BOD Loading Research Articles

Sustainable leather tanning: Enhanced properties and pollution reduction through crude protease enzyme treatment

In this study, proteolytic bacteria, particularly Pseudomonas aeruginosa strain SM4 (OQ349573), were isolated from tannery solid waste dumping yard soil and employed to produce extracellular protease enzymes. The bacteria exhibited optimal growth after 30 h of incubation at 37 °C and pH 7. Under conditions of 55 °C, pH 8, and a substrate concentration of 2 %, the crude enzyme displayed its highest activity at 105 UmL−1. Notably, the produced crude enzyme showed no discernible inhibitory effects on detergents, metal salts, or organic solvents. Application of the crude protease at concentrations of 3 % and 2 % in chrome tanning of goatskins (GS) and cowhides (CH), respectively, yielded significant reductions of 35 % and 30 % in chromium and other post-tanning chemicals compared to conventional processes. Despite the 30 to 35 % reduction in tanning and post-tanning chemicals, the uptake of chrome and associated chemicals by crust leather was higher than observed in conventional processes. Chromium content analysis of the effluent revealed an 81 % reduction during piloting in real industrial operations, accompanied by reductions of about 46 % in BOD and COD pollution loads. The finished leather obtained from the enzymatic process exhibited superior mechanical properties, including higher tensile strengths (210 and 195 kg cm-2), stitch tear (92 and 165 kg cm−1), grain crack load (28 and 32 kg), and distension (73 and 62 mm) for GS and CH, respectively, surpassing or closely aligning with standard values and those obtained in conventional processes.

Deciphering the photoelectrochemical behaviour of MoSe2-decorated BiVO4 as a dual system for concurrent degradation of methylene blue and hydrogen generation

Green hydrogen production through photoelectrochemical (PEC) water splitting offers a sustainable energy solution, but the utilization of low-quality water is essential to conserve freshwater resources. Repurposing industrial wastewater, a substantial global issue, for PEC water splitting remains underexplored due to challenges in photoelectrode efficiency and stability. In this study, we present a MoSe2-decorated BiVO4 heterostructured photoelectrode (MoSe2/BiVO4 or BM) for green hydrogen production and efficient wastewater treatment. The optimized system yields a hydrogen production rate of 0.113 mmol from synthetic textile water (utilizing methylene blue as a model pollutant) while achieving a 94.74% degradation of pollutants. Synthesized via a hydrothermal route, BM demonstrates a high photocurrent density of 2.57 mA/cm2 at 1.23 V vs RHE, surpassing BV alone (0.14 mA/cm2). Further, BM shows incident photon to current efficiency (IPCE) of 12.24% and applied bias to photocurrent efficiency (ABPE) of 0.59%. Scavenger studies elucidate the role of holes in MB degradation. Tested in textile wastewater treatment outlets, BM exhibits a hydrogen production rate of 6.155 μmoles alongside reduced COD, BOD, TOC, and microbial load, showcasing its dual capability for hydrogen generation and simultaneous wastewater treatment. Thus, the efficiently designed type-II heterostructure formed between BV and MS behaves as a dual system with demonstrated usage in low-quality water for hydrogen generation with its simultaneous treatment.

Water quality management by enhancing assimilation capacity with flow augmentation: a case study for the Yamuna River, Delhi.

This paper aims to assess the requirement of load reductions and flow augmentation to enhance the assimilation yield of the Yamuna River, Delhi. The framework QUAL2kw was used to predict river quality. The model was calibrated and confirmed in critical flow conditions of pre-monsoon periods. Three strategies were established for varying pollutant loads. The DO concentration was predicted with changing BOD and COD loads. The 16 outfalling drains were considered pollutant sources between the 22 km stretch of the river. Four cases with 41 scenarios were studied with varying flow augmentation upstream and varying load. It has been observed that with 80 cumecs of upstream flow, the reach can assimilate 31.33 tonnes per day of BOD and 142.85 tonnes per day of COD load, maintaining the desired level of DO (≥4 mg/L) and BOD (≤3 mg/L) throughout the reach.

