BOD Removal Research Articles

Sand filtration for greywater treatment: long-term performance evaluation and optimization by response surface methodology

ABSTRACT Greywater treatment and reuse is getting increasing attention all over the world, and sand filters are one of the on-site greywater treatment alternatives. Effects of media size, media depth and flow rates on the performance of the continuously operated saturated sand filters treating greywater were evaluated in this study. River sand of three different media sizes 0.30-0.60 (fine), 0.60-0.85 (medium), and 0.85-1.18 (coarse) mm was used and sand filters with the same media size were constructed and operated at flow rates of 10 (320 L/m2/day), 20 and 30 L/d. Fine sand media filter operated at a hydraulic loading rate of 320 L/m2/day gave the best performance with 99, 94 and 95% removal of turbidity, BOD and COD, respectively. NH4-N, PO4-P and FC were reduced by 84, 99% and 1.65 log, respectively. An optimization study showed an optimum sand size of 0.68 mm and a hydraulic loading rate of 470 L/m2/day.

Waste Removal Efficiencies of Floating Macrophytes for Restoration of Polluted Stream: An Experimental Analysis

Freshwater sources are affected by a diverse range of pollutants, which increases the demand for effective remediation. Aquatic phytoremediation is a nature-based solution. It has the potential to provide efficient, adaptable, and multi-targeted treatment of polluted waters. The aim of this research is to evaluate non-mechanized, low-cost onsite treatment of waste water intrusions. It includes an experimental set up with three replicates. Each consists of a modified flow pattern under outdoor conditions. Experimental set up A and B were provided with macrophytes, water lettuce and duckweed, respectively, with plant coverage at 50% and 90%. Experimental set up C was a controlled set up without macrophytes. The highest removal of BOD, COD and Total solids by using water lettuce were observed to be 89%, 77% and 38.5%, respectively. By using duckweed, the highest removal of BOD, COD and Total solids were observed at 88%, 66% and 27.59%, respectively. Removal was also observed in Set up C for BOD, COD and Total solids; its efficiency was 48%, 47% and 25%, respectively. Set up A can be recommended for treating wastewater intrusion, so that wastewater will purify to a to satisfactory to disposal standard level before mixing in river water. The area available in the stream itself can be used as a treatment zone.

Reformation of dairy effluent-a phycoremediation approach.

Microalgae are a unique renewable resource utilized since ages, serving as a reservoir for the production of various metabolites. In this study, dairy waste water (DWW) is used as the nutrient media for the cultivation of microalgae. This study focuses on the phycoremediation process of converting rich nutrients in the effluent into biomass and removing contaminants using microalgae. The specific growth rate reached the maximum of 0.55day-1 in Desmococcus olivaceous, followed by 0.39day-1 for Scenedesmus dimorphus, 0.23day-1 in DCS (consortia composing all three strains in equal ratio), and lastly 0.22day-1 in Chlorella vulgaris. The biomass productivity was 1.44g L-1day-1, 1.06g L-1day-1, 0.88g L-1day-1, and 0.65g L-1day-1 in D. olivaceous, S. dimorphus, C. vulgaris, and DCS, respectively. The COD and BOD removal percentage was 82.85% and 45.40% in D. olivaceous, 81.98% and 44.25% in C. vulgaris, 80.73% and 53.45% in S. dimorphus, and 80.10% and 43.10% in DCS, respectively. These results emphasize the promising role of algae in dairy effluent treatment, highlighting the effluent as a suitable medium for microalgae cultivation. It verifies the circular bio-economy concept where the treated wastewater is converted into value-added products.

Moving Bed Biofilm Reactor Performance on Saline Produced Water (Upstream Oil & Gas) at Very Low Hydraulic Retention Time

This paper presents the results obtained on an oil and gas field terminal in Gabon during a continuous 8-month long operation involving the move of a pre-industrial bed biofilm bioreactor pilot for treating highly saline produced water (100 g/L). After several months of efficient acclimation of the biofilm carriers, more than 90% of the biological oxygen demand, 50% of total organic carbon and 35% of the chemical oxygen demand were removed during 1 h of residence time at a maximum organic loading rate of 12 kgCOD.m−3.day−1, making it a highly promising solution for offshore produced water treatment. These values reached more than 95%, 80% and 60% of BOD, TOC and COD removal, respectively, for 12 h residence time. In addition to the significant removal efficiency of the pilot, it is also important to highlight the robustness of the process. The presence of an acclimated biofilm properly attached to the carriers strongly reduced biomass washing during anomalous phases in comparison to a conventional activated sludge configuration. This technology favorably follows the three key pillars for implementing offshore technologies: high removal performance, robustness and low footprint.

