Water quality assessment of Majhiaon block of Garwa district in Jharkhand with special focus on fluoride analysis

Fluoride in groundwater is known to contaminate the water sources globally. Jharkhand, one of the states in the eastern part of India, is known to have excessive fluoride content in groundwater sources. The present work involves assessment of water quality with special reference to fluoride in Majhiaon block of Garwa district in Jharkhand. Iron, nitrate and arsenic were also tested for the water samples collected from site. Eight hundred forty samples were tested for fluoride on site using colourimetry method, and one tenth of the samples were brought to laboratory for iron, nitrate, arsenic and fluoride analysis. Results show that 402 samples were having fluoride above permissible limit. Iron and nitrate were found to be beyond permissible limits in 302 and 286 water samples, respectively. More than 50% of samples collected from school had fluoride levels above permissible limits. Arsenic was well within the limits. However, few samples shown were excessive of iron and nitrate.     

Persistence of fipronil and its metabolites in soil under field conditions

Fipronil belongs to phenylpyrazole class of chemical compounds. Degradation of fipronil in sandy loam soil was investigated under field conditions by applying fipronil (Regent 5 % SC) at 50 (T ₁) and 100 g a.i. ha^?1 (T ₂) in field. Samples were drawn periodically in triplicate on 0 (1 h after treatment), 1, 3, 7, 10, 15, 30, 60, and 90 days after treatment and analyzed on GC-ECD system equipped with capillary column. The residues of fipronil in both the doses dissipated in the range of 93.33–100 % in 90 days. Limit of detection (LOD) and limit of determination (LODe/LOQ) were 0.0003 and 0.001 mg kg^?1, respectively. Dissipation followed a biphasic first-order kinetics with half-life values of 10.81 and 9.97 days for fipronil alone and 8.14 and 13.05 days for fipronil along with metabolites in soil at (T ₁) and (T ₂) treatments, respectively.     

Solvent tolerant marine bacterium Bacillus aquimaris secreting organic solvent stable alkaline cellulase

The organic solvent tolerant bacteria with their physiological abilities to decontaminate the organic pollutants have potentials to secrete extracellular enzymes of commercial importance. Of the 19 marine bacterial isolates examined for their solvent tolerance at 10 vol.% concentration, one had the significant tolerance and showed a relative growth yield of 86% for acetone, 71% for methanol, 52% for benzene, 35% for heptane, 24% for toluene and 19% for ethylacetate. The phylogenetic analysis of this strain using 16S rDNA sequence revealed 99% homology with Bacillus aquimaris. The cellulase enzyme secreted by this strain under normal conditions showed an optimum activity at pH 11 and 45 °C. The enzyme did show functional stability even at higher pH (12) and temperature (75 °C) with residual activity of 85% and 95% respectively. The enzyme activity in the presence of different additives were in the following order: Co⁺² > Fe⁺² > NaOCl₂ > CuSO₄ > KCl > NaCl. The enzyme stability in the presence of solvents at 20 vol.% concentration was highest in benzene with 122% followed by methanol (85%), acetone (75%), toluene (73%) and heptane (42%). The pre-incubation of enzyme in ionic liquids such as 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium bromide increased its activity to 150% and 155% respectively. The change in fatty acid profile with different solvents further elucidated the physiological adaptations of the strain to tolerate such extreme conditions.     

Unboxing the molecular modalities of mutagens in cancer

Environmental Science and Pollution Research - The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological...     

Seasonal variations in abundance of nitrifying bacteria in fish pond ecosystem

Seasonal changes in abundance of nitrifiers (ammonia-oxidizing and nitrite-oxidizing bacteria) in surface and bottom water of freshwater ponds were examined with respect to temperature, DO, pH as well as concentration of ammonia and nitrite. The most probable number (MPN) of ammonia-oxidizers in different ponds varied from 1297 +/- 3.6 to 1673.23 +/- 0.36 ml(-1) in bottom and 720.5 +/- 8.1 to 955.3 +/- 10.8 ml(-1) in surface water during the rainy season while the MPN ranged from 1074 +/- 1.07 to 1372.17 +/- 4.6 ml(-1) in bottom and 515 +/- 10.1 to 678 +/- 11.8 ml(-1) in surface water in winter. However, the MPN were greatly reduced in summer and ranged from 435.05 +/- 15.7 to 547.54 +/- 2.12 ml(-1) in bottom and 218.7 +/- 7.3 to 368.4 +/- 9.32 ml(-1) in surface water. Similar seasonal trends were also observed in MPN of nitrite-oxidizers. Among all the physico-chemical parameters, abundance of nitrifiers was more positively correlated with ammonia and nitrite concentration in all the seasons. The abundance of nitrifiers in surface and bottom water was highest in rainy season followed by winter and modest in summer. The potential nitrification activities and oxidation rates were shown to be linear and activity of ammonia-oxidizing and nitrite-oxidizing bacteria was highest during rainy season.     

