Papers by Veeresh Hogarnal
Applied Geochemistry, 2003
The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil ... more The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil and also on the geochemical phases with which metals are associated. Laboratory batch experiments were carried out to study the sorption and distribution of Cd, Ni and Pb in 3 soils differing in their physicochemical properties from India: Oxyaquic Haplustalf (SL1), Typic Haplustalf (SL2) and Typic Haplustert (SL3). The heavy metal adsorption was studied by isotherms and the distribution coefficient (K D) for each metal was obtained from the linear regressions of the concentration of metal remaining in equilibrium solution and the amount adsorbed. In general, the sorption capacity for all the metals decreased in the order: SL3 > SL2> SL1. Among metals, the sorption capacity in all the soils decreased in the order: Pb >> Ni > Cd. Distribution of sorbed metals at various equilibrating concentrations was studied by sequential extraction. Results showed significant differences in the distribution of metals in these soils. At higher additions (such as 200 mM l À1) most of the metals were extracted in their more mobile fractions, exchangeable and/or inorganic in contrast to their original partitioning in soils, where they were preferentially associated with the less mobile residual fraction. Largest percentages of metals extracted in the exchangeable fraction corresponded to those soil-metal systems with smaller K D values, e.g. Cd, Ni and Pb in SL1 and Cd and Ni in SL2. In neutral and alkaline soils (SL2, pH=7.1, and SL3, pH=8.6) Pb was predominantly extracted from the inorganic fractions and this corresponded to higher K D values for Pb in these soils. The predominance of metals associated with the exchangeable fraction together with low K D values indicates higher mobility of metals retained in the acidic soil (SL1, pH=5.2) compared with the others.
Environmental …, 2003
Laboratory batch experiments were carried out to study the competitive sorption behavior of metal... more Laboratory batch experiments were carried out to study the competitive sorption behavior of metals in three types of Indian soils, differing in their physicochemical properties: acid laterite (SL1), red alfisol (SL2) and black vertisol (SL3) treated with different proportions of ...
Among the various environmental challenges that India faces this century, better management of wa... more Among the various environmental challenges that India faces this century, better management of water quality is of high priority as there is increased stress on surface water sources due to population pressure. The major threat to the sustainability of surface water systems is pollution. Pollution affects the quality of water and limits its multiple uses. Besides, the rate of water system pollution increases as population increases International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 11 (2017) pp. 990-1007 Journal homepage: http://www.ijcmas.com
ABSTRACT The shortage and high cost of fertilizers necessitate that every unit of fertilizer be u... more ABSTRACT The shortage and high cost of fertilizers necessitate that every unit of fertilizer be used judiciously. In view of high location-specific nutrient needs and soil-test based fertilizer recommendation for specific crop and crop sequences, soil testing has updated its methods and techniques to remove soil fertility constraints. A field experiment was conducted during kharif seasons of 2012-13 and 2013-14 at the Main Agricultural Research Station, UAS, Raichur, India to study the response of soil test crop response (STCR) approach on the yield and quality of Sunflower (Helianthus annuus L.). The experiment was laid out by RCBD design with three replications. The analysis of variance revealed that the application of fertilizers based on STCR (Soil Test Crop Response) along with foliar application of micro-nutrients significantly recorded higher head diameter, 100 seed weight, number of filled seed head-1,seed filling per cent, seed yield ha-1, stover yield ha-1, oil content and oil yield ha-1. Further a higher gross return, net returns and benefit-cost ratio (BCR) were observed when compared to the other treatment combinations carried out during the experiment viz., recommended dose fertilizer (RDF) of NPK (Control). Hence, it can be concluded that the input of STCR approach leads to precise use of fertilizer dose as compared to RDF method; ultimately it can serve as to improve farming community by reducing the cost of cultivation, increasing yield and a basic tool for sustainable agriculture production.
Coal Combustion Byproducts and Environmental Issues, 2006
... where, Xlm = Amount of metal adsorbed in KM kg-' C, = Equilibrium solution concentra... more ... where, Xlm = Amount of metal adsorbed in KM kg-' C, = Equilibrium solution concentration of metal in KML-' KD = Distribution Co-efficient or Adsorption affinity of metal n = Freundlich's equation constant In general, the concentrations of metals used during adsorp-tion study ...
Environmental Geology, 2003
The influence of metals, Cd, Cr, Cu, Ni, Pb and Zn, on the microbial biomass and enzyme activitie... more The influence of metals, Cd, Cr, Cu, Ni, Pb and Zn, on the microbial biomass and enzyme activities of an amended acid lateritic soil were investigated under field conditions receiving a onetime application of 52 t ha)1 of sludge, coal ash and their mixtures at 1:3, 1:1 and 3:1 proportions, and including control and chemical fertilizer treatment at crop-specific recommended doses. Paddies and peanuts were grown in the experimental plots and soil was sampled twice after 6 months and 1 year after amendment application. The heavy metals in the soil were fractionated using sequential extraction and the increments in their concentrations in amended soil with respect to the control were determined. Concentrations of Cd, Ni and Zn were determined to have increased in their mobile fractions and were more pronounced in soil collected during the second sampling, which was associated with a decrease in soil organic carbon. The size of the microbial biomass carbon and the soil enzyme activities increased with the addition of an amendment and was highest at equal proportions of coal ash and sludge. Further increase in the proportion of sludge resulted in a significant decrease in biomass carbon. Simple correlation revealed significant and strong negative relations of mobile fractions of Cd and Ni with the ratio between microbial biomass C and organic carbon in soil, while the organic carbon content and the pH were positively correlated. The microbial activities were determined to be sensitive to the concentrations of some heavy metals in mobile fractions and therefore indicated possibilities of being useful as indicators for evaluation of toxic effects of sludge-borne metals on soil organisms.
