Air quality indices are commonly used to indicate the level of severity of air pollution to the public. It is infeasible and perhaps impossible to formulate a universal technique for determining air quality index, one that considers all pollutants and that is appropriate for all situations. The intended use of the air quality index is to identify the vulnerable zone. There are mainly two approaches viz. single pollutant index and multi-pollutant index to determine the air quality index. Every index has its own characteristic strengths and weaknesses that affect its suitability for particular applications. This paper attempts to present a review of all the major air quality indices developed worldwide.

The aim of this study was to assess the decomposition efficiency of earthworms, local (L.mauritii) as well as exotic (Eisenia foetida) in vermicomposting of garden litter in SRM University campus. The vermicompost produced through vermicomposting of garden litter mixed with cow dung in the ratio of 3:1 by using local and exotic earthworms (Eisenia foetida) was rich in ammoniacal nitrogen, nitrate nitrogen, available phosphorus, total potassium and TKN, and there was a reduction in total organic carbon and carbon to nitrogen ratio. The study reveals that the decomposition efficiency of exotic earthworms is better compared to local earthworms.

In this study, a series of experimental studies were conducted with regard to bioconversion of organic fraction of municipal solid waste along with paper mill sludge at different C/N ratios. About 10 kg of shredded waste containing paper mill sludge, saw dust and municipal solid waste was placed in reactors in different proportions and 100 mL of effective microorganisms was added to it. The variation in physical and chemical parameters was monitored throughout the process. The results indicate that co-composting of paper mill sludge with municipal solid waste produces compost that is more stable and homogenous and can be effectively used as soil conditioner.

Newly isolated, Bacillus sp. MTCC-3330 was screened for the decolorization of a sulphonated azodye metanil yellow under aerobic conditions. 100% decolorization was observed of Metanil Yellow at 0.01mM, 0.02mM 0.05mM concentrations within 30h, 35h and 45h respectively. Decolorization was confirmed by UV-VIS spectrophotometer. The initial dye solution showed highest peak at the wavelength of 437 nm (λmax of the Metanil Yellow). The decolorized dye showed disappearance of peak, which indicated that the decolorization is due to dye degradation. The bacterium sp. also decolorized the another azodye Methyl Orange.

Management of household solid waste and agro industrial residues generated from various sources is a serious problem due to huge ever increasing population and pollution. Application of these worthless agro waste materials to generate a commercially valuable product, pectinase enzyme, using locally isolated fungal strain, Aspergillus flavipes, was the main motive of this study. Physiological characterisation and enzyme profile determination were done along with formulation of production media. Fruit skins, rags were used as C source and oil cakes were used for N source. Various combinations of these C and N sources were applied for revised production of pectinase enzyme compared to YEP basal media (29 U/ml). A huge increase in pectinase production of 40 U/ml was obtained with Citrus peel - Sesame oil cake (CS) media. The enzyme had its maximum activity at 500C, 4.5 pH. This was achieved at 45 min in 1.5% substrate concentration.

The aim of this study was to evaluate the efficiency of Mimosa pudica L. that could be effective in phytoremediation of PHC-contaminated soil. Experiments were conducted in net house to determine the tolerance of this species to a heavy crude oil contaminated soil under the application of two fertilizer levels and reduction of PHC was monitored for 180 days. Assessment of plant growth, biomass and Total Oil and Grease (TOG) degradation were carried out at an interval of 60 days. In the presence of contaminants, biomass and plant height were reduced up to 27% and 10.4% respectively. Experiments with different percentages of crude oil showed that M. pudica could tolerate crude-oil contamination up to 6.2% (w/w). The estimation of TOG in soil of the tested plants revealed that M. pudica could decrease 31.7% of crude oil contaminants in low fertilizer level (200N, 100P, 100K) and 24.7% in high fertilizer level (240N, 120P, 120K). In case of unplanted pots, the reduction of TOG was 13.7% in low fertilizer level and 11.2% in high fertilizer level. This experiment has identified the suitability of a native candidate plant species for further investigation of their phytoremediation potential.

