Percentage Of COD Removal Research Articles

Fouling of WO 3 nanoparticle-incorporated PSf membranes in ultrafiltration of landfill leachate and dairy a combined wastewaters: An investigation using model

Abstract As fouling has always been a major drawback of membrane technology, qualitative and quantitative understanding of membrane fouling mechanisms therefore becomes vital in order to help push membrane separation technologies forward. In this study, firstly, self-cleaning Polysulfone (PSf) membranes were synthesized by incorporation of WO3 nanoparticles (0–2 wt%) and subsequent UV irradiation for efficient ultrafiltration (UF) of landfill leachate and dairy wastewater. The membrane surface properties were characterized by scanning electron microscopy (SEM) and contact angle analysis. It was found that UV-irradiated membranes exhibited higher percent COD removals due to the hydrophilicity and photocatalytic properties of nano-WO3. Subsequently, in order to analyze the fouling behavior of the membranes, a set of experimental data from cross-flow ultrafiltration of municipal landfill leachate and industrial dairy wastewater at 25 °C was obtained. A new model of membrane fouling was proposed based on a resistance in series concept and was fitted well with all experimental data sets. Almost all relative errors of prediction provided by the proposed model were less than 2.5%. In addition, it was revealed that this newly-developed model exhibited smooth transition between the common successive two-step pore blockage-cake filtration phenomena and thus eliminates the need to use separate equations for different mechanisms.

THE INFLUENCE OF CALCIUM HYPOCHLORITE DOSAGE ADJUSTMENT ON TAPIOCA WASTEWATER PRE-CHLORINATION TOWARD EFFICIENCY OF ACTIVATED SLUDGE TREATMENT

The objectives of this research are to study about influence of calcium hypochlorite dosage adjustment on tapioca wastewater chlorination toward efficiency of activated sludge treatment especially at MLVSS profile and percentage of COD removal. This research mainly divided into pre-chlorination and activated sludge treatment. Pre-chlorination taken place for 60 minutes at pH 8. The variation of calcium hypochlorite dosages which used are 58, 59, and 60 mg/L. Pre-chlorination effluent with no free chlorine residual then becomes activated sludge treatment influent. Sampling has done each aeration time interval 0, 2, 4, and 6 hour for analysis of COD and MLVSS content. Research result generally shows that addition of aeration time for each variation of calcium hypochlorite dosage will increase MLVSS and decrease COD content. Smallest value of COD effluent could achieved in the activated sludge treatment with calcium hipochlorite dosage 60 mg/L addition at influent during 4 hours aeration time. Addition of 58 mg/l calcium hypochlorite results highest MLVSS and percentage of COD removal.

Effects of electrode material and substrate concentration on the bioenergy output and wastewater treatment in air-cathode microbial fuel cell integrating with constructed wetland

In the study, the effects of electrode material and substrate concentration on the bioelectricity generation and wastewater treatment performances in air-cathode microbial fuel cell coupled with constructed wetland (CW-ACMFC) systems were investigated. Four materials including carbon fiber felt (CFF), stainless steel mesh (SSM), graphite rod (GR), and foamed nickel (FN) were used as air-cathode and anode for each system. The obtained maximum power densities of Systems 1, 2, 3 and 4 were 4.80, 2.30, 3.35, and 5.11mWm−2, respectively. In addition, a relative higher NO3-N removal efficiency was observed in four reactors, However, average COD removal percentages of Systems 1, 2, 3, and 4 were 42.30%, 37.42%, 48.78%, and 35.73%, respectively. The relative abundance of autotrophic denitrifying bacteria in the FN system was relatively higher. In summary, CFF and FN can be used as the electrode materials in the CW-ACMFCs system for wastewater treatment and bioelectricity generation simultaneously.

