Ggum-poly(Itaconic Acid) Based Superabsorbents Via Two-Step Free-Radical Aqueous Polymerization for Environmental and Antibacterial Applications

Ggum-based conducting hydrogels possessing dye removal and antibacterial property were developed by two-step free-radical aqueous polymerization method. Conductivity was introduced with polyaniline (PANI) chains incorporated within the crosslinked network of Ggum-poly(itaconic acid) superabsorbent. The material properties of the synthesized samples were characterized using FTIR spectroscopy, thermal analysis and scanning electron microscopy techniques. Results showed that synthesized samples exhibited the best antibacterial activity against Gram-positive bacteria. Synthesized samples were found to be effective in removal of toxic methylene blue (MB) dye from the waste water. The adsorption kinetics of superabsorbents has been described by using pseudo first and pseudo second order kinetics models. Furthermore, application of hydrogels to improve the water retention properties of different soils was also studied for agricultural purpose.     

Agricultural GHG emission and calorie intake nexus among different socioeconomic households of rural eastern India

A study was conducted to examine the interrelationships among socioeconomic factors, household consumption patterns, calorie intake and greenhouse gas emissions factors in rural eastern India based on household survey data. Findings indicated that higher monthly per capita incomes (12.1–80.1$) were associated with greater average calorie intakes (2021–2525 kcal d^?1). As estimated by the FEEDME model, in total 17.2% of the population was calorie malnourished with a regional disparity of 29.4–18.2% malnourishment. Greenhouse gas (GHG) emissions were calculated only on the basis of crop and livestock production and consumption. Rice accounted for the highest share of total GHG emissions, on average 82.6% on a production basis, which varied from 58.1% to 94.9% in regional basis. Rice contributed the greatest share (~?65% and 66.2%) in terms of both calories and GHG emissions (CO₂ eq y^?1), respectively, on a consumption basis. We conclude that extensive rice farming and increasing animal product consumption are dominant factors in the higher carbon footprint in this region and are likely to further increase with increase in per capita income. This study provides useful information to help for better crop planning and for fine-tuning food access policy, to reduce carbon footprint and calorie malnutrition.

     

Retrieval of Carbon monoxide profiles over Indian region using MOPITT data

Vertical profiles of carbon monoxide (CO) over the Indian region have scarcely been monitored. Satellite sensor, Measurement Of Pollution In The Troposphere (MOPITT) provides profiles of CO using a global retrieval scheme, which converts measured radiances to CO mixing ratios. In this study we have developed a regional retrieval scheme, valid over the Indian region, which employs Line-By-Line (LBL) calculations over a tropical model atmosphere to generate a Look-Up-Table (LUT) forward model function and uses a regional a priori dataset of CO along with seasonally variable emissivity to invert the MOPITT radiances to CO profiles. This baseline study provides an approach to optimizing retrievals for specific regional applications. A case study was carried out over a forest fire prone region in Northern India from February to April 2005 to validate the retrieval algorithm. The results are in agreement with the fire maps generated from MODerate resolution Imaging Spectro-radiometer (MODIS). The shape of the CO profiles over the region matches quite well with the vertical structure of CO during the INDOEX campaign, especially during the polluted month of April. Inter-comparisons with the MOPITT data product indicate some discrepancies in the lower troposphere, especially during the forest fire season. Future studies with in-situ measurements may be able to diagnose these disparities.     

Modelling the Removal of Gaseous Pollutants and Particulate Matters from the Atmosphere of a City by Rain: Effect of Cloud Density

In this paper, an original nonlinear mathematical model for the removal of gaseous pollutants and particulate matters from the atmosphere of an industrial city by rain is proposed and analyzed. It is assumed that five interacting phases in the atmosphere of the city exist, i.e., cloud droplets phase, raindrops phase, gaseous pollutants phase, particulate matters phase, and the phase of absorbed gaseous pollutants in raindrops. It is assumed further that these phases undergo nonlinear interactions in the atmosphere, while gaseous pollutant interacts with cloud droplets as well as with raindrops but particulate matters interact only with raindrops. The gravitational settling and reversible reaction processes have also been considered appropriately in the model. By analyzing the model, it is shown that both the gaseous pollutants and particulate matters may be removed from the atmosphere under certain conditions, provided the rates of formation of cloud droplets and raindrops are sufficiently large. It is noted that under unfavorable atmospheric conditions, rain does not occur and pollutants are not removed from the atmosphere.     

Kelp as a Bioindicator: Does it Matter Which Part of 5 M Long Plant is Used for Metal Analysis?

Kelp may be useful as a bioindicator because they are primary producers that are eaten by higher trophic level organisms, including people and livestock. Often when kelp or other algae species are used as bioindicators, the whole organism is homogenized. However, some kelp can be over 25 m long from their holdfast to the tip of the blade, making it important to understand how contaminant levels vary throughout the plant. We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in five different parts of the kelp Alaria nana to examine the variability of metal distribution. To be useful as a bioindicator, it is critical to know whether levels are constant throughout the kelp, or which part is the highest accumulator. Kelp were collected on Adak Island in the Aleutian Chain of Alaska from the Adak Harbor and Clam Cove, which opens onto the Bering Sea. In addition to determining if the levels differ in different parts of the kelp, we wanted to determine whether there were locational or size-related differences. Regression models indicated that between 14% and 43% of the variation in the levels of arsenic, cadmium, chromium, manganese, mercury, and selenium was explained by total length, part of the plant, and location (but not for lead). The main contributors to variability were length (for arsenic and selenium), location (mercury), and part of the plant (for arsenic, cadmium, chromium and manganese). The higher levels of selenium occurred at Clam Cove, while mercury was higher at the harbor. Where there was a significant difference among parts, the holdfast had the highest levels, although the differences were not great. These data indicate that consistency should be applied in selecting the part of kelp (and the length) to be used as a bioindicator. While any part of Alaria could be collected for some metals, for arsenic, cadmium, chromium, and manganese a conversion should be made among parts. In the Aleutians the holdfast can be perennial while the blade, whipped to pieces by winter wave action, is regrown each year. Thus the holdfast may be used for longer-term exposure for arsenic, cadmium, chromium and manganese, while the blade can be used for short-term exposure for all metals. Cadmium, lead and selenium were at levels that suggest that predators, including people, may be at risk from consuming Alaria. More attention should be devoted to heavy metal levels in kelp and other algae from Adak, particularly where they may play a role in a subsistence diets.     

Heavy Metal Accumulation in Lichens from the Hetauda Industrial Area Narayani Zone Makwanpur District, Nepal

Lichen samples collected in and around Hetauda Industrial area,(HIA) Narayani zone, Makwanpur district, Nepal, were analyzedfor Cr, Ni, Pb, Zn, Ca, Mn, Fe, Si, and Al. The samples fromthe location inside the industrial area have higher levels ofmetal than the outside areas. Pyxine meissnerina growinginside the industrial area accumulated higher levels of all themetals analyzed.     

Delivering Arsenic-free Drinking Water-Made Practically Possible: Continuous Scale Electrochemical Arsenic Remediation Process Furnished,based on Experimental Studies and ANN Simulation

Environment, Development and Sustainability - Arsenic (As) in groundwater has become a worldwide concern due to its high toxicity as it is classified as a potent carcinogen, when exposed to...     

Leaching characteristics of the fine fraction from an excavated landfill: physico-chemical characterization

Journal of Material Cycles and Waste Management - Leaching of fine fraction (<10 mm) obtained from landfill mining activities in an Estonian landfill was done. On-site excavation...