Contaminants of concern (CoCs) pivotal in assessing the fate of MSW incineration bottom ash (MIBA): First results from India and analogy between several countries.

Present study characterizes municipal solid waste incineration bottom ash (MIBA) from three incineration plants in Delhi with an intent to serve the dual objectives: a) assessing the disposal/reuse options for Delhi MIBA, b) evaluating variability in results across the countries (including India) and assessing if is significant enough to influence the fate of MIBA of varied origin. A review on leaching studies of MIBA (50 research papers) was conducted which aided in achieving both the objectives. Delhi MIBA samples were analysed for chemical composition. The two commonly adopted leaching tests i.e., TCLP and EN 12457-2, were conducted and the results were checked against regulatory threshold levels (RTLs) to achieve the first objective. Leaching concentration of the contaminants was compared with the compiled literature and RTLs to accomplish the second objective. The compendium of literature most importantly revealed the physicochemical parameters which are pivotal in determining the fate of MIBA but have been missing from many studies. Ten such parameters were identified: Cr, Cu, Mo, Sb, Cl-,SO42-, Cd, Pb, Ni and Zn and are referred as contaminants of concern (CoCs). Delhi MIBA was found suitable for disposal to non-hazardous waste landfills and unsuitable for unrestricted reuse. CoCs identified in Delhi MIBA were identical to those observed in literature (except Cd, Pb and Zn). The variability in leaching concentration of CoCs, observed from comparative assessment of results, spanned nearly 2 to 3 log10 magnitudes for Cu, Cr, Pb, Sb and Zn while 1 to 2 log10 magnitudes for Mo, Cl-andSO42-.

PM10 in the ambient air of Chandrapur coal mine and its comparison with other environments.

This study compares the ambient air particulate matter (PM10) data of 15 different coal mine environments. For most of these mine environments, the monitoring was carried out by different researchers using respirable dust sampler (RDS) that separates PM10 by centrifugal inertial separation. At two sites--Padmapur and Ghugus (Chandrapur, Maharashtra, India)--mass inertial impaction-based sampler was used for PM10 monitoring. It is observed that the spatiotemporal average value of ambient air PM10 monitored using mass inertial impactor reports relatively higher values (240-372 µg/m(3)) compared to those monitored using RDS (<227 µg/m(3)). In order to realize the severity of mine area pollution, it is compared with PM10 values found in an urban area (Delhi, India). It is found that PM10 values in Delhi (using mass inertial impactor) are much higher (300-400 µg/m(3)) than those reported for the mine environment. The data seems to indicate that the mine environment is relatively cleaner than urban air and therefore raises doubt about the appropriateness of using either mass impactor or RDS for PM10 sampling.

Landfill surface runoff and its effect on water quality on river Yamuna.

During 2000, the estimated quantity of solid waste generated in Delhi, India was more than 9000 tones per day. This is one of the biggest sources of environmental degradation in capital city of India. Since 1950's over 12 large landfill have been packed with all kinds of nonbiodegradable and toxic waste of Delhi. The area covered is at least 1% (14.83 square kilometer) of total Delhi's area. All the landfill sites except Tilak Nagar, Hastal, and Chattarpur are located very closely (0.5-6 km) to the river Yamuna. It contributes the pollution to river Yamuna in a significant way in a form of surface runoff from landfill site especially in rainy season. The chemical analysis of leachate produced by these landfill sites and corresponding river section (at five river points) has been performed for 16 selected parameter (Temperature, Odor, pH, Turbidity, Conductivity, COD, Total Solids, Sulphide, Chloride, Nitrate, Iron) in the first stage and for 8 parameters (pH, Conductivity, COD, Total Solids, Chloride, Nitrate, Iron) in second stage. The study was conducted between August to October, 2000 (rainy season). It is clear from the study that the river water quality is affected by the presence of landfill surface runoff. Its impact can be seen in the region where the drains are meeting the river. This is one of the causes of river pollution apart from other major municipal and industrial sources.