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PublicationArticle Comparative assessment of Azolla pinnata and Vallisneria spiralis in Hg removal from G.B. Pant Sagar of Singrauli Industrial region, India(2009) Prabhat Kumar Rai; B.D. TripathiThe aim of the present work was to monitor the Hg pollution in water and sediments of G.B. Pant Sagar located in Singrauli Industrial Region, India and to suggest the efficient aquatic plants for its phytoremediation. The study assessed the comparative potential of a free floating water fern Azolla pinnata and submerged aquatic macrophyte Vallisneria spiralis to purify waters polluted by Hg. Six days laboratory experiments have been conducted to mark the percentage removal of Hg at initial concentration of 0.1, 0.5, 1.0 and 3.0 mg L-1. The percentage removal of Hg was higher for A. pinnata (80-94%) than V. spiralis (70-84%). Likewise, the Hg accumulated in dry mass was much higher for A. pinnata and a high correlation (R2 = 0.91 for A. pinnata and 0.99 for V. spiralis) was obtained between applied Hg doses and accumulated amounts in biomass. A concentration dependent decrease in chlorophyll a, protein, RNA, DNA and nutrients (NO3- and PO43-) uptake was detected in A. pinnata and V. spiralis due to Hg toxicity. The decrease was more prominent in Azolla than Vallisneria. The results recommended the use of A. pinnata and V. spiralis to ameliorate the industrial effluents (thermal power, chlor-alkali and coal mine effluent) contaminated with Hg. © Springer Science+Business Media B.V. 2008.PublicationArticle Use of sewage sludge as fertiliser supplement for Abelmoschus esculentus plants: Physiological, biochemical and growth responses(Inderscience Publishers, 2009) R.P. Singh; M. AgrawalThis study was conducted to assess the usefulness of sewage sludge amendment (SSA) at 20 and 40% ratios for lady's finger (Abelmoschus esculentus L. var Varsha uphar) by evaluating the morphological, physiological, biochemical and yield responses. Lipid peroxidation, protein and antioxidant levels increased whereas photosynthetic rate, stomatal conductance and variable fluorescence ratio decreased in plants at higher SSA ratio. Biomass, yield and heavy metal concentration increased significantly at both the amendment ratios. The study suggests that SSA ratio below 20% could be an alternative option of fertilisers for good yield of lady's finger and also a useful management option for this solid waste. Copyright © 2009, Inderscience Publishers.PublicationArticle Bioaccumulation of heavy metals and two organochlorine pesticides (DDT and BHC) in crops irrigated with secondary treated waste water(2009) Virendra K. Mishra; Alka R. Upadhyay; B.D. TripathiFour crop plants Oryza sativa (rice), Solanum melongena (brinjal), Spinacea oleracea (spinach) and Raphanus sativus (radish) were grown to study the impact of secondary treated municipal waste water irrigation. These plants were grown in three plots each of 0.5 ha, and irrigated with secondary treated waste water from a sewage treatment plant. Sludge from the same sewage treatment plant was applied as manure. Cultivated plants were analyzed for accumulation of heavy metals and pesticides. Results revealed the accumulation of six heavy metals cadmium (Cd), chromium (Cr), iron (Fe), copper (Cu), nickel (Ni), and zinc (Zn) as well as two pesticides [1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane; DDT] and benzene hexa chloride (BHC). Order of the plants for the extent of bioaccumulation was S. oleracea > R. sativus > S. melongena > O. sativa. The study has shown the secondary treated waste water can be a source of contamination to the soil and plants. © Springer Science+Business Media B.V. 2008.PublicationArticle Accumulation of heavy metals in dietary vegetables and cultivated soil horizon in organic farming system in relation to atmospheric deposition in a seasonally dry tropical region of India(2009) Jiten Pandey; Usha PandeyIncreasing consciousness about future sustainable agriculture and hazard free food production has lead organic farming to be a globally emerging alternative farm practice. We investigated the accumulation of air-borne heavy metals in edible parts of vegetables and in cultivated soil horizon in organic farming system in a low rain fall