Biodegradation of wastewater of Najafgarh drain,Delhi using autochthonous microbial consortia : a laboratory study

There are seventeen drains, which discharge their untreated urban and industrial wastewaters into the Delhi segment of river Yamuna. The Najafgarh drain is the first and the largest drain, and it alone contributes 1667.84 mld i.e. 60% of the total wastewater discharge into the river Yamuna and as such add 81.36 tons of BOD load per day. As per the available data approximately 95% of the wastewater of this drain is biodegradable. In the present study, an attempt has been made to reduce the BOD load and COD levels of wastewater of Najafgarh drain using autochthonous microbial consortium. During this study the raw wastewater samples were treated for 6 h time interval with different concentration of consortium. It was observed that by increasing the existing microbial population in the wastewater sample by 150-200% there is a significant decrease in BOD and COD levels. Finally, BOD/COD ratios before and after biotreatment have been analyzed to assess the efficacy of the natural consortium.     

Assessment of deposition of MEMC (seed dressing fungicide) in exposed rice grain through study of seedling growth parameters

Rice seed grains exposed to 240 ppm of seed dressing fungicide, MEMC showed increase in deposition of mercury with increase in period of observation (0h to 48h) in 765+/-5 mg of intact endosperm. The gradual increase in mercury deposition in intact endosperm caused simultaneous decrease in mercury content of the seed coat. Exposure periods of 5 to 20 min with 240 ppm of MEMC showed 5.5 to 8.72 microg of mercury deposition in 765+/-5 mg of intact endosperm. Increase in period of exposure (3 to 20 min) to 240 ppm of MEMC and also increase in chronic treatment to lower concentrations (1.5 ppm to 24 ppm) to seed grains have shown similar results in seedling growth parameters. Lower period of exposure or exposure to lower concentrations, both showed a significant inhibition of root growth, however the shoot growth showed stimulation. But higher exposure period or exposure to higher concentrations brought inhibition of both root and shoot growth. The exposure period showing 50% of root growth inhibition of 72h old seedling was calculated to be 10 min So also the chronic treatment showing the 50% of root growth inhibition was calculated to be 9 ppm. Ten min exposure of rice grain to 240 ppm of MEMC showed deposition of 7.11 microg of mercury in 765+/-5 mg of intact endosperm at 48h of observation (optimal phase of germinating process). Regression analysis indicated that by the time of 72h the intact endosperm and developing seedling might have acquired with a minimum amount of 10.23 microg of mercury from the seed coat. Finally it can be said that 10.23 microg of MEMC might be bringing 50% root growth inhibition in 72h old seedlings and 16.71 microg of mercury causing 50% inhibition of both root and shoot growth of 120h old seedlings.     

Phytoplanktonic Community of Organically Polluted Tropical Reservoirs in Eastern India

Plankton is a kaleidoscopic spectrum of organisms with repre-sentatives from almost all phyla of animals and thousands of non-flowering plants. Unicellular protozoans, invertebrates and bacteriato diatoms all drift around as the plankton community. The produc-tion rate of plankton is determined by a host of environmental pa-rameters like physico-chemical properties of water and soil, mete-orological characteristics of the region, and morphometric and hy-drographic features of the water body[3]…     

Isotopic evidence for in-lake production of accumulating nitrate in Lake Superior.

A century-long increase in nitrate (NO3-) in the water column of Lake Superior is a classic example of recent nitrogen accumulation in ecosystems, but its cause and relationship to historical NO3- deposition is unknown. We used stable isotope ratios of oxygen and nitrogen in nitrate (delta18O-NO3 and delta15N-NO3) to examine its sources in this large lake, which represents 10% of the world's surficial liquid freshwater. The most parsimonious hypothesis to explain the rise in NO3- is that the lake is accruing NO3- deposited directly on the lake surface because it is too unproductive to completely assimilate all of it. Data for delta18O-NO3 in external sources and the water column, however, are inconsistent with this hypothesis. Instead, the isotopic evidence indicates strongly that the accumulating NO3- is almost entirely derived from nitrification occurring within the lake. While increases in atmospheric deposition of NO3- may have played a role in its buildup in the lake, other factors such as increases in NH4+ and dissolved organic nitrogen inputs from precipitation or rivers, increases in nitrogen fluxes from the sediments, and decreases in burial rates must also be considered as potential drivers of rising NO3-. The sustained accumulation of nitrogen in Lake Superior is thus more complex and incompletely understood than previously assumed.     

Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane

Membrane damage is one of the important consequence of chromium,an environmental toxicant,to produce cytotoxicity.α-tocopherol,a membrane protectant can be used to reduce the chromium-induced membrane damage.In the present study,the impact of chromium in presence and absence of α-tocopherol was studied on plasma membrane of live and kidney in male Wistar rats(80-100g body weight).Significant increase in membrane cholesterol level as well as significant decrease in membrane phospholipid level in chromium exposed(0.8mg/100g body weight/d,i.p.,for 4 weeks)animals suggest structural alteration of both liver and kidney plasma memebrane.The alkaline phosphatase,total ATPase and Na^ -K^ -ATPase activities of plasma membrane were significantly decreased in both liver and kidney after chromium treatment.However,α-tocopherol (30mg/100g diet)supplementation can restrict the changes in these membrane-bound enzyme activities.Thus,the usefulness of dietary supplementation of α-tocopherol to restrain the chromium-induced membrane damage is suggested.     