Bacterial and archaeal diversity in oil fields and reservoirs and their potential role in hydrocarbon recovery and bioprospecting

Environmental Science and Pollution Research - Hydrocarbon is a primary source of energy in the current urbanized society. Considering the increasing demand, worldwide oil productions are declining...     

Studies of thermodynamics of phosphomidon on fly ash

Adsorption thermodynamic studies of phosphomidon on fly ash at 25° and 50°C have been analysed as adsorption isotherms, Freundlich equations, K_d values and various other thermodynamic parameters. These data were in close agreement with Freundlich isotherms and yield ‘S’ type isotherms at both the temperatures. Thermodynamic constants (K_o) and standard free energy (ΔG°), enthalpy (ΔH°) and entropy changes (ΔS°) have been calculated for predicting the nature of adsorption.     

Screening of antibiotic residues in fresh milk of Kathmandu Valley,Nepal

The prevalence of two groups of antibiotics; namely penicillin and sulfonamides was studied in fresh milk available in Kathmandu Valley of Nepal. The milk samples (n = 140) were collected from three different sources; individual farmers, cottage dairies and organized dairies of Kathmandu valley. Qualitative and semi-quantitative analysis with rapid screening kits revealed that 23% samples were positive for antibiotic residues in the fresh milk for penicillin and sulfonamide groups (1–256 µg/kg). High performance liquid chromatography (HPLC) analyses detected 81% samples positive for amoxicillin (68–802 µg/kg), 41% for sulfadimethoxine (31–69 µg/kg), 27% for penicillin G (13–353 µg/kg), and 12% for ampicillin (0.5–92 µg/kg). Due to the precision and accuracy of liquid chromatography method, it detected more positive samples and consequently presented higher prevalence than the rapid screening kits. The antibiotic residues were found above the maximum residue limits that presented serious threat to consumer health and raised a serious concern regarding the implementation and monitoring of international regulations in developing countries.     

Mainstreaming biodiversity conservation: a Peninsular Malaysian case

SUMMARY

The contention is examined that forests can contribute to biodiversity conservation either as protected areas or as production forests, especially where the latter are managed for timber extraction. This notion is explored for the Peninsular Malaysian forests, and it is shown that biodiversity conservation would be optimized if the system of protected areas is located within a broader matrix of carefully managed production forests. A model is developed to illustrate how the biodiversity value of protected areas would be enhanced through interaction with production forests. In no way is the suggestion being made here that production forests could serve as critical centres for the conservation of biotic diversity, but then neither should they be dismissed as areas completely devoid of any contribution to the biodiversity cause. These findings are especially significant in Peninsular Malaysia where two-thirds of the forests legally set aside as Permanent Forest Estate is to be managed as production forests. If the incremental biodiversity value of these forests can be captured through improved management practices, then the overall biodiversity status of the country, and the globe, could be greatly increased. The extent to which any country is willing to set aside forests as protected areas, strictly for biodiversity conservation, is limited, hence the integrated approach to the management of protected and production forests advocated here could prove an attractive and feasible strategy. Where funding is limited, as in the case of the Global Environment Facility, it may be worthwhile to provide incentives for improved management of production forests as a means of conserving biodiversity.     

Measurements of major ion concentration in settled coarse particles and aerosols at a semiarid rural site in India

Deposition rates and deposition velocities of water-soluble ions (F, Cl, NO3, SO4, NH4, Ca, Mg, Na and K) were measured at a rural site (Gopalpura, Agra). Dry deposition samples were collected throughout the year from December 1995 to August 1997, while the aerosol samples were collected only during the winter season of 1996. Surrogate technique was used to collect the dry deposition samples, while aerosol samples were collected on PTFE membrane filter. Deposition velocities (Vd) of SO4 and NO3 are < or = 0.01 m s(-1) while Ca, Mg, Na, K, NH4, F and Cl exhibit greater than 0.01 m s(-1) Equivalent concentration ratios of K/Na, Ca/Na and Mg/Na conform with the corresponding ratios of local soil, indicating the dominant contribution of local sources. Deposition rates are maximum in winter, followed by summer and monsoon. No significant differences are found in dry deposition rates of all ions or in atmospheric concentrations of soil-derived elements with respect to wind direction. However, in aerosols, concentrations of F, Cl, NO3 and SO4 are higher with winds from southwesterly and westerly directions corresponding to pollution sources located in these directions. Deposition data have been used to calculate the critical load of S and N for soil with respect to Triticum vulgaris. The critical load of actual acidity was found to be 622.4 eq ha(-1) year(-1) within the range of 500-1,000 eq ha(-1) year(-1) as assessed by the RAINS-Asia model for this region. The present load of S and N (77.4 and 86.4 eq ha(-1) year(-1)) was much lower than the critical load of S and N (622.4 and 2,000 eq ha(-1) year(-1)), indicating that at present there is no harmful effect on ecosystem structure and function.