Design Criteria for Chicken Slaughterhouse Wastewater Treatment with Granular Activated Sludge in Sequencing Batch Reactor

Chicken Slaughterhouse (RPA) is a business in the field of slaughtering and processing chicken into parts that are ready to sell to customers, where the waste water which contains high levels of organic matter can pollute the environment. Therefore, it is necessary to treat wastewater that is efficient and easy to use such as Granunlar Activated Sludge (GAS) using Sequencing Batch Reactor (SBR). The study was conducted on a laboratory scale to determine the effect of aeration time and settling time using different aeration (7 L/min and 10 L/min). The formation of GAS was cultured by reacting the activated sludge with slow stirring for 28 days, after which it was acclimatized by 50%, 75%, and 100%, then entered into the main study. The results obtained from the processing results are the level of COD removal to 25, 66 mg/L with 97.49% efficiency; BOD became 107.61 mg/L with an efficiency of 85.29%; and removal of TSS to 64 mg/L with an efficiency of 60%. The optimum processing time is 1 hour aeration with 40 minutes of precipitation using an aeration rate of 10 L/min. The design criteria obtained were BOD Load 0.671 kg BOD/m3.day, F/M ratio 0.145 kg BOD/kg MLVSS.day, HRT 26 hours, and SRT 28 days.

Evaluation of Non-Point Source Pollution Load Characteristics and Identifying Management Sub-Basin Area and Best Management Practices Using HSPF Model in Yongdam Dam Watershed

Objectives : To identify and estimate the non-point source (NPS) pollution loads in the Yongdam watershed, and to take an appropriate NPS management plan suitable for the environmental conditions of the sub-basin of Yongdam watershed.Methods : The NPS pollutant loads of the Yongdam watershed was investigated to establish the hydrological simulation program-fortran (HSPF) model for the study area so that the characteristics of non-point runoff were simulated. Furthermore, the detailed catchment area subject to non-point pollution management was selected and the effect of reducing non-point pollution was examined based on the various simulation results.Results and Discussion : The three sub-basins, including specific component of catchments, of Yongdam watershed was selected according to the load intensity and distribution of NPS pollution. The result of analyzing the load flowing into the downstream by rainfall intensity revealed that the pollutant load accounted for 11.8~19.9% in the dry season, and for Jinan-cheon sub-basin the load was high in the range of 10~30 mm while Janggye-cheon sub-basin and downstream of Janggye-cheon junction sub-basin showed a high load in the range 30~60 mm. In addition, the load duration curve (LDC) showed the excess frequency of BOD load was high when the flow rate increased at the end of stream for each sub-basin, whereas the load excess frequency was high in T-P in the entire flow range. LDC analysis led to us that the water quality of stream was affected by point and non-point pollutants in a complex way. When the ground cover in a farm were installed by selecting 10 detailed catchments with high need for NPS pollution management, the reduction of T-P load was estimated to be reduced by 325.256~995.912 g/d in Jinan-cheon sub-basin, 1279.813~3327.513 g/d in Janggye-cheon sub-basin, and 1316.831~3555.443 g/d in downstream of Janggye-cheon junction sub-basin.Conclusion : Through various simulation experiments using the HSPF model, it was feasible to select an catchment subject to NPS pollution control in detail and evaluate the effect of reducing NPS pollution.

