Large-scale carbon stock assessment of woody vegetation in tropical dry deciduous forest of Sathanur reserve forest,Eastern Ghats,India

Tropical dry forests are one of the most widely distributed ecosystems in tropics, which remain neglected in research, especially in the Eastern Ghats. Therefore, the present study was aimed to quantify the carbon storage in woody vegetation (trees and lianas) on large scale (30, 1 ha plots) in the dry deciduous forest of Sathanur reserve forest of Eastern Ghats. Biomass of adult (≥10 cm DBH) trees was estimated by species-specific allometric equations using diameter and wood density of species whereas in juvenile tree population and lianas, their respective general allometric equations were used to estimate the biomass. The fractional value 0.4453 was used to convert dry biomass into carbon in woody vegetation of tropical dry forest. The mean aboveground biomass value of juvenile tree population was 1.86 Mg/ha. The aboveground biomass of adult trees ranged from 64.81 to 624.96 Mg/ha with a mean of 245.90 Mg/ha. The mean aboveground biomass value of lianas was 7.98 Mg/ha. The total biomass of woody vegetation (adult trees + juvenile population of trees + lianas) ranged from 85.02 to 723.46 Mg/ha, with a mean value of 295.04 Mg/ha. Total carbon accumulated in woody vegetation in tropical dry deciduous forest ranged from 37.86 to 322.16 Mg/ha with a mean value of 131.38 Mg/ha. Adult trees accumulated 94.81% of woody biomass carbon followed by lianas (3.99%) and juvenile population of trees (1.20%). Albizia amara has the greatest biomass and carbon stock (58.31%) among trees except for two plots (24 and 25) where Chloroxylon swietenia contributed more to biomass and carbon stock. Similarly, Albizia amara (52.4%) showed greater carbon storage in juvenile population of trees followed by Chloroxylon swietenia (21.9%). Pterolobium hexapetalum (38.86%) showed a greater accumulation of carbon in liana species followed by Combretum albidum (33.04%). Even though, all the study plots are located within 10 km radius, they show a significant spatial variation among them in terms of biomass and carbon stocks which could be attributed to variation in anthropogenic pressures among the plots as well as to changes in tree density across landscapes. Total basal area of woody vegetation showed a significant positive (R ² = 0.978; P = 0.000) relationship with carbon storage while juvenile tree basal area showed the negative relationship (R ² = 0.4804; P = 0.000) with woody carbon storage. The present study generates a large-scale baseline data of dry deciduous forest carbon stock, which would facilitate carbon stock assessment at a national level as well as to understand its contribution on a global scale.     

A Study of Eichhornia crassipes Growing in the Overbank and Floodplain Soils of the River Yamuna in Delhi, India

River Yamuna, like most of the major rivers of India, has become increasingly polluted over the years from both point and non-point sources, particularly in the urban sectors such as Delhi. Field studies, conducted in January, 1994 have investigated the impact of wastewater discharges from four major drains (Najafgarh, Power House, Barapula, Kalkaji) on the overbanks, floodplains and Eichhornia in River Yamuna in Delhi, with particular reference to elemental contamination. It is concluded that except for Cd and Co, overall mean soil concentrations along the full stretch of the river in Delhi are within the world background levels of uncontaminated soils. However, the wastewater discharges from the drains, with the exception of Barapula drain, generally increase the elemental concentrations of overbank soils downstream of the discharges. Eichhornia plants growing along the banks receiving wastewaters from the Najafgarh and Barapula drains are unhealthy and reduced in population which can be attributed to a combination of alkaline pH of the growth medium, metal toxicity and high BOD at the site receiving effluents from the Najafgarh drain, and alkaline pH, metal toxicity and the turbid conditions of water with fly ash particle deposition on the plant surfaces at the site receiving effluents from the Barapula drain. Generally, considering the entire stretch of the river in Delhi, the roots of these plants growing on the overbank soils are found to be accumulators of all elements except Co, Al and Fe, with Co uptake being minimal. There are marked differences in elemental uptake of the water hyacinths growing on the overbanks and floodplains of the river.     