Feasibility study of coagulation system to greywater treatment and economical comparison with electrocoagulation in mining areas

Coagulants exert a significant influence on removing turbidity, TSS and COD. This study has examined the effects of poly-aluminium chloride (PAC), aluminium sulphate (alum) and ferric chloride on removal of turbidity, TSS, COD from greywater in residential complexes of miners working in decorative stone mines. Also, a comparison was undertaken with the electrocoagulation system to find out whether it was economical. Samples were collected over three days from the outlet pipes of greywater in the downstream of a village. The samples were sent to the laboratory to measure their organic materials. However, the Jar test was implemented by using all three coagulants, at concentrations of 100 to 1200 ppm. The results illustrate that the highest percentage of turbidity, COD and TSS removal were 98.24%, 94% and 77.25% respectively, which are related to PAC coagulant. The lowest cost to remove the organic materials in the coagulation method was harvested US $ 0.09/m3 for alum and howbeit. The cost for electrocoagulation method yielded US $ 0.05/m3 water.

ACTIVATED CARBON FROM MUKAH COAL FOR TEXTILE WASTEWATER BIOREMEDIATION TREATMENT

Activated carbon is commonly used in water and wastewater treatment, removing organics that cause unpleasant odors, tastes and other detrimental effects. In this study, bioremediation treatment consists of biofilms of two types of microbes, i.e. Bacillus sp and Escherichia sp are grown and immobilized on the Mukah coal activated carbon from Sarawak. Prepared activated carbon was categorized by different physical geometries design such as SGAC I, SGAC II, SGAC III, HCGAC I, HCGAC II and HCGAC III. The target pollutants to be removed from the Ramatex textile wastewater were BOD5, COD, TSS, color, phosphate, nitrate and sulfate. Escherichia sp with SGAC I was found to give the best results for the bioremediation process and the percentage of BOD5, color,COD,TSS, nitrate, sulfate and phosphate removal were 71.4%, 91.1%, 96.4%, 98.8%, 80.3%, 90.3% and 60.3% respectively. The results indicated that combination between physical and biological treatment was the main factor for the best pollutants removal achievement.

Biological treatment performance of hypersaline wastewaters with high phenols concentration from table olive packaging industry using sequencing batch reactors

Biological treatment of hypersaline wastewaters such as fermentation brine from table olive processing (FTOP), was carried out using four sequential biological reactors (SBRs). These wastewaters were characterized by conductivities higher than 90mScm−1 together with COD and total phenols concentration values of more than 15gL−1 and 1000mgL−1, respectively. In order to increase the organic removal efficiency and to reduce the hydraulic retention time (HRT), extra nutrients were added and pre-treatment by adsorption was performed. Results showed that the COD/N/P relationship, in the FTOP, of 250/5/1 was appropriate for the biological process reaching COD removal efficiencies of around 80%. The FTOP adsorption pre-treatment with powder activated carbon for the reduction of phenols concentration to 400mgL−1 led to a HRT reduction from 40 to 15 days, maintaining the COD and total phenols removal percentages around 78% and 97%, respectively. On the other hand, γ-Proteobacteria was the main bacterial class, representing around 74% of the microbial community in the reactors.

Extraction and use of Cereus peruvianus cactus mucilage in the treatment of textile effluents

The goal of this study was to investigate the application of mucilage extracted from the cereus peruvianus cactus for the optimization of the treatment of actual textile effluents by the coagulation/flocculation technique. The cactus active component obtained by saline extraction gave maximum turbidity removal from standard effluent with a kaolinite turbidity of 95%. The effects of time and storage temperature conditions were investigated and the coagulant activity was found to vary only for the in natura sample after 4 days of storage at room temperature. The textile effluent treatment optimization process was optimized using the response-based Box–Behnken experimental design for the variables coagulant dosage (FeCl3), coagulant adjuvant (Cereus peruvianus) dosage and pH. A quadratic regression model was calculated using the percent COD removal response and the percent removal of turbidity.

Sono assisted electrocoagulation process for the removal of pollutant from pulp and paper industry effluent.

