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The aim of this study was to evaluate the potential of xylanase-pectinase enzymes in bleaching of wheat straw pulp, just to cut down the toxic wastes, in order to manage the environmental pollution. The appropriate parameters of bleaching were evaluated, and best conditions were xylanase and pectinase dose of 5.0 and 1.66 IU/g of pulp, respectively, along with material to liquid ratio of 1:7.5 (g/ml), temperature 55 °C, treatment time 3 h, Tween-80 1%, and pH 8.5. The release of reducing sugar and other non-cellulosic impurities, phenolic-hydrophobic-lignin was maximum at best bleaching conditions. Prebleaching of wheat straw pulp using these enzymes showed 14.75% decline in kappa number. Enzymatic bleaching plus 100% chemical bleaching also led to 27.90% reduction in yellowness. Using this methodology, the consumption of active chlorine was reduced up to 25%, along with an increase in burst index (7.98%), tear index (3.42%), breaking length (5.30%), viscosity (11.22%), gurley porosity (12.50%), and double-fold number (23.08%), which exhibits a remarkable enhancement in all the properties of pulp treated with enzymes. Microscopic images also confirm the effectiveness of enzymatic treatment in bleaching of wheat straw pulp. BOD and COD values of effluent also decreased by 20.74 and 17.87%, respectively. This research focussing on producing better grade paper using an eco-friendly approach would certainly benefit the paper and pulp industry. This is the first report, depicting bleaching capability of xylanase-pectinase enzymes for soda-anthraquinone pulp of wheat straw.

From the recent years, textile industry effluents become one of the intense environmental issues. The textile industries utilize synthetic dyes in the processes like bleaching, coloring, finishing and printing. This resulted in formation of huge amounts of industrial wastewater containing dyes. Textile effluents have a high value of BOD and COD, so these dyes are dangerous to biological life. They also cause rapid consumption of DO in water bodies in which they are discharged. So, most of the dyes are unsafe and biologically intractable, so conventional biological treatment is not an efficient option for textile wastewaters treatment. According to Pakistan Council of Research in Water Resources (PCRWR), the wastewater generated by industries are less than 8% which is being treated in Pakistan and the remaining wastewater is disposed of into the Rivers, Irrigation canals, vegetable farms and drains. In this research, organoclay was used along with ultrasonic bath for the degradation and decolorization of dyes and comparison of sono-electric reactor (SER) and ultrasonic assisted application of organoclay was done. Efficiency of organoclay along with electrochemical and ultrasonic treatments was also compared individually. Research results show that the most efficient method for the removal of dyes from textile wastewater is the use of organoclay along with ultrasonic bath. The percentage removal efficiency for the treatment of textile wastewater by using organoclay with ultrasonic treatment was found to be almost 99% at pH 4, and the removal efficiencies of SER, ultrasonic bath, electrochemical reactor and organoclay are 87.75, 93, 92, and 98.38%, respectively. It was also concluded that these both methods were dependent on pH of the wastewater. Ultrasonic assisted application of organoclay is not a time consuming, unlike ultrasonic bath, electrochemical and SER method.

Textile wastewater is hazardous to the environment due to their high pollution and toxicity. Some non-biodegradable compounds have a significant impact on BOD and COD levels in wastewater bodies. D...

Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value >5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management.

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) as biological and chemical pollutants of wastewater are renowned environmental problems. A study of the performance of BOD and COD degradation via adsorption was undertaken using Bio-derived ZnO nanopowder (ZnO-NP), synthesized using leaf extract of Spinacia oleracea, and Zn (NO3)2 at 500 0C, following a simple and green approach. XRD, SEM, FTIR, EDS and BET analysis were used to characterize the nano-adsorbent. EDS spectrum recorded elemental weight compositions of 67.33% and 32.67% for Zn and O, while the FTIR absorption peaks revealed the presence of Zn-O–H and Zn-O. Surface area analysis revealed the mesoporous structure of the ZnO-NPs. The reduction efficiency of the ZnO-NPs was evaluated in the presence of raw tannery wastewater by application of treatment time and adsorbent dosage as parametric factors; results obtained were compared to environmental regulatory limits (WHO and NESREA). Contact times reported removal efficiencies of 81.5-90.8 % and 12.8-50 % for BOD and COD, while adsorbent dosage-influenced BOD and COD removal at an optimum contact time of 30 minutes was found to be 79.2 - 97.5 % and 27.8 to 55.6 % respectively. This study reveals that ZnO nanopowder is better applied as BOD reductants over COD for spent tan liquor.

Environmental pollution caused by waste is pollution that very dangerous for living things. In particular, water pollution, waste that is disposed of through waterways will disrupt the water ecosystem which will have an impact on human life. On the other hand, the development of entrepreneurship such as home industry has a positive impact on society, especially in terms of the economy. Therefore, water pollution indicators are needed that can be used as guidelines in treating wastes such as BOD and COD. In this study, analyzed the levels of BOD and COD from home industry wastewater in the Cawang area. The home industry includes laundry, cracker business, restaurants, printing houses, photocopying, and snack businesses. Based on the results of data analysis, the highest BOD level was 45.827 in samples taken at night. And, the highest COD levels were 95.923 in samples taken at night. These data indicate that the levels of BOD and COD in the water in the home industry waste disposal sites are below the standard threshold for wastewater quality. The levels of BOD and COD are in the safe category for aquatic biota. Keywords: BOD levels, COD levels, Waste, Water pollution

The objective of this study was to check the potential of crude xylano-pectinolytic enzymes in bleaching of rice straw pulp, in order to reduce the toxic waste load for managing the environmental pollution. The xylano-pectinolytic enzymatic bleaching step for delignification was found to be most effective at pulp consistency 1:10 g/ml, xylanase:pectinase dose of 9:4 IU/ml, pH 8.5 and treatment time 180 min at temperature of 55 °C, and resulted in lowering of kappa number of the rice straw pulp by 15.29%. In subsequent bleaching stages, this enzymatic pre-bleaching treatment also resulted in 30% reduction of active chlorine dioxide dose without any loss of optical properties. Significant improvement in various physical properties of the enzymes treated pulp, tear index (15.43%), breaking length (11.11%), double fold number (25.92%), burst index (9.88%) and viscosity (13.63%), and Gurley porosity (39.86%) was also noticed. This approach resulted in reduction of BOD and COD values by 21.07% and 26.57%, respectively. This is the first study on the use of crude xylano-pectinolytic enzymes for bio-bleaching of rice straw pulp.

This study is performed on six wastewater stations that discharging wastewater into Qarun lake, El-Fayoum Govenorate, Egypt, to assessment wastewater treatment on the period from April 2017 to February 2019. Sewage treatment plants use different biological treatment technologies (conventional activated sludge, oxidation ditch, aeration). In this investigation, wastewater samples were collected from the influent and effluent of each plant and transferred directly to central laboratory of Fayoum Wastewater Company for complete analysis. The obtained data reflects a large amount of drainage on the wastewater treatment stations which means high percentages of total coliform and fecal coliform. Also, the high algal content is detected at Tamiya station with total cell count 282-1210/L. Nutrients as nitrate, nitrite, ammonia and phosphate are assessed and exhibit in ranges 4.4-104.5, 0.0-8.0, 1.1-43.0 and 1.0-42.1 mg/L, respectively. On other hand, the increase of TDS and TSS were achieved during summer season. Furthermore, higher values of DO, BOD and COD considered as a strong indicator for higher microbial activity.

