Air pollution due to coal washery projects and its abatement measures

The demand for washed coal in India has led to the planning of washeries. The sources of air pollution in washeries are described is this paper. A number of new washeries are going to be installed within the vicinity of Jharia Coalfield in eastern India to fulfill the demand for washed coal. Air pollution monitoring was conducted at four coal washeries of Bharat Coking Coal Ltd. (BCCL). Methods adopted for selection of monitoring stations and sampling and analysis of ambient air quality are discussed. Suspended particulate matter (SPM) concentrations in an industrial area, a residential area, and a sensitive area such as a hospital were found to be high and to exceed the limit specified by the Indian Pollution Control Board. NO_x and SO₂ concentrations in some areas were also found to exceed the specified limits. A high percentage of respirable dust in SPM indicates a health hazard. Benzene-soluble material was found to be 40%, which can be fatal to human health. Suppression measures are discussed for dust, and control measures for air pollution in coal washeries are proposed.     

Adaptation strategies to combat climate change effect on rice and mustard in Eastern India

The negative impact of climate change on crop production is alarming as the demand for food is expected to increase in coming years, at a rate of about 2 percent a year. Wet season rice (Oryza sativa) followed by mustard (Brassica juncea) is one of the prominent cropping sequences in Eastern India. Descreases in their productivity due to climate change will not only hamper the regional food security but also affect the global economy. Considering the fact, the present study aims to assess the impact of climate change on productivity of wet-season rice and mustard and to evaluate the effectiveness of agronomic adjustment as adaptation options. Crop growth simulation model (CGSM) is a very effective tool to predict the growth and yield of a crop. One CGSM, namely InfoCrop (Generic Crop Model), was calibrated and validated for the said crops for West Bengal State, Eastern India. After validation, the model was used to predict the yield under elevated thermal condition (1 and 3 °C rise over normal temperature). Moreover, the future weather situation as predicted by PRECIS (Providing Regional Climates for Impacts Studies) model was used as weather input of the CGSM and the yield was predicted for ten selected locations of West Bengal for the year 2025 and 2050. It was observed that the average yield reduction of the wet-season rice would be in the tune of about 20.0 % for 2025 and 27.8 % for 2050. The mustard yield of West Bengal may be reduced by 20.0 to 33.9 % for the year 2025 and up to 40 % for 2050. It was concluded that the negative impact of climate change on mustard grown in winter season will be more pronounced compared to wet-season rice. Adjustment of sowing time will be the simplest and effective adaptation option for both rice and mustard. Increased rate of nutrient application can sustain the rice yield under future climate. The older seedling at the time of transplanting of wet-season rice and increased seed rate of mustard were proved less effective.     

Sorption of organic contaminants to a low carbon subsurface core

Sorption of 1,2,4-trichlorobenzene, o-chlorotoluene and dimethylphthalate to a series of subsurface samples collected with depth is reported. Desorption of sorbate from the sorbent matrix provides better precision than conventional solution phase concentration differences when sorption is low. Clay mineral content influences sorption on low carbon sorbents.     

Perspectives of recycling gamma irradiated sewage-sludge in agricultural applications: a study on methi (Trigonella foenum-graecum L.: leguminosae)

The effects of gamma-irradiated sludge on the growth and yield of methi (Trigonella foenum-graecum L.) in pot cultures have been studied. Gamma-irradiated sludge was found to inhibit the shoot length after 45 and 90 days of plant growth compared to plants grown in soil containing unirradiated sludge. The untreated sludge did not exhibit any detrimental effect on the shoot length of plants compared to the control. The root length of plants grown in soil supplemented with either gamma-irradiated or unirradiated sludge was found to be inhibited after 45 days of growth. However, irradiation of sludge resulted in the higher inhibition of root length of plants compared to when unirradiated sludge was used. The gamma-irradiated sludge appeared to negatively affect the physical growth parameters of the plant. The significant positive effect of gamma-irradiated sludge was observed on the biochemical growth parameters and yield of methi plants. There was a 3.5-, 1.7- and 2-fold increase in the total protein content, total soluble sugars and starch content, respectively, of plants grown in soil supplemented with gamma-irradiated sludge after 45 days of growth. The gamma-irradiated sludge did not show any detrimental effect on any of the three biochemical parameters studied, even after 90 days of plant growth. The sludge obtained from the conventional treatment process was found to be inhibitory to the protein and starch content of plants in the latter stages of plant growth. A significant increase in the yield of methi plants, after 45 as well as 90 days, grown in the presence of gamma-irradiated sludge indicates a beneficial effect of recycling of irradiated sludge for agricultural applications.     

