Future trends in computer waste generation in India

The objective of this paper is to estimate the future projection of computer waste in India and to subsequently analyze their flow at the end of their useful phase. For this purpose, the study utilizes the logistic model-based approach proposed by Yang and Williams to forecast future trends in computer waste. The model estimates future projection of computer penetration rate utilizing their first lifespan distribution and historical sales data. A bounding analysis on the future carrying capacity was simulated using the three parameter logistic curve. The observed obsolete generation quantities from the extrapolated penetration rates are then used to model the disposal phase. The results of the bounding analysis indicate that in the year 2020, around 41–152 million units of computers will become obsolete. The obsolete computer generation quantities are then used to estimate the End-of-Life outflows by utilizing a time-series multiple lifespan model. Even a conservative estimate of the future recycling capacity of PCs will reach upwards of 30 million units during 2025. Apparently, more than 150 million units could be potentially recycled in the upper bound case. However, considering significant future investment in the e-waste recycling sector from all stakeholders in India, we propose a logistic growth in the recycling rate and estimate the requirement of recycling capacity between 60 and 400 million units for the lower and upper bound case during 2025. Finally, we compare the future obsolete PC generation amount of the US and India.     

Estimation of future outflows of e-waste in India

The purpose of this study is to construct an approach and a methodology to estimate the future outflows of electronic waste (e-waste) in India. Consequently, the study utilizes a time-series multiple lifespan end-of-life model proposed by Peralta and Fontanos for estimating the current and future quantities of e-waste in India. The model estimates future e-waste generation quantities by modeling their usage and disposal. The present work considers two scenarios for the approximation of e-waste generation based on user preferences to store or to recycle the e-waste. This model will help formal recyclers in India to make strategic decisions in planning for appropriate recycling infrastructure and institutional capacity building. Also an extension of the model proposed by Peralta and Fontanos is developed with the objective of helping decision makers to conduct WEEE estimates under a variety of assumptions to suit their region of study. During 2007–2011, the total WEEE estimates will be around 2.5 million metric tons which include waste from personal computers (PC), television, refrigerators and washing machines. During the said period, the waste from PC will account for 30% of total units of WEEE generated.     

Photocatalytic formation of hydrogen peroxide over highly porous illuminated ZnO and TiO2thin film

The photocatalytic formation of hydrogen peroxide over ZnO and TiO₂thin films has been investigated in aqueous phase in the presence of molecular oxygen as an electron acceptor. These films are highly porous and showed enhanced catalytic activity in the photochemical formation of hydrogen peroxide. The amount of H₂O₂formed during 2 hour light illumination is 4–6 μM and the rates of formation of hydrogen peroxide of both the films are almost comparable. The yield of hydrogen peroxide increases with the increase in irradiation time and a trend of steady state concentration of H₂O₂is observed in the case of TiO₂thin film. Photodissolution of ZnO particles is observed in some extent during the process of prolonged UV light illumination.     

Essential oils and their bioactive compounds as green preservatives against fungal and mycotoxin contamination of food commodities with special reference to their nanoencapsulation

Environmental Science and Pollution Research - Fungal and mycotoxin contamination of stored food items is of utmost concern throughout the world due to their hazardous effects on mammalian systems....     

Survival of bio-inoculants on fungicides-treated seeds of wheat,pea and chickpea and subsequent effect on chickpea yield

Survival of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (CBD-15 and M₄) was tested on chickpea (Cicer arietinum) seeds treated with fungicides bavistin [methyl N-(1H-benzimidazol-2yl) carbamate] and thiram (tetramethyl-thiuram disulfide), whereas survival of phosphate solubilizing bacteria (PSB), Pseudomonas striata (27) and Bacillus polymyxa (H₅) was examined on two cultivars (Arkel and BV) of pea (Pisum sativum) seeds treated with thiram. Viability of Azotobacter chroococcum (W₅) was also examined on wheat (Triticum aestivum) seeds treated with bavistin, captan (cis-N-trichloromethyl thio-4 cyclohexane-1, 2-dicarboximide) and thiram under laboratory conditions using standard dilution and the plate count technique. All the tested strains of diazotrophs and PSB showed decline in their viable population on prolonged contact with fungicides. However, PSB showed variation in their viable population even with the cultivar.

BV cultivar of pea seeds showed better recovery of viable P. striata (10.75 to 10.61 log no. of viable cells with in 0-24 hrs) in the presence of thiram, whereas the Arkel cultivar of pea resulted in better recovery of viable B. polymyxa. Azotobacter chroococcum (W₅), a potential strain for wheat, showed better survival in the presence of bavistin, compared to thiram and captan. Higher viable population of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (M₄) was recovered from chickpea seeds treated with bavistin compared to thiram. However, thiram-treated seeds resulted in a greater number of extractable Azotobacter chroococcum (CBD-15). Under field conditions, adverse effect of thiram was reflected on the performance of Mesorhizobium ciceri (SP₄) and A. chroococcum (M₄) strains, resulting in reduced root and shoot biomass and grain yield, compared to bavistin treated and culture inoculated treatment. CBD-15 showed better performance in the presence of thiram compared to bavistin.     

Survival of bio-inoculants on fungicides-treated seeds of wheat, pea and chickpea and subsequent effect on chickpea yield

Survival of Mesorhizobium ciceri (SP(4)) and Azotobacter chroococcum (CBD-15 and M(4)) was tested on chickpea (Cicer arietinum) seeds treated with fungicides bavistin [methyl N-(1H-benzimidazol-2yl) carbamate] and thiram (tetramethyl-thiuram disulfide), whereas survival of phosphate solubilizing bacteria (PSB), Pseudomonas striata (27) and Bacillus polymyxa (H(5)) was examined on two cultivars (Arkel and BV) of pea (Pisum sativum) seeds treated with thiram. Viability of Azotobacter chroococcum (W(5)) was also examined on wheat (Triticum aestivum) seeds treated with bavistin, captan (cis-N-trichloromethyl thio-4 cyclohexane-1, 2-dicarboximide) and thiram under laboratory conditions using standard dilution and the plate count technique. All the tested strains of diazotrophs and PSB showed decline in their viable population on prolonged contact with fungicides. However, PSB showed variation in their viable population even with the cultivar. BV cultivar of pea seeds showed better recovery of viable P. striata (10.75 to 10.61 log no. of viable cells with in 0-24 hrs) in the presence of thiram, whereas the Arkel cultivar of pea resulted in better recovery of viable B. polymyxa. Azotobacter chroococcum (W(5)), a potential strain for wheat, showed better survival in the presence of bavistin, compared to thiram and captan. Higher viable population of Mesorhizobium ciceri (SP(4)) and Azotobacter chroococcum (M(4)) was recovered from chickpea seeds treated with bavistin compared to thiram. However, thiram-treated seeds resulted in a greater number of extractable Azotobacter chroococcum (CBD-15). Under field conditions, adverse effect of thiram was reflected on the performance of Mesorhizobium ciceri (SP(4)) and A. chroococcum (M(4)) strains, resulting in reduced root and shoot biomass and grain yield, compared to bavistin treated and culture inoculated treatment. CBD-15 showed better performance in the presence of thiram compared to bavistin.