In the present work, the efficiency of the sonication, electrocoagulation, and sono-electrocoagulation process for removal of pollutants from the industrial effluent of the pulp and paper industry was compared. The experimental results showed that the sono-electrocoagulation process yielded higher pollutant removal percentage compared to the sonication and electrocoagulation process alone. The effect of the operating parameters in the sono-electrocoagulation process such as electrolyte concentration (1-5g/L), current density (1-5A/dm2), effluent pH (3-11), COD concentration (1500-6000mg/L), inter-electrode distance (1-3cm), and electrode combination (Fe and Al) on the color removal, COD removal, and power consumption were studied. The maximum color and COD removal percentages of 100 and 95%, respectively, were obtained at the current density of 4A/dm2, electrolyte concentration of 4g/L, effluent pH of 7, COD concentration of 3000mg/L, electrode combination of Fe/Fe, inter-electrode distance of 1cm, and reaction time of 4h, respectively. The color and COD removal percentages were analyzed by using an UV/Vis spectrophotometer and closed reflux method. The results showed that the sono-electrocoagulation process could be used as an efficient and environmental friendly technique for complete pollutant removal.

Treatment of drilling fluids wastewater by electrocoagulation

Electrocoagulation has been successfully used to treat a variety of industrial wastewaters. The goal is to form flocks of metal hydroxides within the effluent to be cleaned by electro-dissolution of soluble anodes. The present work deals with the removal of petroleum organic matter such as diesel from drilling fluids wastewater by the electrocoagulation technique using a direct current (DC) electrolytic cell. The cell is consisted of a rectangular Plexiglass container of dimension 12*12*15cm equipped with varied number of parallel horizontal meshed Aluminum anodes (9*9cm) and 115.2cm2 effective area, stainless steel (9*9cm) cathode. The electrodes were connected to a digit DC power supply (40V) with a multi-range ammeter connected in series and voltmeter connected in parallel with the cell. The percentage of COD removal was studied under different conditions by varying the following parameters: (1) electrolysis time, from 5 to 45min, (2) current density, from 0.008 to 0.034A/cm2, (3) number of parallel horizontal meshed Al anodes, (4) electrolyte concentration. The new anode design of electrocoagulation cell permits high efficiencies with lower energy consumption in comparison with the other cell design used in previous studies.

Electrocoagulación de aguas residuales de la industria láctea

La industria láctea genera gran cantidad de agua residual en sus procesos, estos desechos líquidos son vertidos directamente a fuentes hídricas, sin ningún tratamiento previo. Para dar una solución a este problema, se estudió una técnica que permite el tratamiento de este tipo de aguas con alta carga orgánica, se la conoce como electrocoagulación. Para llevar a cabo el proceso de electrocoagulación se determinó tres factores que son: tiempo, número de placas del electrocoagulador y voltaje del sistema. Una vez realizadas las corridas experimentales se evidencio la eficiencia del tratamiento de electrocoagulación, obteniendo como porcentajes de remoción de aproximado de DQO fue de 93%, DBO5 de 82 % y de SS de 76 %.

Domestic wastewater disinfection by combined treatment using multi-soil-layering system and sand filters (MSL–SF): A laboratory pilot study

This study aims to present the removal of bacterial indicators of fecal contamination and parasites in a combined treatment using a multi-soil-layering system with sand filters (MSL–SF). This experiment was carried out in a laboratory scale. The MSL pilot (height 65cm, width 36cm, depth 30cm) was composed of soil mixture layers (SML) and gravel layers that are arranged in a brick-layer like pattern. The soil mixture layers are composed of local sandy soil mixed with sawdust, metal iron and charcoal at the ratio of 70, 10, 10 and 10%, respectively, on a dry weight basis. The applied hydraulic loading rate (HLR) was 200Lm−2day−1. The experimental sand filter included three parallel similar sand columns (inside diameter 12.5cm, height 120cm). Each column was filled with 80cm of fine sand and 10cm of gravel in the top and the bottom of the filter. Three sand columns HLRs (100, 200 and 400Lm−2day−1) were compared. The obtained results indicated that the conceptual model based on the combination of the MSL method and sand filter (MSL–SF) showed very high efficiency in organic matter, nutrients, bacteria and the reduction of parasites. The high performances were noted in the low HLR. The main removal percentage of SS, BOD5, COD, TN and TP were respectively 99.73, 97.78, 98.40, 92.93 and 96.21% for the HLR-100. In addition, the Log10 removal for total coliforms, fecal coliforms and fecal streptococci were 4.46, 4.47 and 4.13 Log unit respectively. MSL-SF is capable of removing 100% of helminthes eggs. The MSL system is an efficient method, especially for organic matter and nutrients (N, P) removal. Sand filters have experimentally been proved to be useful for fecal indicators and the removal of parasites. Good operational stability and high contaminants removal efficiency of the combined systems were observed. Therefore, the combination of the MSL system and sand filter offer a good alternative option for agricultural wastewater reuse.