Pesticide residues in river Yamuna and its canals in Haryana and Delhi, India

Yamuna, a prominent river of India covers an extensive area of 345,843 km(2) from Yamunotri glacier through six Indian states. Residues of organochlorine pesticides (OCPs) namely, isomers of HCH and endosulfan, DDT and its metabolites, aldrin, dieldrin, were analysed in water of river Yamuna along its 346 km stretch passing through Haryana-Delhi-Haryana and the canals originating from it. beta-HCH, p.p'-DDT, p.p'-DDE and p.p'-DDD had maximum traceability in test samples (95-100%) followed by gamma-HCH, alpha-HCH and o.p'-DDD (60-84%) and o.p'-DDT, delta-HCH and o.p'-DDE (7-30%) while aldrin, dieldrin, alpha and beta endosulfan remained below detection limits (BDL). The concentration of SigmaHCH and SigmaDDT at different sites of the river ranged between 12.76-593.49 ng/l (with a mean of 310.25 ng/l) and 66.17-722.94 ng/l (with a mean of 387.9 ng/l), respectively. In canals the values were found between 12.38-571.98 ng/l and 109.12-1572.22 ng/l for SigmaHCH and SigmaDDT, respectively. Water of Gurgaon canal and Western Yamuna canal contained maximum and minimum concentration, respectively both of SigmaHCH and SigmaDDT residues. Sources of these pesticides and suggested measures to check pesticide pollution of this major Indian river, keeping in view its vital link with life, are discussed in this paper.     

Seasonal and spatial variation of Yamuna River water quality in Delhi, India

Street dust was collected from five roads with different traffic volumes in the metropolitan area of Beijing and separated into five size fractions. Concentrations of polycyclic aromatic hydrocarbons (PAHs) adsorbed on street dust in different size ranges and their correlation with specific surface area and total organic carbon (TOC) were investigated. Results show that the concentration of 16-PAHs of sieved samples ranges from 0.27 to 1.30 mg/kg for all the sampling sites. Particles smaller than 40 μm in diameter have the highest 16-PAHs concentration among all of the size ranges for street dust from the four sampling sites with vehicles running on. PAHs with three or four rings account for 68% of the overall 16-PAHs on average. Remarkable positive correlation exists between 16-PAHs concentration and specific surface area with R ² values from 0.7 to 0.96 for the four sampling sites with vehicles running on. The relationship between the concentration of 16-PAHs and TOC is less clear.     

PAHs Contamination in Bank Sediment of the Yamuna River, Delhi, India

This study was performed to elucidate the distribution, concentration trend and possible sources of PAHs in bank sediment of river Yamuna in Delhi, India. The levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed during pre-monsoon, monsoon and post-monsoon seasons in the sediment fraction < 53 μm. Reference standards and internal standards were used for identification and quantification of PAHs by HPLC. The sum of 16 PAH compounds ranged from 4.50 to 23.53 μg/g with a mean concentration of 10.15 ± 4.32 μg/g (dry wt.). Among 5 sites studied, the site, Income Tax Office (ITO) was found to be the hotspot attaining highest concentration. Predominance of 2–4 ring PAHs suggests a relatively recent local sources of PAHs in the study area. Moreover, molecular indices based source apportionment also illustrates pyrogenic source fingerprint of PAHs. No significant temporal trend was observed.     

Statistical approaches for hydrogeochemical characterization of groundwater in West Delhi, India

Parametric statistical approaches, correlations and multiple linear regressions were used to develop models for the interpretation of hydrogeochemical parameters in the Western part of Delhi state, India. The hydrogeochemical parameters indicated that the groundwater quality is not safe for consumption. The water is moderately saline and the salinity level is increasing over time. There is also the problem of nitrate pollution. The correlation between electrical conductivity (EC) and other water quality parameters except potassium (K(+)), nitrate (NO(3)(-)) and bicarbonate (HCO(3)(-)) is significantly positive and Ca(++)+ Mg(++)/Na(+)+ K(+) is significantly negative. In predicting EC, the multiple R(2) values of 0.996 and 0.985 indicate that 99.6% and 98.5% variability in the observed EC could be ascribed to the combined effect of Na(+), HCO(3)(-), Cl(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++) for the year of 2005 and 2006 respectively. Out of 99.6% of the variability in EC in 2005, 51.2% was due to Cl(-) alone, and 8.5%, 12.5%, 6.1%, 14.7% and 6.7% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++) + Mg(++). Similarly in 2006, out of 98.5% of the variability in EC, 48.5% was due to Cl(-) alone, and 10.4%, 12.7%, 5.3%, 17.2% and 4.4% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++). The analysis shows that a good correlation exists between EC, Cl(-) and SO(4)(--) either individually or in combination with other ions and the multiple regression models can predict EC at 5% level of significance.     