PENCEMARAN SITU PANGARENGAN: SUMBER, DAMPAK, PENGENDALIAN DAN PENGELOLAAN

Situ Pangarengan is located in Cisalak Village, Sukmajaya District, Depok City, and function as a water catchment area. This study aims to identify activities that caouse pollution and damage, analyze the quality and water quality status, determine the pollutant load capacity and provide recommendations for pollution prevention and control. The main cause of pollution in Situ Pangarengan are from residential and other activities. Parameters BOD, COD and phosphate are exceeded the quality standard. The BOD quality standard is 3 mg/L while the BOD content is 2.33 mg/L-11.83 mg/L. The COD quaiity standard is 25 mg/L, the COD content in water ranges from 9.6 mg/L-48 mg/L. The quality standard for phosphate is 0.03 mg/L while the phosphate content in waters ranges from 1.36 mg/L-2.68 mg/L. The water quality status of Situ Pangarengan is 7.53 (moderately polluted). Pollutant load capacity of BOD is 26,787 kg/year, the existing BOD load is 57,770 kg/year. Integrated effort to prevent and pollution control are developing the potential of Situ Pangarengan as a water conservation and tourism area, structuring the lake landscape, providing understanding to the public about the potential of Situ Pangarengan as a supporting ecosystem for urban sustainability, regular dredging, implementing communal WWTPs and eliminating the entry of garbage into the lake, and maintaining the health of the lake.

A socio-ecological assessment of land-based contamination and pollution: The Magdalena delta, Colombia

River mouth systems, such as estuaries and deltas are important earth system transitional zones linking the land and coastal marine systems. They funnel anthropogenic contaminants and pollutants from the activities in the river catchment into the marine environment. The present study is focused on the Magdalena River-mouth at Bocas de Ceniza where land-based contamination and pollution are important issues. These were subsequently analysed using an expanded DPSIR framework (Drivers Pressures, State, Impacts Responses). Based on export coefficients and secondary information, the loads of BOD, TSS, Nutrients and solid waste from different sources were identified and compared to prioritize their management within the study area. Findings suggest that contaminants generated in the study area may be insignificant compared to the inputs from the Magdalena River, but they can have a significant impact on the state of local ecosystems. Of all the sources analysed, agriculture and livestock are theoretically the largest contributors of nitrogen (i.e., 14.84 t d-1 and 48.99 t d-1) and phosphorus (i.e., 5.90 t d-1 and 19.46 t d-1) in the basin ‘Direct to the Caribbean’ and ‘Cienaga de Mallorquín’ (that altogether are identified as DtC+) and the ‘Western bank of the lower Magdalena’ (DtM-LM), respectively. In the case of BOD, domestic and industrial wastewaters contribute about 5.10 t d-1 and 98.43 t d-1 in the same basins. Contributions of faecal coliforms were more than 4 orders of magnitude higher in untreated wastewater, being 4.86 x1016 NMP d-1 and 1.78 x1016 NMP d-1 in the lower Magdalena and Caribbean catchments, respectively. Inadequately managed waste and plastic represent a serious problem for the Caribbean Basin. Solid waste generated within the study area and coming from the Magdalena basin and the Caribbean Sea, reaches the coast and deteriorates its visual quality, affects mangrove ecosystems, and generates impacts on coastal populations. By basin, the DtM-LM is where the greatest pollutant loads are generated. However, in terms of impact on human well-being, it is the DtC+ that bears the brunt where pressures are translated in impacts such as increased maintenance and cleaning cost of beaches, reduction or loss of tourism revenue, adverse health effects to vulnerable groups, reduce protection against natural hazards, increased living costs and loss of cultural values.

고효율 생물반응기에 의한 과일 가공 음료 폐수처리

It is well-known that fruit processing beverage wastewater is one of the severely contaminated industrial wastewaters containing high BOD concentration. This makes it difficult to maintain the proper DO concentration needed in conventional aerobic wastewater treatment process unless the high BOD concentration is properly reduced by pretreatment processes such as anaerobic digestion. In this study, a full-scale high-efficiency bioreactor was applied to cope with the high BOD loading in fruit processing beverage wastewater as a pretreatment of the activated sludge process. The high-efficiency bioreactor, which has multiple draft-tubes for both internal circulation of mixed liquors and aeration, has a merit of requiring small land area for installation. The results of the full-scale high-efficiency bioreactor for fruit processing beverage wastewater treatment were compared with those of anaerobic filter. It was found that the high-efficiency bioreactor was greatly effective in aeration, maintaining a DO level of 2.47 mg/L on average. Substantial removal of pollutants were achieved in the high-efficiency bioreactor, which were 89.9% for BOD, 86.2% for CODMn, 57% for SS,78.9% for T-N, and 80.3% for T-P, while those of an aerobic filter were 45.5% for BOD, 43.1% for CODMn, 50.8% for SS, 55.3% for T-N, and 59.6% for T-P. Thus, it has been demonstrated that the high-efficiency bioreactor had good stability and suitability for the treatment of fruit processing beverage wastewater, as a pretreatment of conventional aerobic wastewater treatment.