Domestic wastewateris wastewaterthat is from residential businesses or activities, restaurants, offices, businesses, apartments and dormitories. Preliminary test result against BOD, COD, and Total Coliform in domestic wastewaterof steel industry in Surabaya did not qualify in which according to Regulation of Minister of Environment and Forestry in Republic of Indonesia Number 68 of 2016, the requirements were 63 mg/l, 189 mg/l and 13,000 CFU/100ml. Treatment that could be conducted was coagulation-flocculation with the addition of biocoagulant of papaya seed. Moreover, the purpose of this study was in order to analyze the reduction in BOD, COD, and Total Coliform level in domestic wastewaterof steel industry in Surabaya by adding biocoagulant of papaya seed (Carica papaya L). Type of this research was a pure experimental research with pretest-posttest control group design. Object of this research was domestic wastewater in one of steel industries in Surabaya, East Java Province, Indonesia. The dosage variations were 1 gram, 2 grams and 3 grams and 0 gram as a control with replication as much as 6 times. Thus, it was obtained 24 sample size. The results of BOD, COD, and Total Coliform before and after the addition of papaya seed(Carica papaya L)biocoagulant were analyzed by using paired t test and probit test. The results showed thatBOD, COD and Total Coliform levels in domestic wastewater of steel industry in Surabaya after having treatment reduced. The highest percentage in dose of 3 gr could reduce BOD and COD level until 93% and Total Coliform in 66%. The optimum dose in reducing BOD and COD levels were 3,629 gr/l and 3,109 gr/l. Furthermore, coagulation-flocculation wastewater treatment by using biocoagulant of papaya seed could reduce BOD, COD, and Total Coliform levels. Thus, for steel industry, it was necessary to conduct pre-treatmentof coagulation-flocculation treatment against domestic wastewater by using biocoagulant of papaya seed before being dumped into water bodies.

It is with the aim of solving the problem of generating large quantities of effluents from palm oil production in the littoral region of Cameroon that this study was carried out with the general objective of reducing the pollutant load of these effluents by using bacteria. To this end, raw palm oil mill wastewater samples were taken for their characterization by evaluating the in-situ (Temperature, pH and (CND) Conductivity) and ex-situ (SS (suspended solid), COD (chemical oxygen demand), BOD (biological oxygen demand) and O/F (oil and fat)) parameters. In addition, bacterial isolation and screening were carried out from samples of contaminated soil based on the production of lipolytic enzymes, the degradation of oils and fats and the reduction of the pollutant load. Results revealed that 28 isolates were able to reduce the pollution parameters of palm oil mill effluents of which D17, D22 and D23 seemed to be the best purifying isolates. The characterization of the POME (palm oil mill effluent), basing the temperature, pH, CND, O/F, SS, BOD and COD showed us values greater than the recommended rate. Partial characterization of these isolates revealed that D17 and D23 are bacteria that could reduce the polluting parameters of the effluents belonged to the Bacillus sp. genus and D22 to the Acinetobacter sp. genus. These results are satisfactory and the bacteria strains obtained could be used in bioremediation.

Waste from abattoir activities has high organic matter content. One wastewater alternative that suitable for abattoirs is used to utilize a combination of the anaerobic biofilter and aerobic biofilter. Which including a coarse screen, sedimentation, anaerobic biofilter, and aerobic biofilter. It made the treatment system can reduce levels of BOD snd COD waste batters. This study aims to determine the difference between the residence time variations of aerobic biofilter in reducing the BOD and COD levels of wastewater from abattoirs. The research is experimental. Using one group pretest-posttest design. Data analysis used the analysis of variance = 0,05.The analysis result of BOD and COD content wast decreased after treatment at each residence time, with 6 hours of residence time in an aerobics biofilter was reduced 70 percent BOD levels and 66,2 percent COD. 24 hours residence time had the ability to reduced 80 percent BOD content and 7 percent of COD content.Based on a one way analysis of variance results that there is a significant difference from all residence time because of Pvelue (0,00

Dal Lake is the second largest and most beautiful Lake in the state of Jammu and Kashmir and is the major centre of tourist activities. Due to the continuous increase in the population, the generation of domestic wastewater also increased. The present study was carried out to assess the efficiency of Sequential Batch Reactor (SBR) based Sewage Treatment Plant (STP) located at Brari Numbal and its discharge impact on the physicochemical properties of Dal Lake. The sample was collected from the selected sampling sites (inlet and outlet of SBR based STP, upstream, confluence zone, and downstream of Dal Lake) for five months (November 2019 to March 2020) and analysed using the standard methodologies. The plant shows maximum removal efficiency for BOD (79.85%) although the effluent BOD was found above the standard limit. The minimum removal efficiency of the plant was observed in the case of pH (3.46%). The gain in the case of DO was observed +851.55%. All the sites of Dal Lake were found polluted but the confluence zone and downstream were more polluted in comparison to the upstream due to the discharge of STP outlet into Dal Lake with higher BOD and COD (21.39% increase in BOD, 43.29% increase in COD; 80.10% increase in iron, 65.61% increase in ammonical nitrogen, and 101% increase in phosphate concentration). Besides this, discharge of the huge quantity of untreated wastewater from the city into the lake is also responsible for the degraded water quality of Dal Lake. It can be concluded that efficiency of the plant was in moderate condition and it needs further modifications. This is the first study showing the impact of SBR-STP effluent on Dal Lake.

The green revolution in the field of palm oil farming not only contributes to processed products but also produces large-capacity waste originating from its processing starting from the sterilization process, water from the clarification process, hydro cyclone (clay bath) water, and factory washing water. Palm oil mill effluent (LCPKS) contains dissolved and suspended solids in the form of colloids and oil residues with high BOD and COD. If this liquid waste is discharged directly into the water, it can pollute the environment. Some will settle, decompose slowly, consume dissolved dcxdcoxygen, cause turbidity, emit a sharp odor and can damage the aquatic ecosystem. To improve the parameters in the LCPKS so that it is feasible to flow to water bodies or the environment, an LCPKS treatment experiment test is performed by applying corona discharge with variations in voltage and length of time, then comparing the effect on parameters such as BOD, COD, pH and TDS on LCPKS before treatment and after treatment. From the treatment process using a corona discharge application with variations in voltage and time able to reduce BOD levels up to 35%, COD 36%, increase in TDS reached 71.56% and decreased pH by 4.11%.Key words: Palm oil mill effluent (LCPKS), Corona discharge application (Corona Discharge Treatment), COD, BOD, TDS, pH

Sapangdaku River in Toledo City, Cebu is a freshwater source found near a copper mine operating for more than 50 years. The river has been one of the major rivers identified by the Environmental Management Bureau to be at risk, that needs monitoring and more empirical studies. This paper assessed the water quality of the Sapangdaku River through physicochemical, metal, and microbial analyses. Five (5) samples were collected from the downstream, midstream, and upstream sites, and were immediately tested in a water laboratory. Findings revealed that the pH, DO, BOD and COD registered within the acceptable range. Conductivity, turbidity, TDS, and TSS have fluctuating results where the midstream area recorded the highest measurement for the first three and upstream for the latter. Hg and Pb are present in little amounts while Cu in high concentrations. Total coliform counts are low in midstream and upstream while fecal coliform counts are high in all sites. Higher conductivity, higher turbidity, slower flow rate, and cooler condition in the midstream, as well as the presence of more pathogenic bacteria and Cu across sites, indicate poor water quality. Though there is poor quality, the DO, BOD, and COD levels of the river show promising results that aquatic life can still thrive. Educating communities, decreasing means of erosion, and establishing strict policies and ordinances on the use of river resources are recommended.