Bacterial cell immobilized packed bed reactor for the elimination of dissolved organics from biologically treated post-tanning wastewater and its microbial community profile

In conventional, the biologically treated tannery wastewaters are rich in dissolved organics and the application of reverse osmosis (RO) to biologically treated tannery wastewater was challenged with fouling and failure of RO membrane due to existence of lingering dissolved organic compounds. In present investigation the bacterial cell immobilized packed bed reactor (CIPBR) was operated to remove the dissolved organic compounds in biologically treated post-tanning wastewater to avoid membrane fouling in RO. The efficient microbial syndicate to eliminate dissolved organics in post-tanning wastewater was isolated and immobilized on to the carbon silica matrix (CSM) in the range of 2.98 ± 0.2 × 107 cells gm−1 of CSM and the same was used as a carrier matrix in the packed bed reactor. The CIPBR established the CODtot, CODdis and BOD removal efficiency by 61 ± 4%, 57 ± 4% and 87 ± 3% respectively with CODtot, CODdis and BOD remained in the treated wastewater as 236 ± 21 mg/L, 228 ± 21 mg/L, and 12 ± 3 mg/L under continuous operation. The removal of dissolved organic compounds from the post-tanning wastewater was confirmed using UV–Visible and FT-IR spectroscopic studies. Among the total microbial community, the phylum Proteobacteria played most abundant role with 48.47% of relative abundance for the removal of dissolved organics in biologically treated post-tanning wastewater. The significance of the study is to replace the tertiary treatment unit operation in the conventional ETP/CETP to remove dissolved organics in wastewater.

Fluidized Immobilized Carbon Catalytic Oxidation Reactor for Treating Domestic Wastewater.

Treating wastewater and reusing it have become normal in the present era since the scarcity of fresh water prevails in many parts of the world. There are numerous techniques for treating domestic wastewater, and many have been explored to advance the ones already in use. This study is taken up to explore the new technology called fluidized immobilized carbon catalytic oxidation (FICCO). Usually, both organic and inorganic materials are present in residential wastewater. In this study, catalyst-activated carbon produced from rice husk is added to a FICCO reactor to test the effectiveness of decreasing organic contaminants in wastewater. Six FICCO models were fabricated in this research study, and tests were conducted. The effectiveness of COD and BOD removal was investigated using six FICCO models with activated carbon made from rice husk as a catalyst and presented in this paper. The FICCO reactor was also used to treat organic contaminants such as surfactants, starch, oil, and protein with rice husk as activated carbon as a catalyst. Organic pollutants used the FICCO reactor; COD removal varied from 75.6% to 92.4%, BOD removal ranged from 74.9% to 89.5% at the optimum contact time, and catalyst rice husk-activated carbon application. The optimum catalyst dosage was 12 g per 620 ml of wastewater, which is the capacity of each reactor and a substantial reduction in sludge.

Performance Evaluation of Al-Khadraa' Wastewater Treatment Plant, Mosul-Iraq

The study aims to evaluate the operational efficiency of Al-Khadraa' wastewater treatment plant and the compatibility of the quality of treated water with the Iraqi standards for disposal into rivers and valleys. The study showed that there are large variations in the quantities and quality of the influent to the plant which sometimes lead to stop operational units of the plant and this has an adverse effect upon the plant function. The results showed that the strength of the influent is classified as weak to medium. The average BOD5/COD ratio is equals to 0.6. Also it seemed that the efficiency of the treatment was weak and the quality of the effluent is out of the Iraqi standards for disposal into rivers and valleys. The percentage removal of BOD, COD, TSS, PO4, NH3 were 83.15%, 79%, 69.7%,56.15%,41.88% respectively. The sequence of removal efficiency was in the order of: NH3<PO4< TSS< COD< BOD.

