BOD Removal Efficiencies Research Articles

APPLYING THE QUALITY AND POLLUTION INDICES FOR EVALUATING THE WASTEWATER EFFLUENT QUALITY OF KUFRANJA WASTEWATER TREATMENT PLANT, JORDAN

In Jordan, reclaimed wastewater has become a significant component of water resources due to acute water scarcity and increased water demand for different purposes. The vast majority of the reclaimed wastewater is used for restricted and unrestricted agriculture, with agriculture being one of the main economic activities in the country. The purpose of this study is to assess the quality of the wastewater effluent from the Kufranja Wastewater Treatment Plant (WWTP) and its suitability for irrigation and discharge into streams, wadis, or water bodies using the water quality index (WQI) and the water pollution index (WPI). The WQI and WPI were calculated using 15 physiochemical and biological parameters in total. The results of WQI and WPI based on the Jordanian standards for the reuse of reclaimed wastewater showed that the wastewater effluent of Kufranja WWTP falls within the category of "good quality" for the irrigation of industrial crops, field crops, and forest trees, while it falls within the category of "unsuitable quality or highly polluted water" for other irrigation uses. Moreover, the Kufranja WWTP effluent is of "unsuitable quality or highly polluted water" for discharging into streams, wadis, or water bodies. The findings from this study show that the Kufranja WWTP performed well during the year of study, where the average removal efficiency (EFF%) for BOD5, COD, and TSS was 95.1%, 95.6%, and 96.0%, respectively. The WQI results in this study revealed that E. coli has the greatest contribution to the WQI values, followed by PO43-, pH, and SAR, implying that the previous parameters are to blame for the deterioration of the effluent quality of the Kufranja WWTP and its inappropriateness for most uses. Therefore, further advanced treatments are required to reduce the loading of these parameters.

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.

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.

Treatment of Dairy Waste Water using Adsorbents from Solid Waste

Abstract: Dairy industry is a major food processing industry. The waste water from dairy industries are mainly produced in the receiving station, starting, stopping and washing any of the processing units, using the processes pasteurization, homogenization of fluid milk and the production of dairy products. It is estimated that dairy industries generate 2.5 to 10L of wastewater per L of milk processed. Major pollutants found in dairy waste water are organic components like dissolved sugars, carbohydrates, proteins and fat, Suspended Solid, Total Dissolved Solid, Sulfur, Phosphorous and Nitrogen. So the dairy wastewater is considered as high concentration of organic matter and high BOD. Disposal of the waste water is a major challenge for dairy industries. As it produced pungent odor it should be treated before disposal to keep environment free from various problems. In this work, the synthetic dairy waste water was prepared and was treated with activated carbon prepared from waste dried coconut shell. The activated carbon prepared from Coconut shell CGAC could be able to remove COD and BOD of the used water up to satisfactory level at different bed height and contact time. This paper shows the removal efficiency of COD and BOD using the activated carbon. In the experiment, the maximum removal efficiency of COD and BOD from the dairy wastewater was found in bed height 10cm with contact time 2hours

Physiochemical Treatment of Wastewater Utilizing Polyaluminum Chloride for Khartoum North Wastewater Effluent