Kali Asin is an important river for the drainage system in North Semarang. This river is often drained by domestic and industrial waste. The inclusion of these wastes can cause a decrease water quality marked by an increase Biological Oxygen Demand ( BOD) and Chemical Oxygen Demand (COD) concentrations. The purpose of this study was to determine the load of BOD and COD pollution and assess the status of pollution using the Pollution Index Method based on Government Regulation Number 82 of 2001 class II. Sampling was carried on 17 December 2019-28 January 2020. Sampling was carried out three times, once in 3 weeks. The material used was water samples taken from three stations (estuary, middle of the settlement, and far from the settlement) based on regional characteristics, land use, and sources of pollution. The research method uses a survey method with the technique of determining the location of sampling using purposive sampling. Water quality variables analyzed were temperature, discharge, pH, DO, BOD, COD. Based on the research results, these variables mostly do not meet the quality standards such as BOD and COD variables. The results of the calculation of pollution load in terms of BOD and COD variables obtained an average number of 952.54 kg / day and 3,425.86 kg / day. The results of the pollution index calculation at stations A, B, and C are 3.88; 3.78 and 3.53. The level pollution of Kali Asin was categorized in mild contamination. Keywords: Pollution Load, BOD, COD, Pollution Index, Kali Asin

In this study, action of ultrafiltered xylano-pectinolytic enzymes from a bacterial strain has been evaluated for bleaching of rice straw soda-anthraquinone pulp. Maximum bio-bleaching effect and release of non-cellulosic impurities were noticed with xylano:pectinolytic enzymes dose of 6.0:2.1-IU/g pulp, treatment time of 180 min at 10% pulp consistency, pH 8.5, and temperature 55 °C. Microscopic images of bio-bleached rice straw pulp also confirmed the efficacy of ultrafiltered enzymes, as bleaching agent. This bio-bleaching treatment resulted in 15.38% and 32% reduction in kappa number and active chlorine dioxide dose, respectively, along with increase in various physical properties, burst index (12.50%), tear index (19.07%), breaking length (14.30%), double fold number (26.31%), Gurley porosity (45.32%) and viscosity (16.17%). This bio-bleaching approach not only improved the pulp quality but also reduced environmental pollution load by decreasing effluent parameters values of BOD and COD by 23.67% and 27.44%, respectively. This study indicates that use of ultrafiltered xylano-pectinolytic synergism for rice straw pulp bleaching will ultimately help in making the process eco-friendly, along with better quality pulp. This is the first report on use of ultrafiltered xylanase and pectinase, produced from a bacterial isolate, for bleaching of rice straw pulp.

The algal-bacterial process has received more attention in the present scenario as a new low-cost method towards pollutant removal from wastewater because symbiotic relationship between algae and bacteria is efficient when compared to traditional secondary treatments. The present work evaluated the optimum concentration of microalgal-bacterial consortia for significant reductions in physicochemical parameters of raw domestic wastewater. In the study, three different concentrations (20%, 30% and 40%) of microalgal-bacterial consortia were studied at 8 hours and 16 hours HRT. Among the different concentrations of consortia studied, 30% consortia gave maximum removal efficiency at both the HRTs. The maximum removal efficiency of phosphate, ammonia, BOD and COD was about 99.79%, 94.85%, 89.02% and 88.96%, respectively, at 8 hours HRT. However, at 16 hours, HRT maximum removal efficiency observed was 97.40%, 94.05%, 83.52% and 88.40% for phosphate, ammonia, BOD and COD respectively. The study depicts that microalgal-bacterial consortia can efficiently remediate nutrients and organic matter from domestic wastewater in both cases when sunlight was ample and even with minimal / no sunlight; hence this system can work effectively throughout the day with much lesser HRT and higher removal efficiency.

Baru Barat River is a man made river for flood and irrigation control. This study aims to determine the effect of activities on the bank on Baru Barat River on the water quality. Identification of activities is carried out along the bank of river. Water quality parameters are compared with the Governor of Jakarta no. 582 year 2005. The status of water quality is determined using the Pollution Inde (PI). The activities around the Baru Barat River are settlements, officem workshop, schools, deales, food stall, laundry, shops, beauty salons, guesthouses and gas station. BOD concentration range from 8.4-43.7 mg/L with a quality standard of 10 mg/L and COD range from 16-99.2 mg/L with a quality standard of 20 mg/L. Concentration of BOD and COD that exceed of quality standard at almost all sampling ponts. The level of pollutionj in the Baru Barat River is moderate polluted. The main problem at Baru Barat River are the presence of several illegal waste point left from activities that eventually enter the river and the absence of waste water treatment. The concept of community based must be implemented to waste management and communal wastewater treatment that are easy, inexpensive and integrated with the landscape. Keywords: Baru Barat River, river bank, water pollution index, river quality, domestic waste water

The construction of artificial weirs as part of the Four Major Rivers Restoration Project is expected to result in the Nakdong River Basin having the characteristics of closed water bodies and properties of water quality that convert suspended components into soluble ones due to a long retention time, thereby leading to the continuous deterioration of water quality. In this regard, this study investigated the changes of water quality on four weirs in the mid-lower Nakdong River Basin. In addition, it examined the organic matters and nutrient salts affecting the water quality, established mass balance with respect to the nutrient salts, and analyzed the load accumulations of each weir to present the directions for water quality management. With regard to the water quality, the items of BOD and COD, T-N and NH4-N, and T-P and PO4-P showed similar tendencies, and most of the items exhibited high concentrations from July to September. Furthermore, it was confirmed that the concentrations of the water quality items were high in Dalseong Weir and Hapcheon-Changnyeong Weir. In July, most of the weirs showed the greatest difference of DO in the surface layer and deepwater layer, while the DO concentration of the deepwater layer dropped below 4.0 mg/L in all four weirs. The sediment survey showed that the SS, T-N, and T-P have a larger amount of sediment in the aphotic zone than in the photic zone, and the amount of sediment per unit area was greatest in Dalseong Weir. According to the sediment release survey results, the release concentration was high in July, which was due to the effects of high water temperature and low DO concentration. T-N was eluted mostly from Dalseong Weir and Gangjeong-Goryeong Weir, and T-P was eluted mostly from Dalseong Weir and Hapcheon-Changnyeong Weir. Among the mass balance, nitrogen balance showed the highest amount of accumulation in Gangjeong-Goryeong Weir (6109 kg/d), and phosphorus balance showed the highest amount of accumulation in Changnyeong-Haman Weir (447 kg/d). These results are expected to be utilized as important materials for setting the management directions for each weir.

The efficiency of xylano-pectinolytic enzymes, co-produced by a single microbial strain Bacillus pumilus, was analysed for the recycling of mixed office waste paper through deinking and compared with the alkaline chemical deinking method. Enzymes showed maximum deinking at pH 8.5, pulp consistency of 10%, xylanase-pectinase dose of 12 and 4 IU per gram pulp, respectively, after 120 min of deinking period, and temperature at 50 °C. A chemi-enzymatic approach was employed with xylano-pectinolytic enzymes and various concentrations of deinking chemicals, which showed that enzyme-treated mixed office waste pulp requires only 40% chemicals for deinking, in order to get the almost same level of various handsheets properties, as obtained by the chemical method with 100% chemicals. Similarly, the effluent load of BOD and COD contents was also decreased by 17.90 and 19.75%. This combinational approach of deinking significantly improved the various properties of the handsheets and resulted in gain of 7.5, 9.38, 6.33 and 11.65% in tear factor, burst factor, breaking length and viscosity of the handsheets, while the effective residual ink concentration analysis of deinked handsheets of mixed office waste paper showed deinking efficiency of 22.45%, which revealed the removal of ink particles during enzymatic deinking steps.