Potential of Fungal-Microalgal species in the Environmental Biotechnology

Biotechnology involves the provision of services to society by microbial communities. By using microorganisms to detoxify contaminated water, one such service offers environmentally friendly solutions to the treatment of wastewater. Isolates of fungi Aspergillus niger, Candida albicans and microalgal isolates Tetradesmus nygaardi and Scenedesmus quadricauda were efficiently utilized for the treatment of wastewater. The wastewater sample was taken from Erbil wastewater channel near Dhahibah village, the sample was analyzed for physicochemical parameters such as pH, EC, TDS, BOD5, PO4, NH4, NO3, and NO2 (every 3rd day) during 21 days of experiment. Results revealed that a mixed culture of S. quadricauda with T. nygaardi were shows the best removal of PO4, NH4, NO3 and NO2 in which 94.94%, 90.73%, 88.23%, 93.84% respectively. Whereas a mixed culture of T. nygaardi with A. niger showed the best removal of BOD5 (94.9%), while the highest reduction in electrical conductivity and total dissolved solid were recorded by mix culture of Aspergillus niger with Candida albicans 81.65% and 81.52%. Statistically, there were a significant difference (p≤0.05) between control and all microbial stains for all wastewater tested variables.

Microfauna no tratamento de lodo ativado de efluente de uma indústria de processamento de soja: uma forma de avaliação e controle do processo

ABSTRACT Wastewater treatment system by activated sludge, the purification of the organic matter by specific heterogeneous microorganisms, occurs in the presence of oxygen in aeration tanks. The analysis of the microfauna present in the sludge is an important indicator of the performance and efficiency of the activated sludge system. Considering this importance, the objective of this work was to identify the microorganisms which are part of the microfauna present in the aeration tank of the effluent treatment plant of a soybean processing industry in the state of Mato Grosso, evaluating the biological activity of the sludge and the efficiency of the process. Protozoa and bacteria were identified through electronic microscopy and physical-chemical analyses such as pH, dissolved oxygen, nitrogen, phosphorus, BOD, COD, suspended solids, and SVI. During the study, it was possible to identify bacteria related to flake formation, organic matter degradation, nitrification and denitrification, and also microorganisms such as thecamoebas, micrometazoa, fixed ciliates and ciliates free natantes, characterizing the process with good purification and the structure of the sludge flakes between ideal and filamentous bulking with a high sludge age. The identification of the microfauna present was efficient as a bioindicator of the treatment system condition with removal of BOD and COD of 59.75 and 67.09%, respectively.

Treatment of Dairy Wastewater with Pretreatment Techniques and Sequencing Batch Reactor for the Removal of Pollutants: Kinetics and Optimization

In order to remove pollutants like BOD, COD, TKN, TP, TSS, sulphates, chlorides, oil and grease effectively, this study outlines the treatment of dairy effluent by employing the advanced oxidation process (AOP) as pretreatment method with a sequencing batch reactor. It also describes the impact of aeration time and bacterial mass concentration (MLSS) in the sequencing batch reactor for pollutant removal. The high percentage of nutrient contents can be removed by the sequencing batch reactor (SBR), which only needs a single tank for the entire treatment procedure. The pretreatment technique of a combination of ozone and AOP was introduced into the dairy effluent to increase the removal efficiency of pollutants. In this research, the optimal conditions for ozone were a pH of 10, a reaction time of 5 minutes, and an amount of H2O2 of 10 mL/L. The experiments were conducted in the 4 L Plexiglas reactor and the analysis was carried out for different aeration times of 4, 6, 8, 12, 16 and 24 h at the different MLSS concentrations of 2100, 2400, 2900, 3200, 3700 and 4200 mg/L after the addition of ozone and hydrogen peroxide. In this analysis, the higher percent removal of BOD, COD, TKN, TP, TSS, sulphates, chlorides, oil and grease was obtained for the MLSS of 2100 mg/L at the aeration time of 16 h. The percent removal of above pollutants for the above MLSS concentration was in the order of 99.8%, 99.6%, 76.7%, 99%, 99.3%, 34%, 46% and BDL, respectively. The GC-MS analysis was carried out to find the level of contaminants present in the raw and treated water. Further, the sludge analysis was done for the wasted sludge to find its characteristics and its uses. This study suggests that at low MLSS concentrations, a large percentage of pollutants can be removed.

