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The studies on occurrence of contaminants of emerging concern in drinking water treatment plants or even wastewater treatment plants in developing country like India, are very limited. Trihalomethanes (THMs) is one such contaminant of concern in drinking water treatment sector. THMs are the major disinfection byproducts (DBPs) formed during the widely used chlorination process. Their identification and removal is of utmost importance in developed as well as developing nations. This study is first of its kind to assess the removal of mixture of urban run-off driven organic matter, agricultural run-off driven organic matter, untreated sewage effluent driven organic matter and little natural organic matter (NOM) (altogether NefOM) (major DBP precursors) using advanced oxidation processes (AOPs) in the Indian region. Since, NOM vary geographically, this study will add up to applicability of generally utilized AOPs for removal of site explicit (Indian) NefOM. Trihalomethanes at a conventional water treatment plant at Mathura and a moving bed biofilm based non-conventional water treatment plant at Agra were monitored over a year, demonstrating the inability of the water treatment plants to limit formation of DBPs from Yamuna inlet water at any time of the year. Various AOPs (UV-H 2 O 2 , O 3 -H 2 O 2 , O 3 ) and UV (ultraviolet) photolysis were assessed for their ability to decrease the trihalomethane forming potential (THMFP) by degrading the contaminants in the waters of Yamuna. Kinetic studies were conducted to evaluate the selected AOPs based on their ability to mineralize dissolved organic carbon (DOC), and decrease UV 254 at various pH, UV intensities, and ozone and hydrogen peroxide concentrations. UV-L/H 2 O 2 at an intensity of 47 mJ/cm 2 /min, pH = 7, and at hydrogen peroxide concentration of 0.5 mM provided an optimum reduction of DOC (64%) and UV 254 (87%). Fractionation studies indicated that treatment by UV-L/H 2 O 2 leads to the most significant decrease in the hydrophobic fraction of the water, while further study indicated that UV-L/H 2 O 2 also showed maximum attenuation of THMFP., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Formation potential and speciation characteristics of two important groups of disinfection byproducts (DBPs), namely, trihalomethanes (THMs) and haloacetic acids (HAA S ), during Cl 2 and ClO 2 treatment of water samples collected from three different sources, namely, sea, river, and reservoir, were investigated with reference to key controlling parameters. Formation of inorganic DBPs such as chlorate and chlorite was evaluated. Dissolved organic carbon (DOC) and UV absorbance (UV 254 ) of the sea, river, and reservoir samples were 3.35 ± 0.05, 3.12 ± 0.05, and 3.23 ± 0.05 mg/L and 0.062 ± 0.01, 0.074 ± 0.01, and 0.055 ± 0.01 cm -1 , respectively. For Cl 2 and ClO 2 treatments, the respective formation potential of THMs and HAAs from the three water sources studied exhibited unidentical trend suggesting that higher THM formation was not necessarily associated with higher HAA formation. On chlorination, the concentrations of total HAAs formed were 9.8 μg/L (sea), 12.8 μg/L (river), and 20.6 μg/L (reservoir) and total THM yields were 38.3 μg/L (sea), 18.8 μg/L (river), and 21.5 μg/L (reservoir) for a Cl 2 dose of 1 mg/L and 30 min reaction time. The trend of formation of THMs and HAAs for Cl 2 treatment was similar to that for ClO 2 treatment. However, the amount of HAAs (3.5 μg/L (sea), 1.8 μg/L (river), and 1.9 μg/L (reservoir)) and THMs (not detected) formed was much lower than that formed during chlorination. Regardless of source water type, di-HAAs were the most favored HAAs, followed by tri-HAAs with a small amount of mono-HAAs formed for both Cl 2 and ClO 2 treatment. Chlorination yielded more THMs than HAAs, whereas it was reverse for chlorine dioxide treatment. Irrespective of treatment with ClO 2 or Cl 2 , seawater samples showed the highest bromine incorporation percentage (BIP) in both THMs and HAAs followed by that for river and reservoir water samples. HAAs were found to be always associated with lower amount of BIP than THMs., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In the present study, plant-scale process integration was applied to an Indian paper mill using the water cascade analysis (WCA) technique. Three limiting constraints, chemical oxygen demand (COD), total dissolved solids (TDS), and adsorbable organic halides (AOX), were considered for the study. A nearest neighbor algorithm was used to distribute the freshwater and recycled water among the plant operations. It was found that the limiting critical constraint depends upon the types of processes and streams involved in the integration. The limiting critical constraint can differ for different sections of the same industry, and can differ in different schemes of integration. After process integration, a 55.6% reduction in effluent flow, a 36% reduction in COD, and a 73% reduction in AOX were observed. After process integration, a 35.21% reduction in pollution costs can be achieved and, assuming the average production of the mill to be 225 tons per day, a savings of Indian rupees (INR) 1.73 per kg of paper produced can be achieved by employing process integration. The water cess was calculated as INR 3024.77 per day without integration for the sections that were considered for integration, while after integration, a 41.53% savings in the form of water cess was calculated., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

To assess water contamination and the relative effectiveness of three options for point-of-use water treatment in South India, we conducted a 6-month randomized, controlled intervention trial using chlorine, Moringa oleifera seeds, a closed valved container, and controls. One hundred twenty-six families participated. Approximately 70% of public drinking water sources had thermotolerant coliform counts > 100/100 mL. Neither M. oleifera seeds nor containers reduced coliform counts in water samples from participants' homes. Chlorine reduced thermotolerant coliform counts to potable levels, but was less acceptable to participants. Laboratory testing of M. oleifera seeds in water from the village confirmed the lack of reduction in coliform counts, in contrast to the improvement seen with Escherichia coli seeded distilled water. This discrepancy merits further study, as M. oleifera was effective in reducing coliform counts in other studies and compliance with Moringa use in this study was high.

Paper industries using different raw materials such as hard wood, bamboo, baggase, rice-straw and waste papers and bleaching chemicals like chlorine, hypochlorite, chlorine dioxide, hydrogen peroxide, sulphite and oxygen were studied to estimate organic pollution load and Adsorbable Organic Halides (AOX) per ton of production. The hard wood based paper industries generate higher Chemical Oxygen Demand (COD) loads (105-182 kg t(-1)) and Biochemical Oxygen Demand (BOD) loads (32.0-72 kg t(-1)) compared to the agro and waste paper based industrial effluents. The bleaching sequences such as C-EP-H-H, C-E-H-H, C-E-Do-D1 and O-Do-EOP-D1 are adopted in the paper industries and the molecular elemental chlorine free bleaching sequence discharges low AOX in the effluent. The range of AOX concentration in the final effluent from the paper industries was 0.08-0.99 kg t(-1) of production. Water consumption was in the range of 100-130 m(3) t(-1) of paper production for wood based industries and 30-50 m(3) for the waste paper based industries. Paper machine effluents are partially recycled after treatment and pulp mill black liquor are subject to chemical recovery after evaporation to reduce the water consumption and the total pollution loads. Hypochlorite bleaching units of textile bleaching processes generate more AOX (17.2-18.3 mg l(-1)) and are consuming more water (45-80 l kg(-1)) whereas alkali peroxide bleaching hardly generates the AOX in the effluents and water consumption was also comparatively less (40 l kg(-1) of yarn/cloth).