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Patel U.D.,Sardar Vallabhbhai Patel Institute of Technology | Ruparelia J.P.,Nirma University | Patel M.U.,Gujarat Pollution Control Board
Journal of Hazardous Materials | Year: 2011

Floor-wash from dye finishing plant is a major source of color and wastewater volume for dyes industries. Batch electrocoagulation (EC) of simulated floor-wash containing Reactive Black 5 (RB5) was studied as a possible pretreatment option. More than 90% of initial 25mg/L of RB5 was removed at current densities of 4.5, 6, and 7.5mA/cm 2 in the presence of Na 2SO 4 and NaCl as supporting electrolytes; in less than one hour. Identical k obs (pseudo first-order reaction rate constant) values were obtained at initial pH of 3.74 for both electrolytes. However, at initial pH of 6.6, k obs values decreased in the presence of Na 2SO 4 and remained same for NaCl as compared to that at pH 3.74. Highest extent of decolorization and k obs values were obtained at initial pH 9.0 for both electrolytes. Under identical conditions, specific energy consumption (SEC) was almost half in the presence of NaCl (~29kWh/kgRB5) than that of Na 2SO 4. Vinyl sulfone (VS) was detected as one of the products of EC indicating reduction of azo bonds as a preliminary step of decolorization. Mechanism of decolorization with respect to various experimental conditions was delineated. Generation and accumulation of VS was dependent on initial pH and type of electrolyte. Results of this study revealed that EC in the presence of sodium chloride can be efficiently used as a primary treatment for decolorization of floor-wash containing RB5. © 2011 Elsevier B.V. Source

Suneel V.,National Institute of Oceanography of India | Vethamony P.,National Institute of Oceanography of India | Naik B.G.,National Institute of Oceanography of India | Vinod Kumar K.,National University of Singapore | And 4 more authors.
Environmental Science and Technology | Year: 2014

Deposition of tar balls (TBs) along the south Gujarat coast, situated on the west coast of India (WCI), commonly occurs during the southwest monsoon season. Several offshore oil fields off the Mumbai-Gujarat coast, and refineries along the coast might be sources of oil spills/leakages and lead to the formation of TBs. To identify the sources, we collected 12 TB samples from the beaches of Gujarat (Tithal, Maroli, Umbergam, and Nargol) during 15-17 July 2012 as well as samples of crude oils, namely, Cairn, NIKO, MSC Chitra, and two at Bombay High (BH). These TBs were subject to the following multimarker approach for source identification: Diagnostic Ratios of n-alkanes, polycyclic aromatic hydrocarbons, pentacyclic triterpanes, compound specific isotope analysis, Principle Component Analysis and numerical simulations (hydrodynamic model coupled with particle trajectories). The chemical fingerprint results reveal that the source of the TBs is BH crude oils, and the model results confirm that the source location is BH north oil fields. This is the first study of its kind in India to use fingerprinting and transport modeling techniques for source identification of TBs. © 2014 American Chemical Society. Source

Patel U.D.,M. S. University of Baroda | Tandel D.V.,Gujarat Pollution Control Board
World Environmental And Water Resources Congress 2016: Water, Wastewater, and Stormwater and Urban Watershed Symposium - Papers from Sessions of the Proceedings of the 2016 World Environmental and Water Resources Congress | Year: 2016

Development of low-cost, self-sustainable, and easy-to-operate sewage treatment reactors for rural areas of India for non-potable reuse is an earnest need-of-the-hour. Three low-cost sewage treatment systems: vermifiltration (VF), soil biofilter (SBF), and sponge-filled trickling filter followed by SBF (SPTF-SBF) were studied for removal of COD, turbidity, and transformation of N and P, at hydraulic loading (HLR) varying as 0.5, 1.0, and 1.5 m/day. All the reactors achieved almost complete removal of turbidity and increase in PO4-P in the effluent due to decomposition organic matter. VF1 and VF2 (containing 36 and 72 g earthworms, respectively) achieved 88-94% and 90-95% COD and 58-80% and 30-90% NH4-N removal, respectively, with removal decreasing slightly with increase in HLR. The earthworm massin VF decreased with time indicating that an additional source of food may be required for survival and growth of earthworms. SBF achieved 86-91% COD and 41-60% NH4-N removal. The performance of VF and SBF was inconsistent due to chocking of soil layer with SBF chocking more frequently. It was observed that decrease in nitrification and PO4-P formation indicated onslaught of chocking in VF and SBF. Overall COD removal of 95-96% and almost complete nitrification was obtained in SPTF-SBF, independent of HLR. The performance of SPTF-SBF system was consistent, free of any chocking, and did not require any supervision. Increase in PO4-P (-48%) in the effluent of SPTF-SBF was the highest among the three systems. The nutrients (NO3-N, PO4-P) were retained which suggests that effluent of SPTF-SBF system can be reused for irrigation. © ASCE. Source

Bhadrecha M.H.,Gujarat Pollution Control Board | Khatri N.,Gujarat Environment Management Institute office of the Director | Tyagi S.,Gujarat Environment Management Institute office of the Director
Environmental Monitoring and Assessment | Year: 2016

The water quality of Mahisagar river, near Galteshwar in Kheda district of Gujarat, India, was assessed through a rapid integrated technique by physicochemical parameters as well as benthic macroinvertebrates. Physicochemical parameters retrieved were pH, color, conductivity, total solids, total suspended solids, total dissolved solids, chlorides, total hardness, calcium hardness, magnesium hardness, alkalinity, turbidity, ammoniacal nitrogen, chemical oxygen demand, biochemical oxygen demand, dissolved oxygen, sulfates, and nitrates. The biological indices calculated were BMWP (Bio Monitoring Working Party) score or saprobic score and sequential comparison index or diversity score. In total, 37 families were encountered along the studied river stretch. The findings indicate that the water quality of Mahisagar river at sampled locations is “slightly polluted.” Moreover, the results of physicochemical analysis are also in consonance with the biological water quality criteria developed by Central Pollution Control Board. © 2016, Springer International Publishing Switzerland. Source

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