Assessment of groundwater pollution in West Delhi, India using geostatistical approach

The exploration, exploitation, and unscientific management of groundwater resources in the National Capital Territory (NCT) of Delhi, India have posed a serious threat of reduction in quantity and deterioration of quality. The objective of the study is to determine the groundwater quality and to assess the risk of groundwater pollution at Najafgarh, NCT of Delhi. The groundwater quality parameters were analyzed from the existing wells of the Najafgarh and the thematic maps were generated using geostatistical concepts. Ordinary kriging and indicator kriging methods were used as geostatistical approach for preparation of thematic maps of the groundwater quality parameters such as bicarbonate, calcium, chloride, electrical conductivity (EC), magnesium, nitrate, sodium, and sulphate with concentrations equal or greater than their respective groundwater pollution cutoff value. Experimental semivariogram values were fitted well in spherical model for the water quality parameters, such as bicarbonate, chloride, EC, magnesium, sodium, and sulphate and in exponential model for calcium and nitrate. The thematic maps of all the groundwater quality parameters exhibited an increasing trend of pollution from the northern and western part of the study area towards the southern and eastern part. The concentration was highest at the southernmost part of the study area but it could not reflect correctly the groundwater pollution status. The indicator kriging method is useful to assess the risk of groundwater pollution by giving the conditional probability of concentrations of different chemical parameters exceeding their cutoff values. Thus, risk assessment of groundwater pollution is useful for proper management of groundwater resources and minimizing the pollution threat.     

Role of meteorology in seasonality of air pollution in megacity Delhi,India

The winters in megacity Delhi are harsh, smoggy, foggy, and highly polluted. The pollution levels are approximately two to three times those monitored in the summer months, and the severity is felt not only in the health department but also in the transportation department, with regular delays at airport operations and series of minor and major accidents across the road corridors. The impacts felt across the city are both manmade (due to the fuel burning) and natural (due to the meteorological setting), and it is hard to distinguish their respective proportions. Over the last decade, the city has gained from timely interventions to control pollution, and yet, the pollution levels are as bad as the previous year, especially for the fine particulates, the most harmful of the criteria pollutants, with a daily 2009 average of 80 to 100 μg/m³. In this paper, the role of meteorology is studied using a Lagrangian model called Atmospheric Transport Modeling System in tracer mode to better understand the seasonality of pollution in Delhi. A clear conclusion is that irrespective of constant emissions over each month, the estimated tracer concentrations are invariably 40% to 80% higher in the winter months (November, December, and January) and 10% to 60% lower in the summer months (May, June, and July), when compared to annual average for that year. Along with monitoring and source apportionment studies, this paper presents a way to communicate complex physical characteristics of atmospheric modeling in simplistic manner and to further elaborate linkages between local meteorology and pollution.     

Mapping aboveground woody biomass using forest inventory,remote sensing and geostatistical techniques

