Asian Journal of Water, Environment and Pollution - Volume 4, issue 2

Authors: Ranjan, Priyantha | Gupta, Ashim Das | Kazama, So | Sawamoto, Masaki

Article Type: Research Article

Abstract: In the present study, DRASTIC model has been used as a feasible methodology to assess the groundwater vulnerability in the Walawe river basin, Sri Lanka. Geographical Information System (GIS) has been used to develop vulnerability maps, explaining the relative vulnerability of the area. The DRASTIC output concluded that the upper and western parts of the basin show very low vulnerability while the lower part shows higher vulnerability. The groundwater vulnerability maps are compared with the agricultural …land-use pattern of the area and it is noticed that the intense agricultural areas and high DRASTIC index areas are overlapped. To emphasise the natural state of the aquifer media as well as the potential pollution of extensive land use, a new indicator has been introduced as Aquifer-Land use Composite Vulnerability Index. This indicator further concludes that the lower part of the Walawe River basin depicts a higher risk for future groundwater quality and hence more attention should be focused to establish monitoring network for adequate groundwater quality control in the area. Show more

Keywords: Groundwater pollution, vulnerability, DRASTIC index, land use, GIS

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 1-10, 2007

Article Type: Other

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 1-6, 2007

Authors: Kashefipour, S.M. | Tavakoli, A.A. | Falconer, R.A.

Article Type: Research Article

Abstract: Sediment and solute transport processes are the most important existing problems in the coastal, estuarine and riverine waters. Prediction of these processes may be carried out using the numerical solution of the partial differential and dynamic Advective–Diffusion Equation (ADE). The type of the numerical solution is considerably effective on the stability and accuracy of the solution. In this paper an integrated new and effective scheme has been presented, combining two different numerical methods including ULTIMATE …QUICKEST (UQ) and finite difference central scheme for solving ADE. This integrated model was verified using a standard example, and was then successfully applied to predict the suspended sediment concentrations in the Humber river (UK). Show more

Keywords: Numerical modelling, sediment and solute transport, ULTIMATE QUICKEST scheme, advective diffusion equation

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 11-15, 2007

Authors: Prasad, Bably | Kr. Mondal, Kajal

Article Type: Research Article

Abstract: More than 100 million tonnes of coal fly ash is produced annually in India from combustion of coal in power plants. It is expected that up to 2020 AD about 150 million tonnes of coal ash will be produced due to burning of coal in power plants. This will require about 30,000 hectare of land for ash disposal. One of the main problems in disposing of big quantities of coal ash is the possible leaching of different pollutants, including fluoride. …A thorough investigation regarding leaching of fluoride from fly ashes is much essential to know the impact of fluoride due to its leaching from fly ash to ground water as well as surface water. In the present paper, short term and long term leaching studies have been carried out on fly ash, bottom ash, pond ash and weathered ash of Chandrapura thermal power station (CTPS), Jharkhand and Ramagundam thermal power station (RTPS), Andhra Pradesh. The amount of fluoride released in different experiments has been evaluated. A field investigation at Damoda abandoned open cast mine of Bharat Coking Coal Limited, filled with pond ash of CTPS has been done. Concentration of fluoride in ground water beneath the ash filled mine has been evaluated on monthly basis. Environmental impact of fluoride and remedial measures for ash disposal has been discussed. Show more

Keywords: Fluoride leaching, fly ash, ground water

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 17-21, 2007

Authors: Abbas, Abderrahim

Article Type: Research Article

Abstract: The steady-state and periodic performances of a seawater desalination unit based on a small-scale commercial spiral-wound membrane were studied. For the steady-state case, operating pressures ranging from 30 bar to 50 bar and temperatures ranging from 22°C to 28°C were investigated. As expected, increasing the pressure resulted in improvements in the water recovery, salt rejection and energy consumed by the feed pump per m^3 of permeate produced. The improvements were larger for …operation at low to moderate pressures than at high pressures. Both the permeation rate and salt rejection changed linearly with temperature; the permeate flux increased by 2.8%/°C whereas the salt rejection decreased by 0.007%/°C. For the case of unsteady-state operation, the operating pressure was varied according to a symmetric square wave function around an average pressure of 50 bar. The production rate increased as the period of the wave decreased. Such an improvement was obtained at the expense of a marginal increase in the total energy consumed. For a wave period of two minutes, the production rate increased by 8% over that obtained from steady-state operation while the energy consumed increased by a mere 0.15%. A simple theoretical analysis showed that a 12.3% improvement in the permeation rate would be obtained in the absence of concentration polarization. The salt rejection was not affected by this mode of operation. Show more

Keywords: Reverse osmosis, spiral-wound membranes, seawater desalination, membrane performance, periodic operation

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 23-29, 2007

Authors: Kot, F.S. | Bakanov, K.G.

