Study of electromagnetic shielding effectiveness of metal oxide polymer composite in their bulk and layered forms

Environmental Science and Pollution Research - In this paper, we present the studies on electromagnetic interference (EMI) shielding effectiveness (SE) of K2CrO4-PMMA composites developed by two...     

Lead content in new decorative paints in India

The paint industry in India is broadly classified into two categories: organized sector and unorganized sector. Multinational and big Indian companies form the organized sector, whereas the small- and medium-scale industries which produce paints for the local market form the unorganized sector. The present study was undertaken to determine the level of lead in decorative paints in India. A total of 148 paint samples sourced from four organized sector companies and six unorganized sector companies were analyzed for the total lead content. Results of this study reveal that 39 % of the total paints tested (n = 148) contain lead more than 300 ppm, the voluntary limit prescribed by Bureau of Indian Standards, BIS (IS 15489:2011), and 45 % of the tested paints contain lead more than 90 ppm, the US limit. Further analysis of the data indicates that only 5 % of the tested paints manufactured by organized sector companies contain lead more than 300 ppm (n = 91), whereas 93 % of the tested paints manufactured by unorganized sector companies contain lead more than 300 ppm (n = 57). Comparison with earlier reported data suggests that while organized sector companies are gradually abandoning the use of lead-based compounds in their paints, the unorganized sector companies are still adding lead-based compounds intentionally in their paints despite the potential health hazards associated with it. The maximum concentration of lead obtained was 80,350 ppm in one of the paints manufactured by an unorganized sector company. The presence of high concentration of lead in yellow and green color paints indicates that color can be a predictor of lead content in decorative paints.     

Study on chemical kinetics and catalytic cracking of tar from gasification of rice straw using various catalysts

Journal of Material Cycles and Waste Management - The tar formed within the producer gas is a major problem in the biomass gasification process. The catalytic cracking of tar is the best method to...     

Lead detoxification by coontail (Ceratophyllum demersum L.) involves induction of phytochelatins and antioxidant system in response to its accumulation

Coontail (Ceratophyllum demersum L.) plants when exposed to various concentrations of Pb (1-100microM) for 1-7days, exhibited both phytotoxic and tolerance responses. The specific responses were function of concentration and duration. Plants accumulated 1748mugPbg(-1) dw after 7d which reflected its metal accumulation ability, however most of the metal (1222microgg(-1) dw, 70%) was accumulated after 1d exposure only. The toxic effect and oxidative stress caused by Pb were evident by the reduction in biomass and photosynthetic pigments and increase in malondialddehyde (MDA) content and electrical conductivity with increase in metal concentration and exposure duration. Morphological symptoms of senescence phenomena such as chlorosis and fragmentation of leaves were observed after 7d. The metal tolerance and detoxification strategy adopted by the plant was investigated with reference to antioxidant system and synthesis of phytochelatins. Protein and antioxidant enzymes viz., superoxide dismutase (SOD, EC 1.15.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7) ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2) showed induction at lower concentration and duration followed by decline. All enzymes except GPX showed maximum activity after 1d. An increase in cysteine, non-protein thiols (NP-SH) and glutathione (GSH) content was observed at moderate exposure conditions followed by decline. Phytochelatins (PC(2) and PC(3)) were synthesized to significant levels at 10 and 50microM Pb with concomitant decrease in GSH levels. Thus production of PCs seems important for the detoxification of metal, however it may lead to depletion of GSH and consequently oxidative stress. Results suggest that plants responded positively to moderate Pb concentrations and accumulated high amount of metal. Due to metal accumulation coupled with detoxification potential, the plant appears to have potential for its use as phytoremediator species in aquatic environments having moderate pollution of Pb.     

The United States Department of Energy's Regional Carbon Sequestration Partnerships program: a collaborative approach to carbon management