Mapping forest biomass is fundamental for estimating CO₂ emissions, and planning and monitoring of forests and ecosystem productivity. The present study attempted to map aboveground woody biomass (AGWB) integrating forest inventory, remote sensing and geostatistical techniques, viz., direct radiometric relationships (DRR), k-nearest neighbours (k-NN) and cokriging (CoK) and to evaluate their accuracy. A part of the Timli Forest Range of Kalsi Soil and Water Conservation Division, Uttarakhand, India was selected for the present study. Stratified random sampling was used to collect biophysical data from 36 sample plots of 0.1 ha (31.62 m?×?31.62 m) size. Species-specific volumetric equations were used for calculating volume and multiplied by specific gravity to get biomass. Three forest-type density classes, viz. 10–40, 40–70 and >70 % of Shorea robusta forest and four non-forest classes were delineated using on-screen visual interpretation of IRS P6 LISS-III data of December 2012. The volume in different strata of forest-type density ranged from 189.84 to 484.36 m³ ha^?1. The total growing stock of the forest was found to be 2,024,652.88 m³. The AGWB ranged from 143 to 421 Mgha^?1. Spectral bands and vegetation indices were used as independent variables and biomass as dependent variable for DRR, k-NN and CoK. After validation and comparison, k-NN method of Mahalanobis distance (root mean square error (RMSE)?=?42.25 Mgha^?1) was found to be the best method followed by fuzzy distance and Euclidean distance with RMSE of 44.23 and 45.13 Mgha^?1 respectively. DRR was found to be the least accurate method with RMSE of 67.17 Mgha^?1. The study highlighted the potential of integrating of forest inventory, remote sensing and geostatistical techniques for forest biomass mapping.     

SEM-EDX analysis of various sizes aerosols in Delhi India

Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) was used to understand the differences in morphology, elemental composition and particle density of aerosols in different five size ranges to further investigate the potential sources as well as transport of pollutants from/at a much polluted and a very clean area of Delhi. Aerosol samples were obtained in five different size ranges viz. > or = 10.9, 10.9-5.4, 5.4-1.6, 1.6-0.7 and < or = 0.7 microm from a considerably very clean and a much polluted area of Delhi. It was observed that at polluted area most of the particles irrespective of size are of anthropogenic origin. At clean area, in coarse size fractions particles are of natural origin while in fine size range the presence of anthropogenic particles suggests the transport of particles from one area to the other.     

Impact of Diwali celebrations on urban air and noise quality in Delhi City,India

A study was conducted in the residential areas of Delhi, India, to assess the variation in ambient air quality and ambient noise levels during pre-Diwali month (DM), Diwali day (DD) and post-Diwali month during the period 2006 to 2008. The use of fireworks during DD showed 1.3 to 4.0 times increase in concentration of respirable particulate matter (PM₁₀) and 1.6 to 2.5 times increase in concentration of total suspended particulate matter (TSP) than the concentration during DM. There was a significant increase in sulfur dioxide (SO₂) concentration but the concentration of nitrogen dioxide (NO₂) did not show any considerable variation. Ambient noise level were 1.2 to 1.3 times higher than normal day. The study also showed a strong correlation between PM₁₀ and TSP (R ² ≥ 0.9) and SO₂ and NO₂ (R ² ≥ 0.9) on DD. The correlation between noise level and gaseous pollutant were moderate (R ² ≥ 0.5). The average concentration of the pollutants during DD was found higher in 2007 which could be due to adverse meteorological conditions. The statistical interpretation of data indicated that the celebration of Diwali festival affects the ambient air and noise quality. The study would provide public awareness about the health risks associated with the celebrations of Diwali festival so as to take proper precautions.     

Assessing the water quality index of water treatment plant and bore wells, in Delhi, India

Water quality monitoring exercise was carried out with water quality index (WQI) method by using water characteristics data for bore wells and a water treatment plant in Delhi city from December 2006 to August 2007. The water treatment plant received surface water as raw water, and product water is supplied after treatment. The WQI is used to classify water quality as excellent, good, medium, bad, and very bad. The National Sanitation Foundation WQI procedure was used to calculate the WQI. The index ranges from 0 to 100, where 100 represents an excellent water quality condition. Water samples were collected monthly from a bore well in Nehru Camp (site 1), a bore well in Sanjay Gandhi pumping station (site 2), and water treatment plant in Haiderpur (site 3). Five parameters were analyzed, namely, nitrate, pH, total dissolved solids, turbidity, and temperature. We found that the WQI was around 73–80 in site 3, which corresponds to “good,” and it decreased to 54.32–60.19 and 59.93–70.63 in site 1 and site 2, respectively, indicating that these bore wells were classified as “medium” quality.     