The constructed wetlands as well engineered techniques have been used effectively for phytoremediation of wastewater and pollution control during the last decades. In these technologies, the naturally occurring processes of plants alongside micro-organisms present in the bio-film attached to the roots, soil substrate and water column degrade the organic pollutants. The study seeks to compare the potential use of Phragmites sp. reed bed and floating macrophyte water hyacinth (Eichhornia crassipes) system for domestic wastewater treatment. The sewage treatment performance is evaluated as 80% & 76% chemical oxygen demand (COD), 90% & 87% biological oxygen demand (BOD5), 24% & 18% total dissolved solids (TDS), 69% & 67% total suspended solids (TSS), 12% & 5% Chlorides, 73% & 69% ammonia nitrogen (NH3-N), 42% & 31% phosphate (PO4-P), 93% & 91% most probable number (MPN) and 95% & 92% total viable count (TVC) reduction at optimum hydraulic retention time (HRT) of 24 & 43 h in Phragmites sp. and water hyacinth systems, respectively. Likewise, the floating macrophyte pond contrary to reed bed process shows insignificant pollutant diminution at 24 h HRT. This paper also highlights the microbial population present through the wetland systems by estimation of total viable count (TVC). The botanical aspect with reference to the plant growth is shown a significant increase in vegetation yield. The overall studies indicate the better treatment efficiency by preferred Phragmites sp. root zone system at low foot print area for domestic wastewater.

Volatile organic compounds (VOCs) are major group of air pollutants which play critical role in atmospheric chemistry. These contribute to toxic oxidants which are harmful to ecosystem, human health and atmosphere. A sampling program was conducted to determine the ambient VOC levels in the city of Agra (Uttar Pradesh), India during day time and overnight in 2010. Sampling sites were selected at three industrial area of Agra. Samples were analyzed for styrene. Concentration of Styrene was determined at different sampling points in the air of Agra in order to investigate their spatial distributions. The vertical motions of air masses also had a large impact on the variations of the level of VOC. The inter-species ratios exhibit clear seasonal variation indicating deferential reactivity of the VOCs species in different seasons.

The effects of various concentrations of chromium on the activity of dehydrogenase, catalase and soil respiration were studied after 14, 28, 56 and 112 days of incubation period. Chromium was applied as K2Cr2O7 in the amounts of 0, 25, 50, 100, 200, 400, 800 ìg g(-1) of soil. Soil contamination with Cr decreased the activity of dehydrogenase, catalase and soil respiration. About 36.92% and 44.88% inhibition in the activity of dehydrogenase was caused by 50 and 100 ìg g(-1) Cr addition respectively, after 14 days of incubation. Catalase activity significantly (P < 0.001) decreased with applied doses of chromium after 14 days of incubation. A significant inhibition in soil respiration was observed after 56 days of incubation with applied doses of chromium. These results suggest that soil respiration, dehydrogenase and catalase enzyme activities are suitable parameters for the toxicity test.

The present study was undertaken to determine the pollution load to the environment causing by the wastewater effluents releasing from organized and unorganized slaughterhouses in and around Hyderabad city. The wastewater effluents collected from three slaughterhouses, at the sites of releasing out to the surrounding environment,were characterized in terms of physico-chemical and microbiological parameters. The physico-chemical parameters, such as temperature, pH, alkalinity, turbidity, total suspended solids, electrical conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, total organic carbon, calcium, NH4-N, nitrates and phosphates were estimated in the wastewater effluents collected from three different slaughterhouses. The heavy metals, such as lead, nickel and cadmium contents were detected. The microbiological characteristics, such as total viable count, total coliform count recorded and also the pathogens of public health significance, such as Salmonella spp., Shigella spp., Streptococcus faecalis, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were isolated and identified. The results revealed significantly much higher values of almost all pollution parameters both physicochemical and microbiological of wastewater effluents collected from three slaughterhouses, and these values exceeding the effluent discharge standards for releasing the effluents into public sewers and inland surface waters, recommended by the pollution control board. The slaughterhouses must maintain the wastewater collection and treatment facilities and modify the existing treatment systems in order to comply the general effluents discharge standardsrecommended by the pollution control board.