Dairy Wastewater Treatment with Rotating Biological Contactor as Secondary unit and use of Treated Effluent for Agriculture

Rotating Biological Contactor (RBC) is a biological fixed film treatment method that can be applied as part of secondary treatment for wastewater treatment. The present investigation was conducted on dairy wastewater treated by employing RBC as a secondary biological unit, which demonstrated encouraging results. Wastewater 3-day BOD was reduced to 85 mg/L from the influent BOD of 995 mg/L and COD from 1220 mg/L to 130 mg/L. Overall efficiency accomplished by RBC was 91.5% for BOD removal and 89.3% for COD reduction. The treated waste was then used for irrigation of soy and corn crops. Results exhibited an increase in organic matter from 0.262% to 0.395% for corn and 0.416 for soya, whereas available total nitrogen, phosphorus, and potassium as nutrients also increased compared to the regular groundwater application for irrigating the crop. Further, crop yield was also higher than normal, exhibiting advantages drawn from the application of treated wastewater for irrigation.

폐 패각을 이용한 다공성 여과재의 수질정화 성능평가

In this study, in order to evaluate the water purification performance of media filter using shell recycling, specific surface area and water purification experiments were performed after fabricating a filter medium mixed with fine oyster shell powder, zeolite, cement, water, and effective microorganims (EM). A comparative experiment was performed on the amount of change in specific surface area and BOD, SS, and T-P according to the blending amount of the media filter material. When zeolite was added to the media filter using shell recycling, the specific surface area increased, which was twice that of the meida filter using shell recycling without the addition of zeolite. In terms of water purification performance, the removal efficiency of SS and T-P was very high regardless of the type of media filter, but the BOD removal efficiency was different depending on the blending amount of the media filter. The BOD removal efficiency of MF-3 (120 g of fine oyster shell powder, 40 g of zeolite, 40 g of cement, 140 g of water and 10 g of EM based on 350 g) was 86.8 % after 3 and 4 weeks. So it is suitable for use. If the media filter using shell recycling is developed using the optimal blending amount of the media filter obtained in this experiment, it is expected that it can replace the existing media filter and become a new utilization method of the neglected shells.

Design Of Lamella Separator For Enhanced Pollution Removal From NED University Wastewater

The wastewater treatment process incorporates various settlers in the treatment train such as primary, secondary, or tertiary. The conventional settlers used are not adequate to remove suspended solids and create hindrances in the operation of further treatment processes. Therefore, to effectively remove suspended solids lamella clarifier was used in combination with the existing primary settler at the NED wastewater treatment plant. The water quality parameters analyzed include TSS (mg/l), BOD5 (mg/l), and COD (mg/l) in phase 1 before lamella clarifier installation and phase 2 after lamella clarifier installation. Satisfactory results for TSS removal were achieved before and after lamella clarifier i.e., 227-277mg/l to 87-163 mg/l. Similarly, BOD 5 was reduced from 49-277mg/l up to 35-163mg/l. Also, the COD was reduced from 229-277mg/l and was reduced up to 156-163mg/l. Therefore, the lamella clarifier installed at the NED wastewater treatment plant seems to be an effective technology to remove suspended solids along with COD and BOD removal. Therefore, the lamella clarifier installed at the NED wastewater treatment plant seems to be an effective technology to remove suspended solids along with the COD and BOD removal.