Inventory compilation and distribution of heavy metals in wastewater from small-scale industrial areas of Delhi, India

Delhi has the highest cluster of small-scale industries (SSI) in India. There are generally less stringent rules for the treatment of waste in SSI due to less waste generation within each individual industry. This results in SSI disposing of their wastewater untreated into drains and subsequently into the river Yamuna, which is a major source of potable water in Delhi, thus posing a potential health and environmental risk to the people living in Delhi and downstream. To study the quantity, quality and distribution of heavy metals in liquid waste from industrial areas, wastewater, suspended materials and bed sediments were collected from industrial areas and from the river Yamuna in Delhi. This study has also focused on the efficiency of production processes in small-scale industries in India. Heavy metals such as Fe, Mn, Cu, Zn, Ni, Cr, Cd, Co and Pb were detected using a GBC 902 atomic absorption spectrometer. The concentration of heavy metals observed was as follows: Fe 2-212, Mn 0.3-39, Cu 0.2-20, Zn 0.2-5, Ni 0.6-6, Cr 0.2-53, Cd 0.08-0.2, Co 0.013-0.55, Pb 0.3-0.7 mg L(-1) in wastewater; Fe 5842-78 000, Mn 585-10 889, Cu 206-7201, Zn 406-9000, Ni 22-3621, Cr 178-10 533, Co 17-114, Cd 13-141, Pb 67-50 171 mg kg(-1) in suspended material; and Fe 3000-84000, Mn 479-1230, Cu 378-8127, Zn 647-4010, Ni 164-1582, Cr 139-3281, Co 20-54, Cd 37-65, Pb 228-293 mg kg(-1) in bed residues. This indicates that SSI could be one of the point sources of metals pollution in the river system.     

Sensitivity analysis of water quality for Delhi stretch of the River Yamuna,India

Simulation models are used to aid the decision makers about water pollution control and management in river systems. However, uncertainty of model parameters affects the model predictions and hence the pollution control decision. Therefore, it often is necessary to identify the model parameters that significantly affect the model output uncertainty prior to or as a supplement to model application to water pollution control and planning problems. In this study, sensitivity analysis, as a tool for uncertainty analysis was carried out to assess the sensitivity of water quality to (a) model parameters (b) pollution abatement measures such as wastewater treatment, waste discharge and flow augmentation from upstream reservoir. In addition, sensitivity analysis for the “best practical solution” was carried out to help the decision makers in choosing an appropriate option. The Delhi stretch of the river Yamuna was considered as a case study. The QUAL2E model is used for water quality simulation. The results obtained indicate that parameters K ₁ (deoxygenation constant) and K ₃ (settling oxygen demand), which is the rate of biochemical decomposition of organic matter and rate of BOD removal by settling, respectively, are the most sensitive parameters for the considered river stretch. Different combinations of variations in K ₁ and K ₂ also revealed similar results for better understanding of inter-dependability of K ₁ and K ₂. Also, among the pollution abatement methods, the change (perturbation) in wastewater treatment level at primary, secondary, tertiary, and advanced has the greatest effect on the uncertainty of the simulated dissolved oxygen and biochemical oxygen demand concentrations.     

Influence of aerosol spectrum and air pollutants on fog formation in urban environment of megacity Delhi, India

Urban areas are facing increasing fog frequencies that may result due to increased air pollution emanating from variety of sources. The increased pollution levels may lead to the atmospheric reactions resulting into the formation of secondary pollutants that may also lead to increased aerosol number concentrations (ANC) in the atmosphere. This could cause enhanced water aerosols in the presence of favourable meteorological conditions and high relative humidity. This study deals with the atmospheric pollution and visibility during winter season of megacity Delhi in order to assess the relationship between the two specifically during fog episodes. Thus, this study analyses the levels of air pollutants, aerosol spectrum and meteorological conditions during one week each in the winter season of the years 2004 and 2006 in order to have an improved understanding of their role in fog formation in mega-city Delhi. More than 300 h of measurements which included episodes of dense, thick and moderate fogs of about 25 h, were studied. The measurements cover most of the accumulation mode and greater size spectrum of aerosols. Thus, the analysis is performed for the entire period, specifically, before the fog sets up, during and afterwards. In general, the relatively small variations in number concentration show larger variations in visibility prior and post dense fog formation than during dense fog episodes. Preliminary analysis of monthly averaged RSPM (Respirable Suspended particulate Matter or PM(10)) concentration values for four winter months for a period of 6 years (1996-2001) and visibility did not show a good correlation with total occurrences of fog. However, daily averaged RSPM concentration showed a good correlation with the occurrences of thick fog. Diurnal variation of Sulfur-dioxide and Nitrogen dioxide were found to have inverse relationship with visibility during fog which may be due to formation of secondary pollutants such as sulfate and to a lesser extent nitrates. Amongst, the daily averaged concentrations of all the criteria pollutants, RSPM was found to be best correlated with the fog in comparison to other pollutants.     