Environmental Geology, 2003
A sequential extraction procedure has been used to study the changes in the distribution and mobi... more A sequential extraction procedure has been used to study the changes in the distribution and mobility of Cd, Cr, Cu, Ni, Pb and Zn in an acid lateritic soil amended with alkaline coal ash and neutral sludge individually and with their mixture of equal proportions at 25, 50 and 75 Mg/ha application rates and grown in a crop with peanuts. A separate set of experiments consisting of the same treatments was repeated with the addition of lime at 2 Mg/ha. Increases in total heavy-metal levels with application of various amendments were mainly associated with increases in the insoluble and less mobile forms of metals except for Cd, which showed an increase in its exchangeable form. An increase in pH of the amended soil restricted the metal mobility in their labile forms and was more pronounced after liming the treatments. Positive yield responses were observed in the amended soil, the magnitude being higher in only sludge-applied treatments. The vegetative plant parts showed maximum accumulation of metals indicating a physiological barrier in the transfer of metals from the root to the kernel. Linear relationships of total concentrations of heavy metals in soil with that in the crop were observed. Lime addition to the treatments further reduced the transfer and accumulation of metals from the soil to the plant, even though the relationship remained linear.
Environmental Geology, 2003
Laboratory batch experiments were carried out to study the competitive sorption behavior of metal... more Laboratory batch experiments were carried out to study the competitive sorption behavior of metals in three types of Indian soils, differing in their physicochemical properties: acid laterite (SL1), red alfisol (SL2) and black vertisol (SL3) treated with different proportions of fly ash and sewage sludge mixture. Representative samples were equilibrated with 10 to 200 lM L-1 concentrations of metals simultaneously containing Cd, Cu, Ni, Pb and Zn in 5 mM of Ca(NO 3) 2 solution. In most of the cases the affinity sequence of metals was Pb>Cu>Zn>Ni>Cd based on their amount of sorption, which varied little with either metal equilibrating concentrations or the soil/ mixture type. The observed metal affinity sequences in different soils amended with mixtures were compared to the predicted affinity sequences based on metal properties and a good match was found with those predicted by metal hydrolysis constants. This indicated that formation and subsequent sorption of metal hydrolysis products on soil surface is the predominant mechanism for sorption. In all the cases, Pb and Cu showed higher affinity followed by Zn, Ni or Cd. The increase in the metal additions further enhanced the competition among metals for exchange sites. Adsorption isotherms showed that metal sorption was linearly related to its concentration in the equilibrium solution. The distribution coefficients (K D) computed from the slopes of linear regression for different metals were higher in SL3 than in both SL2 and SL1. All the mixture amended soils produced higher K D values than their respective controls. Selectivity between metals resulted in the following affinities based on their K D values-Pb>Cu>Zn>Ni or Cd-which was in line with the value of the hydrolysis constant of the metals under study.
Chemistry of trace …, 2003
The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil ... more The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil and also on the geochemical phases with which metals are associated. Laboratory batch experiments were carried out to study the sorption and distribution of Cd, Ni and Pb in 3 soils differing in their physicochemical properties from India: Oxyaquic Haplustalf (SL1), Typic Haplustalf (SL2) and Typic Haplustert (SL3). The heavy metal adsorption was studied by isotherms and the distribution coefficient (K D ) for each metal was obtained from the linear regressions of the concentration of metal remaining in equilibrium solution and the amount adsorbed. In general, the sorption capacity for all the metals decreased in the order: SL3 > SL2> SL1. Among metals, the sorption capacity in all the soils decreased in the order: Pb >> Ni > Cd. Distribution of sorbed metals at various equilibrating concentrations was studied by sequential extraction. Results showed significant differences in the distribution of metals in these soils. At higher additions (such as 200 mM l À1 ) most of the metals were extracted in their more mobile fractions, exchangeable and/or inorganic in contrast to their original partitioning in soils, where they were preferentially associated with the less mobile residual fraction. Largest percentages of metals extracted in the exchangeable fraction corresponded to those soil-metal systems with smaller K D values, e.g. Cd, Ni and Pb in SL1 and Cd and Ni in SL2. In neutral and alkaline soils (SL2, pH=7.1, and SL3, pH=8.6) Pb was predominantly extracted from the inorganic fractions and this corresponded to higher K D values for Pb in these soils. The predominance of metals associated with the exchangeable fraction together with low K D values indicates higher mobility of metals retained in the acidic soil (SL1, pH=5.2) compared with the others. #
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Papers by Veeresh Hogarnal