A novel hybrid treatment for pharmaceutical wastewater implying electroflocculation, catalytic ozonation with Ni-Co Zeolite 5A° catalyst followed by ceramic membrane filtration

The removal of veterinary antibiotics in pharmaceutical wastewaters become more challenging with modern-day technologies due to their persistent nature. In a sequence, the release of veterinary antibiotics containing wastewater such as Enrofloxacin (EFC) and Tylosin Tartrate (TT) in water bodies has increased the chance for bacteria to attain the antibiotic resistance genes and also moved to others via horizontal gene movement. As a result, the microbes become more resistant even to conventional antibiotics due to the growth of antibiotic resistance genes in microbes. Consequently, conventional treatment technologies just partially remove the pharmaceuticals from the wastewater and are not fully effective because they are not premeditated to remove antibiotics drugs. This alarming situation seriously threatens human well-being and aquatic life. Therefore, it is indeed important to develop an economical advanced oxidation treatment method for the efficacious treatment of pharmaceutical wastewater (PhWW). In the current study, a novel approach was adopted by implying Electroflocculation (EF), Catalytic ozonation (CO) in combination with novel catalyst Ni-Co-Zeolite 5A° followed by Ceramic membrane filtration (CMF). For the first time, in the current investigation, the studied hybrid process (EF + CO–CMF) using Zeolite 5A° coated with double metal salts of Nickel and Cobalt was applied as a catalyst in ozonation (O3) for the treatment of PhWW. Moreover, the removal of COD, BOD5, and turbidity was also studied and compared with national and international effluent quantity discharge standards. The obtained results exhibited that the combined EF + CO process has achieved removal efficiencies of 33 %, 93 %, 78 %, 45 %, and 60 % for EFC, TT, COD, BOD5, and turbidity respectively. Furthermore, the integration of CMF after EF + CO has enhanced the removal of pollutants up to the mark. It was revealed that the novel combined treatment method EF + Ni-Co Zeolite 5A°/O3–CMF has removed the EFC, TT, COD, BOD5, and turbidity of 97 %, 98 %, 90 %, 86 %, and 93 % respectively at optimum conditions (pH = 7.1 ± 0.2; treatment time = 30 min; EF voltage = 10 V; catalyst dose = 10 g/L; O3 = 1.1 mg/min). Additionally, it was observed that biodegradability (BOD5/COD ratios) enhanced from 0.48 to 0.60, and become easily biodegradable for further treatment. Henceforth, EF + Ni-Co Zeolite 5A°/O3–CMF treated wastewater has also complied with the Punjab Environmental Quality Standards (PEQS). Therefore, this novel hybrid treatment process may efficaciously apply at an industrial scale for the treatment of veterinary antibiotics containing PhWW.

Polishing of Treated Palm Oil Mill Effluent Using Azolla pinnata

Phytoremediation was used in this study to polish treated palm oil mill effluent using Azolla pinnata. The effectiveness of phytoremediation using A. pinnata can be proved through the reduction of the contamination concentration of wastewater before and after treatment. Preliminary study was made to determine the range of variables that are required for Response Surface Methodology (RSM) software. The variables for this study are the quantity of A. pinnata (20-30 grams), the concentration of palm oil mill effluent (60% -10%), and retention time (1-5 days). Characterization of palm oil mill effluent showed the BOD concentration (285 mg/L), and oil and grease (68.1 mg/L) above the emission standards, the Environment Quality Act 1974, (2005). The highest percentage of effectiveness to eliminate contamination after treatment is ammonia nitrate with an average efficiency of 93%. Meanwhile, the process of BOD removal efficiency percentage is the lowest at 46%. The optimization process has been done using the software Design Expert®. Through Variance analysis, the percentage of effectiveness to eliminate the BOD is not significant for the quadratic equation. Optimum conditions for phytoremediation of the palm oil mill effluent using A. pinnata are quantity of A. pinnata (30 g), the concentration of palm oil mill effluent (10%) and retention time (4.7 days) with the reliability or desirability at 0.9. Maximum percentage of effectiveness removal for BOD, COD, TS, TSS, oil and grease, NH3-H and phosphate are 63.67%, 80.02%, 85.89%, 80.58%, 81.50%, 98.44%, 92.92% and 0.90%, respectively.

