Contaminant Source Identification Using Dating and Ann Techniques

-- S V N Rao, Bhishm Kumar and S Manju

Two approaches involving source identification using dating and artificial neural network (ANN) are demonstrated within a conceptual modeling framework. The first approach helps in reconstructing historical contaminant loading at a given location, using concepts of dating or age of the contaminant material moving with groundwater at an observation well. The second approach using ANN is superior as it helps identifying both source strength and its explicit location in a finite difference grid system. Both the cases are demonstrated using synthetic data by assuming contaminant sources at random locations and by generating concentration profiles at observation wells with the help of existing groundwater flow and transport simulators.

© 2008 IUP . All Rights Reserved.

Heavy Metal Concentrations in the Soils and Shrubs Near a Metal Processing Plant in Peninsular Malaysia

-- Chua S Y and Hashim N R

Industrial areas pose pollution risks because the emissions of heavy metals from these sources are normally high. This study was conducted to determine the concentrations of selected heavy metals (zinc, chromium and copper) in the soils and leaves of a shrub species, Melastoma malabathricum around a metal processing plant. Soil samples were taken in three directions away from the source. After soil digestion using the aqua regia method, the total concentration of each heavy metal was determined using Atomic Absorption Spectrometer (AAS). Leaf samples were taken from one plant per location whenever available. Prior to heavy metal determination using AAS, the foliar samples were prepared using the dry ash method. Results showed that heavy metal concentrations were lowest in the northeast direction, where the wind was blowing for most of the time, but for only a short distance (<600 m) from the source. It is suggested that inputs from other sources, e.g., vehicles and agricultural activities also increased the total heavy metal concentrations in the soils. When compared to general heavy metal concentrations in soils (Alloway, 1990), the zinc and copper concentrations in this study were in the low range (below critical soil total concentration), but chromium concentrations were varied (low to high range). The results for foliar heavy metal concentrations showed no clear pattern between the soil total and plant concentrations for zinc. For chromium and copper, foliar heavy metal concentrations were higher than the soil total concentrations for three locations (5 km northeast, 5 km north and 100 m east). Two locations, however, showed the opposite patterns. When compared to the general foliar heavy metal concentrations (Alloway, 1990), foliar zinc concentrations in the study were below the critical concentration as did most of the foliar copper concentrations, but foliar chromium concentrations were higher than the critical concentrations where toxicity effects might have been likely. But the sampled M. malabathricum plants did not show any visible sign of foliar injury. Nonetheless, M. malabathricum showed a capacity for Cr, Cu and Zn uptake regardless of the soil total concentrations of these heavy metals. This study provides important information on the state of heavy metal pollution in lowland soils and plants of Peninsular Malaysia.

© 2008 IUP . All Rights Reserved.

Mercury Exposure in Coastal Communities of Kedah and Kelantan, Malaysia

-- Tengku Hanidza T I, Tunku Khalkausar T F,
Yasutake A, Sharifuddin M Zain,
Hafizan Juahir and Rosta Harun

A cross-sectional study of mercury concentration in hair was conducted in two rural coastal communities of Yan (state of Kedah) and Bachok (state of Kelantan) from March to May 2006. For the comparative groups, the urban communities of Alor Setar (Kedah) and Kota Bharu (Kelantan) were chosen. This study was carried out in collaboration with the National Institute for Minamata Disease (NIMD), Minamata, Japan. A total of 201 hair samples were collected from the residents. Samples were analyzed by the NIMD, using the oxygen combustion-gold amalgamation method. The geometric means for total mercury in each district were 1.38 ppm (Yan), 1.20 ppm (Alor Setar), 1.24 ppm (Bachok) and 1.07 ppm (Kota Bharu). Two persons, each from Alor Setar and Kota Bharu, had high total mercury (washed sample 223.58 ppm and 803.16 ppm respectively). However, further analysis for methyl mercury showed that the levels were within 1.36 ppm and 1.91 ppm, respectively. Of the ten exposure parameters tested, only age (p < 0.001) and fish consumption (p < 0.01) appeared to have significant effect on hair mercury levels.

© 2008 IUP . All Rights Reserved.

Studies on Surface Water Quality Evaluation and Soil Nutrient Status of Bellary Nala Catchment, Belgaum

-- B K Purandara and N Varadarajan

Belgaum is considered as the second capital of Karnataka. The process of urbanization here is very fast, bringing more and more villages into the city arena. However, there are limited facilities for sewage treatment and recycling. Sewage water from the city is diverted through Bellary nala which flows through the major part of the city. In some parts of the city farmers use this sewage water for agriculture purpose. Sewage water when used for agriculture, poses the threat of soil and water contamination in the locality. Some of these (chemicals) contaminants remain in the root zone, whereas some are transported downward with water, particularly where more water infiltrates into the soil than is used by the crop. To understand the impact of some of these chemicals, it is important to investigate the processes that control their movement from the soil surface through the root zone down to the groundwater table. In this connection, a preliminary investigation was conducted in the year 1999 and again 2004 to evaluate the water quality parameters of Bellary nala and the nutrient status of the soil where sewage water is used for agriculture. The study indicated that water is highly contaminated in terms of its major constituents particularly during the summer months. DO - BOD estimation also indicated that the Bellary nala water needs some treatment before being used for agriculture purpose. In order to get preliminary information, groundwater status in the adjoining areas of the catchment data has been collected and analyzed which indicated that the impact of sewage water is negligible except in few patches like Kudchi and Shahpur areas of the city.

© 2008 IUP . All Rights Reserved.

Study of Hydrological Characteristics and Level of Metals Present in Four Sites of Sewage Released into Holy River Saryu of Ayodhya-Faizabad

-- Sanjeev K Srivastava and G C Pandey

The holy river Saryu has been facing serious pollution problem as the input of sewage, industrial, agricultural and domestic wastes are contaminating the river resources. Therefore, it was envisaged to analyze the hydrological characteristics and level of metals of holy river at four major sites (A-Kakarahi Bazar, B-Retia, C-Jamthara Ghat and D-Sahebganj Nalla) of Ayodhya-Faizabad. A laboratory study was conducted to understand the hydrological characteristics (pH, Temperature, EC, Free CO₂, TDS, DO, BOD, COD, Total Hardness, Nitrate-N, Phosphate-P and Sulphate as SO₄) and the level of metals (Cu, Cd, Zn, Fe, Pb, Mn and Cr) of city sewage water which was released into holy Saryu river through four major discharging sites. The results revealed that out of the four sites, site-D was more polluted, as all these parameters were found to be beyond the permissible limit. Since the municipal sewage treatment plants are not available, therefore it is suggested that before releasing the sewage, treatment plants should be properly made to maintain ecological balance of the holy river for the growth and survival of the organisms including human health.

© 2008 IUP . All Rights Reserved.

Rainwater Chemical Characteristics for Climate Change Studies

-- Hariprasad P, Valli Manickam and Murali Krishna I V

Rainwater chemical composition was studied in eight selective mandals for two years during monsoon season. Rainwater was collected at mandal head quarters during 2006-2007. The Total Anions/Total Cations (TA/TC) ratio indicated that the chemical nature of rainwater was alkaline. Alkalinity may be due to anthropogenic origin as the area shown high corrections of calcium and magnesium due to industrialization.

© 2008 IUP . All Rights Reserved.