Study of cyanide removal from contaminated water using zinc peroxide nanomaterial

The present study highlights the potential application of zinc peroxide(ZnO_2)nanomaterial as an efficient material for the decontamination of cyanide from contaminated water. A process patent for ZnO_2 synthesis has been granted in United States of America(US Patent number 8,715,612; May 2014),South Africa,Bangladesh,and India. The ZnO_2 nanomaterial was capped with polyvinylpyrrolidone(PVP)to control the particle size. The PVP capped ZnO_2nanomaterial(PVP-ZnO_2)before and after adsorption of cyanide was characterized by scanning electron microscope,transmission electron microscope,X-ray diffractometer,Fourier transform infrared spectroscopy and time of flight-secondary ion mass spectrometry. The remaining concentration of cyanide after adsorption by PVP-ZnO_2 was determined using ion chromatograph. The adsorption of cyanide over PVP-ZnO_2 was also studied as a function of p H,adsorbent dose,time and concentration of cyanide. The maximum removal of cyanide was observed in p H range 5.8–7.8 within 15 min. The adsorption data was fitted to Langmuir and Fruendlich isotherm and it has been observed that data follows both the isotherms and also follows second order kinetics.     

Municipal waste compost as an alternative to cattle manure for supplying potassium to lowland rice

The importance of the use of potassium in agriculture is increasing in South Asia for making most productive use of the nutrient in terms of economic returns. Nutrient supply traditionally by cattle manure is constrained by its insufficient availability. Municipal waste compost may be an alternative source of nutrient supplements. Field experiments were conducted at the Experimental Farm of Calcutta University, West Bengal, India during the wet seasons of 1997, 1998 and 1999 on flooded lowland rice. Potassium fractions in municipal waste compost and cattle manure were determined by sequential extraction and also the potassium uptake by rice to compare the effectiveness of municipal waste compost with traditional manure. Potassium was significantly bound to the organic matter in municipal waste compost. Potassium uptake by rice grain and straw increased significantly with the combined application of organics and fertilizers and it was higher in grain than in straw. Water-soluble and non-exchangeable potassium contents of municipal waste compost and cattle manure were highly correlated with the uptake of potassium by straw and grain. Exchangeable and residual potassium were also significantly correlated with the uptake of potassium by straw and grain of rice. Much higher uptake of K in rice straw and rain resulted from applying the manures in conjunction with fertilizers than when applied singly.     

Secondhand smoke exposure at home and public places among smokers and non-smokers in India: findings from the Global Adult Tobacco Survey 2016–17

Environmental Science and Pollution Research - Secondhand smoke (SHS) accounts for 0.9 million deaths and 24 million disability adjusted life years (DALYs) annually. Nearly 30% of adults in India...     

Chromium uptake by rice and accumulation in soil amended with municipal solid waste compost

Effect of addition of municipal solid waste compost (MSWC) on chromium (Cr) content of submerged rice paddies was studied. Experiments were conducted during the three consecutive wet seasons from 1997 to 1999 on rice grown under submergence, at the Experimental Farm of Calcutta University, India. A sequential extraction method was used to determine the various chromium fractions in MSWC and cow dung manure (CDM). Chromium was significantly bound to the organic matter and Fe and Mn oxides in MSWC and CDM. Chromium content in rice straw was higher than in rice grain. Chromium bound with organic matter in MSWC best correlated with straw Cr (r=0.99**) followed by Fe and Mn oxides (r=0.97*) and water soluble as well as exchangeable fractions (r=0.96*). The water soluble and the exchangeable fractions in MSWC best correlated with grain Cr (r=0.98*). The Cr content of rice grain had the highest correlation with water soluble and exchangeable Cr (r=0.99**) while the straw Cr best correlated with the Fe and Mn oxides (r=0.98*). Both the carbonate bound and residual fractions in MSWC and CDM did not significantly correlate with rice straw and grain Cr. MSWC would be a valuable resource for agriculture if it can be used safely, but long-term use may require the cessation of the dumping by the leather tanneries and other major contributors of pollutants.     

Fractionation and bioavailability of metals and their impacts on microbial properties in sewage irrigated soil

A study was conducted to evaluate the effect of long-term irrigation of sewage contaminated with heavy metals like Cd, Cr, Cu and Pb on microbial and biochemical parameters of soils of West Bengal, India. The microbial parameters included microbial biomass carbon (MBC), microbial metabolic quotient; the biochemical parameters included fluorescein diacetate hydrolyzing activity, beta-glucosidase, urease, phosphatase, and aryl sulphatase activities. A sequential extraction technique was used to quantify water soluble, exchangeable, carbonate bound, Fe/Mn-oxide bound, organically bound, and residual metal fractions. Metal concentrations in the two most labile fractions (i.e., water soluble and exchangeable fractions) were generally low. Total metal concentrations at each site seemed to be associated with soil amorphous Fe and Al minerals. The MBC and the enzymes studied were significantly and negatively correlated with water soluble and exchangeable metals but not significantly correlated with other forms, indicating that water soluble and exchangeable forms exerted a strong inhibitory effect on the soil microbial and biochemical parameters. It was concluded that irrigating soils with metal contaminated sewage seemed to damage soil quality in the long term.     

