2015年10月南京霾污染过程分析

为探讨南京秋季霾污染过程发生的主要影响因素,利用南京信息工程大学太阳光度计观测霾污染发生天气下AOD（aerosol optical depth,气溶胶光学厚度）数据,计算AE_440-1020（?ngstr?m Exponent,波长指数）以及a₂（光谱曲率）,结合CALIPSO（Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations）卫星气溶胶组分分析以及MODIS（Moderate Resolution Imaging Spectroradiometer）火点数据,对2015年10月南京霾污染过程进行分析.结果表明:2015年10月出现的两次霾污染过程期间南京地区AE_440-1020均高于1.0并且a₂呈负值,其中10月16日AQI达到峰值（201）,AOD₅₀₀达1.51,AE_440-1020达1.37,a₂达-0.77;这两次较为严重的霾污染过程均主要由人为因素（工业污染、城市建设、生物质燃烧、汽车尾气排放等）产生的细粒子所致.后向轨迹分析发现,2015年10月16日南京地区霾污染天气发生的主要原因是区域型污染,同时受长距离输送影响,大量携带人为因素产生的细粒子以及少量沙尘等污染物的空气团途经内蒙古、山东等地到达南京,加剧了当日的污染程度;2015年10月23日南京地区霾污染天气的发生则主要受长距离输送影响,同时也受到区域型污染影响,加剧了当日的污染程度.研究显示,在稳定的气象条件下,较高的相对湿度、较低的地表风速、低混合层高度以及贴地逆温的出现是诱发霾污染天气产生的有利气象条件.      

Evaluating the effectiveness of marine actinobacterial extract and its mediated titanium dioxide nanoparticles in the degradation of azo dyes

Aim of the present study was to synthesize titanium dioxide nanoparticles （YiO2 NPs） from marine actinobacteria and to develop an eco-friendly azo-dye degradation method. A total of five actinobacterial isolates were isolated from Chennai marine sediments, Tamilnadu, India and analyzed for the synthesis of TiO2 NPs using titanium hydroxide. Among these, the isolate PSV 3 showed positive results for the synthesis of TiO2 NPs, which was confirmed by UV analysis. Further characterization of the synthesized TiO2 NPs was done using XRD, AFM and FI＇-IR analysis. Actinobacterial crude extract and synthesized TiO2 NPs was found efficient in degrading azo dye such as Acid Red 79 （AR-79） and Acid Red 80 （AR-80）. Degradation percentage was found to be 81% for AR-79, 83% for AR-80 using actinobacterial crude extract and 84% for AR-79, 85% for AR-80 using TiO2 NPs. Immobilized actinobacterial ceils showed 88% for AR-79 and 81% for AR- 80, dye degrading capacity. Degraded components were characterized by FT-IR and GC-MS analysis. The phytotoxicity test with 500 μg/mL of untreated dye showed remarkable phenotypic as well as cellular damage to Tagetes erecta plant. Comparatively no such damage was observed on plants by degraded dye components. In biotoxicity assay, treated dyes showed less toxic effect as compared to the untreated dyes.     

Seasonal variation of leaf dust accumulation and pigment content in plant species exposed to urban particulates pollution

To assess the dust interception efficiency of some selected tree species and impact of dust deposition on chlorophyll and ascorbic acid content of leaves the present study was undertaken. The plant species selected for the study were Ficus religiosa, Ficus benghalensis, Mangifera indica, Dalbergia sissoo, Psidium guajava, and Dendrocalamus strictus. It was found that all species have maximum dust deposition in the winter season followed by summer and rainy seasons. Chlorophyll content decreased and ascorbic acid content increased with the increase of dust deposition. There was significant negative and positive correlation between dust deposition and chlorophyll and ascorbic acid content, respectively. Maximum dust interception was done by Dalbergia sisso and least by Dendrocalamus strictus. Thus plants can be used to intercept dust particles which are of potential health hazards to humans.     