There is a severe shortage in irrigation water supply in North Delta area, especially Kafr El-Sheikh Governorate, Egypt. The shortage in fresh water supply in farmlands located on the tail end of irrigation canals has to be replenished by the available drainage water. So, the current work focused on assessing water quality of El-Hoks Drain for irrigation with respect to its contents of ammonium- N (NH4-N), nitrate-N (NO3-N), salts, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), boron (B) and some heavy metals. Sixty water samples were collected from ten branch drains’ discharge in El-Hoks Drain during winter (2017/018) and summer (2018) seasons. According to FAO (1985) and Egyptian standards (Law 48/1982), results showed that BOD, COD and NO3-N are the main pollutants, which BOD and COD values are classified between bad to slight and moderate, whereas, NH4-N and NO3-N values fall within the normal range for irrigation, but it is in the abnormal range based on the Egyptian standards. DO Values are in the normal range for irrigation according to Egyptian standards. Also, values of heavy metals Cu, Mn, Pb and Cd exceed the allowable limits for irrigation except Ni which falls within the normal range. B values in water samples fall between bad and good. Meanwhile, pH values ranged from 7.37 to 7.95, EC values ranged from 1.16 to 2.71 dSm-1, while SAR values varied from 5.74 to 8.64 which are suitable for irrigation and their values were higher in winter than in summer.

El presente estudio evaluó el impacto de las aguas residuales sobre la calidad físico-química de dos sitios de muestreo, aguas arriba y aguas abajo, en un transecto seleccionado del Río Chiquito de la ciudad de León. Se tomaron muestras durante cuatro campañas de muestreo, dos en época lluviosa y dos en época seca. Quince parámetros físico-químicos y doce metales, metaloides y no metales fueron comparados con directrices nacionales (NTON) e internacionales (U.S.EPA, CCME, NOM, INEN y FAO). Se utilizó el Software canadiense WQI 1.2 para evaluar integralmente la calidad del agua basado en un índice de calidad (CWQI), para distintos usos del agua: protección para la vida acuática, e irrigación. Sobresalieron elevados niveles de contaminación por sólidos suspendidos, materia orgánica (aceites y grasas, DBO y DQO, turbidez), nutrientes (amonio, hierro) y metales como el Al, Cr3+, Cu, Mn, Se, V y Zn. El índice de calidad de agua categorizó el sitio aguas arriba como marginal a regular y pobre para aguas abajo, lo que implica que estuvo casi siempre amenazada y se apartó en la mayoría de los casos de los niveles deseables para los usos específicos a los cuales se sometió. Según CONAGUA, la calidad del agua se encontró deteriorada clasificándola de Contaminadas a Fuertemente Contaminadas para ambos sitios, prevaleciendo la materia orgánica, implicando contaminación por descargas de aguas residuales municipales y de tenerías. Se detectó Cromo hexavalente en mayo en el sitio aguas arriba lo que hace más tóxica el agua de esta zona, y la mayoría de cromo presente está en estado reducido.

Salt-based preservation of hides/skins contributes to about 50% total dissolved solids (TDS) in tannery wastewaters. In this study, raw skins have been preserved by exposing them to a continuous flow of supercritical carbon dioxide (SCCO2) in a pressurized reactor. The process was carried out in reactors of two different capacities to ensure scalability. The skins thus dried could be stored at room temperature for a period of 30 days. The SCCO2–dried skins were less conducive for microbial growth than wet-salted skins. The soak liquor of SCCO2–dehydrated skin showed a 90% reduction in chloride content and significantly lower BOD and COD levels than soak liquor from wet-salted skins. The leathers produced from SCCO2-preserved skins and wet-salted skin had no significant quality differences. As SCCO2 systems have been reported as alternatives to all other unit operations, establishing SCCO2–based preservation will complete the circle of total leather manufacture with SCCO2.

The present study focuses on treatment of tannery effluent samples using microalgae and isolated cyanobacteria. Different concentrations of both the effluent samples were treated with the algal isolates and a highest biomass of 0.295 g/l was attained in 50% of concentration on the 12th day in BHEL site. The biomass production in Walajapet site was found to be 0.387 g/l in the effluent treated with 50% of algae. The treated effluent was tested for growth and chlorophyll content was estimated, Chlorella sp. SRD3 showed higher chlorophyll content. The 50% treatment was processed at large-scale treatment in lab and biomass yield of 0.65 ± 0.04 g/l was achieved in BHEL site and 0.49 ± 0.028 g/l in Walajapet site. The treatment led to higher reduction rates in BOD and COD levels in treated effluents. The BOD in effluent from BHEL site was reduced to 83.41% and that from Walajapet site showed 87.46% reduction, whereas the COD values also showed 78% reduction. Based on the results, effluent sample serves as a medium for growth and bioremediation of tannery effluents by microalga, Chlorella sp. SRD3 revealed promising results which may prove efficient in the near future.

The waste effluents from sugar industries create lot of pollution problems in the adjacent areas. Sugarindustries discharge huge quantities of residual water causing damage to the biotic as well as abiotic environment dueto its pungent smell, higher BOD and COD values and the exceeded concentration of chlorides, sulphates, heavymetals, carbohydrates, nutrients, oil and grease. Current studies were performed to evaluate the available strategies usedto minimize the pollution load created by sugar industries. Attempts have been made to overview various availableprocedures such as construction of microbial fuel cell, hydrolytic pre-treatment, valorization of sugar industry waste,synthesis of silver nanoparticles, symbiotic process, chemical and electrical oxidation processes, which are used for thetreatment of sugar industry effluents.

The present study evaluates the performance efficiency of a wastewater treatment plant. A sewage treatment plant operating on biological treatment method (Rotating Media Bio-Reactor) with an average wastewater inflow of 6 MLD has been considered for the case study. Wastewater samples were collected at different stages of treatment units and analyzed for the major waste water quality parameters such as biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and biodegradability. The performance efficiency of waste water treatment plant along with the major secondary treatment unit as Rotating Media Bio-Reactor (RMBR) was calculated. The performance analysis on above two aspects was studied over 17 weeks. Overall performance was found to meet the design and discharge/effluent criteria as prescribed by the authorities. The studies of six units of Rotating Media Bio-Reactor (RMBR) over a period of 13 weeks have shown the reduction profile of the unit in treatment of wastewater with parameters of BOD and COD. The RMBR treatment profile is useful for the design and operation of the unit.