Low concentration of HgCl2 drives rat hepatocytes to autophagy/apoptosis/necroptosis in a time-dependent manner

Mercury (Hg) is known to produce hepatotoxicity driving cells towards apoptosis. It was recently reported that low concentrations of Hg (5 μM) initiate autophagy in vitro within 30 min of incubation modulated by several autophagy-related gene proteins, and co-regulators through ubiquitination. The present study aimed to elucidate in vitro mode of cytotoxic responses including programed cell death in 5-μM Hg-treated rat hepatocytes. Autophagy proceeded from 30 min to 4 hr mediated by crosstalk between specific regulating factors of cell-death-signaling mechanisms. It was noted that after 4-hr incubation with 5 μM HgCl₂, cells were driven towards apoptosis followed by necroptosis within 6.5 hr. Receptor-interacting serine-threonine protein 3 (RIP3) and caspase-8 played a significant role in interlinking function. The positive role of caspase-8 with RIP3 significantly triggered caspase-3 via extrinsic apoptotic pathway. A shift from apoptosis to necroptosis occurred after 6 hr via tumor necrosis factor α-RIP3-caspase-8 pathway. No alteration in caspase-3 expression and presence of high-mobility group box 1 protein in nucleus indicated absence of apoptosis and necrosis in rat hepatocytes between 6.5 and 8 hr. Data indicated that cellular homeostasis is regulated by modulating different proteins and driving hepatocytes through autophagy to apoptosis to necroptosis in a time-dependent manner.     

Heavy metal uptake by Scirpus Littoralis Schrad. from fly ash dosed and metal spiked soils

Scirpus littoralis is a wetland plant commonly found in Yamuna flood plains of Delhi, India. The ability of Scirpus littoralis to take up and translocate five metals- Mn, Ni, Cu, Zn and Pb from fly ash dosed and metal spiked soils were studied under waterlogged and field conditions for 90 days. Scirpus littoralis accumulated Mn, Ni, Cu, Zn and Pb upto a maximum of 494.92, 56.37, 144.98, 207.95 and 93.08 ppm dry wt., respectively in below ground organs (BO) in 90 days time. The metal content ratios BO/soil (B/S) were higher than shoot/soil ratios (T/S) for all the metals, the highest being for Ni. Metal ratios BO/water (B/W) were also higher than shoot/water (T/W) ratios but the B/W ratio was maximum for Zn. The changes in nutrient status (N, P) in soil water and plants were also studied at interval of 30 days. The Pearson's correlation between metal uptake and N, P uptake were calculated. All the metals except Ni showed negative correlation with nitrogen but they were all non-significant. However, P uptake showed positive correlations with all the metals and all were significant at 1% confidence limit.     

Seagrass metabolism and carbon dynamics in a tropical coastal embayment

Net ecosystem metabolism and subsequent changes in environmental variables were studied seasonally in the seagrass-dominated Palk Bay, located along the southeast coast of India. The results showed that although the water column was typically net heterotrophic, the ecosystem as a whole displayed autotrophic characteristics. The mean net community production from the seagrass meadows was 99.31 ± 45.13 mM C m^?2 d^?1, while the P/R ratio varied between 1.49 and 1.56. Oxygen produced through in situ photosynthesis, exhibited higher dependence over dissolved CO₂ and available light. Apportionment of carbon stores in biomass indicated that nearly three-fourths were available belowground compared to aboveground. However, the sediment horizon accumulated nearly 40 times more carbon than live biomass. The carbon storage capacities of the sediments and seagrass biomass were comparable with the global mean for seagrass meadows. The results of this study highlight the major role of seagrass meadows in modification of seawater chemistry. Though the seagrass meadows of Palk Bay are increasingly subject to human impacts, with coupled regulatory and management efforts focused on improved water quality and habitat conservation, these key coastal ecosystems will continue to be valuable for climate change mitigation, considering their vital role in C dynamics and interactions with the overlying water column.     

Evaluation of ozonation technique for pesticide residue removal and its effect on ascorbic acid,cyanidin-3-glucoside,and polyphenols in apple (<Emphasis Type="Italic">Malus domesticus</Emphasis>) fruits

Ozonated water dip technique was evaluated for the detoxification of six pesticides, i.e., chlorpyrifos, cypermethrin, azoxystrobin, hexaconazole, methyl parathion, and chlorothalonil from apple fruits. Results revealed that ozonation was better than washing alone. Ozonation for 15 min decreased residues of the test pesticides in the range of from 26.91 to 73.58%, while ozonation for 30 min could remove the pesticide residues by 39.39–95.14 % compared to 19.05–72.80 % by washing. Cypermethrin was the least removed pesticide by washing as well as by ozonation. Chlorothalonil, chlorpyrifos, and azoxystrobin were removed up to 71.45–95.14 % in a 30-min ozonation period. In case of methyl parathion removal, no extra advantage could be obtained by ozonation. The HPLC analysis indicated that ozonation also affected adversely the ascorbic acid and cyanidin-3-glucoside content of apples. However, 11 polyphenols studied showed a mixed trend. Gallic acid, 3,4-dihydroxybenzoic acid, catechin, epicatechin, p-coumaric acid, quercetin-3-O-glucoside, quercetin, and kaempferol were found to decrease while syringic acid, rutin, and resveratrol were found to increase in 30-min ozonation.