Indicator and probability kriging methods for delineating Cu, Fe, and Mn contamination in groundwater of Najafgarh Block, Delhi, India

Two non-parametric kriging methods such as indicator kriging and probability kriging were compared and used to estimate the probability of concentrations of Cu, Fe, and Mn higher than a threshold value in groundwater. In indicator kriging, experimental semivariogram values were fitted well in spherical model for Fe and Mn. Exponential model was found to be best for all the metals in probability kriging and for Cu in indicator kriging. The probability maps of all the metals exhibited an increasing risk of pollution over the entire study area. Probability kriging estimator incorporates the information about order relations which the indicator kriging does not, has improved the accuracy of estimating the probability of metal concentrations in groundwater being higher than a threshold value. Evaluation of these two spatial interpolation methods through mean error (ME), mean square error (MSE), kriged reduced mean error (KRME), and kriged reduced mean square error (KRMSE) showed 3.52% better performance of probability kriging over indicator kriging. The combined result of these two kriging method indicated that on an average 26.34%, 65.36%, and 99.55% area for Cu, Fe, and Mn, respectively, are coming under the risk zone with probability of exceedance from a cutoff value is 0.6 or more. The groundwater quality map pictorially represents groundwater zones as ??desirable?? or ??undesirable?? for drinking. Thus the geostatistical approach is very much helpful for the planners and decision makers to devise policy guidelines for efficient management of the groundwater resources so as to enhance groundwater recharge and minimize the pollution level.     

Changes in forest biomass carbon stock in Northern Turkey between 1973 and 2006

New forest management and planning approaches are designed to optimize forest structure. Optimal forest structure was determined using newly established growth models while considering primary timber production objectives as well as non-timber objectives for inaccessible areas and social and political pressures on land management. With currently planned management the forests of the Ormanüstü Planning Unit (OPU) in the Black Sea region of northern Turkey are likely to become an important C sink. To quantify this potential C sink and understand its implication to the regional carbon budget and future forest management, we estimated the changes in the OPU between 1973 and 2006. Based on four periods of data for the OPU forests obtained from the Forest Management and Planning Office of Turkey, we used allometric biomass and C regression equations along with biomass expansion factors to estimate the forest biomass carbon pool for each of four inventory years 1973, 1984, 1997, and 2006. Since 1973, OPU forests have accumulated 110.2?×?10³ tons of C as a result of forest expansion and the growth of extant forests, increasing by 50.8 % from 217?×?10³ tons in 1973 to 327.2?×?10³ tons C in 2006. Hardwood and softwood forests accounted for 44 and 56 % of carbon accumulation during this period, respectively. From 1973 through 2006, forest C accumulated at a rate of 3.3?×?10³ tons C year^?1. Carbon density of the OPU forests in the Black Sea region increased by 48.2 % from 5,679 to 8,419 tons/ha.     

Factors and sources influencing ionic composition of atmospheric condensate during winter season in lower troposphere over Delhi, India