Meat factory effluent contains fat, protein, diluted blood, and suspended solids. As a result, nutrient and organic concentrations in this effluent are incredibly high, and residues are slightly solubilized, likely to impact environmental pollution on streams, rivers, and other watercourses if discharged untreated. The biodegradation of abattoir waste was studied using a laboratory-scale cylindrical sequencing batch reactor (SBR) in aerobic mode. The aerobic sludge was collected from the aeration compartment of a paper and pulp effluent treatment facility and cultivated in a 2.83-L Perspex-based laboratory SBR. The raw wastewater comprised 6494 ± 2144 mg/l chemical oxygen demand (COD), 1946 ± 607 mg/l biochemical oxygen demand (BOD), 1722 ± 159 mg/l total suspended solids (TSS), 3062 ± 592 mg/l CaCO3 alkalinity, 7.00 ± 0.27 pH. The duration of a complete cycle was 24 h and comprised four phases: fill (5 min), react (23 h 10 min), settle (40 min) and draw (5 min). The whole experiment was divided into four phases and the dilution was done with the help of domestic sewage. In the first stage, the reactor was fed four times diluted slaughterhouse effluent on a 24-h cyclic operation for two weeks. After achieving a significant reduction in COD, the organic content of the input was raised by lowering the dilution factor. In the second and third phases, the reactor was fed three times and twice diluted samples for two weeks each operating at the same cyclic interval. In the final stage, raw effluent was fed to the reactor for two more weeks. The average COD value of diluted wastewater in the first, second, third and fourth phase was 1040 mg/l, 3168 mg/l, 4800 mg/l, and 5200 mg/l, respectively. The COD removal efficiency at the end of the first, second, third and fourth phase was 83%, 93%, 85% and 97%, respectively. The average BOD value of diluted wastewater at the end of the first, second, third and fourth phase was 1120 mg/l, 610 mg/l, 1502 mg/l, and 1350 mg/l, respectively. The BOD removal efficiency at the end of the first, second, third and fourth phase was 84%, 88%, 85% and 98%, respectively. After 8 weeks, at an organic loading rate of 3.06 kg/m3/d, the final phase has achieved BOD and COD removal efficiency of 98% and 97%, respectively. The pH and alkalinity levels were within acceptable ranges. After two months, the sludge's settling characteristics have improved, and the nitrification efficiency of the reactor was roughly 60% at the time of deactivation of the reactor.

A database was built with the results of the physicochemical analysis of 23,435 samples of wastewater discharges obtained from the operational reports presented and the cross-checks carried out by the Ministry of Health to the operating entities, in accordance with the provisions of Decree 30661-MINAE-S, for the period 2016–2020. Using Bayesian networks, the probabilities of compliance with current regulations were estimated by preparing an acyclic directed graph for three alternative scenarios. At the national level, the BOD and the COD are the variables that record the lowest values, showing important differences between the results obtained for the central region of the country with respect to the other regions. Another determining variable turned out to be the type of final disposal, wherein the reuse of wastewater presents important compliance deficiencies for all regions except for Chorotega. In the case of BOD, COD and TSS, the lowest probabilities are recorded for ISIC codes 3821 (treatment of non-hazardous waste), 1040 (manufacture of animal and vegetable fats) and 145 (pig farming). Additionally, the integrated environmental risk was calculated as a product of the discharges, obtaining that for the evaluated parameters, the BOD and COD represent the highest risk values given their probability of occurrence rate, as well as the magnitude of the environmental impact. The Pacifico Central and Brunca regions recorded the highest integrated environmental risk value for BOD, COD and TSS compared to the other areas of the country. Based on the results obtained, proposals for improvement were generated for the control of wastewater discharges carried out by the environmental authorities in search of achieving a better comprehensive management of the water resource.

Water is an essential resource and is a basic need for all living beings. A combination of natural and human factors impacts the consistency of water. In compliance with international norms in Padmanabhapuram, District of Kanyakumari, this analysis is projected to study the water suitability for household and irrigation determinations. Eighteen sampling locations with Global Positioning System were surveyed with coordinates. Water quality index (WQI) was developed for evaluating the suitability of water for drinking and irrigation. The results showed that twelve sampling locations are suitable for drinking. The spatial interpolation approach was employed to provide the distribution map of drinking water quality. The integrated map shows that 883,417m2 (46.03%) and 950,704m2 (49.54%) of area fall under the poor and very poor quality of water, respectively. For drinking purpose, the area of 2725 m2 (0.14%) and 7659 m2 (0.4%) was covered in excellent and good grade in water quality, respectively. The remaining 74,336 m2 (3.87%) of the study area is unsuitable for consumption. Total dissolved solids (TDS), electrical conductivity (EC), sodium adsorption ratio, magnesium hazard, permissible index, residual sodium carbonate (RSC), Kelly’s ratio, % sodium, soluble sodium ratio and geographically distribution maps are prepared to determine the irrigation suitability. TDS and EC are more than the permissible limit at sampling stations (S14, S15 and S16) whereas more RSC values at S8. The Piper trilinear diagram and Durov’s diagram of the hydrogeochemistry analysis show the most significance in the parameter of Ca and Cl whereas less significance in Na and K. In the statistical analysis, TDS and EC are highly correlated with TA, Ca, Na and Cl while less correlated with BOD and COD.

Safe discharge of wastewater is still a difficult problem in every part of the world mainly in developing countries. The discharge of wastewater affects the physicochemical properties of receiving water streams and soil which enters into the food chain and affects agriculture products, animal and human health. The present study was focused on the physicochemical properties of pre and post-treated wastewater samples from 04 different municipal wastewater treatment plants (WWTP) of Jhunsi (16 MLD), Salori (29 MLD), Rajapur (60 MLD), Naini (80 MLD) and their receiving Ganges river in Prayagraj (Allahabad), India. Water quality parameters such as pH, total dissolved solid (TDS), dissolved oxygen (DO), electrical conductivity (EC), turbidity, biological oxygen demand (BOD), chemical oxygen demand (COD), chloride and total hardness were analyzed. All parameters investigated were analyzed using standard methods. The results indicated that the WWTPs of Prayagraj region were effectively working and reducing the TDS, BOD and COD to acceptable limits.

Waste water recycling may cater to the water scarcity problems which are prevailing in our daily life. The conventional studies in photocatalytic degradation of organic dyes use some specifically synthesized metal-oxide nanoparticles as photocatalyst, which may leave its traces as residue in degraded water. In this prototypical study, we have reported for the first time about light induced organic dyes degradation of methylene blue (MB), malachite green (MG) and congo red (CR) carried out using a novel photosensitizing agent, Spirulina platensis cultivated water (Spcw). The aim of the present study is to probe a simple, novel, an eco-friendly and a cost effective degradation of dyes without using any chemicals. It was observed that 15 ppm MB, 70 ppm MG and 6 ppm CR got degraded to 100% within 2, 1 and 3 h respectively. The presence of trace amount of elements such as Ca, Cu, Fe, K, Mg, Mn, Na, Mo, Co and Zn and phycobiliproteins found in the Spcw were analyzed using Fourier Transform Infra-Red (FT-IR) Spectroscopy, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM–EDX), UV–vis Spectroscopy, microscopic studies and mineralization studies with TOC, TSS, BOD and COD analysis. The results obtained from various control experiments with fresh medium and dark treatment clearly confirms that the light induced organic dyes degradation occurs only in the Spcw under sunlight irradiation. The effect of pH was studied with the Spcw added dye solutions and also in the degraded water from highly acidic to basic conditions to find the optimum pH. The kinetics of the light induced organic dyes degradation follows pseudo- first order reaction and the mineralization studies of the degraded water meets the water quality standards. The reason behind the photosensitization activity is due to the presence of traces of metal ions and light absorbing phycobiliproteins released during natural cell lysis process.