Assessing wastewater pollution from outdoor night markets and its impacts on river quality.

Night markets are attractive tourist sites in Asian cities. However, the outdoor activities produce different types of pollutants. Air pollution and solid waste in night markets have received much attention, but wastewater pollution from night markets has rarely been examined. The untreated wastewater are discharged into roadside gutters and might contaminate receiving waterbodies. In this study, night markets in Taipei city, Taiwan, were surveyed to clarify the characteristics of wastewater. The sampled wastewater showed high levels of organic substances, oil and grease, and phosphorous but low levels of nitrogen compounds. In addition, the unit pollution loads in night market stalls were obtained. The BOD load of each stall in the night markets was 2,509 g/day, which is higher than the sewage emissions of 50 people. In order to know the impacts of night market wastewater on the receiving waterbody, a water quality model, the Water Quality Analysis Simulation Program (WASP), was used in the studied river, Keelung River. If night market wastewater could be collected (not discharged), the BOD concentration could be reduced by 9.8%, but the NH3-N and DO concentration could be reduced by less than 1%.

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.

Physico-chemical, chemical and biological characterization of wastewater treatment plant of Oujda (Eastern Morocco) and possibility of reuse in irrigation

The wastewater treatment plants (WWTP), in particular those using aerated lagoons, can be subject to failures that limit the reliability of treatment performance over the operating period. This is observed at the wastewater treatment plant of the city of Oujda, object of our study, the objective of which is to verify the purification performance from the diagnosis of the WWTP. To do this, we diagnosed the functioning of the different treatment stages during one year of operation (2020) by determining the physico-chemical, chemical, parasitological and bacteriological (biological) characteristics of the treated wastewater, throughout their treatment process, in comparison with the standards for reuse in irrigation and the Moroccan standards for direct liquid discharge into the natural environment.Data analysis showed that the efficiency of the combined system reached 79 %, 85 % and 84 % of suspended solids (SS), chemical demand in oxygen (COD) and biochemical oxygen demand (BOD5) respectively. With pollutant loads at the WWTP inlet of 13 306.45 Kg/d of suspended solids, 32 407.39 kg/d of COD and 20 752.29 kg/d of BOD5 and polluting loads at the WWTP outlet of 3 379.80 kg/d of suspended solids, 4 949.08 kg/d of COD and 3 261.93 Kg/d of BOD5.The bacteriological analysis shows faecal pollution of human origin, which is of the average order of 3.2 E + 07 at WWTP entry and 4.4 E + 03 at WWTP exit, with an abatement yield of 99.99 %.The analysis of the purified effluent at the WWTP outlet revealed that the discharge standards for the flows at the outlet of the station in terms of physico-chemical and parasitological parameters, in particular the BOD5, COD, SS, salmonella and cholera vibrios are well respected. While, the system shows signs of imbalance that is expressed in the non-compliance of fecal coliforms (FC).

A Study on Deriving Operation Conditions for Biological Treatment of Dry Condensate Generated in The Food Waste Drying Process

This study was conducted to derive operating conditions for biological wastewater treatment targeting highconcentration dry condensate generated in the drying process of food waste. In the biological treatment of dry condensate, lab. scale (40 L/d) bioreactor was manufactured and used in the study to evaluate the water quality of the treated water according to the change in operating conditions and to derive stable operating factors. Changes in the influencing factors inside the aeration tank according to the change of BOD load, hydraulic retention time (HRT) and F/M ratio were observed during the operation of the lab. scale bioreaction process. Thereafter, the treatment efficiency was evaluated by measuring the water quality concentration of the treated water. As a result of the study, the water quality of the treated water was BOD 71.14 ± 10.19 mg/L, TOC 49.54 ± 9.64 mg/L, T-N 33.78 ± 5.00 mg/L, T-P 3.35 ± 1.24 mg/L was evaluated as the highest treatment efficiency, under the HRT 5 day, BOD Load 0.30 ± 0.02 kg BOD/d, F/M ratio 0.40 ± 0.02 kg BOD/kg MLSS/d operating condition. It is concluded that the results of this study can be used as data for ensuring stable treated water quality and complying with the emission standards at real plant.

