Renewable energy programmes in India

There is increasing optimism regarding the possible role that renewable energy technologies can play in the coming decade in the energy sector in India. Some recent developments and trends within the renewable energy sector that are responsible for this optimism, and the likely investments of the order of US$1210 million in the next four to five years, are discussed. The paper includes discussion of the recent changes in the implementing institutions, innovation in financing renewable technology investments, and a shift from financial to fiscal incentives. In addition, wind power generation, small hydro, photovoltaic and gasifier programmes are analysed in some detail.     

Analyzing composition and generation rates of biomedical waste in selected hospitals of Uttarakhand,India

In India, a few studies have been conducted for analyzing the generation rates and composition of medical waste (MW). Inadequate information about the amount and composition of MW results in ineffective management practices. The present study seeks to evaluate healthcare waste (HCW) generation rates by healthcare facilities (HCFs) available in Uttarakhand, a northern state of India. Study also focuses on modeling the quantity of different types of MW generated at various HCFs and determining significant factors contributing towards MW generation. Seasonal variation in amount of MW generated from various HCFs has also been considered. To achieve these objectives, cross-sectional as well as longitudinal data have been collected from various HCFs in Uttarakhand, India. The survey revealed that around 36% of the total HCFs did not segregate their MW as per policy guidelines. Cross-sectional data for May 2015 were collected from 75 HCFs to analyze and model the composition and quantity of HCW generated. Multiple Linear Regression and Artificial Neural Network techniques were applied to model cross-sectional data. In the composition of the overall MW, ‘yellow waste’ carries the maximum share, followed by ‘red waste’ and then the ‘blue waste’. In addition, the ‘type of HCF’ and ‘bed occupancy’ have been modeled as the important factors, contributing towards the MW generations rates. Longitudinal data for 2 years (2013 and 2014) were collected to examine seasonal variation in HCW generation rates using polynomial regression analysis. Result shows that MW quantity also varies with the change in the season. Findings of the study will help hospitals and waste treatment facilities to predict amount of waste that may be generated, and plan resources towards efficient handling and disposal of MW.     

Analysis of a solar still with photovoltaic modules and electrical heater - Energy and exergy approach

The availability of drinkable water, along with food and air, is a fundamental human necessity. Because of the presence of higher amounts of salt and pollution, direct use of water from sources such as lakes, sea, rivers, and subsurface water reservoirs is not normally suggested. Solar is still a basic technology that can use solar energy to transform accessible waste or brackish water into drinkable water. Exergy analysis is a strong inferential technique for evaluating the performance of thermal systems. Exergy is becoming more popular as a predictive tool for analysis, and there is a rising interest in using it. In this paper, performance analysis on the aspect of energy and exergy from the proposed solar still (PSS) (conventional solar still with the photovoltaic modules-AC heater) was analyzed on three different water depths (W_d) conditions (1, 2, and 3 cm). Using a solar still with an electric heater, the daily potable water production was found as 8.54, 6.37, and 4.43 kg, for the variations in water depth (W_d) of 1, 2, and 3 cm respectively. The energy and exergy efficiency of the PSS at the W_d of 1, 2, and 3 cm were 75.67, 51.45, and 37.21% and 5.08, 2.29, and 1.03%, respectively. At 1 cm W_d, PSS produced the maximum freshwater yield as compared to the other two water depths. When the W_d is increased from 1 to 2 cm and from 1 to 3 cm, the yield is decreased up to 27.3 and 52.7%, respectively. Similarly, the energy and exergy efficiency is decreased up to 36.8 and 53.2% and 50.4 and 80.6%, respectively. The water cost of the modified solar still is calculated as 0.028 $/kg for the least water thickness.

     

Virtual landscape-scale restoration of altered channels helps us understand the extent of impacts to guide future ecosystem management

Human modification of hydrological connectivity of landscapes has had significant consequences on ecosystem functioning. Artificial drainage practices have fundamentally altered northern landscapes, yet these man made channels are rarely considered in ecosystem management. To better understand the effects of drainage ditches, we conducted a landscape-scale analysis across eleven selected study regions in Sweden. We implemented a unique approach by backfilling ditches in the current digital elevation model to recreate the prehistoric landscape, thus quantifying and characterizing the channel networks of prehistoric (natural) and current (drained) landscapes. Our analysis detected that 58% of the prehistoric natural channels had been converted to ditches. Even more striking was that the average channel density increased from 1.33 km km⁻² in the prehistoric landscape to 4.66 km km⁻² in the current landscape, indicating the extent of ditching activities in the northern regions. These results highlight that man-made ditches should be accurately mapped across northern landscapes to enable more informed decisions in ecosystem management.     

Photoelectrocatalytic systems for simultaneous energy recovery and wastewater treatment: a review

Environmental Chemistry Letters - The rising energy conflicts and environmental pollution are calling for the rapid development of advanced techniques such as photoelectrocatalysis to...     