tropical region of India. The factorial design of whole experiment consisted of six vegetable crops (tomato, egg plant, spinach, amaranthus, carrot and radish) × two treatments (organic farming in open field and organic farming in glasshouse (OFG)) × seven independent harvest of each crop. The results indicated that except for Pb, atmospheric deposition of heavy metals increased consistently on time scale. Concentrations of heavy metals in cultivated soil horizon and in edible parts of open field grown vegetables increased over time and were significantly higher than those recorded in OFG plots. Increased contents of heavy metals in open field altered soil porosity, bulk density, water holding capacity, microbial biomass carbon, substrate-induced respiration, alkaline phosphatase and fluorescein diacetate hydrolytic activities. Vegetable concentrations of heavy metal appeared in the order Zn > Pb > Cu > Ni > Cd and were maximum in leaves (spinach and amaranths) followed by fruits (tomato and egg plant) and minimum in roots (carrot and radish). Multiple regression analysis indicated that the major contribution of most heavy metals to vegetable leaves was from atmosphere. For roots however, soil appeared to be equally important. The study suggests that if the present trend of atmospheric deposition is continued, it will lead to a destabilizing effect on this sustainable agricultural practice and will increase the dietary intake of toxic metals. © Springer Science+Business Media B.V. 2008.PublicationArticle Effects of wastewater irrigation on physicochemical properties of soil and availability of heavy metals in soil and vegetables(2009) Anita Singh; Rajesh K. Sharma; Madhoolika Agrawal; F. MarshallThe present study investigated the impact of irrigation with wastewater on nutritional property and heavy-metal concentrations in the soil and consequent accumulation in vegetables at sites having long-term uses of wastewater for irrigation. Samples of irrigation water, soil, and root and shoot parts of palak plants were analyzed to determine the concentration of heavy metals. Wastewater irrigation led to increases in the total and phytoavailable heavy-metal concentrations in the soil at all the sites. Heavy-metal concentrations in soil under wastewater irrigation were negatively and positively correlated with soil hydrogen potential (pH) and organic carbon (OC), respectively. The enrichment factor and metal pollution index were higher at wastewater-irrigated sites as compared to the clean water-irrigated ones. The study concludes that wastewater irrigation modified the physicochemical properties of the soil, leading to more availability of heavy metals in the soil and consequently to the plant. © Taylor & Francis Group, LLC.PublicationArticle Accumulation of chromium and zinc from aqueous solutions using water hyacinth (Eichhornia crassipes)(2009) Virendra Kumar Mishra; B.D. TripathiUnder present investigation Eichhornia crassipes (water hyacinth) has been tested for removal of two important heavy metals chromium (Cr) and zinc (Zn) from metal solution. This species was grown at four concentrations of Cr and Zn, i.e. 1.0, 5.0, 10.0 and 20.0 mg l-1 in single metal solution. This plant has performed extremely well in removing the Cr and Zn from their solution and was capable of removing up to 95% of zinc and 84% of chromium during 11 days incubation period. Removal of Cr at lower concentrations (1.0 and 5.0 mg l-1) was found harmless, without any symptom of toxicity but at 10.0 and 20.0 mg l-1, plants have shown some morphological symptoms of toxicity. On the other hand E. crassipes removed Zn safely at all the four concentrations, i.e. 1.0, 5.0, 10.0 and 20.0 mg l-1. In this case morphological symptoms of toxicity were not evident in the test plant. Biochemical parameters viz. protein, sugar and chlorophyll in experimental plants have shown a decreasing trend due to accumulation of Zn and Cr. Overall this methodology is safe for the removal of Zn and Cr and can be utilized at large scale after few further investigation. © 2008 Elsevier B.V. All rights reserved.PublicationArticle Heavy metals in vegetables collected from production and market sites of a tropical urban area of India(2009) Rajesh Kumar Sharma; Madhoolika Agrawal; Fiona M