Seasonal variation in heavy metal contamination in water and sediments of river Sabarmati and Kharicut canal at Ahmedabad, Gujarat

The objective of the study is to reveal the seasonal variations in the river water and sediment quality with respect to heavy metal contamination. To get the extent of trace metals contamination, water and sediment samples were collected from five different sites along the course of Sabarmati River and its tributary Kharicut canal in pre-monsoon, monsoon and post-monsoon seasons. The concentration of trace metals such as chromium, copper, lead, nickel and zinc was determined using inductively coupled plasma spectroscopy. The concentrations of heavy metals were found to be higher in the pre-monsoon season than in the monsoon and post-monsoon seasons in water samples. The pollution load index, contamination factor and degree of contamination (C _d) in sediments were calculated to know the extent of anthropogenic pressures. The values of C _d clearly indicated very high degree of contamination at Kharicut canal (S-4: 32.25 and S-5: 54.52) and considerable degree of contamination at three sites of Sabarmati river viz; S-1, S-2 and S-3 with values 14.30, 14.42 and 17.21, respectively. Lead and nickel could not be traced in any of the river water samples.     

The use of ultra filtration in trace metal speciation studies in sea water

During this work, size fractionation technique "ultra filtration" is used in speciation studies of trace elements in the coastal sea water. Filtration is the most commonly used method to fractionate trace metal species, but often only "dissolved" and "particulate" fraction. The purpose of the present study is to determine colloidal and suspended particulate concentrations of Fe, Zn, Cu, Ni, and Mn in sea water. Suspended particulate matter were separated in three different size groups namely (>2.7 microm, <2.7->0.45 microm and <0.45->0.22 microm) by suction filtration using cellulose acetate and nitrate filter membranes. Thereafter to concentrate the solution with colloidal particle <0.22 microm-1.1 nm (0.5 k Nominal Molecular Weight cut-off Limit {NMWL}), the solution obtained from filtration through <0.22 microm, is sequentially passed through the ultra-filtration membranes having pore diameters of 14 nm (300 k NMWL), 3.1 nm (50 k NMWL), 2.2 nm (30 k NMWL), 1.6 nm (10 k NMWL) and 1.1 nm (0.5 k NMWL) by using Stirred Ultra-filtration Cells, operating in concentration mode. The concentration of Fe, Zn, Cu, Ni, and Mn were measured in suspended and dissolved fraction by ion chromatography, ICP-AES and Atomic Absorption Spectrometer. The salinity of the solution in various dissolved fractions of sequential filtration varies between 30.89-34.22 parts per thousand. The maximum concentrations of colloidal Zn, Cu, Ni and Mn in dissolved fraction were in <2.2->1.6 nm fraction. In case of Fe, colloidal fractions <2.2->1.6 nm and <1.6-<1.1 nm shows higher concentration. The concentration of Zn, Cu, Ni and Mn increase with decrease in size in suspended particulate matter, while the reverse is observed in case of Fe. This size separation data that specifies the partitioning of metals between dissolved and suspended solid phases is necessary for developing physically based models of metal transport in aquatic system.     

Determination of hierarchical relationships among sustainable development goals using interpretive structural modeling

This paper analyses the complex interactions among the seventeen sustainable development goals (SDGs) and presents them in a hierarchical framework using interpretive structural modeling technique. The driving and dependence powers of each of these goals have been ascertained to help the developing and least developed countries improve their strategic orientation for a particular goal within a given time frame. This would also help them in prioritizing their resource allocations on a specific SDG by focusing on its hierarchical ranking on one hand and driving and dependence powers on the other.     

Vulnerability of forests in the Himalayan region to climate change impacts and anthropogenic disturbances: a systematic review

Regional Environmental Change - The Himalayan region is not only threatened by rapid changes in anthropogenic activities but also by global climate change. Given the uncertainties of magnitude and...     

A linear and nonlinear approach for interpretation of groundwater quality based on water quality index

In this study using linear and nonlinear approach, aggregate indices for various water quality parameters were analyzed. Using a linear and nonlinear interpolating surface, various water quality variables at grid points were investigated that is essential for mapping. The values help in constituting a key approach for determining the water quality index (WQI), which converts pollutant concentration data into subindex values and then combines them into a single score. One of the biggest advantages of WQI is its summary and intuitive communication capability which will be extremely helpful for demarcating safe aquifer zones of groundwater and in the selection of suitable method for remedial. The present study also describes pollution potential in ground water of Madhya Pradesh, India. The aggregate indices suggest intermediate to high pollution susceptibility in some region of Madhya Pradesh that may increase further if not managed. The overall interpretation of the study will be helpful in formulating suitable approach for water quality interpretation and sustainable planning of groundwater resources.     

A lab fermenter level study on anaerobic hydrogen fermentation using potato peel waste: effect of pH,temperature, and substrate pre-treatment

Journal of Material Cycles and Waste Management - Decades have passed, facing the energy crisis and environmental pollution and researching various possible solutions to tackle them. The use of...