS comparing with membrane anaerobic system (MAS) in treating SCME. IUMAS depicted better performance as compared to MAS in treating the sugarcane mill effluent (SCME) as it achieved higher percentage removal efficiencies for COD, BOD, turbidity and TSS which were 96.12%, 67%, 94%and 98.8%, respectively. While higher percentage removal efficiencies for MAS were 93.8%, 66.3%, 73.8% and 97.4%. The highest methane percentage was 80.9 % for IUMAS compared with MAS was 77.3%. The SCME characterized to investigate by using a different analytical approach such as SEM/EDX, and FTIR. SEM morphology analysis for IUMAS, the permeate flux for the membrane filtration of SCME increased while for MAS decreased the permeate flux due to fouling problem. For FTIR in both methods obtained 5 identified peaks before treatment. However, after treatment indicated 6 and 5 identified peaks for IUMAS and MAS. Kinetic equations from Monod, Contois and Chen and Hashimoto were employed used IUMAS to describe the kinetics of SCME treatment. The correlation coefficient was 54% for Monod, 85% for Contois model and 91% for Chen and Hashimoto model. From the highest, R2 the best fitting in Chen and Hashimoto model. The growth yield coefficient Y and the specific microorganism decay rate b were determined as 0.23 g VSS/g COD and 0.0214 day-1 respectively. An optimization study for the preparation conditions of the selected optimum parameters for maximum methane gas was investigated using Response Surface Methodology (RSM). The determining factors such as pH, OLR, COD, and HRT were initially screened using 2 level factorial approach. The screening revealed that the effect of the above parameters was significant. Furthermore, the impact of these four operating parameters were investigated using the central composite design (CCD) techniques. The results presented the optimum conditions for methane yield from SCME were pH 7.1, OLR 8 kg COD/m3/day, COD HRT 5.65 day with CH4 84.7%. The results obtained in this study have exposed the capability of ultrasonic-assisted membrane anaerobic system (IUMAS) in treating SCME wastewater. Thus, this method can be a promising source for treating all industrial wastewater

TREATMENT OF PETROLEUM REFINERY WASTEWATER USING MULTI-STAGE BIOLOGICAL REACTOR

Refining crude oil in petroleum refinery results in relatively large quantities of wastewater. Petroleum refinery wastewater (PRW) is highly polluted, hence proper and effective treatment is needed; currently requires multiple treatment processes. Therefore, the need for improved treatment processes never stops. Thinking green, biological treatment is always a cheaper and safer solution for wastewater treatment, as it involves the use of microorganisms to degrade organic matter. This study focused on development of integrated multi-stage biological treatment process for petroleum refinery wastewater. The study consisted of four phases, namely, biodegradability of PRW, PRWtreatability in three configuration of sequencing batch reactors (SBR), degradation of volatile organic compounds in anaerobic-anoxicaerobic SBR and testing of multi-stage biological reactor (MSBR) under different loads. PRW was found to be biodegradable in a 28-day batch study, with more than 95% COD removal in 24 hr under aerobic mode and 9 days under anaerobic mode. Three SBR configurations (aerobic, anaerobic-aerobic and aerobic with PRW and domestic wastewater mixed influent) were operated in parallel to determine the most effective configuration and reaction time

Tratamento de águas residuais industriais com nanomateriais sintetizados para um ambiente sustentável