MarshallVegetables (Beta vulgaris L., Abelmoschus esculentus L. and Brassica oleracea L.) from the production and market sites of India were tested for Cu, Cd, Zn and Pb. At market sites, the mean concentration of Cu in cauliflower, and of Zn and Cd in both palak and cauliflower had exceeded the PFA standard. Zn at the production sites also exceeded the PFA standard in cauliflower. Cd concentration in vegetables tested from both production and market sites was many folds higher than the EU standard. In contrast, Pb in vegetables tested from both production and market sites was below the PFA limit, but was considerably higher than the current EU and WHO standards. Heavy metals accumulation in vegetables tested are higher at market sites than those at the crop production sites. The contributions of these vegetables to dietary intake of Cu, Zn, Cd and Pb were 13%, 1%, 47% and 9% of provisional tolerable daily intake, respectively. The study concludes that the transportation and marketing systems of vegetables play a significant role in elevating the contaminant levels of heavy metals which may pose a threat to the quality of the vegetables with consequences for the health of the consumers of locally produced foodstuffs. © 2008 Elsevier Ltd. All rights reserved.PublicationArticle Atmospheric deposition and heavy metal contamination in an organic farming system in a seasonally dry tropical region of India(2009) J. Pandey; U. PandeyIncreased consciousness about agricultural sustainability and health risks associated with agrochemicals has lead organic farming to be a globally emerging alternative farm practice. We report the effect of atmospheric deposition on soil quality and heavy metal contamination of agricultural produce under an organic farming system using wheat and corn as test crops. Data obtained in the open field (OFO) were compared with a plastic-covered glass-house-grown system (OFG). The results showed that depositions of Cd, Cu, Ni, Pb, and Zn increased with time. Soil porosity, water holding capacity, microbial biomass carbon (Cmic), substrate-induced respiration (SIR), alkaline phosphatase, and FDAase activity decreased, whereas the bulk density and contents of Cd, Cu, Ni, Pb, and Zn increased over time in open plots receiving atmospheric deposition. Concentrations of metals in grains in OFO crops exceeded the safe limits of Indian standards and were three to sixfold higher than those recorded in OFG plots. These results indicate that atmospheric deposition of heavy metals can have a destabilizing effect on soil fertility in organic farming and can greatly increase the dietary intake of toxic metals. This may have long-term implications for human health as well as for agricultural sustainability. The data presented here have particular concern for developing countries, where unprecedented urban-industrial growth and consequently increased input fluxes of heavy metals will continue for decades to come.PublicationArticle Removal and accumulation of mercury by aquatic macrophytes from an open cast coal mine effluent(2009) Virendra Kumar Mishra; B.D. Tripathi; Ki-Hyun KimIn this study, the mercury (Hg) removal capacities of two aquatic macrophytes, Pistia stratiotes and Azolla pinnata, were investigated against the coal mining effluent. These plants reduced mercury from the effluent via rhizofiltration and subsequent accumulation in plant. The removal rate of P. stratiotes and A. pinnata was 80% and 68%, respectively, after 21 days of exposure to the effluent containing 10 μg L-1 of Hg. As mercury from the effluent was accumulated in the root and shoot tissues of both aquatic macrophytes, they were proven to be a root accumulator with a translocation factor of less than one during the entire study. The decreasing Hg content in effluent (from 10 to 2.0 μg L-1) was reflected by its accumulation in roots (0.57 ± 0.02 mg g-1 in P. stratiotes) and leaves of the experimental plants (0.42 ± 0.01 mg g-1, P. stratiotes). As a result, Hg concentrations in the coal mining effluent were tightly associated with those observed from macrophytes. Considering the high removal efficiencies of Hg by these aquatic macrophytes, these plants can be recommended for the actual treatment of Hg-containing waste waters. © 2009 Elsevier B.V. All rights reserved.