This paper reviews the Regional Carbon Sequestration Partnerships (RCSP) concept, which is a first attempt to bring the U.S. Department of Energy's (DOE) carbon sequestration program activities into the "real world" by using a geographically-disposed-system type approach for the U.S. Each regional partnership is unique and covers a unique section of the U.S. and is tasked with determining how the research and development activities of DOE's carbon sequestration program can best be implemented in their region of the country. Although there is no universal agreement on the cause, it is generally understood that global warming is occurring, and many climate scientists believe that this is due, in part, to the buildup of carbon dioxide (CO(2)) in the atmosphere. This is evident from the finding presented in the National Academy of Science Report to the President on Climate Change which stated "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Temperatures are, in fact, rising. The changes observed over the last several decades are likely mostly due to human activities, ...". In the United States, emissions of CO(2) originate mainly from the combustion of fossil fuels for energy production, transportation, and other industrial processes. Roughly one third of U.S. anthropogenic CO(2) emissions come from power plants. Reduction of CO(2) emissions through sequestration of carbon either in geologic formations or in terrestrial ecosystems can be part of the solution to the problem of global warming. However, a number of steps must be accomplished before sequestration can become a reality. Cost effective capture and separation technology must be developed, tested, and demonstrated; a database of potential sequestration sites must be established; and techniques must be developed to measure, monitor, and verify the sequestered CO(2). Geographical differences in fossil fuel use, the industries present, and potential sequestration sinks across the United States dictate the use of a regional approach to address the sequestration of CO(2). To accommodate these differences, the DOE has created a nationwide network of seven Regional Carbon Sequestration Partnerships (RCSP) to help determine and implement the carbon sequestration technologies, infrastructure, and regulations most appropriate to promote CO(2) sequestration in different regions of the nation. These partnerships currently represent 40 states, three Indian Nations, four Canadian Provinces, and over 200 organizations, including academic institutions, research institutions, coal companies, utilities, equipment manufacturers, forestry and agricultural representatives, state and local governments, non-governmental organizations, and national laboratories. These partnerships are dedicated to developing the necessary infrastructure and validating the carbon sequestration technologies that have emerged from DOE's core R&D and other programs to mitigate emissions of CO(2), a potent greenhouse gas. The partnerships provide a critical link to DOE's plans for FutureGen, a highly efficient and technologically sophisticated coal-fired power plant that will produce both hydrogen and electricity with near-zero emissions. Though limited to the situation in the U.S., the paper describes for the international scientific community the approach being taken by the U.S. to prepare for carbon sequestration, should that become necessary.     

Marine water quality assessment at Mumbai West Coast

In recent past, Mumbai Municipal corporation was not able to keep pace with required infrastructural facilities due to unprecedented population growth. Sewage disposal is one of the major issues, which needed immediate attention because huge quantity of sewage with only preliminary treatment is disposed into the nearby coastal areas and has deteriorated the water quality of the near coastal region. World Bank assisted Bombay Sewage Disposal Project (BSDP) undertaken by the Municipal Corporation of Bruhan Mumbai (MCBM) envisaged sewage discharges through marine outfalls at Worli and Bandra and treatment by aerated lagoons for other areas before disposal in creeks. During BSDP programme, studies were undertaken on water quality assessment along the west coast of Mumbai before and after commissioning of the Worli outfall. A pre- and post-commissioning water quality database for selected parameters was generated for near shore as well as west coast region up to 5 km seaward distance to assess the efficacy of the Worli outfall and delineate the areas affected around diffuser location of the outfall due to sewage disposal. This paper presents observations of the coastal studies at Mumbai and the impact zone of Worli outfall.     

Management of Lignite Fly Ash for Improving Soil Fertility and Crop Productivity

Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients, has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid, and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with and without press mud), yield increased significantly (7.0–89.0%) in relation to the control crop. The press mud enhanced the yield (3.0–15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications, the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits, was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner.     

In-situ monitoring of chromium cytotoxicity in sugarcane

The potential of in-situ monitoring of cytotoxic effects of chromium through root-tip assay was studied in a sugarcane cultivar CoLk 8102 (Saccharum spp. hybrid). Sugarcane setts supplied with graded concentrations of chromium (VI), exhibited a reduction of 85.92 and 95.10 % in mean root length at 40 and 80 ppm Cr dosages along with 61.25 and 82.50% reduction in mean root number/node respectively. Mitotic index of root tip cells of treated setts declined and the frequency of aberrant mitotic phases increased pari passu to the increasing chromium concentration. To compare and quantify the effect of graded chromium dosages on frequency of chromosome aberrations vis-à-vis inhibition of mitotic activity, a 'Decretion factor' (D.F.) has been used for the first time. The value of DF increased with the increase in the chromium dosages. The increase in chromosome aberration frequency was low at low chromium dosages (1 or 2 ppm), but the high Cr dosages (40 and 80 ppm), induced sharp reduction in mitotic efficiency of root system along with anomalies in the process of cell division and induced chromosome aberrations in sugarcane root meristem, which in turn affected the over all plant growth.