The effluent of secondary treatment process at Al-Quds University wastewater treatment plant was tertiary treated using an Epuvalisation technique in which geranium plants (Pelargonium hortorum) was employed as a treatment vehicle. The Epuvalisation system was installed in a greenhouse in which germanium was planted hydroponically in a closed-loop mode using secondary treated wastewater (TWW) and fresh water (FW) as a control. The water quality analysis results before and after the growing season of TWW showed a reduction of 23% and 41%, for BOD and COD, respectively. The electrical conductivity (EC) and total dissolved solids (TDS) for TWW demonstrated a reduction of 52% and 53%, respectively. Similar trend was observed for FW in which the reduction in EC and TDS were 48% and 49%, respectively. Furthermore, the percent reduction of the concentration of suspended solids, phosphate ions (PO4−3), chloride ion (Cl−), total nitrogen (TN), and potassium ion (K+) in TWW were found to be 95%, 89%, 60% 98% and 59%, respectively. Plant growth parameters (plant height, fresh and dry weight, number of branches and flowers number) of geranium revealed no significant difference between irrigation with TWW and FW. The chemical plant analysis of roots, leaves, stems and flowers revealed no significant difference between hydroponic plantation in TWW and in FW. From these results it is safe to conclude that the Epuvalisation technique is a promising technique for advanced wastewater treatment using ornamental plants such as geranium due to its simplicity, low cost and easy use. Keywords: Epuvalisation, Wastewater, Nutrients, Percentage removal, Secondary treatment, Geranium plants

Textile industry processes are among the most environmentally unfriendly industrial process, because they produce colored wastewaters that are heavily polluted the environment. Therefore, wastewater from textile industry has to be treated before being discharged into the environment. In this present study, an attempt has been made to evaluate the effectiveness of locally available natural coagulant Neem leaves powder for reduction of characteristics in the wastewater in order to improve its quality. A common herb like Neem leaves powder is utilized to illuminate and sterilize the water. The coagulant chemicals play the vital role in wastewater treatment. At the same time spending more amounts for these chemical coagulants increase the total treatment cost and become more burdens to the industry. In view of the replacement or reduction of chemical coagulants which are used in wastewater clarification, coagulants which are effective, productive and also free from physio-chemical characteristics are considered. Using natural coagulants is more eco-friendly and sustainable when compared to the chemical coagulants which is biodegradable.

Every Industry has problems of effluent treatment. This can be revealed by the effective treatment of the effluent. The effective treatment can be done by using microorganisms to stabilize the organic and inorganic load of the effluent. The aim of the present work is to study the Industrial effluent microbiota and to identify some new active strains which can bring about fast biodegradation of the organic compounds. Studies were carried out to isolate the microorganisms from the collected effluent sample from the Industries of Bollaram, Hyderabad. An investigation was carried out to analyze Physicochemical parameters like Total suspended solids (TSS), Total dissolved solids (TDS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) of untreated effluent and to degrade the effluent using native and non-native bacteria. The results of the parameters analysis revealed that untreated effluent was black in colour with an offensive odour. pH was alkaline with a high organic load such as TSS, TDS, BOD and COD which were higher than the permissible since the effluent had a high organic load, microbes (bacteria) present within the effluent was identified and isolated. The results of the study revealed the occurrence of Pseudomonas spp. And named as Pseudomonas auruginosa ES10. The presence of bacteria indicates the pollution status of the untreated tannery effluent, suggesting that it should be treated before its disposal using the biological method, particularly native and non-native bacteria for comparing their degrading efficiency. The results of the degradation study show that native bacteria Pseudomonas auruginosa ES10 was found to be very much successful in the reduction of toxic substances at the percentage range of 60-90% at different pH and incubation time, the bio-treated water can be reused for the agricultural and aqua-cultural purposes.

This study aimed to develop and evaluate five simplified AGW treatment options with or without low-cost ceramic filters, including direct ceramic filtration, alum coagulation–sedimentation, alum coagulation–sedimentation–ceramic filtration, alum coagulation–sedimentation–activated carbon, adsorption–sedimentation, and ceramic filtration–activated carbon adsorption–sedimentation. In raw AGW, concentrations of turbidity (14.8 NTU), TSS (24 mg/L), COD (63.2 mg/L), BOD (37.0 mg/L), and fecal coliform (884 MPN/100 mL) exceeded the greywater reuse standards for unrestricted irrigation, toilet flushing, and firefighting. In laboratory experiments, first three treatment options produced almost similar effluent with residual turbidity 1.5 NTU, COD 35 mg/L, and BOD 20 mg/L. Addition of the activated carbon to the last two treatment options enhanced the BOD and COD removals (

This study aims at preliminary analysis of pollution profile of western backwater. The site is very important from the ecological perspective. The mangrove ecosystem of the study area is of prime significance, whilst the study area is receiving heavy pollution load from Lyari River. The water samples were collected from the pre-designated locations and analyzed for physical and biochemical characteristics. The BOD and COD concentrations of the samples were extremely higher from the environmental and ecological viewpoint. The heavy inorganic and organic load is coming from the domestic and industrial effluents coming from Lyari River. Oil and grease concentrations were also extremely higher in all these sites indicating the hampering of natural purification system of water. The concentration of phenol also indicates the emptying of industrial effluent at the Lyari River outfall. The heavy influx of the nutrients in the form of nitrogen and phosphate represents the problem of eutrophication at the study area. Out of all 7 sites, L-7 was most polluted as it was closed to the Lyari River outfall. The extent of pollution is at the following order L-7 > L-5 > L-6 > L-4 > L-3 > L-2 > L-1.

Herein, we analyzed the spatial and temporal variation of DO (dissolved oxygen), BOD (biochemical oxygen demand), and COD (Chemical Oxygen Demand) with the monthly mean observed data for 10 years (2008~2017) in the main stream of the Nakdong River. The water quality of the stations declined in a downstream direction, with the BOD and COD showing their highest values at the ST5 station. From the analysis of the correlation of water quality components at 10 stations, the correlation coefficient between the DO and water temperature was more than -0.90, and that between BOD and Chl-a was 0.48~0.85, and that between COD and TOC was more than 0.65 except for the ST5 and ST10 stations. From the regression analysis using data collected from all stations, the water temperature and DO decreased linearly with a coefficient of determination of 0.90, and the Chl-a and BOD could be described by increasing power functions with a coefficient of determination of 0.83. The TOC and COD followed increasing logarithm functions with a coefficient of determination of 0.58. The TOC efficiency at the 10 stations was estimated and the average efficiencies of BOD and COD were 15.5~36.3% and 57.4~89.6%, respectively.

The present study describes a downflow microaerophilic fixed film (DFMFF) reactor based treatment of dye house effluents. The major characteristics of the two effluents E-2 and E-5 under study were; chemical oxygen demand (COD) 4680-16,266 mg L−1, biological oxygen demand (BOD) 1575–3151 mg L−1 and American Dye Manufacturers' Institute (ADMI) color index of 10,794–21,413. DFMFF reactor was packed with ultra-high molecular weight polyethylene (UHMWPE) shredding. The developed consortium was allowed to grow and form bio-film on packed UHMWPE. Degradation of the effluents at a various hydraulic retention time (HRT) and organic loading rate (OLR) was studied. Batch mode studies in the reactor showed > 80% removal of BOD and COD at OLR of 4.3 kg L−1 day−1 of E-2 and 2.4 kg L−1 day−1 of E-5 at 48 h HRT. Fourier Transform Infrared Spectroscopy (FTIR) and High Performance Liquid Chromatography (HPLC) analysis confirmed biodegradation and obtained results indicated significant induction of oxidoreductive enzyme activities of azoreductase, NADH–DCIP reductase and laccase enzymes. Reduction in phytotoxicity and microbial toxicity was observed after the treatment of both the effluents. The reactor was also operated on continuous mode for treatment of E-2 under sequential anaerobic–aerobic phase and charcoal treatment. Results of sequential effluent treatment resulted in a reduction of > 99% of COD, BOD and ADMI along with > 88% of solids removal from the effluent. The resulting effluent was clear and meets the discharge criteria so as to release into the sewers. .