Quality of the final discharged effluents from industrial activities has been the subject of significant efforts over several decades to improve the performance of the methods applied for their treatment, either by physico-chemical, biological, or a combination of these processes. Among the emerging technologies, the application of various types of engineered nanomaterials (ENMs) has gained a particular attention in recent years. The present thesis aimed to carry out either experimental studies, surveys and critical reviews in order to synthesize the most sustainable nanomaterials for the treatment of recalcitrant pollutants from the content of industrial effluents. In parallel, the sustainability of other biological and physicochemical methods has been critically assessed and the most sustainable treatment methods have been suggested to be adopted by the industries. It was demonstrated in this thesis that the application of Tagguchi approach can considerably aid to control the properties of iron-based nanoscale particles synthesized by a liquidphase reduction process. Working with this system revealed that both the (reductant/Fe3+) ratio, (R), and the Fe3+concentration, [Fe3+], are the parameters that determine critical characteristics including particle crystalline phase composition, crystallinity and surface area although R has been revealed as the most important one. Nano zero valent iron particles with enhanced properties, synthesized by utilization of ultrasonic irradiation, was successfully tested to degrade organic dyes (methylene blue, as a case study) which are dominant in the wastewater from some industries such as textile factories. Recovery of the nanomaterials after being applied for the treatment purposes is also among the most important parameters for the selection and synthesis of the most sustainable nanomaterials for environmental applications. A novel ZnO/Fe3O4 on Bentonite nanocomposite prepared in this thesis showed acceptable photocatalytic decomposition of 2,4 dichlorophenol besides the ability to be recovered after being used. Magnetic nanocomposites were also tested for the degradation of AOXs from pulp and paper mill effluents and showed acceptable performance in such applications. A framework was also developed in this thesis for the sustainability assessment of the best available technologies to deal with industrial effluents, showing the efficiency of biological treatment methods to deal with industrial effluents although having some limitation to deal with phenolic industrial effluents. With a precise acclimatization process, very high efficiency for the biodegradation of phenol with a high degree of resistance to the shock of initial phenol concentration was achieved using activated sludge process. The results of a critical review, as the future outlook of this thesis, indicated the possibility of integration of engineered nanomaterials and also biological treatment with the membrane technologies in order to overcome the existing barriers for the rapid development of membrane technologies for the treatment of industrial effluents.A qualidade dos efluentes finais de atividades industriais tem sido, ao longo de várias décadas, objeto de esforços significativos para melhorar o desempenho dos seus métodos de tratamento, seja por via físico-química, biológica ou uma combinação destes. Entre as tecnologias emergentes, o recurso a nanomateriais sintetizados (ENMs) tem sido alvo de especial atenção nos últimos anos. A presente tese teve como objetivo realizar estudos experimentais, levantamentos de informação e revisões críticas, a fim de sintetizar nanomateriais sustentáveis para o tratamento de poluentes recalcitrantes existentes em efluentes industriais. Paralelamente, a sustentabilidade de outros métodos biológicos e físico-químicos foi avaliada criticamente, tendo-se sugerido os métodos de tratamento mais sustentáveis para serem adotados pelas indústrias. Foi demonstrado nesta tese que o recurso à abordagem de Tagguchi pode auxiliar consideravelmente no controlo das propriedades de partículas nanométricas à base de ferro, sintetizadas por um processo de redução em fase líquida. O estudo deste sistema revelou que tanto a razão (agente redutor/ Fe3+) como a concentração de Fe3+ são os parâmetros que determinam características críticas dos precipitados, incluindo a sua composição de fases cristalinas, grau de cristalinidade e área superficial específica. As nanopartículas de ferro de valência zero com propriedades melhoradas, sintetizadas pela utilização de irradiação por ultrasons, foram testadas com sucesso para degradar corantes orgânicos (azul de metileno como corante modelo) que são compostos dominantes nas águas residuais de algumas indústrias, designadamente de fábricas de têxteis. A recuperação dos nanomateriais após a sua aplicação em tratamentos de efluentes também é um dos aspectos mais importantes a ter em consideração na seleção e síntese de nanomateriais sustentáveis para aplicações ambientais. Um novo nanocompósito de ZnO/Fe3O4 sobre Bentonite, produzido neste trabalho, revelou uma capacidade aceitável para decomposição fotocatalítica do 2,4 diclorofenol, além da capacidade de ser recuperado após utilização. Testaram-se também nanocompósitos magnéticos na degradação de AOXs de efluentes da indústria do papel e celulose que evidenciaram um desempenho aceitável nessas aplicações. Definiu-se também nesta tese um contexto para a avaliação da sustentabilidade das melhores tecnologias disponíveis para lidar com efluentes industriais, tendo-se revelado a eficiência dos métodos de tratamento biológico para lidar com efluentes industriais, embora com alguma limitação para lidar com efluentes industriais fenólicos. Com um processo de aclimatação preciso, conseguiu-se uma eficiência muito elevada para a biodegradação do fenol, com alto grau de resistência ao choque da concentração inicial de fenol, utilizando-se o processo de lamas ativadas. Mediante uma revisão crítica da literatura, e como perspectivas de futuro a extrair do presente trabalho, aponta-se a possibilidade de integrar nanomateriais sintetizados e tratamento biológico nas tecnologias de membrana, para superar as barreiras actualmente existentes ao rápido desenvolvimento das tecnologias de membrana para o tratamento industrial efluentes.Programa Doutoral em Ciências e Engenharia do Ambient