Analysis and optimization on the biodegradable plate making process parameters using RSM-based Box–Behnken Design method

Journal of Material Cycles and Waste Management - The present research work focused on fabricating Biodegradable Plate (BD plate) composed of rice husk ash, bagasse and corn starch which is...     

Seasonal variations in physico-chemical characteristics of River Yamuna in Haryana and its ecological best-designated use

Various physico-chemical characteristics of the River Yamuna flowing in Haryana through Delhi were studied in the summer (April 1998) and winter (Jan.-Feb. 1999). Ecological parameters like dissolved oxygen (DO), pH, nitrate (NO3-), sulfate (SO4(2-)), and phosphate (PO4(3-)), were analyzed and compared with standard permissible limits to assess the best-designated use of the river water for various purposes. The river in Delhi upstream was of better quality whereas the Delhi downstream stretch was polluted as indicated by very low DO and high total dissolved solids (TDS), electric conductivity (EC), total hardness, Na+, K+, Cl-, F- and SO4(2-). The differences in various parameters were statistically significant (p < 0.01) when compared for the Delhi upstream and downstream stretches of the river, particularly in summer. DO and TDS were found to be two important parameters, which showed strong correlation with several other parameters and hence can serve as good indices of river water quality. The river tended to recover from the pollution stress after flowing through a distance of about 80 km downstream of Delhi.     

Intra-monsoonal variation of zooplankton population in the Sundarbans Estuarine System,India

The present study was conducted during July 2013 (early phase of monsoon or EM) and September 2013 (later phase of monsoon or LM) to ascertain the intra-monsoonal variation on zooplankton, by selecting 15 study stations in the river Saptamukhi, one of the main estuaries in the Sundarbans Estuarine System (SES). In 2013, SES experienced an unusually high monsoonal rainfall also exacerbated by cloud burst event at Himalayan region (upper stretches of SES) which tremendously increased the river runoff. The present work was aimed to decipher the effect of this unusual precipitation during the monsoon season on zooplankton assemblages along with different hydrological parameters. The abundance of zooplankton was recorded as lower during EM compared to LM. Altogether, 56 zooplankton taxa were identified with copepods forming the predominant population. Thirty-three copepod species were reported with 25 calanoid species forming the bulk of the biomass followed by 5 and 3 species of cyclopoids and harpacticoid, respectively. A combination of multivariate cluster analysis, biotic indices, and canonical correspondence analysis revealed noticeable alterations in the zooplankton community structure across the spatio-temporal scale. Furthermore, significant intra-monsoonal changes in zooplankton population correlated with several hydrological parameters were clearly noticed. Paracalanus parvus, Bestiolina similis and Oithona similis were observed to be the most dominant copepod species in both sampling periods. The result of the present study provides new insight on estuarine zooplankton community after unusual rainfall during monsoon season, and provides further evidence to support the conservation and management of the SES ecosystem.     

Shell repair in Nautilus macromphalus

The shell of Nautilus macromphalus, like that of N. pompilius, consists of an outer spherulitic-prismatic layer, a middle nacreous layer, and an inner semiprismatic layer. No periostracum was observed. When an area of shell 2 cmx2 cm over the living chamber was removed experimentally, it was replaced by shell of normal structure. Regeneration required 45 days. Observations of regenerated shell made with a scanning electron microscope showed that the spherulitic portion of the spherulitic-prismatic layer was formed from crystal grains that developed into spherulites. The nacreous layer was formed by the deposition of stacks of hexagonal crystals which, through lateral growth, made contact with crystals in adjoining stacks and formed continuous layers 1 crystal in thickness. The deposition of all the shell layers during regeneration was probably accomplished by a single mantle region rather than by different mantle regions as in normal shell growth.     

Groundwater purification by membrane technology

Hyperfiltration and nanofiltration membranes were tested with different water matrices for the removal of excess fluoride from underground water. Initially, the experiments were done with synthetic samples prepared by adding known amounts of sodium fluoride and calcium chloride in distilled water. The effect of feed water composition, pH, temperature of feed water, operating pressure, and feed water flow rate on separation efficiency of both types of membrane was studied by varying one parameter at a time and keeping all other parameters constant. Thus, the optimum operating conditions for the process were determined and after that ground water samples collected from three villages of district Gurgaon, Haryana, India (Farukhnagar, Wazirpur, and Mevka) were treated under optimum operational conditions. The mass transfer coefficient and membrane parameters were estimated for each data point using two-parameter model (Film theory and Solution-diffusion model) to study the concentration polarization on membrane surface. The nanofiltration membrane showed high percentage rejection of bivalent ions when compared to monovalent ions in a binary system. But in multicomponent system, when fluoride and calcium coexisted, the removal of fluoride was comparable to calcium removal because of the low solubility product of calcium fluoride. The results with RO membrane revealed that it removes practically all the ions present in water at high pressure, which need to be passed through a lime column to remineralize the water, to make it suitable for drinking purposes, whereas by running the system at low pressure which will further reduce the cost of operation, rejection percentage goes down to get permeate of required quality.     