CexV1−xO2 (x: 0, 0.25–1) nanocomposites as efficient catalysts for degradation of 2,4 dichlorophenol

Composite oxides of CexV1−xO2 (x: 0, 0.25–1) were synthesized, characterized and applied for removal of 2,4-dichlorophenol. The catalysts were prepared by co-precipitation method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), N2 adsorption at −196°C, Fourier transform Infra Red (FT-IR) and Fourier Transform Raman (FT-Raman) techniques. The X-ray diffractograms of Ce –V oxide powders with different Ce/V molar ratios revealed the coexistence of CeO2 with a tetragonal CeVO4 and orthorhombic V2O5 phase. The Brunauer–Emmet–Teller (BET) surface areas and pore volumes of synthesised composites were in the range of 26.21–1.26m2/g and 0.01–0.0007cm3/g respectively. FT-Infra Red and FT-Raman measurements confirmed the formation of different mixed oxides. Effects of Ce-V ratio, H2O2 dose, reaction temperature, and 2,4-dichlorophenol (2,4-DCP) concentration on CWPO of 2,4-DCP were investigated in detail. CexV1−xO2 were effective catalysts for wet peroxide oxidation of 2,4-DCP and the highest catalytic activity was obtained using the Ce0.5V0.5O2 catalyst with complete 2,4-DCP degradation at 60min, and at 180min COD and TOC removal percentage was 84% and 41.03% respectively. Atomic Absorption Spectrometry (AAS) indicated the extent of leaching of vanadium to be negligible. The mixed oxides were reusable and stable on consecutive use as indicated by XRD and surface area measurements.

Removal of contaminants in a paper mill effluent by Azolla caroliniana

This study was focused on removal of various parameters in paper mill effluent using a method called bioremediation by Azolla caroliniana. The experimental investigations have been carried out using Azolla caroliniana for conducting the sorption study with various dilution ratios (2, 4, 6, 8, and 10), pH (3, 4, 5, 6, 7, 8 and 9) and biomass (200, 400, 600, 800 and 1000 g). The maximum removal percentage of TDS, BOD and COD in a paper mill effluent was obtained at the optimum dilution ratio of 6, pH of 8 and biomass of 800 g. The results of this study indicated that the maximum removal percentage of TDS, BOD and COD in a paper mill effluent was 82.3 %, 88.6 % and 79.1 % respectively. Also, the study focused on uptake of TDS, BOD and COD in paper mill effluent by Azolla caroliniana through bioaccumulation factor and translocation factor. The results of bioaccumulation factor revealed that TDS, BOD and COD in paper mill effluent were adsorbed by Azolla caroliniana. The results of translocation factor revealed that the roots of Azolla caroliniana translocate the TDS, BOD and COD in a paper mill effluent to the shoots of Azolla caroliniana. From the results, this study concluded that bioremediation by Azolla caroliniana could be effectively used for removing TDS, BOD and COD in a paper mill effluent. This study also suggested that Azolla caroliniana may be used for removing various contaminants, not only from paper mill effluent, but also from any other industrial effluents.