Atmospheric condensate (AC) and rainwater samples were collected during 2010–2011 winter season from Delhi and characterized for major cations and anions. The observed order of abundance of cations and anions in AC samples was NH ₄ ⁺ ?>?Ca²⁺?>?Na⁺?>?K⁺?>?Mg²⁺ and HCO ₃ ^? ?>?SO ₄ ^2? ?>?Cl^??>?NO ₂ ^? ?>?NO ₃ ^? ?>?F^?, respectively. All samples were alkaline in nature and Σ _cation/Σ _anion ratio was found to be close to one. NH ₄ ⁺ emissions followed by Ca²⁺ and Mg²⁺ were largely responsible for neutralization of acidity caused by high NO _x and SO₂ emissions from vehicles and thermal power plants in the region. Interestingly, AC samples show low nitrate content compared with its precursor nitrite, which is commonly reversed in case of rainwater. It could be due to (1) slow light-mediated oxidation of HONO; (2) larger emission of NO₂ and temperature inversion conditions entrapping them; and (3) formation and dissociation of ammonium nitrite, which seems to be possible as both carry close correlation in our data set. Principal component analysis indicated three factors (marine mixed with biomass burning, anthropogenic and terrestrial, and carbonates) for all ionic species. Significantly higher sulfate/nitrate ratio indicates greater anthropogenic contributions in AC samples compared with rainwater. Compared with rainwater, AC samples show higher abundance of all ionic species except SO₄, NO₃, and Ca suggesting inclusion of these ions by wash out process during rain events. Ionic composition and related variations in AC and rainwater samples indicate that two represent different processes in time and space coordinates. AC represents the near-surface interaction whereas rainwater chemistry is indicative of regional patterns. AC could be a suitable way to understand atmospheric water interactions with gas and solid particle species in the lower atmosphere.     

Distribution and Fractionation of Heavy Metals in Solid Waste from Selected Sites in the Industrial Belt of Delhi, India

Solid waste samples were collected from five small-scale industrial sites in the National Capital Territory (NCT) of Delhi. These industrial sites represent the regional spread of the industrial belt in the NCT of Delhi. Solid waste samples were digested using aqua-regia and HF in air tight teflon bombs for the quantitative analysis of heavy metals (Hg, Pb, Cd, Mn, Fe, Ni, Cu and Zn) by GBC model 902 atomic absorption spectrophotometer. Hg was analysed using hydrid generator attachment. Beside this sequential extraction was used to fractionate five heavy metals (Pb, Ni, Cd, Cu and Zn) into six operationally defined phases, viz. water soluble, exchangeable, carbonate-bound, Fe-Mn oxides, organic-bound and residual fractions to ascertain the relative mobility of these metals. The result obtained showed metal concentration to be in the range of Hg 0.42-2.3; Pb 23-530; Cd 014-224; Mn 494-19 964; Fe 35 684-233 119; Ni 192-1534; Cu 3065-10 144 and Zn 116-23 321 (all units in mg kg(-1)) in all the industrial areas studied. The fractionated toxic metals like Pb, Ni and Cd were observed to be in the range of 25-35, 15-50 and 40-50%, respectively, in mobile or bio-available fractions of solid waste. As this waste is often disposed-off by the roadsides, low lying areas, abandoned quarries or in landfill sites which are often not properly planned, thus posing potential risk to ground and surface water quality to millions of people living downstream.     

Hydrochemical characterization and pollution assessment of groundwater in Jammu Siwaliks,India

Physico-chemical groundwater (GW) parameters were evaluated to understand the hydrogeochemical processes in the Siwalik plains of Jammu and Kashmir, India. During the 2012–2013 post-monsoon (POM) and pre-monsoon (PRM) seasons, GW samples (n = 207) from deep bore wells and shallow open wells were chemically analysed. Cations (Ca²⁺, Mg²⁺, Na⁺, K⁺ and Fe²⁺) and anions (HCO₃ ^?, Cl^?, SO₄ ^2? and F^?) showed a wide spatio-temporal variation. Results suggest that weathering and dissolution of carbonates and silicate rocks is the main source of water mineralization. The major hydrochemical facies is characterized by Ca-Mg-HCO₃ and Ca-HCO₃ during the PRM and POM seasons respectively. The presence of sulphate-bearing water in a large number of the samples indicates a significant role of gypsum dissolution and anthropogenic contamination of the GW. Factor analysis (FA) and hierarchical cluster analysis (HCA) revealed that the variability of hydrochemistry is mainly related to rock-water interaction, dissolution of carbonates and other lithological units as well as the influence of anthropogenic activities in the area. Overall, it was found that the GW quality is within the limits of human consumption. The higher concentration of a few chemicals indicates an increasing trend of industrial contamination of the GW. For sustainable development of the portable GW in Siwaliks, it is necessary to minimize the adverse impacts of the anthropogenic and industrial contamination on the GW resources through best management practices and prevent its further contamination to a level that could make GW unsuitable for human uses.