In recent years, the recurring environmental issues regarding hazardous waste, global climate change, stratospheric ozone depletion, groundwater contamination, disaster mitigation and removal of pollutant have become the focus of environmental attention. In the management of water resources, quality of water is just as important as its quantity. In order to assess the quality and/or suitability of groundwater for drinking and irrigation in Erode District, 144 water samples each in post-monsoon and pre-monsoon during the year 2007 were collected and analyzed for various parameters. These parameters were compared with IS: 10500-1991 drinking water standards. Out of 144 samples, 29 samples exceeded the permissible limit for both the monsoons, 71 samples were within the permissible limit for both the monsoons and the remaining samples exceeded the permissible limit for any one of the monsoon. During both monsoons, except some samples, most of the samples were suitable for drinking and irrigation.

The study was conducted to evaluate the suitability of ground water for irrigation purpose at twenty seven locations in Coimbatore South Taluk, Coimbatore District. The analytical result shows that Na and Cl are the dominant cation and anions respectively in the groundwater. The values of TDS and EC exceed the permissible limits at some locations due to increase in ionic concentrations. Based on SAR, RSC, US Salinity diagram and Wilcox diagram it is observed that the water ranges from excellent to good quality in most of the places and can be used for irrigation without any hazard. Gibbs variation diagram indicates that lithology is main controlling factor for water chemistry. However, the high SAR and RSC values at few locations restrict suitability for irrigation purpose.

An attempt has been made to study the hydrochemistry of groundwater in Sarada River Basin (SRB).The groundwater samples were collected from dug wells and bore wells which have been analysed for cations and anions in the study area. The river basin is divided into six sub-basins for the purpose of study. The six hydrochemical groups namely sodium bicarbonate, magnesium bicarbonate, sodium chloride, calcium bicarbonate, sodium sulphate, and magnesium chloride, according to their dominant cations and anions were observed and studied in different types of rock formations, soil groups, geomorphic settings, slopes and groundwater aquifers in the area of the investigation. The hydrochemical data indicated that the groundwater was contaminated in the southern part of lower Sarada River Basin by sub-surface sea water intrusion, pollution due to the industrial wastes discharged by existing sugar factories and chemical contamination due to over use of fertilizers and pesticides in the areas of intense irrigation could be identified. In many locations maximum parameters were within the permissible limits and some were beyond the limits of drinking water standards. However, most of the groundwater of the SRB is found suitable for drinking, irrigation, and industrial purposes.

The study explains water quality of the Cauvery River in the southern region of Peninsular India. Thirteen parameters including trace elements (Cd, As, Cu, Cr, Zn and Pb) have been monitored on 50 sampling points from a hydro-geochemical survey, conducted in the river stretch under study. Several water quality parameters showed considerable changes due to increased runoff from the catchments and other seasonal factors. Multivariate discriminant analysis delineated a few parameters responsible for temporal variation in water quality. Factor analysis (FA) identified three factors responsible for data structure explaining 91% of total variance in surface water. It allowed grouping selected parameters according to common features. The results indicated that point source pollutants primarily affected the water quality of this region. This study indicates the necessity and usefulness of multivariate statistical techniques for evaluation and interpretation of the data. It facilitates better information about the water quality and designs some remedial techniques to prevent future contamination.

This study is aimed at providing useful information about the hydrochemistry of some parts of Abakaliki city for proper understanding of the groundwater quality. Twelve representative groundwater samples from water boreholes/wells in the study area were analyzed for their hydrogeochemical properties: pH, Electrical Conductivity (EC), Turbidity, Total Dissolved Solids (TDS), Total Hardness (TH), COD, Ca2+, Mg2+, Na+, K+, HCO3-, SO4(2-), Cl-, NO3-, and CO3(2-). Aquifers in the study environment were located in the fractured shales of Abakaliki Formation. The composition of the major ions outlined the relationships between the aquifer chemistry. Strong positive correlations exist between EC-TDS, Na(+)-TDS, Mg(2+)-SO4(2+) and Ca(2+)-SO4(2+). Piper trilinear diagram has also been utilized in data interpretation and to classify the hydrogeochemical facies. Majority of the analyzed samples were characterized by the dominance of Ca2+, Mg2+, SO4(2-) and Cl- and the Piper trilinear diagram indicated two water types: Ca (Mg)-Cl and Ca-Mg-Na-Cl-SO4 water types. Na/Cl ratio ranging from 0.12 to 0.73 (all below 1.0) with a mean of 0.55 inferred fresh water existence. Results of this study generally showed that the analyzed groundwater samples pose no threat to human consumption, health and environment since the concentrations of the physico-chemical parameters were within the WHO standards.