Optimization of COD and Color Removal for Matang’s Landfill Leachate Treatment by Using Polyaluminum Chloride

In this research, a physico-chemical treatment method of coagulation-flocculation process is implemented in treating partially stabilized leachate from Matang Landfill, Perak, Malaysia. Central composite design has been used to optimize the independent variables namely polyaluminum chloride (PAC) coagulant dosage (A), rapid mixing speed (B) and rapid mixing time (C). The experimental results were analyzed by using analysis of variance (ANOVA). The results revealed that the percentage of color and COD removal was found increased by increasing rapid mixing speed with optimum removal of 95 % and 56 % respectively. Besides, the R-squared values implied that 86.22 % and 97.34% of the total variation explained by the model equation. Furthermore, the model analysis revealed that rapid mixing speed were significant for removal of color and COD through single parameter (B) and interaction between parameter (AB) respectively. This finding proves the influence of mixing parameter in coagulation-flocculation process for leachate treatment.

Optimization of POME treatment process using microalgae and ultrafiltration

Palm oil mill effluent (POME) was produced in huge amounts in Malaysia, and if it discharged into the environment, it causes a serious problem regarding its high content of nutrients and high levels of COD and BOD concentrations. This study was devoted on POME treatment and purification using an integrated process consisting of microalgae treatment followed by membrane filtration. The main objective was to find the optimum conditions as retention time and pH in the biological treatment of POME. Since after the optimum conditions there is a diverse effect of time and the process become costly. According to our knowledge, there is no existing study optimized the retention time and percentage removal of nutrients for microalgae treatment of POME wastewater. In order to achieve with optimization, a second order polynomial model regression coefficients and goodness of fit results in removal percentages of ammonia nitrogen (NH3-N), orthophosphorous (PO4-3), COD, TSS, and turbidity were estimated. WinQSB technique was used to optimize the objective function of the developed model, and the optimum conditions were found. Also, ultrafiltration membrane is useful for purification of POME samples as verified by experiments.

The high reutilization value potential of high-salinity anchovy fishmeal wastewater through microbial degradation.

To provide an option for the reutilization of high-salinity anchovy fishmeal wastewater (FMW), generated during the anchovy fishmeal manufacturing processes, its potential for biodegradation was assessed in 1-l five-neck flasks using a halotolerant and proteolytic microbial consortium. During the first 41 h of biodegradation, the pH, DO, ORP, and dry-sludge weight decreased as the total cell number of the microbial consortium increased steadily; the COD(Cr)/TN ratios remained between 4.0 and 5.5, respectively, indicating the stable metabolic degradation of organic matter. The ORP tended to increase after 41 h, and the unpleasant fishy smell disappeared once positive ORP values were achieved. The removal percentages of COD(Cr) and TN were 59.0 and 54.4%, respectively, and the dry-sludge weight decreased from 115.5 to 68.0 g, with a degradation rate of 0.59 g h(-1), during the 80 h experiment. The supernatant from the culture of the anchovy FMW at 70 h (culture supernatant) was phytotoxin-free, and the level of total amino acids was 8.04 g 100 g(-1), comparable to that of commercial fertilizers. In hydroponic cultures containing red bean and barley, the culture supernatant demonstrated a good fertilizing ability. The culture supernatant also exhibited a high degree of antioxidant activity, with a 52.3% hydroxyl radical-scavenging activity and 0.16 reducing power (at OD 700 nm). Moreover, the culture supernatant inhibited DNA damage from hydroxyl radicals, enhancing the reutilization value of anchovy FMW. This report presents the first description of high-salinity anchovy FMW possessing a high reutilization value potential both for agriculture and medicine.

Reusability of Fenton Sludge to Reduce COD and Color on Palm Oil Mill Secondary Effluent (POMSE)

This paper reports on the reusability of iron sludge generated from the solar Fenton oxidation on Palm Oil Mill Secondary Effluent (POMSE) samples. The aim of this study was to observe the reusability of Fenton sludge to be used as iron sources for reducing the COD and color of POMSE. The feasibility of iron sludge was determined by recycling the iron sludge five times. Result showed that the percentage removal of COD and color was generally reduced from fresh iron used (F1) to Recycled 1 (R1) and eventually Recycle 5 (R5). The percentage removal of COD for F1, R1, R2, R3, R4, and R5 were 83.8%, 71.2%, 40.3%, 45.1%, 39% and 35.9% respectively. Meanwhile the color removal for F1-R5 were 97.18%, 87.29%, 75.33%, 73.08%, 68.60% and 70.84% respectively. The amount of ferrous iron and total iron in supernatant however, fluctuated between 0.00 to 0.37 and 2.86 to 9.24mg/L respectively. Amount of iron that remained in the sludge in every cycle starting from F1 to R5 were 7271, 7404, 7275, 7546, 7238 and 7025mg iron/kg sludge respectively. In conclusion, it was justifiable to recycle Fenton sludge as a high amount of iron remained even after the fifth time of recycling.

