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Item Treatment of domestic wastewater by association of up flow anaerobic and aerobic biofilters(2007) Srinikethan, G.; Shrihari, S.; Pradeepan, V.S.Laboratory studies were conducted to assess the performance of association of up flow anaerobic & aerobic biofilters in treating domestic wastewater. Two simple models of 8 litres capacity, one up flow anaerobic biofilter (AnBF) packed with support media granite of size 20 mm and another up flow aerobic biofilter(ABF) packed with support media granite of size 10 mm respectively were installed. The experimental anaerobic & aerobic biofilters were made of PVC tubes. The hydraulic retention time (HRT) was maintained as 12 hours in anaerobic biofilter and 8 hours in aerobic biofilter. The study was carried out for a period of 90 days. The association of up flow anaerobic & aerobic biofilters demonstrated the average Turbidity, Suspended Solids, BOD and COD removal 96.56%, 96.53%, 95.67% and 90.42% respectively. The waste treatment performance indicates that the association of up flow anaerobic & aerobic biofilters is a promising technique for (sub) tropical countries. Copyright � Enviromedia.Item Treatment of domestic wastewater in up flow anaerobic biofilters (using granite as packing material)(2005) Srinikethan, G.; Shrihari, S.; Pradeepan, V.S.Laboratory studies were conducted to assess the influence of media related factors such as porosity and pore size and specific surface area on performance of up flow anaerobic biofilters (ABFs). Two simple model of 8 litres capacity up flow anaerobic biofilters (ABFs), one packed with support media granite of size 50 to 40 mm and the other packed with granite of size 25 to 20 mm were installed. The experimental anaerobic biofilters were made of PVC tubes. The hydraulic retention time (HRT) was maintained as 12 hours. The study was carried out for a period of 90 days. The waste treatment performance indicates that the biofilter associated with media of the lesser pore size and porosity with higher specific surface area demonstrated the highest BOD and COD removal 91.03% and 82.50% respectively. Copyright � Enviromedia.Item Performance evaluation of sewage treatment plant - A case study(2004) Yaragal, S.C.; Shrihari, S.A study was conducted to assess the performance of the domestic wastewater treatment plant designed for the New Mangalore Port Trust (NMPT) township, Panambur. The data of raw, aerated and treated wastewater samples were collected for a period of 24 months (January - 1998 to December 1999) with a sampling frequency of one month. The sewage treatment plant is designed to treat an average flow of 1.2 MLD. The treatment scheme is based on extended aeration activated sludge process and consists of bar screens, collection sump, grit channel, aeration tank, secondary clarifier, treated sewage sump and sludge drying beds. The salient design features of the plant, process description, physico-chemical characteristics of sewage at different stages of treatment, sludge and grit are presented. Various parameters were tested in the laboratory and analyzed to assess the performance of the treatment plant. The effluent concentrations revealed that the treatment plant was found to be working quite satisfactorily though the influent wastewater quality was varying considerably. Enviromedia.Item Organics and nutrients contributions by benthalsludges under continuously accumulating conditions(2000) Bhargava, D.S.; Shrihari, S.In this paper, the nutrient and organics release under continuously accumulating conditions of benthalsludge, the affect of frequency of addition and organic loading rates are analysed and discussed. The rate of organics release decrease with increasing time from start of experiment. The rate of organics release has been lower when the organics loading rate is less, and frequency of addition is more. However, the nutrients release is less when the frequency of addition is lower.Item Modelling for organics and nutrients release during Benthal sludge stabilisation : Part I -organics(2008) Bhargava, D.S.; Shrihari, S.Settleable solids in the untreated and partially treated domestic and industrial effluents discharged into a river system undergoes settling and decomposition in the form of benthal sludge deposits, Early models of biochemical oxygen demand (BOD) assimilation in rivers do not account for the BOD contribution by these benthal sludge deposits. In this paper, a model for computations of the BOD contribution by benthos (both from the top aerobic layers and the leached portion of BOD from the bottom anaerobic layers) was presented. Observations from three sets of experiments at the chosen overlying water flow rates (500 ml/min, 1000ml/ min and 1500 ml/min) show a higher BOD contribution by benthos at higher overlying water flow rates. The ratio of the BOD contributions by benthos to the volatile solids in the top aerobic layers was lower when compared to the similar ratio in respect of the bottom layer volatile solids showing that a higher contribution was made by