High-expression and characterization of a novel serine protease from Ornithinibacillus caprae L9T with eco-friendly applications.

In the current work, a novel thermophilic serine protease gene (P3862) from Ornithinibacillus caprae L9T was functionally expressed in Bacillus subtilis SCK6. The monomeric enzyme of about 29 kDa was purified to homogeneity with 43.91% of recovery and 2.81-folds of purification. Characterization of the purified protease revealed the optimum activity at pH 7 and 65 °C. The protease exhibited excellent activity and stability in the presence of Na+, Mg2+, Ca2+, ethanediol, n-hexane, Tween-20, Tween-80 and Triton X-100. P3862 displayed favorable caseinolytic activity, moderate keratinolytic activity but no collagenolytic activity. Besides, the homology model of P3862 possessed a globular configuration and characteristic of α/β hydrolase fold, and displayed stable interactions with casein, glycoprotein and keratin rather than collagen. Moreover, the crude enzyme could completely dehair goatskin within 6 h, resulting in decrease in BOD5, COD and TSS loads by 72.86, 74.07, and 73.79%, respectively, as compared with Na2S treatment. Biocatalytic applications revealed that it could effectively remove egg-stains from fabrics at 37 °C for 30 min with low supplementation (300 U/mL), and was able to degrade the feathers of duck and chicken. Overall, these outstanding properties make P3862 valuable in the development of environmentally friendly biotechnologies .

Unhairing of bovine hide using wastewater from Merox unit of oil refinery: techno-environmental aspect.

The effluent generated by Merox unit of oil refinery was used instead of freshwater for bovine hide unhairing because of its proper composition and alkalinity. The effect of temperature, treatment period, sodium sulfide (Na2S), and calcium carbonate (CaCO3) dosage was investigated on unhairing efficiency using lutrom (unhairing slurry) prepared from the Merox effluent (effluent-based lutrom). Under similar operating conditions and chemicals' dosage, the effluent-based lutrom resulted in a higher efficiency (98.6%) than water-based lutrom (67.3%) indicating faster unhairing kinetics for the former lutrom. Moreover, an acceptable swelling (48%) and suitable mechanical properties were also observed. The experimental strategy can save 50 to 67% toxic chemicals and 100% of water consumption in unhairing, which is equivalent to US$ 34 per ton of hide, leading to zero discharge from Merox unit. Recycling of effluent-based lutrom after 3 consecutive runs was associated with a significant reduction in COD (55.6kg/t hide) and BOD5 (11.6kg/t hide) load. The effluent-based and conventional lutroms, before and after unhairing, were treated with ozone under moderate conditions. The FTIR results indicated a high-quality and low costly pelt benefits from the integration of wastewater treatment units of both industries in an environment-friendly manner.

Assessing performance of local materials for the treatment of dry weather flows in open drains: Results of semi-controlled field experiment research in Bangalore, India

