Shakeel A. Khan

Climate Change, Climate Variability and Indian Agriculture: Impacts Vulnerability and Adaptation Strategies

Climate is changing naturally at its own pace, since the beginning of the evolution of earth, 4–5 billion years ago, but presently, it has gained momentum due to inadvertent anthropogenic disturbances. These changes may culminate in adverse impact on human health and the biosphere on which we depend. The multi-faceted interactions among the humans, microbes and the rest of the biosphere, have started reflecting an increase in the concentration of greenhouse gases (GHGs) i.e. CO2, CH4 and N2O, causing warming across the globe along with other cascading consequences in the form of shift in rainfall pattern, melting of ice, rise in sea level etc. The above multifarious interactions among atmospheric composition, climate change and human, plant and animal health need to be scrutinized and probable solutions to the undesirable changes may be sought.

A review of emerging adsorbents and current demand for defluoridation of water: Bright future in water sustainability

Fluoride contamination of groundwater is a serious problem in several countries of the world because of the intake of excessive fluoride caused by the drinking of the contaminated groundwater. Geological and anthropogenic factors are responsible for the contamination of groundwater with fluoride. Excess amounts of fluoride in potable water may cause irreversible demineralisation of bone and tooth tissues, a condition called fluorosis, and long-term damage to the brain, liver, thyroid, and kidney. There has long been a need for fluoride removal from potable water to make it safe for human use. From among several defluoridation technologies, adsorption is the technology most commonly used due to its cost-effectiveness, ease of operation, and simple physical process. In this paper, the adsorption capacities and fluoride removal efficiencies of different types of adsorbents are compiled from relevant published data available in the literature and represented graphically. The most promising adsorbents tested so far from each category of adsorbents are also highlighted. There is still a need to discover the actual feasibility of usage of adsorbents in the field on a commercial scale and to define the reusability of adsorbents to reduce cost and the waste produced from the adsorption process. The present paper reviews the currently available methods and emerging approaches for defluoridation of water.

GIS-based evaluation of groundwater geochemistry and statistical determination of the fate of contaminants in shallow aquifers from different functional areas of Agra city, India: levels and spatial distributions

The quality of groundwater is very important in Agra because groundwater is the main source of water for drinking, domestic, agricultural and industrial uses. A groundwater geochemistry study was conducted in Agra where 28 samples were collected from shallow aquifers in May 2016 from different sites. The aim of this research was to assess the quality of groundwater for drinking purposes in the study area. Arc-GIS has been used to prepare geographic information system-based spatial distribution maps of different major elements. The groundwater quality was analyzed for various physico-chemical parameters, major cations and anions and some trace metals. The observed values were compared with BIS and WHO standards. Statistical parameters such as the mean, median, standard deviation, skewness and kurtosis were used to analyze the hydrogeochemical characteristics of the groundwater. Correlation coefficient analysis and principal component analysis (PCA) were performed to identify the sources of the water constituents. Our results showed that most of the samples exceeded the acceptable limit for drinking water standards. The sequence of abundance of the main cations was generally Na+ > Ca2+ > Mg2+ > K+, while the anions in order of abundance were HCO3− > Cl− > SO42− and NO3− > F−. All of the trace metals were within the permissible limit except for iron and manganese. The hazard index value of 5.7 × 10−2 indicated that there was no potential health risk in the study area. Ca2+, Mg2+, Cl− and SO42− were the dominant hydrogeochemical facies in the majority of the groundwater samples. Most of the parameters such as TDS, Cl−, HCO3−, SO42−, NO3−, Ca2+, Mg2+, Na+, K+ and TH showed strong correlations with each other, which were due to natural processes such as weathering, exchangeable ions and reduction/oxidation, as well as anthropogenic activity around the study area. The water quality index indicated that the water quality was poor at 46.43% of the sampling sites, very poor at 28.57% of the sites and unsuitable for drinking purposes at 25% of the sampling sites. Gibbs diagrams suggested rock weathering as a major driving force for controlling the groundwater chemistry in the study area, along with evaporation as a minor influence.

Impacts of Biogas Slurry Application on Soil Environment, Yield and Nutritional Quality of Baby Corn

Large amount of biogas slurry is pro-duced in India and their disposal is a major con-cern for the environment. So resource utilization of biogas slurry appears to be prospective and obligatory for now days. This study investigates the potential use of by-products of biogas pro-duction, i.e. biogas slurry (BGS) from agricultural waste treatment, as nutrient sources in agricul-ture. The BGS contain considerable amounts of plant nutrients, their use as soil amendment may improve crop production and physical properties of soil by preventing adverse environmental im-pacts of chemical fertilizers and waste disposal. Thus, field trials were conducted in 2013–2014 indicating that 50% BGS along with 50% chemi-cal fertilizer gave 20% more yield in terms of cob as well as biomass. Combination of BGS and N fertilizer increase protein and total sugar content of the baby corn cob up to almost 100% and 41% respectively over control. There was en-hancement in the organic matter, bulk density and porosity of soil matter in the soil after BGS application. It indicates that BGS in combination with fertilizers (1: 1) should be used as soil sup-plement for production increments and soil ame-lioration.