the top layers.Item Hydraulic and compaction characteristics of leachate-contaminated lateritic soil(2007) Nayak, S.; Sunil, B.M.; Shrihari, S.Large quantities of leachate-contaminated lateritic soil results from dump yards in the southwest coast of India. These dump yards receive large quantities of municipal solid waste which includes chemical, industrial and biomedical wastes. Large areas of land are currently being used for this purpose. An extensive laboratory testing program was carried out to determine the compaction characteristics and hydraulic conductivity of clean and contaminated lateritic soil. Batch tests were used to study the immediate effect of leachate contamination on the properties of lateritic soil. Contaminated specimens were prepared by mixing the lateritic soil with leachate in the amount of 5%, 10% and 20% by weight to vary the degree of contamination. The results indicated a small reduction in maximum dry density and an increase in hydraulic conductivity due to leachate-contamination. The change induced by chemical reaction in the microstructure of the soil was studied by scanning electron microscope before and after contamination of soil with leachate. The structure of the leachate contaminated soil sample appeared to be aggregated in scanning electron microscope analysis. The aggregated structure increases the effective pore space and thus increases the hydraulic conductivity. Fifty percent increase in hydraulic conductivity was observed for specimens prepared at standard Proctor density and mixed with 20% leachate. Compaction characteristics did not change much with the presence of leachate up to 10%. With 20% leachate the maximum dry density decreased slightly indicating excess leachate in the soil. However the changes are not significant. 2007 Elsevier B.V. All rights reserved.Item Kinetics of benthal sludge stabilization(2002) Bhargava, D.S.; Shrihari, S.Benthal-sludge deposits utilize the oxygen available in the overriding waters, (contacting the sludge deposits) for their bacterial decomposition. The rate of benthal decomposition depends on the availability of decomoposable material and the amount of oxygen being supplied. This paper provides a simple relationship of benthal oxygen demand with time. The rate of benthal degradation decreased with increase in the influent water flow rate.Item E-waste management(2007) Avvannavar, S.M.; Shrihari, S.E-waste is a new term coined in the market of hazardous substances. It has taken a new bourgeoning route since the boom of Information Technology (IT). The problems regarding the transportation, handling and dispose have to be tackled at the earliest as it might cause detrimental effects on environment. Presently in India there is no distinct and lucid regulation(s) regarding e-waste management. There should one stop solution! In the present paper, some of the Technical and E-Management Strategies that can be implemented by adopting 4 R s policy-reduce, recovery, recycle and reuse are discussed. 2007, Gheorghe Asachi Technical University of Iasi, Romania. All rights reserved.Item Evaluation of water quality index for drinking purposes for river Netravathi, Mangalore, South India(2008) Avvannavar, S.M.; Shrihari, S.An attempt has been made to develop water quality index (WQI), using six water quality parameters Dissolved oxygen (DO), Biochemical oxygen Demand (BOD), Most Probable Number (MPN), Turbidity, Total Dissolved Solids (TDS) and pH measured at eight different stations along the river basin. Rating curves were drawn based on the tolerance limits of inland waters and health point of view. Bhargava WQI method and Harmonic Mean WQI method were used to find overall WQI along the stretch of the river basin. Five point rating scale was used to classify water quality in each of the study areas. It was found that the water quality of Netravathi varied from Excellent to Marginal range by Bhargava WQI method and Excellent to Poor range by Harmonic Mean WQI method. It was observed that the impact of human activity was severe on most of the parameters. The MPN values exceeded the tolerable limits at almost all the stations. It was observed that the main cause of deterioration in water quality was due to the lack of proper sanitation, unprotected river sites and high anthropogenic activities. Springer Science+Business Media B.V. 2007.Item Effect of solid waste leachate on chemical properties of lateritic soil(2005) Bala, Murali, Krishna, C.; Yaji, R.K.; Shrihari, S.Unscientific methods of disposal of solid waste as landfills on low lying area cause serious environmental geotechnical problems. The leachate generated from the decomposition of solid waste causes the pollution of soil layers. In this study an attempt has been made to investigate the effect of leachate on soil chemical properties by laboratory tests. The tests included the pH, Electrical conductivity, Hardness, Chlorides, Sulphates, Nitrates, Sodium, Potassium, Ammonia, Nitrogen and Phosphate contents of lateritic soil. The results of this study are presented in this paper. Copyright Enviromedia.