This paper focuses on the possibility of applying physiochemical treatment for industrial wastewater combined with domestic wastewater that are currently treated by the conventional activated sludge process in Khartoum North Treatment plant at Haj Yousif (Wad Dafeah). A lab-scale experiment was carried out utilizing Poly aluminum chloride (PAC) as a coagulant for determining the optimum dose to reduce the turbidity of the wastewater sample to the lowest level. The results of the lab-scale model showed that a dose of 0.8 ml/l of the PAC achieved significant removal of turbidity (from turbidity >1000 NTU of raw sewage to turbidity level of 18 NTU of the treated effluent). This dose of 0.8ml/l obtained from the lab-scale experiment was applied in a pilot plant of capacity 30 m3/d erected at the site of the treatment plant (Wad Dafeah). The process units utilized in the pilot plant were of minimum or negligible electrical power consumption. They include an inverted hydro cyclone for flash mixing of the coagulant, pipes arrangement to achieve hydraulic gentle mixing as flocculation process, vertical sedimentation tank to enhance efficient settling of particles and tertiary treatment using a rapid sand filter. Raw sewage of BOD5 = 5000 mg/l was introduced into the pilot plant and excellent quality of treated effluent was obtained. Removal efficiencies of both BOD5 and SS were high (97 % & 98% respectively).Treated effluent had BOD5 = 23 mg/l & SS = 22 mg/l. The high dose of PAC utilized for the treatment (0.8 ml/l= 1040 mg/l) can be reduced significantly if raw wastewater of lower BOD content such as domestic wastewater is treated. In a parallel study with the domestic sewage of BOD5 =350 mg/l, the PAC dose required was 0.1 ml/l (130 mg/l). Recycling of residual PAC in the sludge is recommended to decrease the cost of treatment. The approach & methodology followed in this study can be further adopted using other coagulant material such as ferric salts or other similar local product which can achieve high efficiency in reducing the load of organic substances in the wastewater with minimum cost.Keywords: Physiochemical; Poly aluminum chloride; inverted hydro cyclone

A novel two-stage process for the effective treatment of swine wastewater using Chlorella sorokiniana AK-1 based algal-bacterial consortium under semi-continuous operation

This study aimed at developing an eco-friendly and effective treatment for swine wastewater (SWW) using a designer microalgae-bacteria consortium. A functional algal bacterial consortium was developed with SWW-derived bacteria and Chlorella sorokiniana AK-1. Light intensity (300 µmol/m2/s) and inoculum size (0.15 and 0.2 g/L for microalgae and bacteria) were optimized. Semi-batch operation treating 50 % SWW resulted in a COD, BOD, TN, and TP removal efficiency of 81.1 ± 0.9 %, 97.0 ± 0.7 %, 90.6 ± 1.6 % and 91.3 ± 1.1 %, respectively. A novel two-stage process with an initial bacterial start-up stage followed by microalgal inoculation was applied for attaining stable organic carbon removal, in addition to satisfactory TN and TP removal. Full strength SWW was treated with this strategy with COD, BOD, TN, and TP removal efficiencies of 72.1 %, 94.9 %, 88 %, and 94.6 %, respectively. The biomass consisted of 36 % carbohydrates, indicating a potential feedstock for biochar production. In addition, the effluent met the standards for effluent discharge in Taiwan.

In-situ degradation of Amphotericin B in a microbial electrochemical cell containing wastewater

Antimicrobial resistance raises serious medical implications and is primarily caused by indiscriminate usage and environmental contamination with antimicrobial agents. To prevent microbes from developing resistance against antimicrobial agents, they must be effectively degraded. This is the first study that investigates the degradation of Amphotericin B(AmB) with simultaneous wastewater treatment in a Microbial Peroxide producing cell (MPPC). Two sets of MPPCs (A and B) were used to degrade AmB oxidatively, one with H2O2 and the other with the microbial electro Fenton process in a catholyte containing 0.1% AmB. MPPC A and B had voltage outputs of 0.356 ± 3 V and 0.411 ± 2 V, producing 26 ± 0.04 mM and 44 ± 0.8 mM of H2O2 respectively. The structural changes of treated samples were analyzed using Fourier Transformed Infrared Spectroscopy, which revealed the disappearance of major characteristic bands such as the NH band (1556 cm−1), the CH band Polyene ring (3358 cm−1), and others, implying the disruption of multiple double bonds in polyene, resulting in the structure's lactone ring breakdown. Liquid chromatography quadrupole time-of-flight revealed the changes in retention time and peak area of treated samples in comparison to native AmB which also confirmed its structural changes. Such structural disruption induced the drug to lose its antifungal action since no zones of inhibition were detected in an antimicrobial susceptibility test against Candida albicans. The degradation of 57.05% and 69.83% of AmB by H2O2 and the Fenton process was also correlated with a reduction in COD. Simultaneously the anodic wastewater treatment in both the MPPCs had COD removal efficiency of 78% and 82% and the BOD removal efficiency was 75.38% and 90% respectively. The MPPC system's process conditions and reactor design could be optimized further to enhance antimicrobial degradation and wastewater treatment. This research offers a sustainable and efficient method for expediting antimicrobial degradation while simultaneously treating wastewater.