Article Type: Research Article

Abstract: Natural waters of the spacious Arctic regions of Russia are studied insufficiently and they are still opened to the most important questions. This paper presents the results of in situ hydrochemical study of a small catchment in Arctic mountain tundra of the Koryak Highland, north-eastern Siberia, situated far from industrial centres and populated territories. The results showed a surprisingly high content of inorganic nutrients in natural waters – stream, swampy and rainy. For the basin main …water collector – the Levtyrinyvayam River – it was as following (μM): NO_3^- -N (134 ± 66), NO_2^- -N (1.1±0.4), NH_4^+ -N (11.1±5.6), PO_4^{3-} -P (2.42±1.79) and K^+ (31±36), indicating the intensive organic matter decomposition and the nutrient saturation in the local terrains. Specific conditions of the mountain ecosystem, i.e. contrast soils, and influence from shallow-lying permafrost resulted in the rate of the nutrients' saturation of the waters. The results prove the great importance of organic matter and its derivatives in investigation of natural waters. Show more

Keywords: Nutrients, nitrogen, Arctic mountain tundra, natural waters, small catchment, Koryak Highlands

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 31-36, 2007

Authors: Imo, S.T. | Hirosawa, E. | , M.A. | Sheikh , | Tamaki, F. | Oomori, T.

Article Type: Research Article

Abstract: We investigated eight organochlorine pesticides (OCPs) in the rivers of southern part of Okinawa Island, Japan, from July to September 2005. The mean concentration for ΣBHC (α, β, γ, δ-BHC) in four rivers was 25.67 ± 58 ngL^{-1} (mean ± SD). The highest concentration of BHC detected in water samples was 49.10 ngL^{-1} . Other OCPs such as Aldrin, Dieldrin, Heptachlor epoxide (Isomer B) and Methoxychlor were also detected in most water samples …with their mean concentrations of 6.96 ± 80, 4.33 ± 59.9, 3.16 ± 55 and 2.01 ± 57.6 ngL^{-1} . Within the monitoring period, the concentration of OCPs increases in July and August (Aldrin, α-BHC and β-BHC). The possible sources of these OCPs might be the effluents and dusts from residential areas and agricultural activities. The levels of OCPs in rivers in southern part of Okinawa were generally below the guideline values in Japan. This preliminary documentation of OCPs in river waters from southern part of Okinawa Island revealed that the rivers are lightly contaminated and suggesting more monitoring studies in order to protect the health of aquatic systems and accompanied life. Show more

Keywords: River waters, organochlorine pesticides, Okinawa Island

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 37-42, 2007

Authors: Mansouri, Rachid | Yahia, Hammar | Tröger, Uwe

Article Type: Research Article

Abstract: In this study a physically based hydrological model coupled with the SCS curve number method is presented to assess the runoff changes due to land-use changes. In order to approach a reasonable result in hydrologic modelling, satellite-based remote technologies are used to extract land surface parameters. For known rainfall event, future changes in land use can also be incorporated in the model once digital database is available and the change in runoff hydrographs can be estimated. …The study clearly demonstrates that the integration of spatial data and the application of a physically based model in a remote sensing environment provide a powerful tool for the assessment of an effect due to land-use change. Show more

Keywords: Runoff hydrographs, land-use changes, urbanization, remote sensing, hydrological model, SCS curve number

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 43-47, 2007

Authors: Yadav, Brijesh K. | Keshari, Ashok K.

Article Type: Research Article

Abstract: In coastal environment, the availability of good quality surface water draws significance because of salinity problems that mainly arise because of salt-water intrusion and tidal flow. The temporal extent of salinity and dynamics of surface water through a lake are basic information needed for water resources management. In this study, a coupled mathematical model for water and salt balance has been presented to simulate the bank storage, outflow and outflow salt concentration. The model has been …applied to the lake Flat bay, situated on the northern side of Port Blair in Andaman and Nicobar Islands, India. Water and salt budgets are used to predict the behaviour of this natural lake in terms of both quality and quantity. Convolution relation is used to simplify the mathematics of bay-bank interaction for estimating bank storage flow. Flow in and out of the aquifer at the bay bank is determined for the semi-infinite aquifer for different aquifer parameters to investigate the sensitivity of the bank storage flow. The model developed herein will be an efficient tool for appropriate development of coastal bays and reservoir regulation strategies to meet the fresh water demand in coastal areas and also to ensure appropriate management of water resources in terms of both quality and quantity. Show more

Keywords: Bank storage, water budget, salt budget, Flat bay, lake modelling

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 49-55, 2007

Authors: Madhoo, Yeti Nisha

Article Type: Research Article

Abstract: The paper attempts to ascertain the feasibility of reducing potable water deficits by charging residential consumers higher prices. The Contingent Valuation Method (CVM) is used to find out whether an upward revision of residential water tariffs would be compatible with consumer preferences and hence also politically feasible. Survey techniques using dichotomous choice format questions have been employed to elicit respondents' willingness to pay (WTP) for improved water services. The bid variable is found …to be statistically significant in both the bivariate and multivariate logit models. Moreover, mean and median WTP estimates generated from these models are found to be much higher than what would be required by the first best standard (long run marginal cost) and the second best (average cost). Show more

Keywords: Public utility budgets, marginal cost pricing, contingent valuation methodology, Mauritius

Citation: Asian Journal of Water, Environment and Pollution, vol. 4, no. 2, pp. 57-64, 2007