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Periodic sampling of the discharged seawater effluent from Madras Atomic Power Station (Kalpakkam, Tamil Nadu, India) was carried out during 2013–2017 to assess the residual chlorine and trihalomethanes content in the outfall discharge water. The variations in dissolved oxygen, temperature, and pH were correlated with the residual chlorine and trihalomethanes content in the discharged effluent. The difference in temperature (ΔT) between influent and effluent seawater samples ranged from 1.95 to 11.0 °C (6.47 ± 1.87). More than 95% of the Δ T values were within the guideline value of 7 °C. The discharge water was associated with a marginal reduction in dissolved oxygen and a marginal increase in conductivity values. The total residual chlorine content in the discharged seawater at outfall ranged from 0.06 to 0.42 (0.16 ± 0.08) mg/L, which was within the stipulated values of 0.5 mg/L. Trihalomethanes values ranged from 0.04 to 65.03 (13.06 ± 14.38) μg/L. In addition to bromoform as the major constituent, occurrence of significant amount chloroform of was occasionally observed in the discharge water.

The objective of the present study was to characterize the concentrations of selected dissolved trace metals in the coastal waters (500 m from shore) of Kalpakkam, Tamil Nadu, India. The order of dissolved concentration of these metals was found to be as follows: Co (cobalt) < Cd (cadmium) < Cr (chromium) < Mn (manganese) < Cu (copper) < Ni (nickel) < Pb (lead) < Zn (zinc). The levels of these trace metals were found to be relatively low as compared to the reported values for other Indian coastal waters, which indicates negligible pollution at this location. Cadmium was the only metal found to increase its concentration during the monsoon period, suggesting its allochthonous input. Factor analysis indicated that chromium, nickel, zinc, cobalt, copper, manganese, and lead were of common origin, and external inputs through land runoff had nominal or little impact, typifying in-situ regeneration and remineralization linkage with their temporal variation. However, levels of zinc, cobalt, and copper remained relatively high during the summer period, and abrupt increases in their concentration during December (monsoon season) may be due to their dual (autochthonous as well as allochthonous) input.

A study was carried out at Kalpakkam coast to find out the distribution of various fractions of phosphorus (P) in the marine sediment during pre-northeast monsoon period. Samples were collected from ten locations covering ~80 km² of the inner-shelf region. Sedimentary parameters such as sand, silt, clay, and organic carbon percentage were analyzed in order to find out their relation with various P fractions. The sediment was found to be predominantly sandy in nature with low silt and clay content. Among all the fractions (loosely bound (LoP), calcium bound (CaP), iron bound (FeP), aluminum bound (AlP), and organic (OP)), CaP fraction constituted the largest portion (68.7 %) followed by organic fraction (16.3 %). The bioavailable P fractions ranged from 5 to 44 % of the total P (TP) content. Relatively high LoP content was observed at the offshore locations with comparatively high mud percentage as compared with the near-shore locations. As FeP and AlP concentrations were directly proportional to the amount of fine-grain sediment, the low levels of these fractions found in this coastal area were therefore attributed to the sandy nature of the sediments. The order of abundance of the major forms of P in the surface sediments of Kalpakkam coast was as follows: CaP > OP > LoP > AlP > FeP.

Formation character of brominated-trihalomethanes (Br-THMs) in chlorinated seawater and its dependence on applied chlorine dose, reaction time, and temperature were investigated in the laboratory. Seawater was collected from the east coast of India and a chlorine dose of 1, 3, 5, and 10 ppm was each applied at a temperature of 20, 30, and 40 °C to investigate the yield and kinetics of Br-THMs formation. Qualitative and quantitative estimation of THM formation at various intervals of time ranging from 5 min to 168 h was determined by a gas Chromatograph equipped with an electron capture detector (GC-ECD). Chlorine dose, chlorine contact time, and reaction temperature positively affected the load of THMs. The ratio of chlorine dose to halogen incorporation decreased from 12% to 5% with increasing applied chlorine dose from 1 to 10 ppm. Significant levels of THMs were found to be formed within 0.5 h of reaction, followed by a very slow rate of formation. Elevated temperature favored both increased rate of formation and overall THM yield. The formation order of different trihalomethane species at all studied temperatures was observed to be bromodichloromethane (CHCl₂Br) < dibromochloromethane (CHClBr₂) < bromoform (CHBr₃). Formation of chloroform was not observed, and bromoform was the dominant (96% to 98%) among the three THM species formed.

The study provides a thorough examination of the biofuel potential of three unique lignocellulosic crop residues, including rice straw ( Oryza sativa ), corn stalk ( Zea mays ), and sugarcane bagasse ( Saccharum officinarum ) of Odisha. In the investigation, we explored the compositional, thermal, and structural characteristics of these biomass sources to make clear their application for sustainable bioenergy production. Proximate analysis indicated variances in critical factors ranging from 5.9–14.8% (moisture content), 1.8–19.4% (ash content), 60–72.4% (volatile matter), and 9.6–14.7% (fixed carbon). Proximate analysis contributes to the various energy-generating capacities of these materials. An in-depth investigation of cellulose, hemicellulose, and lignin concentration revealed the promise of sugarcane bagasse as a cellulose-rich option for bioethanol synthesis. Thermochemical profiling using thermogravimetric and FTIR analysis revealed information about thermal stability and chemical changes, with pretreatment essential in increasing biomass accessibility and crystallinity. The significance of pretreatment-induced crystallinity for effective enzymatic hydrolysis and fermentable sugar generation was highlighted by X-ray diffraction (XRD). Overall, this study advances our understanding of the intricate relationships between biomass composition, structure, and bioenergy potential, offering valuable insights for developing sustainable biofuel production strategies.