Tainted Wastewater Remediation through Inverted Multimedia Biofilter

The growth of industry leads to the contamination of surface as well as groundwater. Improper industrial wastewater disposal causes a serious problem of metal accumulation in the soil and freshwater. To tackle this issue there is a need of recycling and reuse wastewater using low-cost sustainable treatment. The main objective of this research is to check the feasibility of multimedia vermifilter for the efficiency removal of physicochemical parameter and fluoride metal ions of fluoride-tented used water (wastewater). For the treatment, we used fluoride contaminated used water (wastewater) from the fluoride contaminated site. In this study multimedia vermifilter integrated with moringa seed extract, activated charcoal powder, and earthworm Eisenia fetida were used as bio-media to treat contaminated used wastewater, In this experimental analysis, we checked the removal efficiency on different HLR in m3/day/m2. The result showed that percentage removal efficiency for BOD, COD, TDS and Fluoride using inverted multimedia filter was observed for the optimized hydraulic loading rate at 0.933m3/day/m2 was found to be BOD (81.64%), COD (51.47%), TDS (82.17%), Fluoride (35.81%) respectively. The earthworm, moringa seed extract, and activated charcoal play a vital role in the removal of Bioconversion of organic matter. Furthermore Treated effluent waste-water is then used for gardening and irrigation purposes.

Treatment of slaughterhouse industry wastewater with ultrafiltration membrane and evaluation with life cycle analysis

Slaughterhouse wastewater is one of the most produced industrial wastewater in the world and has a high pollution potential, and this wastewater can cause a high level of polluting effect when it is given directly to river beds or sewage systems. Wastewater contains proteins, fats, carbohydrates in the treatment of blood, skin and feathers, which results in much higher biological oxygen demand (BOD) and chemical oxygen content (COD). The possibility of using ultrafiltration for slaughterhouse wastewater treatment was investigated. The results showed that ultrafiltration can be an efficient purification method. COD and BOD5 remova lefficiency is around 96% and 95%. In addition to these results, the Life Cycle Analysis (LCA) of the ultrafiltration system was also carried out. Accordingly, the effects of ultrafiltration system on human health, ecosystem quality, climate change and resources were calculated as 0,00000046 Disability-Adjusted Life Years (DALY), 0,134 PDFxm2yr, 0,336 kg CO2 eq and 6,937 MJ respectively. As a result of the study, it is thought that slaughterhouse wastewater can be used as irrigation water after passing through the ultrafiltration membrane due to the high content of N and P.

Waste Water Treatment Performance of Two Vertical Flow Constructed Wetlands for Agricultural Reuse in Jordan: Enhancing Nitrogen Removal

This study demonstrates the treatment performance of two vertical flow constructed wetlands (VFCWs) for decentralized wastewater treatment plants in Jordan, for reuse purposes to meet the WHO regulations for reuse in agriculture and the Jordanian standards (JS 893/2006). The first system is a recirculating VFCW that has shown high removal efficiency of COD, TSS, and CBOD5 over the study period, conforming to the JS (Category A). Whereas, the Total Nitrogen (TN) and Nitrate (NO3-) removal were limited (55 and 44 mg/L) over the baseline monitoring, conforming to the JS Category-B (TN: 70 mg/L and NO3-N: 45 mg/L). Therefore, the system was modified by converting the recirculation tank into attach growth tank (using electric conduit pipes as plastic media). TN concentration reduced effectively of 40 mg/L, conforming to the JS category-A (TN: 45 mg/L), whereas, NO3–N concentration reduced to 37 mg/L, conforming to the JS Category-B (TN: 45 mg/L). Over the study period, E. coli reduction were constant, 2 log10 reduction, conforming to the JS category C (more than 1000 MPN/100 mL). The second system is two-stage VFCW that has shown high removal efficiency of COD, TSS, and BOD5, conforming to the JS Category-A over the study period. But, TN and NO3–N concentrations were limited (55 and 44 mg/L), conforming to the JS Category-B, due to insufficiency of carbon source to promote denitrification (high BOD5 removal by first filter). Thus, the two-stage VFCW was modified with raw wastewater step-feeding application to the intermediate pump shaft before the second stage filter. The results of operational modification showed a small significant improvement in TN removal (p = 0.005); TN and NO3–N concentrations were reduced to 52 and 50 mg/L, respectively; conforming to the JS Category-B. Higher E. coli removal was observed in the two-stage system than the recirculating system, with an overall average removal of 4.5 log10 units, conforming to the JS category B (less than 2.0 log10 units). While, E. coli reduction influenced negatively by step-feeding modification, conforming to the JS category C