Local cassava agro-processing industries in Nigeria generate toxic organic effluent with negative environmental impact if disposed without adequate treatment. This study examines the performance of a lab-scale aerated sequencing batch reactor (SBR) in degrading cassava mill effluent using palm kernel ( Elaeis guineensis ) shell (PKS) as biofilter media. Wastewater samples were collected before and after flowing through each compartment at hydraulic retention times of 3, 5 and 7 hours. Continuous aeration and nature-based degradation of the effluent recorded overall removal efficiencies of 73.5% (Hydrogen cyanide), 70.59% (BOD), 69.18% (COD), 29.93% (Turbidity), 4.92% (Sodium), 25% (Magnesium) and 14.32% (Calcium) respectively. Effluent electrical conductivity (EC) slightly increased by 7.84%. The Sodium Adsorption Ratio (SAR) of the treated wastewater ranged from 6.9 to 7.3 while the final pH ranged from 4.5 to 4.6. The values of EC, BOD and COD were significantly different ( P

Background The existence of heavy metals and coliform bacteria contaminants in aquatic system of Akaki river basin, a sub city of Addis Ababa, Ethiopia has become a public concern as human population increases and land development continues. Hence, it is the right time to design treatment technologies that can handle multiple pollutants. Results In this study, we prepared a synthetic zeolites and copper doped zeolite composite adsorbents as cost effective and simple approach to simultaneously remove heavy metals and total coliforms from wastewater of Akaki river. The synthesized copper–zeolite X composite was obtained by ion exchange method of copper ions into zeolites frameworks. Iodine test, XRD, FTIR and autosorb IQ automated gas sorption analyzer were used to characterize the adsorbents. The mean concentrations of Cd, Cr, and Pb in untreated sample were 0.795, 0.654 and 0.7025 mg/L respectively. These concentrations decreased to Cd (0.005 mg/L), Cr (0.052 mg/L) and Pb (bellow detection limit, BDL) for sample treated with bare zeolite X while a further decrease in concentration of Cd (0.005 mg/L), Cr (BDL) and Pb (BDL) was observed for the sample treated with copper–zeolite composite. Zeolite X and copper-modified zeolite X showed complete elimination of total coliforms after 90 and 50 min contact time respectively. Conclusion The results obtained in this study showed high antimicrobial disinfection and heavy metal removal efficiencies of the synthesized adsorbents. Furthermore, these sorbents are efficient in significantly reducing physical parameters such as electrical conductivity, turbidity, BOD and COD.

Batik is one of ethnical cultures of Indonesia. The batik production has spread throughout Indonesia. One of the batik industry areas is located in Jetis, Sidoarjo, Indonesia. This industry has been operating for approximately 350 years without processing its wastewater. The batik wastewater contains several toxic compounds such as high BOD, COD and color pigment. These compounds can be harmful for the environment if discharged directly to water bodies. Phyto-treatment might be a solution to overcome this problem. The use of Scirpus grossus and Iris pseudacorus with variations of waste irrigation system using the intermittent method showed a COD removal up to 89% and BOD removal up to 97%. Mixed culture of S. grossus and I. pseudacorus showed a better removal than its single culture. The highest removal of BOD and COD was obtained in reactor with mixed culture plants under Flood/ Drain ratio of 2:1.

This study examines the quality of effluents discharged from the Century paper and pulp mill into the Gola River to assess its suitability for irrigation. Water quality depends on the assessment of the many parameters determined by chemical methods. A number of water quality parameters such as pH, electrical conductivity, turbidity (Tb), alkalinity, acidity, total hardness, total dissolved solids, calcium, magnesium, potassium, chloride, sodium, nitrate-nitrogen (NO3-N), sulfate, phosphate, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were determined for the effluents in Gola River. For this study, samples from 20 locations along the length of the Gola River in Uttarakhand were collected. The result of water quality analysis showed that the concentration of Tb, NO3-N, COD, and BOD in the effluent water from the Century paper and pulp mill was beyond the permissible limit for its discharge in the water body or river. The concentration of all the parameters was decreasing along the length of the channel. A high concentration of COD, BOD, and NO3-N was found in downstream areas as compared to upstream discharge areas of effluent channels. The determination of biological water parameters such as BOD and COD is often tedious, time consuming, and error prone. Moreover, the relationships that exist between different water quality parameters to predict BOD and COD are complex and nonlinear. Artificial neural networks (ANNs) are accurate models for predicting nonlinear and complex processes. The main objective of this study is to estimate BOD and COD accurately with limited significant water quality parameters as input data using the ANN model and compare the performance of ANN with the multiple linear regression (MLR) models. In this study, a three-layer feed-forward back-propagation-type ANN was used to model the relationship between the water quality parameters and BOD and COD. Training, validation, and testing of ANN models were done by splitting data into various proportions. An optimum ANN model was decided based on the number of trial and error processes using hidden nodes, epochs, and other training parameters. Performance of the models was evaluated by root mean squared error, mean absolute error, coefficient of determination, and ratio of output by target. Comparison of results showed that the ANN model gave reasonable estimates for the BOD and COD prediction. Hence, it is concluded that the ANNs were able to show remarkable performance to predicting the BOD and COD in Gola River.

This research was conducted to assess the quality of river water in the context of controlling water pollution in the TalawaanRiver in North Minahasa Regency, North Sulawesi Province. This research is a descriptive-quantitative research. The fieldresearch was carried out in the Talawaan River, North Minahasa Regency. Water quality measurement includes physicalparameters: TSS, and chemical parameters; BOD and COD were carried out at five monitoring points. The results showedthat the content of BOD, COD, and TSS in Talawaan River water met the water quality standards (Type B water). Thecharacteristics of the waste (BOD, COD and TSS), the concentration values of BOD, COD and TSS concentration values donot exceed the quality standard according to their designation. The potential for domestic waste pollution load reaches 1,495kg/day from a total population of 16,040 people. The status of Telawan River water quality is classified as ”lightly polluted”based on the studied parameters; there are several other variables that were not included in this study, such as T-P, TotalColi, and Fecal Coli

With the global concern on the role of wastewater treatment technologies in manifesting the emergence and dissemination of antibiotic-resistant bacteria (ARB), it has now become imperative to analyze the emerging technologies for handling them. This study assesses the efficiency of two deep constructed wetlands (CWs) receiving partially treated sewage from a residential complex and a hospital designed for the removal of organics and pathogens. These systems were further analyzed for the presence of major ARB to identify the role of CWs in mitigating antibiotic resistance among microbial communities. The bacterial community responsible for metabolic conversions was analyzed by metagenomic sequencing. Finally, the efficiencies of deep CWs were analyzed for the removal of specific bacteria resistant to three antibiotics—piperacillin, colistin (polymixin E), and cefoperazone. The overall removal of extended spectrum beta lactamase producers and carbapenemase producers was also studied. Our results indicate that CWs offer decent BOD and COD removal efficiencies of 74.04–78.71% and 53.85–64.37% respectively. However, a zero-order reaction between loading rate and removal rate was obtained after loading rate of 170 g/m2.day indicating the organic loading capacity of the system. Metagenomic analysis revealed the presence of bacteria with diverse metabolic potentials for substrate conversion. Removal of fecal coliforms was high in the CWs, but the most interesting observation was the attenuation in ARB, which was found to be comparable to, or even better, than the reported values from conventional moving bed bioreactor. This observation may be attributed to the high retention times offered by CWs compared to that of conventional systems making them an attractive future alternative for treating domestic as well as hospital sewage for emerging pollutants.