The efficacy of two low-cost locally available aggregate filter materials (gravel and terracotta rubble) were tested in a semi-controlled pilot setup deployed to treat dry weather flows in an open stormwater drain in Bangalore, India. The treatment setups were operated at a similar hydraulic loading rate (HLR) of 265 mm/day using dry weather flows (DWF) in open stormwater drains from surrounding land uses for a period of 14 months. Significant variability in the quality dry weather flows was observed during the testing period. The average COD, BOD5, TN and TP levels of 1528 mg/l, 439 mg/l, 28.6 mg/l and 9.8 mg/l respectively were observed corresponding to high strength wastewater. Differences in porosity resulted in different hydraulic retention times (HRT), with 1.21 days and 1.52 days for the gravel and terracotta setup. While no significant difference was observed in the quality of effluent from both setups, the KBOD5 estimated for gravel setup (0.89) was significantly higher than the terracotta setup (0.70). Similar BOD5 mass removed per day (MMR) efficiency of 78% was observed for both setups. Data suggests the usefulness of gravel material in treating inflows rich in organic matter. Terracotta setup provided higher MRR reduction of 48%, 24% and 43% for DCOD, TP and TN, whereas higher MRR reduction of 70% and 65% for TSS and COD was observed in gravel setup. Neither materials were effective at removing Fecal Coliform (FC), particularly in the later stages of the study. Ammonium-N levels showed periodic increases in both setups, which could be attributed to low HRT leading to incomplete nitrification-denitrification processes. While outflows did not meet discharge standards, specified by India's Central Pollution Control Board (CPCB), the results suggest that a significant reduction in common contaminants can be achieved informing future interventions and modelling studies promoting sustainable urban water management in the megacity context. Study shows that an average BOD5 and COD mass loading rate (MLR) of 28 g/m2/day and 138 g/m2/day respectively should be targeted as a baseline condition in inflows to meet national discharge standards set by the CPCB (30 mg/l and 250 mg/l respectively).

Determination of load capacity of BOD pollutant in Cisadane River with Qual2kw model & its effect on DO parameters

The research to determine the carrying capacity of pollutant loads in the middle to downstream Cisadane River segment started from Jl. Teuku Umar, Tangerang and ends at Muara Tanjung Burung, Tangerang Regency with a research time starting from March – June 2021. Increased land-use change due to human and industrial activities so that population growth and limited residential land make watersheds a target for land conversion. The purpose of this study is to identify sources of pollutants that have the potential to contaminate the Cisadane River in the middle to downstream segments, analyze water quality and pollutant load capacity, the Cisadane River in the middle to downstream segments along 34 km. The method used for identification of pollutant sources is carried out by conducting field surveys, water quality analysis is carried out by SNI and compared with quality standards according to Peraturan Pemerintah No. 22 of 2021, as well as analysis of the Pollutant Load Capacity (PLC) BOD and DO using the QUAL2Kw model. The results of identifying potential pollutant sources in the middle to a downstream segment of the Cisadane River are dominated by settlements, agriculture, industry, and other domestic activities, namely restaurants and stalls. The results of water quality analysis for BOD parameters ranged from 2.51 mg/L - 5.1 mg/L, and DO range from 5.4 mg/L – 7,2 mg/L. BOD parameters from all points 1-2 meet the quality standard class 2 (3 mg/L) & points 4-6 do not meet the quality standard. The DO parameter is still in good condition because the more significant the DO value, the waters are in good condition. The high levels of BOD in the Cisadane River are influenced by domestic waste that enters the river, and the land is dominated by built-up spaces as settlements, schools, hotels and malls. Land use around the river is very influential on the load of pollutants that enter the river. The lowest DTBP of the Cisadane River for BOD is 22497,9 kg/day, and the highest is 33201,6 kg/day. The decrease in the concentration of BOD load must be lowered in the Cisadane River by 29% - 42%.

Efficient Control Methods for Greenhouse Gases from Domestic Sewage Treatment Facilities

In this study, we performed analysis to identify the effective method for suppression of Green House Gasses(GHGs) emissions from the public swage treatement plants. In particular, according to the IPCC guidelines, GHG emissions from public sewage treatment plants were calculated by dividing them by size and construction method. Among the methods investigated, the standard activated sludge method and the MEDIA method generated the least amount of greenhouse gas 0.000267 kgCO₂-eq/㎥ and 0.000327 kgCO₂-eq/㎥ respectively in the sewage treatment plant size of 10,000 ㎥ to 50,000 ㎥. On the other hand, the A₂O and SBR methods generated the most greenhouse gas emissions at 50,000 ㎥~100,000 ㎥ of sewage treatment plants, respectively, with 254 kgCO₂-eq/㎥ and 248 kgCO₂-eq/㎥. In addition, we verify the BOD load was the largest influencing factor on the quantity of generated greenhouse gas at the sewage treatment plants, and the factor is followed by the facility capacity, the inflow flow and T-N load, and the power consumption.