French Type Constructed Wetlands for Sewage Treatment: Experiences from the Swings Prototype in India

This study aimed to investigate the performance of the French Type Constructed Wetlands (FTCW) at a pilot scale level in real field conditions for sewage treatment in India. The pilot plant consisted of hybrid wetlands in two stages, vertical and horizontal sub-surface flow types. The first stage comprised three compartments, vegetated with three different native plants (phragmites australis, canna indica, and sagittaria), operated in parallel, and sequentially loaded. Each VSSF bed of 12.25m2 was fed with raw sewage directly for 3.5 days followed by twice the time resting period. The second stage consisted of one bed of an area of 45m2, planted with canna indica. The filter media used in stage 1 was a dual type (gravel and coarse sand) in three layers. The first stage was designed for the loadings of 33.75gBOD/m2d and 14.1 gNH4-N/m2d with the flexibility to operate at a variable hydraulic loading rate (HLR). Two years of monitoring data after the steady-state condition show variable performances at different hydraulic loading rates. Removal efficiencies of COD, BOD5, TSS, TN, and TP of the hybrid system at HLR of 0.4m/day were 87.1%, 87.3%, 84.6%, 67.93%, and 69.32% respectively. Doubling the HLR, the efficiency of the system decreased marginally for the same parameters. Out of the three vegetation, the bed planted with phragmites has shown the highest removal efficiency. The study has demonstrated that FTCW can be a suitable proposition as one of the potential methods for sewage treatment in India and similar regions.

Removal of heavy metal from wastewater using ion exchange with membrane filtration from Swarnamukhi river in Tirupati

Environmental problems and pollution are the most critical issues worldwide. Ecological awareness is necessary to protect the environment from pollution. According to a research investigation, around 62 million people are in Tirupati in India. The water of this location is highly polluted and needs treatment. This study analyses the removal of heavy metals with the ion exchange process with the addition of membrane filtration. The wastewater has present heavy metals, which are required to remove. The basic idea of this study is to protect the environment and people and provide them with fresh water. This study focuses on the treatment process and survey of generated wastewater from the Swarnamukhi River of Tirupati. The major issue in the water stream is the presence of TSS, TDS, BOD, COD, heavy metals, and fecal coliform bacteria. The evaluation of the treatment process is briefly described and designed in this study as the reclamation of wastewater. The removal efficiencies of total suspended solids (TSS) and total dissolved solids (TDS) were found to be 95% and 93.33%, respectively. The removal efficiencies of BOD and COD were found to be 76.25% and 85%, respectively. The ion exchange process with the addition of membrane filtration is the effective method to remove BOD, COD, and heavy metals from water.

The Development of Polymeric Composite Membrane Containing Plant Waste Derived Activated Carbon and TiO2 for Raw Petroleum Refinery Wastewater Treatment

Petroleum industry results in a huge amount of harmful oily wastewater that must be properly treated. The fabricated composite membrane comprising polyvinylidene fluoride (PVDF), cassava peel-derived activated carbon (AC), and TiO2 was then developed for treating raw petroleum refinery wastewater containing high loading of organic and inorganic pollutants. This study applied different ratios of AC/TiO2 by 0, 1, 2, and 3% in the membrane fabrication solution to study the effect of composite ratio on the quality of permeate, fouling rate, and membrane tensile strength. The experimental work found that the ratio of AC/TiO2 by 3% in the composite membrane outperformed the other ratios. The additives addition by 3% could achieve more than 40, 71, 40, and 67.5% of COD, oil, BOD5, and phenol removal efficiency, respectively. It also reached a lower flux decline by 25% within 250 min of filtration time. Hermia’s model was then applied to study the fouling mechanism occurring during membrane operation. Additionally, it was indicated that membrane tensile strength was also influenced by composite ratio, where higher PVDF amount resulted in higher membrane tensile strength. Overall, this study concluded that composite membrane could be a reliable alternative for treating raw industrial wastewater to existing wastewater treatment technologies. Further research related to the composite membrane integration system with other treatment techniques can then be conducted to lengthen membrane lifespan and improve the permeate quality.