The change in water quality arising from the open storage of groundwater (GW) and its impact on chlorination and chlorination by-product formation were investigated. Water quality descriptors, such as temperature, pH, chlorophyll, and dissolved oxygen contents of GW undergo substantial alteration when stored in a reservoir. Dissolved organic content (DOC) measured in the two water sources studied, i.e., GW and open reservoir water (RW), varied from 0.41 mg/L to 0.95 mg/L and 0.93 mg/L to 2.53 mg/L, respectively. Although DOC demonstrated wide variation, UV absorbance at 254 nm (UVA254) values for GW (0.022–0.067) and RW (0.037–0.077) did not display reciprocal variations. The chlorine demand (CD) of RW was always higher than that of GW for the corresponding sampling period. Average trihalomethane (THM) formation for RW was 50–80% higher compared to GW and thus poses an enhanced health risk. Appreciable amounts of bromide present in these water sources (0.15–0.26 mg/L in GW and 0.17–0.65 mg/L in RW) have resulted in the non-selective distribution of the four THM species. The formation of more toxic brominated THM due to chlorination of these near-coast drinking water sources must be regarded as a decisive factor for the choice of water disinfection regime.

Source appointment for groundwater nitrate contamination is critical in prioritizing effective strategy for its mitigation. Here, we assessed the use of Cl/Br ratio and statistical correlation of hydro-chemical parameters to identify the nitrate source to the groundwater. A total of 228 samples from 19 domestic wells distributed throughout the study area were collected during June 2011–May 2012 and analyzed for various physicochemical parameters. Study area was divided into three spatial zones based on demographic features, viz., northern, southern, and central part. Nitrate concentration in 57 % of samples exceeded the prescribed safe limit for drinking stipulated by the World Health Organization (WHO) and Bureau of Indian standards (BIS). The central part of the study area showed elevated nitrate concentration ranging from below detection limit (BDL) to 263.5 mg/l as NO 3 − and demonstrated high attenuation within the immediate vicinity thereby restricting diffusion of the nitrate to the adjacent parts. Resolution of correlation matrix as statistical indicator for nitrate contamination was poor. Seventy-seven percent of samples with high nitrate concentration (>45 mg/l as NO 3 − ) showed strong association with high Cl/Br mass ratio (350–900), indicating mixing of sewage and septic tank effluents with groundwater as a primary source for the nitrate in the studied area. Nitrate level during monsoon (BDL, 229.9 mg/l as NO 3 − ), post-monsoon (BDL, 263.5 mg/l as NO 3 − ), and pre-monsoon (0.5–223.1 mg/l as NO 3 − ) indicated additional contribution of surface leaching to groundwater.

A functioning vascular access is crucial to the wellbeing of patients on hemodialysis. Thrombosis is the most common complication of arteriovenous fistula (AVF) resulting in late fistula failure; Its treatment is difficult, and results are often suboptimal. Interventional treatment of AVF thrombosis may not be available all the time, and timely application of an available noninterventional treatment may salvage the fistula. We report the successful treatment of AVF thrombosis using local thrombolytic therapy using tissue plasminogen activator in a patient, for the first time in India.

Oxygen depletion in the subsurface waters and formation of hypoxic/anoxic systems has expanded significantly in coastal systems around the world in the last few decades super(1). Depletion in dissolved oxygen concentration in the water column leads to hypoxic (O sub(2) less than or equal to 2 mg 1 super(-1)) and/or anoxic (O sub(2) less than or equal to 0 mg 1 super(-1)) conditions, and further formation of oxygen minimum zones (OMZs) in the coastal areas. Oxygen deficiency in the shelf region could be a critical determinant for fisheries, ecological and biogeochemical processes super(2) along with the economic condition of the region. Rise or expansion of hypoxia and anoxia at par with the urbanization and industrialization indicates major perturbation to the structure and functioning of coastal marine ecosystems. Here we report the vertical expansion of hypoxia within OMZ along the outer shelf and slope region, and emergence of an inner-shelf hypoxia that was not apparent in the southwestern Bay of Bengal (BoB).

Hydrodynamics of conical fluidized bed differ from that of columnar beds by the fact that a velocity gradient exists along the axial direction of the bed. The gas-liquid-solid fluidized bed has emerged in recent years as one of the most promising devices for three-phase operations. Such a device is of considerable industrial importance as evident from its wide applications in chemical, refining, petrochemical, biochemical processing, pharmaceutical, and food industries. To explore this, experiments have been carried out to find the bed pressure drop, bed fluctuation, and expansion ratios for ternary mixtures of dolomite in a three-phase conical fluidized bed. The effect of superficial liquid and gas velocity, initial static bed height, average particle size, and cone angle on the above-mentioned three responses have been studied. Mathematical models have been developed for the responses using both dimensional and statistical analyses. The calculated values of the responses from the developed models have shown a very good agreement with the experimental ones.