Influence of soil type and extraction conditions on perchlorate analysis by ion chromatography

Perchlorate is a stable anion that has been introduced into the environment through activities related to its production and use as a solid rocket propellant. Perchlorate is thought to transport through soils without being adsorbed; thus, for determination of perchlorate in soil, samples are typically extracted with water prior to analysis. The completeness of extraction depends on perchlorate existing as a free ion within the soil matrix. In this study, perchlorate extraction efficiency was evaluated with five soil types under two different oxygen states. For each soil, 30% (w/w) slurries were prepared and equilibrated under either oxic or anoxic conditions prior to spiking with a stock solution of sodium perchlorate, and the slurries were then maintained for 1-week or 1-month. At the end of the exposure, slurries were centrifuged and separated into aqueous and soil phases. After phase separation, the soil was washed first with deionized water and then with 50mM NaOH, producing second and third aqueous phases, respectively. Perchlorate concentrations in the three aqueous phases were determined using ion chromatography. The results obtained from this study suggest that matrix interference and signal suppression due to high conductivity have greater effects upon observed perchlorate concentrations by ion chromatography than does perchlorate interaction with soil. Thus, a single water extraction is sufficient for quantitative determination of perchlorate in soil.     

Inhibition of nitrification in soil by metal diethyldithiocarbamates

IntroductionNitrificationisaprocessinwhichammoniumformofnitrogenisconvertedintonitrateform .Nitrogenuseefficiencyintermsofplantuptakeisgenerallylowandvariesgreatlyunderdifferentsoilandcroppingconditions.MostfertilizerNappliedtosoilsisintheformofammonium orammoniumproducingcompoundssuchasurea,andisusuallyoxidizedrapidlytonitratebynitrifyingmicroorganismsinsoils.Applicationofnitrogenfertilizersmorethanoptimumlevelsleadstolownitrogenrecoveriesandgreaternitrogenaccumulationinthesoilprofile .Theac…     

Treatment of distillery spent-wash by ozonation and biodegradation: significance of pH reduction and inorganic carbon removal before ozonation.

This study is aimed at exploring strategies for mineralization of refractory compounds in distillery effluent by anaerobic biodegradation/ozonation/aerobic biodegradation. Treatment of distillery spent-wash used in this research by anaerobic-aerobic biodegradation resulted in overall COD removal of 70.8%. Ozonation of the anaerobically treated distillery spent-wash was carried out as-is (phase I experiments) and after pH reduction and removal of inorganic carbon (phase II experiments). Introduction of the ozonation step resulted in an increase in overall chemical oxygen demand (COD) removal, with the highest COD removals of greater than 95% obtained when an ozone dose of approximately 5.3 mg ozone absorbed/mg initial total organic carbon was used. The COD removal during phase II experiments was slightly superior compared with phase I experiments at similar ozone doses. Moreover, efficiency of ozone absorption from the gas phase into distillery spent-wash aliquots was considerably enhanced during phase II experiments.     

Water-holding capacity of earthworms’ vermicompost made of sugar industry waste (press mud) in mono- and polyculture vermireactors

Efforts were made to recycle sugar industry waste ‘press mud’ (PM) with an objective to ascertain the water-holding capacities with monoculture vermireactor systems using Eisenia fetida (MVR1); Eudrilus eugeniae (MVR2); Megascolex megascolex (MVR3); and polyculture vermireactor systems using Eisenia fetida + Eudrilus eugeniae (PVR1); Eisenia fetida + Megascolex megascolex (PVR2); Eudrilus eugeniae + Megascolex megascolex (PVR3). The vermicompost harvested after 40 days was subjected to a standard Proctor compaction test by using 3 kg industry soil and 200 g of vermicompost for each cycle of compaction up to seven cycles. The least dry density and highest water content 0.6, 170%; 0.66, 170%; 0.71, 170% and 0.52, 210%; 0.51, 180%; 0.71, 150% for vermicomposts of MVR3, MVR2, MVR1 and PVR3, PVR2, PVR1, respectively. The monoculture reactor using Megascolex megascolex can hold 110–170% and polyculture vermireactor using indigenous Megascolex megascolex + Eudrilus eugeniae (PVR3) can hold 140–210% of water under experimental conditions. The species Megascolex megascolex used individually and in combinations with Eudrilus eugeniae are best suited for biodegradation of press mud, and composts derived are having increase water-holding capacities. The addition of VC to the soil increases water-holding capacity and by maintaining evaporation losses to minimum as good adsorbent of atmospheric moisture eventually helps in maintaining the ecology of hydrologic cycle. Increasing water-holding capacity is one of the soil erosion control measures that influences soil productivity in both managed and natural ecosystems.     

Prediction of groundwater nitrate concentration in a semiarid region using hybrid Bayesian artificial intelligence approaches

Environmental Science and Pollution Research - Nitrate is a major pollutant in groundwater whose main source is municipal wastewater and agricultural activities. In the present study, Bayesian...     

Projections of highway vehicle population,energy demand,and CO2 emissions in India to 2040

This paper presents projections of motor vehicles, oil demand, and carbon dioxide (CO₂) emissions for India through the year 2040. The populations of highway vehicles and two‐wheelers are projected under three different scenarios on the basis of economic growth and average household size in India. The results show that by 2040, the number of highway vehicles in India would be 206‐309 million. The oil demand projections for the Indian transportation sector are based on a set of nine scenarios arising out of three vehicle‐growth and three fuel‐economy scenarios. The combined effects of vehicle‐growth and fuel‐economy scenarios, together with the change in annual vehicle usage, result in a projected demand in 2040 by the transportation sector in India of 404‐719 million metric tons (8.5‐15.1 million barrels per day). The corresponding annual CO₂ emissions are projected to be 1.2‐2.2 billion metric tons.     

Artificial intelligence as a fundamental tool in management of infectious diseases and its current implementation in COVID-19 pandemic

Environmental Science and Pollution Research - The world has never been prepared for global pandemics like the COVID-19, currently posing an immense threat to the public and consistent pressure on...     

Pertinence of nutriments for a stalwart body

Environmental Science and Pollution Research - Nutrition plays a significant role in the prevention and treatment of common diseases. Some superb dietary choices such as functional foods and...