Investigation on the Treatment of Slaughterhouse Wastewater in a Sequential Batch Reactor

In the present study, the treatment of slaughterhouse wastewater was carried out in a sequential batch reactor. A lab-scale column type reactor was fabricated with Perspex material having dimensions of 10 cm diameter, 100 cm height, and an effective volume of 7 liters provided with ports at different levels. The reactor performance was evaluated in terms of COD, BOD, TSS, TKN, and phosphorus removal. The reactor was operated for 432 days; the effectiveness of the reactor is the temperature of wastewater in the reactor. The removal efficiencies of COD and BOD were84% and 80% in the reactor. The maximum TSS removal was around 87% and TKN’s maximum removal efficiency was 61% in aerobic treatment. Phosphorus maximum removal efficiency was around 68%, in the meantime pH and alkalinity were also monitored, and no change in the pH was reported throughout the experiment. On the other hand, an aerobic SBR is also operated using wastewater after the DAF unit. In the same manner, the reactor was operated with initially diluted wastewater (05 times) and kept HRT 8 h. The reactor performance was studied in terms of COD, BOD, TSS, TKN, and phosphorus. The maximum removal efficiencies of COD and BOD were 80% and 81% respectively. The maximum removal efficiencies of TSS, TKN, and Phosphorus were 73%, 81%, and 69% respectively. It is concluded that the removal efficiency of COD was better in the anaerobic process as compared with the aerobic process in addition the generation of methane gas during the degradation of organic matter can be used for operating the aerobic unit by making some necessary arrangements. Besides this, it is also concluded that the removal efficiency of TKN was better in the aerobic process as compared with the anaerobic process. There was a buildup of VSS from 4500 mg.L-1 to 6500 mg.L-1 in the study.

Assessment in treatment efficiency of a small-scale municipal wastewater treatment plant with activated sludge

Abstract In this paper, the treatment efficiency of a small-scale wastewater treatment plant (WWTP) with activated sludge was analysed in order to examine the impact of variations in the composition of incoming raw municipal wastewater. The characteristics of the wastewater were analysed with respect to COD, BOD5 and TSS values and loading during the two years, 2018 and 2019. The mixed liquid suspended solid (MLSS), sludge volume index (SVI), food to microorganism ratio (F/M), sludge age and hydraulic retention time (HRT) were used for evaluation of the performance of WWTP. Removal percentage is in the order of TSS > BOD5 > COD during 2018, while in 2019 is in the order BOD5 > TSS > COD. However, better values of removal efficiency for COD, BOD and TSS are obtained in 2019, which is connected to lower oscillation values of MLSS and SVI index. Biodegradability ratio of raw and treated wastewater, plant reliability factor (RF) and equivalent number of inhabitant (ENI) were determined. In addition, the economic cost of small-scale wastewater treatment plant (WWTP) with activated sludge was evaluated and discussed.

Performance and modeling studies of rotating biological contactor for treatment of vegetable oil wastewater

AbstractThis study focuses on a lab‐scale rotating biological contactor (RBC) treating vegetable oil wastewater with high BOD and COD. The fabricated RBC was checked for efficiency in degrading polluted wastewater under different operating conditions. The maximum removal efficiencies for BOD and COD were 95.75% and 89%, respectively. This high removal percentage was obtained with 30% submergence of 10 discs rotating at 8 rpm. For the first time, bio‐kinetic models were applied to the experimental results for vegetable oil wastewater. The best fit was obtained with the modified Stover‐Kincannon and Grau model. The saturation constant (Ks) values were 1.872 and 3.024 g/L/d for BOD and COD, respectively, for the modified Stover‐Kincannon and Grau model. For the Grau second‐order model, the saturation constant was 1.416 and 3.744 g/L/d for BOD and COD, respectively. The predicted effluent BOD and COD values of the modified Stover–Kincannon model fitted almost exactly with the experimental values. This clearly predicts that this model can be best used to predict effluent BOD and COD concentration in a Rotating Biological contactor treating vegetable oil wastewater. The kinetic parameters determined in this study can be used to improve the design and operation of continuous mode RBC systems.