A comparative study on the efficiency of ozonation and coagulation–flocculation as pretreatment to activated carbon adsorption of biologically stabilized landfill leachate

The present work investigates the potential of coagulation–flocculation and ozonation to pretreat biologically stabilized landfill leachate before granular activated carbon (GAC) adsorption. Both iron (III) chloride (FeCl3) and polyaluminium chloride (PACl) are investigated as coagulants. Better organic matter removal is observed when leachate was treated with FeCl3. At a dose of 1mg FeCl3/mg CODo (CODo: initial COD content), the COD and α254 removal was 66% and 88%, respectively. Dosing 1mg PACl/mg CODo resulted in 44% COD and 72% α254 removal. The settle-ability of sludge generated by PACl leveled off at 252mL/g, while a better settle-ability of 154mL/g was obtained for FeCl3 after dosing 1mg coagulant/mg CODo. For ozonation, the percentage of COD and α254 removal increased as the initial COD concentration decreased. Respectively 44% COD and 77% α254 removal was observed at 112mg COD/L compared to 5% COD and 26% α254 removal at 1846mg COD/L. Subsequent activated carbon adsorption of ozonated, coagulated and untreated leachate resulted in 77%, 53% and 8% total COD removal after treatment of 6 bed volumes. Clearly showing the benefit of treating the leachate before GAC adsorption. Mathematical modeling of the experimental GAC adsorption data with Thomas and Yoon–Nelson models show that ozonation increases the adsorption capacity and breakthrough time of GAC by a factor of 2.5 compared to coagulation–flocculation.

The comparison of sonochemistry, electrochemistry and sonoelectrochemistry techniques on decolorization of C.I Reactive Blue 49

In this paper, the ability of three decolorization techniques including sonochemistry, electrochemistry and sonoelectrochemistry for decolorization of C.I Reactive Blue 49 in aqueous solutions have been compared. Various parameters affecting decolorization efficiency, such as pH, initial concentration of the dye, the decolorization time, H2O2 concentration and effect of applied potential on electrochemistry and sonoelectrochemistry, were evaluated. For further comparison, the methods were evaluated based on their ability in COD removal percentage. The maximum COD removal at the optimum condition of each method were 36.0%, 68.0%, 87.8% and 76.2% for sonochemistry, electrochemistry, sonoelectrochemistry with H2O2 and sonoelectrochemistry without H2O2, respectively. The result was an environment friendly method for removal of C.I Reactive Blue 49 from aqueous solutions.

Combining fluidized metal-impregnated granular activated carbon in three-dimensional electrocoagulation system: Feasibility and optimization test of color and COD removal from real cotton textile wastewater

The present study focused on the treatment of real cotton textile wastewater by combining metal (Al/Fe)-impregnated granular activated carbon (MIGAC) as moving particle electrodes in electrocoagulation, referred to here as the MIGAC-TEC system. The feasibility test clearly indicated that MIGAC significantly accelerated the decolorization and COD removal efficiency. The effects of four parameters: applied voltage, initial pH, MIGAC dosage, and reaction time on the percentage of color and COD removal were investigated using response surface methodology with a central composite design. As results, it was found that the decolorization (R2=0.9576) and COD removal (R2=0.9395) were well fitted by a developed quadratic polynomial models and the initial pH was the most influential factor. Through numerical optimization, highly acceptable removal performances of 99.13±0.21% decolorization and 97.01±0.18% COD removal efficiency were achieved under statistically optimized conditions, and suggested that the developed system is a very suitable technique for the enhancement of electrocoagulation-based cotton textile wastewater treatment.