Assessment of Godavari estuarine mangrove ecosystem through trace metal studies

Trace metals (Fe, Mn, Cu, Co, Ni. Pb, Cd and Cr) analyses in particulate matter and sediments were carried out at 16 different stations in the Godavari mangrove ecosystem covering the three regions viz., Kakinada (KKD) bay, Goutami-Godavari estuary (GGE) and Coringa and Gaderu mangrove environments (CGME). Higher concentrations of trace metals in particulate matter and in sediments were noticed in the mangrove environment compared to the KKD bay and GGE region. The significant correlations observed between several couples of metals in different regions as well as between numbers of heavy metals (Fe, Mn, Zn) with Total Suspended Matter (TSM) in particulate organic matter could be an indication of the role of the complexation with organic matter in the distribution pattern of these metals. Further significant correlations between organic carbon (OC) and Cr, Co, Pb, Cu and Mn in sediments of all the three regions indicate that organic matter acts as a metal carrier. The values of Pollution Load Index (PLI) were low and varied between 0.34 and 0.68 in KKD bay, 0.47 and 0.49 in GGE and, from 0.62 to 1.03 in CGME area, which indicate that the estuarine ecosystem is not of pollution concern under the present scenario.     

Effect of dimecron on the blood parameters of Heteropneustes fossilis

The effects of an organophosphate insecticide. dimecron. has been studied on certain haematological parameters, viz., haemoglobin concentration, RBC number, haematocrit, O2 carrying capacity of blood, etc. of Heteropneustes fossilis following exposures to the LC50 for 24 h and 96 h and 1/10 and 1/50 parts of 96 h LC50 for 90 days. There was a significant decrease in the Hb%, RBC number, HCt% and O2 carrying capcity of blood. But, there was significant increase in the MCH and MCV values following both acute and chronic exposures. The results indicate possible induction of anaemia in the exposed fish.     

Delineation of groundwater contamination around an ash pond: geochemical and GIS approach

The study has investigated the levels of metal contamination in groundwater due to particulate matter fallout and leaching from ash pond and assigned contamination indices for the adjacent localities around an ash disposal site with application of geographic information systems (GIS). Fe, Ba, Cu, Mn, S, Pb, V, and Zn were found to be the major contaminants in groundwater. Enrichment factors (EF) of these elements with respect to the United States Environmental Protection Agency (USEPA) maximum contaminant levels show high values for Mn, Fe, and Pb in groundwater. The zone of attenuation for Ba, Fe, Cu, Mn, S, and Zn in groundwater is about 600-900 m from the ash pond, while Pb did not show any significant attenuation even at a distance of 1200 m. Tube wells around Rankasingha and Kukurhanga villages are most contaminated whereas open wells of Lachhmanpur, Kaniapada, and Kurudul villages showed higher degrees of contamination.     

AUTOMATED WEB GIS BASED HYDROGRAPH ANALYSIS TOOL,WHAT1

The separation of the base flow component from a varying streamflow hydrograph is called “hydrograph analysis.” In this study, two digital filter based separation modules, the BFLOW and Eckhardt filters, were incorporated into the Web based Hydrograph Analysis Tool (WHAT) system. A statistical component was also developed to provide fundamental information for flow frequency analysis and time series analysis. The Web Geographic Information System (GIS) version of the WHAT system accesses and uses U.S. Geological Survey (USGS) daily streamflow data from the USGS web server. The results from the Eckhardt filter method were compared with the results from the BFLOW filter method that was previously validated, since measured base flow data were not available for this study. Following validation, the two digital filter methods in the WHAT system were run for 50 Indiana gaging stations. The Nash‐Sutcliffe coefficient values comparing the results of the two digital filter methods were over 0.91 for all 50 gaging stations, suggesting the filtered base flow using the Eckhardt filter method will typically match measured base flow. Manual separation of base flow from streamflow can lead to inconsistency in the results, while the WHAT system provides consistent results in less than a minute. Although base flow separation algorithms in the WHAT system cannot consider reservoir release and snowmelt that can affect stream hydrographs, the Web based WHAT system provides an efficient tool for hydrologic model calibration and validation. The base flow information from the WHAT system can also play an important role for sustainable ground water and surface water exploitation, including irrigation and industrial uses, and estimation of pollutant loading from both base flow and direct runoff. Thus, best management practices can be appropriately applied to reduce and intercept pollutant leaching if base flow contributes significant amounts of pollutants to the stream. This Web GIS based system also demonstrates how remote, distributed resources can be shared through the Internet using Web programming.     

Development,validation of QuEChERS-based method for simultaneous determination of multiclass pesticide residue in milk,and evaluation of the matrix effect

Extraction and quantification of pesticide residue from the milk matrix at or below the established maximum residue limit (MRL) is a challenging task for both analytical chemists and the regulatory institutions to take corrective actions for the human health and safety. The main aim of the study is to develop a simple rapid and less expensive QuEChERS extraction and cleanup method for simultaneous analysis of 41 multiclass pesticide residue in milk by gas chromatography-electron capture detector (GC-ECD), followed by confirmation of the residues with gas chromatography-mass spectrometer (GC-MS). Effect of sorbent type, temperature, spiking concentration, matrix effect (ME), measurement uncertainty (MU), inter- and intra-assay repeatability, reproducibility of recovery, and trueness of the results were investigated to validate the effectiveness of the method. Limit of determination (LOD) and limit of quantitation (LOQ) for all the analytes ranged within 0.001–0.02 and 0.002–0.05 µg mL^?1, respectively. The % recovery of all the pesticides ranged between 91.38 and 117.56% with relative standard deviation (RSD) below 2.79%. The MU for all the analytes was ≤29% of respective LOQs, and except for few pesticides, the ME was largely negative. The method fulfilled all the SANTE guidelines and thus can be extended for routine analysis of multiclass pesticide residue in milk.