Assessment of Water Resources Pollution Carrying Capacity in The Sa Kaeo Special Economic Zone, Thailand

The Phromhot Canal is the only natural water source for consumption and agriculture the Sa Kaeo special economic zone, Thailand. At present, the Phromhot Canal is facing a serious problem with water quality. Our study carried out to analyze and assess the pollution carrying capacity of the natural water resource. The sampling sites were examined 7 stations cut across the downstream areas. All these stations were served as the control station to represent the actual condition of the Phromhot Canal. The results indicated that the water quality of the Phromhot Canal after flowing through the Aranyaprathet Municipality's wastewater treatment plant (AM's-WWTP) was severely contaminated. Effluents from the AM's-WWTP does not meet the effluent quality standard of the Ministry of Natural Resources and Environment, Thailand. In addition, it can flow into the water body up to 6,439.55 m3/day. The maximum amount of a pollutant (in terms of BOD loading) allowed to enter a water body of the Phromhot Canal should be ≤ 0.08 kgBOD/day (dry period) and 16.52 kgBOD/day (wet period). While the Phromhot Canal has to carry BOD loading up to 51.12 kgBOD/day. For this reason, the Phromhot Canal at after flowing through the WWTP was unable to the pollution carrying capacity. From the field survey, the AM's-WWTP is not suitable for wastewater treatment, which has a capacity of 923.93 m3/day. Therefore, it is necessary to strictly control the drainage of the wastewater from the Aranyaprathet Municipality's wastewater treatment system, both quantitative and geographic.

Biosorption of LMW PAHs on activated sludge aerobic granules under varying BOD loading rate conditions

Polycyclic aromatic hydrocarbons belong to the main priority substances for the aquatic environment. One of the emission sources of these compounds to environment is wastewater discharged from conventional wastewater treatment systems, which are not designed to cope with this type of pollution. Thus, due to the widely discussed properties of aerobic granular activated sludge in the literature – a conducted study has proven its ability to remove LMW PAHs (naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorene (Flu), phenanthrene (Phe) and anthracene (Ant)) from wastewater by biosorption process at varying loadings of organic compounds expressed as BOD (kg/kg·d) on the activated sludge mass. The maximum biosorption of Nap was 605 µg/kgd.m., Acy equals to 134 µg/kgd.m., Ace equals to 355 µg/kgd.m. Flu equals to 104 µg/kgd.m. Phe equal to 204 µg/kgd.m. and Ant equal to 173 µg/kgd.m. The study showed that the BOD loading rate is one of the factors affecting the biosorption process of LMW PAHs. However, as the amount of adsorbed LMW PAHs increased, the condition of aerobic granular activated sludge deteriorated, which was evidenced by gradual increase in the values of technological parameters of activated sludge (SVI, HRT, SRT) and a smaller increase in activated sludge dry mass.

A case study on pulp and paper industry effluent treatment

Industrial effluent Management is one of the major environmental concerns, especially in developing countries under rapid industrialization. The grossly polluting industries recognized by Central Pollution Control Board (CPCB), such as Pulp and Paper Industries, poses even bigger environmental threats, owing to quantity and quality of effluent generated. This paper aimed at analyzing effluent management practices in pulp and paper industries in India, and asses the performance variability of a paper mill effluent treatment plant (ETP), as a Case Study. Majority of pulp and paper industries found to still employ conventional methods of effluent treatment. Although, most of the parameters of treated effluent are commonly reported within CPCB’s permissible discharge limits, the treatment is usually cost and energy intensive, and produce high amount of solid residuals as sludge. For the case study paper mill ETP, the treatment efficiencies of the ETP units were analyzed under variable inlet pH, TSS, TDS, BOD and COD loads. The pH variations in the range of 6.5 to 9 had little effect of COD or TSS removal, however removal efficiencies were higher for larger inlet COD or TSS loads. The results of the study could be helpful in optimizing operation of the existing ETPs, as well as, guiding on upgrading ETPs with more cost-effective and efficient units.