Microbial Fuel Cell (MFC) is an innovative bio-electrochemical approach which converts biochemical energy inherent in wastewater into electrical energy, thus contributing to circular economy. Five electrogenic bacteria, Kocuria rosea (GTPAS76), two strains of Bacillus circulans (GTPO28 and GTPAS54), and two strains of Corynebacterium vitaeruminis (GTPO38 and GTPO42) were isolated from a common effluent treatment plant (CETP) and were used individually as well as in consortium form to run double chambered “H” type microbial fuel cell. Individually they could produce voltage in the range of 0.4–0.7 V in the MFC systems. Consortium developed using GTPO28, GTPO38, GTPAS54 and GTPAS76 were capable of producing voltage output of 0.8 V with 81.81 % and 64 % COD and BOD reduction, respectively. The EPS production capacity and electricity generation by the isolated bacteria correlated significantly (r = 0.72). Various parameters like, effect of preformed biofilm, length of salt bridge and its reuse, aeration, substrate concentration and external resistance were studied in detail. The study emphasizes on improving the commercialization aspect of MFC with repeated use of salt bridge and improving wastewater treatment potential after optimization of MFC system. Polarization curve and power density trends were studied in optimized MFC. A maximum power density and current density achieved were 18.15 mW/m2 and 370.37 mA/m2, respectively using 5 mM sodium benzoate. This study reports the use of sodium benzoate as a substrate along with reusing of the salt bridge in MFC study with promising results for BOD and COD reduction, proving it to be futuristic technology for bio-based circular ecosystem development.

Laundry services are rapidly becoming ubiquitous in rural and urban areas, generating high domestic waste volumes. Their growth has raised concerns about the quality of natural waters, particularly the rivers into which most laundry businesses discharge their wastewater. The research set out to study laundry wastewater characteristics and their relationship with the river water quality as water pollution indicators in Code Watershed (Indonesia). It lies in three administrative units where many human activities take place in the watershed’s upper to the lower reaches. BOD and COD of 25 sampled laundry businesses were analyzed descriptively and compared to the laundry wastewater standards stipulated in Regulation No. 7 of 2016 and the class II water quality standards issued in Governor Regulation No. 20 of 2008. The results showed that the BOD of four laundry businesses and the COD of 18 laundry businesses exceeded the predetermined standards. Overall, rivers in Code Watershed meet the class II river water criteria for BOD at three of the seven sampling points and COD at all points.

Batch adsorption and preliminary column studies were conducted to assess the removal of Pb(II) from aqueous medium using Lumbang (Aleurites moluccana)-derived activated carbon. Various activating conditions were investigated to select the suitable activated carbon composite with high adsorption capacity. Lumbang biocharcoal that was chemically activated with KOH was surface-modified by coating with chitosan and crosslinking with epichlorohydrin. Through batch adsorption studies, the following optimum conditions were observed for the composite: pH, 6; contact time, 30 min; temperature, 30 °C; adsorbent dosage, 9 g/L; and Pb(II) concentration, 25 ppm. Preliminary column study of the synthesized composite using laboratory wastewater showed a percentage removal of 96.82% for Pb (II) and a percentage drop of BOD and COD to 89.09% and 86.35%, respectively.

Tofu is a common food in Indonesia, made from soybean, and needs gigantic water for the process. The liquid waste of the tofu industry is usually directly discharged into the river without being processed. Liquid wastes of tofu have high organic content and become a problem in water pollution. Rotating Biological Contactor (RBC) is efficient method to treat waste with a high organic matter load by utilizing microorganisms to consume organic matter through biofilms. Biofilm will degrade organic matter aerobically. The purpose of the study is to determine the capability of RBC to reduce the organic content of tofu wastewater with different rotations of the disk. Rotation was experimentally varied from 30, 40, 50, 60 RPM and control. Results were considered in percentage decrease from the untreated waste: TSS of 87.56 ± 6.48%, BOD of 99.13 ± 0.21 %, and COD of 98.53 ± 0.08%. To conclude, the optimum rotation is 50 RPM for decreasing BOD and COD, otherwise 40 RPM for reducing TSS. The results effluent RBC on three parameters passed the quality standards legally for the soybean processing company or activity.

Many places in the world suffer from a shortage in potable water because of the population growth, contamination of water supplies and the problems related with global warming issue. The contamination of drinking water is a considerable problem in the world. In this study, the possibility of using a Pervious Concrete Pavement (PCP) in wastewater clarification was studied. Twenty-four Portland cement mixtures were prepared and tested in order to estimate the effect of coarse aggregate size, water-to-cement ratio and cement content as well as the relationships between compressive strength, porosity, and permeability. Two gravel grades were used (G1 and G2), G1 includes the aggregate size between 4.75–9 mm, while the aggregate size between 9−19 mm was represented by G2. Three water cement ratios (W1 = 0.28, W2 = 0.30, W3 = 0.32) and four cement contents (C1 = 275, C2 = 300, C3 = 325 and C4 = 350 kg/m3) were used. The maximum compressive strength obtained in this study was 17.75 Mpa, which resulted from gravel size of G1 and the highest W/C ratio and cement content. The evaluation of water treatment properties of PCP involved pavement samples of 300 × 300 mm with three different thicknesses of 100, 150 and 200 mm that subjected to synthetic wastewater flow with volume of 5 L. Removal efficiencies of several pollutants such as the chemical oxygen demand (COD), biological oxygen demand (BOD) were inspected. The removal percentage of such pollutants increased with the increment of gravel size and pavement thickness. Maximum removal for COD and BOD were 54 % and 68 %, respectively, they were obtained using the aggregate size of G2, water cement ratio of W3 and pavement thickness of 20 cm. The modification in pollutants removal percentages can be done depending on the enhancement and refreshment of the bacterial growth by adding the required feed for the bacteria in wastewater in form of mineral salt solution MSM. The resulted removals due to this process also occurred when the large gravel size of G2, water cement ratio of 0.32 and pavement thickness of 20 cm were used, the removal percentages were increased in this case to be 61 % and 79 % for COD and BOD, respectively.

The "X" batik industry is a textile industry with industrial waste water discharged into water bodies which causes high pollution in the Lodji river. Data from the Environmental Office of Pekalongan on the status of biological oxygen demand (BOD) and chemical oxygen demand (COD) in the Lodji River are classified as high, namely between 2.741 – 1.464 mg/l, exceeding the quality standard Enchinodorus palaefolius(water jasmine) in reducing levels of biological oxygen demand and chemical oxygen demand in batik industrial wastewater "X". The method used is a quasi experiment with a non-equivalent control group design approach. Analysis of biological oxygen demand and chemical oxygen demand content using the analytical titration method. The Biological Oxygen Demand degradation modeling in treatment 1 kg, y = - 540.13 x + 2495.6, treatment 0.75 kg, y = -525.3x + 1938.7, treatment 0.5 kg y = - 515.09 x + 1923 while modeling for chemical oxygen demand reduction in treatment 1 kg, y = - 2543.7 x + 10130, treatment 0.75 kg, y = - 2500.7 x + 9913.8, treatment 0.5 kg, y = - 2578 x + 10045 Echinodorus palaefolius (water jasmine) was able to reduce Biological Oxygen Demand and Chemical Oxygen Demand levels by linear modeling on biological oxygen demand parameters with the best results on 0.5 kg treatment and chemical oxygen demand in 1.0 kg treatment.