Production,engine performance,combustion, emission characteristics and economic feasibility of biodiesel from waste cooking oil: A review

The depletion of fossil fuel reserves and increasing demands for diesel are considered to be important triggers for many of the initiatives that have been taken to search for possible sources for the production of biodiesel from materials available within the country. It is possible to produce biodiesel from waste/used cooking oils (WCO) that is comparable in quality to that of fresh vegetable oil. Not only does reuse of WCO, which can otherwise harm human health, reduce the burden on the government of treating oily wastewater, disposing of the waste, and maintaining public sewers, it also significantly lowers the production cost of biodiesel. In the process of frying, oil undergoes many reactions, leading to the formation of a number of undesirable compounds, such as polymers, free fatty acids, and many other chemicals. This poses challenges in the transesterification of WCO. This article covers different techniques in the production of biodiesel from WCO. It also compares combustion, emissions, and engine performance characteristics of biodiesel from WCO as well as factors affecting biodiesel production from WCO and its economic feasibility.     

Cloning and expression of α-amylase in E. coli: genesis of a superior biocatalyst for substrate-specific MFC

One of the most practical approaches for establishing a successful microbial fuel cell (MFC) is to fasten the oxidation rate of the substrate by the microorganisms to get quick paced electron transfer between microbes and electrode. A genetically modified Escherichiacoli, overexpressing α-amylase, is constructed and applied as biocatalyst in MFC using starch as substrate. The results are compared with nonrecombinant, native E.coli. The results show better performance for the MFC containing the recombinant strain demonstrated by higher power density (PD), lower resistance, and significant electrochemical activity. Maximum PD has been recorded as 279.04 mW m^?2 compared to 120.33 Mw m^?2 for the MFC operated with nonrecombinant E.coli. The impedance results also suggest the effectiveness of the recombinant strain by lowering the internal resistance by more than half order as compared to the nonrecombinant one. These results affirm that the engineered strain can be used as a superior biocatalyst in contrast to the native strain and by using the technique of genetic alteration; gene of interest can be inserted based on the substrate to be treated. So, this work gives a useful insight for accomplishing successful MFC operation with the use of bacterial stains engineered at the molecular level.     

Effect of different design aspects of pipe for earth air tunnel heat exchanger system: A state of art

Earth air tunnel heat exchanger (EATHE) is a promising passive technique to provide thermal comfort condition in buildings. EATHE system uses undisturbed temperature of the ground for heating/cooling of air. Despite the several advantages, this technique has not become much popular owing to its high capital cost (mainly pipe cost and trench excavation cost) and large land area requirements. The primary objective of this study is to present a comprehensive review of different EATHE pipe layouts, pipe properties and positioning of the pipe with their advantages and limitations. It is observed that the ring pipe layout is the most cost-effective pipe-layout for small size EATHE system because it saves excavation cost by using a trench of the existing foundation of the building. However, Grid pipe-layout is an ideal layout for a large size EATHE system. Multi-layer pipe layouts should be used to reduce the land area requirement significantly. Moreover, EATHE system can be installed beneath the building (under building foot-print) to eliminate extra land area requirement for the installation of EATHE system. This review article shows that the Initial capital cost and land area requirement for the EATHE system can be substantially reduced by using appropriate pipe layout. It can be concluded that if EATHE system is installed with proper design strategies, it will be a clean and cost-effective method for building heating/cooling with significant power savings.     

南京市两次秋季污染过程及成因分析

为探究南京秋季污染过程的特征和影响因素,利用MODIS(Moderate Resolution Imaging Spectroradiometer)传感器获得的气溶胶光学厚度(Aerosol Optical Depth)、波长指数(Angstrom Exponent)、火点数据及CALIPSO(Cloud-Aerosol Lidar And Infrared Pathfinder Satellite Observations)卫星数据和来自NECP、MICAPS的温度、相对湿度、风向风速等常规气象要素数据,对南京2015年10月、2016年9月两次污染过程进行分析.研究结果表明:两次污染过程的AE412-470值(埃斯特朗波长指数α)均高于1,由此判断两次污染均以人为排放产生的细粒子为主.但2015年10月的AE412-470值明显低于2016年9月,说明在2015年10月污染过程中粗粒子所占比重高于2016年9月.结合对后向轨迹的分析发现,南京地区2015年10月污染天气的发生还受长距离输送的影响,污染源主要为来自内蒙古、山西等地的污染型沙尘粒子.研究还发现,较高的相对湿度、较低的地表风速、低混合层高度及贴地逆温等气象条件会导致污染物难以扩散稀释而累积在南京地区,造成该区域在秋季出现较严重的污染天气.