Synchronous COD removal and nitrogen recovery from high concentrated pharmaceutical wastewater by an integrated chemo-biocatalytic reactor systems

Present report, an investigation of highly concentrated and low bio-degradable pharmaceutical wastewater (HCPWW) treatment; simultaneously ammoniacal nitrogen recovery for struvite fertilizer. The use of multiple solvents and many formulation processes in HCPWW, resulting highly refractory chemicals. Here, in this study focused on evaluation of chemo-biocatalysts for the removal of refractory organics, nitrogen recovery from HCPWW. The initial organics, and nitrogen content in HCPWW was 20,753 ± 4606 mg/L; BOD, 6550 ± 1500 mg/L and NH4+-N, 1057.9 ± 185.8 mg/L. Initially, the biodegradability (BOD5: COD ratio from 0.32 to 0.45) of HCPWW, which was improved by heterogeneous Fenton oxidation (HFO) processes, and porous carbon (PCC, 30 g/L), along with FeSO4.7H2O, 200 mg/L and H2O2 (30% v/v), 0.4 ml/L were used as a catalyst in a weakly acidic medium. For the biocatalytic processes, the microbial culture cultivated from sewage and incorporated into a Fluidized Immobilized Carbon Catalytic Oxidation reactor (FICCO), and dominant species are Pseudomonas Putida sp., Pseudomonas Kilionesis sp., and Pseudomonas Japonica sp., which is identified by using 16 S rDNA sequencing analysis. The COD and BOD5 removal efficiency of 65–93% and 70–82%, and follow the pseudo-second-order kinetic model with the rate constants of 1.0 × 10−4 L COD−1 h−1, 1.5 × 10−3 L COD−1 h−1 and 3.0 × 10−3 L COD−1 h−1 in the HFO–FICCO-CAACO catalytic processes. The optimized hydraulic retention time (HRT) of FICCO reactor was 24 h, and 1 h for the Chemo-Autotrophic Activated Carbon Oxidation (CAACO) reactor for maximum organics removal. MAP (Magnesium Ammonium Phosphate precipitation) process showed 90% of NH4+-N elimination and recovered it as a struvite fertilizer at an optimum molar ratio of 1:1.3:1.3 (NH4+-N: Na2HPO4.2H2O: MgO). FT-IR, UV–visible, and UV-fluorescence data confirm the effective elimination of organics. Hence, this integrated treatment system is appropriate for the management of pharmaceutical wastewater especially elimination of complex organic molecules and the recovery of nitrogen in the wastewater.

Co-treatment of landfill leachate with urban wastewater by chemical, physical and biological processes: Fenton oxidation preserves autochthonous bacterial community in the activated sludge process

The impact of Fenton oxidation (FO) and Air stripping (AS) pre-treatments on the bacterial community of a biological activated sludge (B-AS) process for the co-treatment of mature landfill leachate (MLL) and urban wastewater (UWW) was assessed. In this work high-throughput sequencing was used to identify changes in the composition of the bacterial communities when exposed to different landfill leachate's pre-treatments. The combination of FO and AS to increase biodegradability (BOD5/COD) and reduce ammonia concentration (NH3) respectively, allowed to successfully operate the B-AS and effectively treat MLL. In particular, BOD5/COD resulted to be the key factor for bacterial community shifting. The microbiological community of the B-AS, mainly composed by the phylum Bacteroidota (Saprospiraceae, PHOS-HE51, Chitinophagaceae) after FO pre-treatment, shifted to Pseudomonadota (Caulobacteraceae and Hyphomicrobiaceae) when FO was not used. At the same time a drastic reduction in BOD5 removal was observed (90%–58%). On the other hand, high NH3 concentration affected the abundance of the family Saprospiraceae, known to play a key role in the degradation of complex organic compounds in B-AS. The results obtained suggest that a suitable combination of pre-treatments can reduce the negative effect of MLL on the B-AS process, reducing the pressure on autochthonous bacteria and therefore the acclimatization time of the biological process.

Feasibility of a Novel (SHEFROL) Technology in Pre-Treating Eatery Wastewater at Pilot Scale