Groundwater: a regional resource and a regional governance

Groundwater is a valuable renewable resource for human life. The two major threatening issues being faced by groundwater are its depletion and degradation which affect both the quantity and the quality of groundwater. Though scientific output has progressed well ahead in the domain of groundwater, very little has been done with respect to the establishment of the groundwater governance framework. Groundwater is perceived as a widely distributed resource, but it is fundamentally a local entity. The paper presents the groundwater governance framework from the regional perspective of Fatehgarh Sahib district of Punjab, India—an over-exploited groundwater region.     

A review about COVID-19 in the MENA region: environmental concerns and machine learning applications

Environmental Science and Pollution Research - Coronavirus disease 2019 (COVID-19) has delayed global economic growth, which has affected the economic life globally. On the one hand, numerous...     

Global methane emissions from the world coal industry

The Coal Industry Advisory Board (CIAB) of the International Energy Agency (IEA) estimated the total methane emissions from worldwide mining, treatment and storage of coal to be approximately 25 million tonnes/year for 1990. Slightly more than one million tonnes of methane are utilized by the industry. Thus, the net annual discharge to the atmosphere is 24 million tonnes. Methane emissions data were available for the U.S., the U.K., former U.S.S.R., Australia, China, Germany, Poland and Czechoslovakia. Methane emissions for India and S. Africa were estimated from a linear correlation between the average depth of mining and specific methane emissions derived from the available data for the eight countries. These ten largest coal producing countries represented nearly 90% of world coal production in 1990. Total methane emissions for the world coal industry were calculated by prorating the methane emissions from these ten countries in proportion to coal production.The reported values represent the best international data available at present. The net total emissions of 24 million tonnes/year are substantially less than some previously reported indirect estimations and constitute only 4 to 6% of the global methane emissions.     

Molecular/chemical ecology in sponges: evidence for an adaptive antibacterial response in<Emphasis Type="Italic"> Suberites domuncula</Emphasis>

Sponges (Porifera) represent the evolutionary oldest metazoan phylum still extant today. They have developed a complex Bauplan, based on the existence of structural and regulatory molecules; many of these have been cloned and analyzed in the past years. The demosponge Suberites domuncula has been used as a suitable model to demonstrate that these animals not only possess an adaptive immune response on the level of cytokines, but also, as pointed out here, on the level of synthesis of bioactive alkyl-lipid derivatives. From specimens of S. domuncula the two lyso-PAF (platelet-activating factor) compounds, 1-O-hexadecyl-sn-glycero-3-phosphocholine and 1-O-octadecyl-sn-glycero-3-phosphocholine, have been identified and characterized. These two lyso-PAFs showed pronounced anti-bacterial activity. In the central part of this paper it is shown that the level of synthesis of the lyso-PAF congeners increased in response to the model compound, the endotoxin lipopolysaccharide (LPS). Treatment of the tissue with LPS for 72 h substantially increased the synthesis. In order to prove that the lyso-PAFs are really synthesized by the sponge, the key enzyme of the alkyl-dihydroxyacetonephosphate pathway, i.e. alkyl-dihydroxyacetonephosphate synthase (ADS), was cloned from S. domuncula. This sponge enzyme comprises the characteristic features of metazoan ADS enzymes; it is increasingly expressed in the tissue and in the in vitro cell culture system after exposure to LPS. These data are taken as a strong indication that bioactive, low-molecular weight, non-proteinaceous lipid derivatives function in an adaptive manner in response to the endotoxin.Communicated by R. Cattaneo-Vietti, Genova     

Rapid measurement of indoor mass-transfer coefficients

Indoor air pollutant concentrations can be influenced by how rapidly species are transported to and from surfaces. Consequently, a greater understanding of indoor transport phenomena to surfaces improves estimates of human exposure to indoor air pollutants. Here, we introduce two methods of rapidly and directly measuring species fluxes at indoor surfaces, allowing us to evaluate the transport-limited deposition velocity, v_t (a mass-transfer coefficient). The deposition velocity sensor (DeVS) method employs a small microbalance coated with a pure hydrocarbon, preferably octadecane. We quantify flux (or evaporation rate) of the hydrocarbon into a room by observing the rate of mass loss on the microbalance. The transport-limited deposition velocity, v_t,octadecane, is then obtained by combining the flux with the vapor pressure of the hydrocarbon. Simultaneously, v_t,ozone is quantified using the deposition velocity of ozone (DeVO) method, which acts as a standard to calibrate and evaluate DeVS. Specifically, DeVO evaluates ozone transport to surfaces by quantifying the conversion by ozone of nitrite to nitrate on a glass fiber filter. Simultaneous laboratory chamber experiments demonstrates that v_t for octadecane and ozone are strongly correlated, with the values for ozone 1.5 times greater than that for octadecane. In an office experiments, the DeVS method responds within minutes to step changes in conditions such as occupancy, activities and ventilation. At present, the results are in order-of-magnitude agreement with predicted indoor mass-transfer coefficients.