Pengolahan Lindi Menggunakan Advanced Oxidation Process (AOPs) Berbasis Ozon

Leachate can be formed from the percolation of water that passes through the garbage. The high content of organik and metallic substances in leachate can cause environmental damage, so it must be treated first before being discharged into the environment. This study aims to determine the effectiveness of ozonation in neutralizing pH and reducing the levels of TSS, BOD, COD in the leachate of the Griyo Mulyo landfill using the AOPs method based on ozonation. Studies on ozonation in leachate treatment have been carried out by varying the ozonation time (15, 30, 45, and 60 minutes). Parameters that have been observed are pH, TSS, BOD, COD. The results showed that the best ozonation time for leachate pH was at 15 minutes with a value of 7, the best ozonation time for leachate TSS was at 15 minutes with a value of 56 mg/L. The best ozonation time for BOD and COD was at 45 minutes with values ​​of 511 mg/L and 1260 mg/L, respectively. The best percentage of removal efficiency for TSS, BOD and COD reached 67%; 84.1%; and 88.41%.

An innovative reuse of bottom ash from municipal solid waste incinerators as substrates of constructed wetlands

The incineration of municipal solid waste has been important in waste management, but it raises another environmental issue concerning residue treatment. This study describes an innovative use of naturally aged incineration bottom ash (AIBA) as an alternative substrate for horizontal subsurface flow (HSSF) constructed wetlands (CW). Although experimental results from a period lasting for 396 days only revealed slightly higher removal ratios in HSSF with AIBA (HSSF-E) than in HSSF-traditional pebble beds (HSSF-C), increasing from 67% to 76% for BOD, 44%–51% for TKN, 47%–54% for NH3-N, and 44%–52% for TN. The data indicate that the use of AIBA in HSSF CW can achieves a certain removal efficiency of BOD and nitrogen species. Interestingly, the total phosphorus removal rates also increased significantly from 20% in HSSF-C to 36% in HSSF-E. These observations on the use of AIBA in HSSF CW confirmed that AIBA is a suitable alternative for use as a substrate for HSSF CWs and identified an additional way to reuse incineration bottom ash. Design criteria for a CW using AIBA as a partial substrate is proposed to improve the pollutant removal performance of HSSF CWs.

Activated sludge microbial communities and hydrolytic potential in a full-scale SBR system treating landfill leachate

Landfill leachate, due to its recalcitrant nature and toxicity, poses a serious environmental threat, which requires the implementation of effective treatment processes. In this work, a full-scale treatment system consisting of two Sequencing Batch Reactors (SBRs) was used for the processing of landfill leachate of intermediate to mature age (BOD/COD ratio of 0.16). Biosystem operation resulted in BOD5, COD and TKN removal efficiencies of 81%, 39% and 76%, respectively, whereas the low residual NO3 --N concentration in the effluent (4.01 ± 0.10 mg/L) was indicative of the efficient denitrification process. Assessment of hydrolytic potential of activated sludge revealed high endocellular and extracellular lipase activities, which reached values up to 206 and 141 U/g protein respectively, possibly as the consequence of plastics degradation during maturation process. Implementation of Illumina sequencing indicated the predominance of Alphaproteobacteria, accompanied by members of Bacteroidetes, Betaproteobacteria and Chloroflexi. Paracoccus was the predominant genus identified, followed by representatives of the genera Bellilinea, Flavobacterium, Thauera and Truepera. Nitrosomonas was the major ammonia-oxidizing bacterium (AOB), while nitrite oxidation was mainly achieved by the uncultured nitrite-oxidizing bacterium (NOB) Candidatus Nitrotoga.