The wastewater ensuing from public eateries is higher in its chemical and biological oxygen demand (COD and BOD) as also its oil, grease, and protein content than sewage. For this reason such wastewater is much harder to treat; its content of fats, proteinaceous material, and xenobiotics mounting major challenges. But in most of the developing world about 80% of such wastewater is discharged untreated and the remaining is mixed with sewage going to the treatment plants. This happens due to the prohibitively high cost of treatment that is entailed if these wastewaters are to be treated by conventional activated sludge processes (ASPs) or a combination of anaerobic digestion and ASPs. The practice of allowing eatery wastewater to join sewage en route sewage treatment plants increases the load on the latter, especially due to the high fat and protein content of the former. The present work describes attempts to use the recently developed and patented SHEFROL® technology in affecting treatment of wastewater coming from a typical eatery. After establishing feasibility at bench scale, the process was tested in a case study at pilot plant scale for treating 12,000 litres/day (LPD) of wastewater being generated by the eateries situated in the campus of Pondicherry University, India. The capacity of the pilot plant was then expanded to 30,000 LPD. Despite operating the units at a very low hydraulic retention time (HRT) of 2 ± 0.5 h, due to the limitations of land availability, which translates to a rate about three times faster than a typical ASP, over 50% removal of COD and BOD, and similarly substantial removal of other pollutants was consistently achieved. Given that the SHEFROL units can be set up at a negligible cost, the findings indicate that SHEFROL technology can be used to significantly yet inexpensively pre-treat eatery wastewaters before either sending them for further treatment to conventional sewage treatment plants, higher-end SHEFROL units, or discharging them directly if neither of the other two options is available.

Biogas Production from Palm Oil Mill Effluent Using Dielectric Barrier Discharge Integrated with the Aerated Condition

In this study, the performance of dielectric barrier discharge (DBD) with the aerated condition at discharge voltages of 15, 20, and 25 kV on the production of biogas; CH4, H2, CO, and CO2 and the removal of COD and BOD from POME were investigated. The experimental results showed that the aerated condition with a rate of 2.5 L/min at a high voltage (25 kV) produced CH4, CO, and CO2 that was 9.4, 21.5, and 19.6 times higher than the non-aerated one, respectively. The maximum cumulative volume of CH4, H2, CO, and CO2 was 95.4 ± 8.92, 0.94 ± 0.71, 3.06 ± 0.73, and 2.45 ± 0.35 mL/mg COD, respectively, under the aerated condition at 25 kV and the experimental data fit well with the polynomial regression (R2 > 95) for the initial biogas production. The decrease in COD and BOD was greatly affected by the high discharge voltage under the aerated condition, resulting in a high removal rate. These findings suggest that good performance was observed when the DBD was integrated with the aerated condition under the optimum discharge voltage. The study can give information on the optimum condition in a laboratory scale to produce CH4, H2, CO, and CO2, as well as the reduction of organic pollutants from POME.

Performance evaluation of the combined process of ozonation, biological activated carbon reinforced by bacterial consortium, and ultrafiltration in greywater treatment

Background: Background: Because of the growing population and increasing freshwater consumption, treatment and reuse of greywater have been widely considered. The application of a new and environmentally friendly treatment method for synthetic and real greywater (RGW) is of utmost importance. This study aimed to evaluate the efficiency of the combination of ozonation, biological activated carbon, and ultrafiltration (O3 /BAC/UF) in the removal of chemical oxygen demand (COD), turbidity, five-day biochemical oxygen demand (BOD5 ), and linear alkylbenzene sulfonates (LAS) from synthetic greywater and RGW. Methods: Bacillus Subtilis, Acinetobacter radioresistens, Pseudomonas aeruginosa, and Ochrobactrum oryzae were selected from nine pure bacterial species and transferred to granular activated carbon (GAC), then, mineral culture medium was added to the reactor for the growth and establishment of bacterial consortium. The SEM method was employed to ensure the formation of a microbial layer on GAC. Then, the continuous flow of synthetic greywater (for six months) at a low: 6.1, medium: 12.2, and high: 18.3 gCOD/L.d organic loading rates as well as RGW (for two weeks) entered the treatment system. Results: The percentages of COD removal in low, medium, and high organic loads of synthetic greywater and RGW were 85.12%, 79.05%, 85.3%, and 98.65%, respectively. Moreover, the percentages of BOD5 removal were 87%, 82%, 51%, and 92%, respectively. Furthermore, the percentages of turbidity removal were 93.5%, 97%, 96.69%, 73.33%, and the percentages of LAS removal were 91.4%, 88.1%, 84.8%, and 93.7%, respectively. Conclusion: The treatment system has a remarkable ability to remove pollutants from greywater and can be used as a new method of greywater treatment in Iran.