Carbon storage versus fossil fuel substitution: a climate change mitigation option for two different land use categories based on short and long rotation forestry in India

Short rotation bioenergy crops for energy production are considered an effective means to mitigate the greenhouse effect, mainly due to their ability to substitute fossil fuels. Alternatively, carbon can be sequestered and stored in the living biomass. This paper compares the two land use categories (forest land and non-forest land) for two management practices (short rotation vs. long rotation) to study mitigation potential of afforestation and fossil fuel substitution as compared to carbon storage. Significant carbon benefit can be obtained in the long run from using lands for growing short rotation energy crops and substituting fossil fuels by the biomass thus produced, as opposed to sequestering carbon in the biomass of the trees. When growth rates are high and harvest is used in a sustainable manner (i.e., replanting after every harvest), the opportunities for net carbon reductions appear to be fossil fuel substitution, rather than storage in ecosystem biomass. Our results suggest that at year 100 a total of 216 Mg C ha⁻¹ is sequestered for afforestation/reforestation using long rotation sal (Shorea robusta Gaertn.f) species, as opposed to offset of 412 Mg C ha⁻¹ for carbon storage and fossil fuel substitution for short rotation poplar (Populus Deltoides Marsh) plantations. The bioenergy option results in a continuous stream of about 3 Mg C ha⁻¹ yr⁻¹ of carbon benefits per year on forest land and 4 Mg C ha⁻¹ yr⁻¹ on non-forest land. Earlier studies have shown that in India waste land availability for establishing energy plantations is in the range of 9.6 to 36.5 Mha. Thus, using the 758 Tg biomass per year generated from 9.6 Mha waste land gives a mitigation potential in the range of 227 to 303 Tg C per year for carbon storage and fossil fuel substitution from poplar plantation for substituting coal based power generation. Depending upon the land availability for plantation, the potential for energy generation is in the range of 11,370 PJ, possibly amounting to a bioenergy supply of 43% of the total projected energy consumption in 2015. Further studies are needed to estimate the mitigation potential of other species with different productivities for overall estimation of the economic feasibility and social acceptability in a tropical country like India.     

Arsenic testing field kits: some considerations and recommendations

In recent years field test kits have been largely used to identify arsenic (As) levels in contaminated water sources in Bangladesh, West Bengal (India), and elsewhere in the world to establish whether or not the water is safe. Most of the kits are based on the reaction of arsine gas with some chemical agent to form a coloured complex; the intensity of the colour is compared visually with a colour-coded chart or measured electronically to calculate the concentration of As in the water sample. In this paper, a step-wise review is presented of the analytical process used in the most commonly available As field test kits and the associated shortcomings of each of these kits. We also identify the research gaps for future work to enhance the accuracy and reliability of test results produced by these kits.     

Carbon storage and sequestration potential of selected tree species in India

A dynamic growth model (CO2FIX) was used for estimating the carbon sequestration potential of sal (Shorea Robusta Gaertn. f.), Eucalyptus (Eucalyptus Tereticornis Sm.), poplar (Populus Deltoides Marsh), and teak (Tectona Grandis Linn. f.) forests in India. The results indicate that long-term total carbon storage ranges from 101 to 156 Mg C?ha^?1, with the largest carbon stock in the living biomass of long rotation sal forests (82 Mg C?ha^?1). The net annual carbon sequestration rates were achieved for fast growing short rotation poplar (8 Mg C?ha^?1?yr^?1) and Eucalyptus (6 Mg C?ha^?1?yr^?1) plantations followed by moderate growing teak forests (2 Mg C?ha^?1?yr^?1) and slow growing long rotation sal forests (1 Mg C?ha^?1?yr^?1). Due to fast growth rate and adaptability to a range of environments, short rotation plantations, in addition to carbon storage rapidly produce biomass for energy and contribute to reduced greenhouse gas emissions. We also used the model to evaluate the effect of changing rotation length and thinning regime on carbon stocks of forest ecosystem (trees?+?soil) and wood products, respectively for sal and teak forests. The carbon stock in soil and products was less sensitive than carbon stock of trees to the change in rotation length. Extending rotation length from the recommended 120 to 150 years increased the average carbon stock of forest ecosystem (trees?+?soil) by 12%. The net primary productivity was highest (3.7 Mg ha^?1?yr^?1) when a 60-year rotation length was applied but decreased with increasing rotation length (e.g., 1.7 Mg ha^?1?yr^?1) at 150 years. Goal of maximum carbon storage and production of more valuable saw logs can be achieved from longer rotation lengths. ‘No thinning’ has the largest biomass, but from an economical perspective, there will be no wood available from thinning operations to replace fossil fuel for bioenergy and to the pulp industry and such patches have high risks of forest fires, insects etc. Extended rotation lengths and reduced thinning intensity could enhance the long-term capacity of forest ecosystems to sequester carbon. While accounting for effects of climate change, a combination of bioenergy and carbon sequestration will be best to mitigation of CO₂ emission in the long term.     

Construction of ternary (1D/2D/3D) Fe2O3-supported micro pillared Cu-based MOF on chitosan with improved photocatalytic behavior on removal of paraquat

Environmental Science and Pollution Research - A hetero-structured metal organic framework of Cu-BTC and Fe2O3 nano-photocatalyst were tethered over chitosan using the hydrothermal method and...     

Hepato and nephrotoxicity in rat exposed to endosulfan

The indiscriminate and injudicious use of pesticides particularly endosulfan in agriculture and animal husbandry practices has considerably increased the risk of human health hazard. The present work was therefore undertaken to evaluate the toxic effect of endosulfan on the vital organs viz. liver and kidney of rat. Oral administration of endosulfan at the dose level of 10 mg/kg b.wt./day for two and four weeks showed toxic interference with the biochemistry and histology of rat liver and kidney. The biochemical parameters viz. Aspartate amino transferase, alanine amino transferase, acid phosphatase, alkaline phosphatase, bilirubin urea and creatinine were increased which clearly showed the hepato and nephrotoxic effect of endosulfan. Histopathologically the size of liver was increased, sinusoidal dilation, pyknotic nuclei, cytoplasmic degranulation and various nuclear aberrations were observed. Similarly pathological alterations viz. chronic glomerulonephritis, glomerulosclerosis, odenoma and glomerulus deposits were observed in the kidney.