Potential Groundwater Pollution Research Articles

Assessment of Groundwater Pollution Potential Using GIS and Modified Drastic Model in Selangor, Malaysia

This study covered the assessment of groundwater pollution potential using modified DRASTIC model and GIS based on hydro-geological environmental parameters Selangor State in Malaysia. The modification of ranges and ratings index in DRASTIC was done using GIS to accommodate hydro-geological settings to implement and adopt data according to Selangor hydro geological environmental parameters. The groundwater pollution potential map showed that the high risk groundwater pollution potential covered 17% of study area in west side of Selangor however, 27% of the east side of Selangor exposed to low risk groundwater pollution potential. Most of the affected area was considered in low land area along the coastal in shallow groundwater table alluvial aquifer. The results significantly show that groundwater pollution potential map was successfully developed using hydro-geological parameters for Selangor area.

Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates

Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD₅) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD₅/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.

Development of reactive artificial liner using recycled materials. 1. Mechanical properties and chemical compatibility

There have been several studies showing that volatile organic compounds (VOCs) can diffuse a geomembrane within days and migrate to groundwater and the surrounding environment. To ease the concern of potential pollution of the surrounding environment, an alternative artificial liner consisting of recycled materials is proposed. This composite liner consisted of recycled crumb rubber, organo-clay, silica fume, and epoxy binder. Dimethyl sulfoxide, an environmentally-friendly solvent recycled from paper pulp, was used as a plasticizer. The objective of this study was to determine the best combination of ingredients used at the initial stage and to develop artificial liners suitable for containing VOCs in leachate by comparing various physical properties. A series of screening tests including bending, tearing and elongating was performed to determine the most suitable mixture ratios. Then, more intensive tests were performed with the specimens that had the best physical properties. The new artificial liner demonstrated satisfactory mechanical properties with the minimum elongation and maximum strength after 40 years. Both artificial liners and high-density polyethylene (HDPE) specimens had ~136 kg cm(-2) after 4 months of thermal stress while the artificial liner had 40% less elongation at break than HDPE. The artificial liner's fully developed strength was about ten times stronger than HDPE. This new type of composite material that can be applied on site may provide a new perspective in liner design and alleviate the issue of potential groundwater pollution caused by landfill leachate and highly mobile VOCs which is a matter of much concern.

Groundwater Vulnerability Assessment and Validation for a Fast Growing City in Africa: A Case Study of Lagos, Nigeria

Lagos is the world’s sixth largest city, the most populous city in Africa and the most populous city inNigeria. A total of eighteen groundwater exploitation borehole logs together with hydrogeological and geotechnical data were used for the study. The eighteen available borehole logs were categorized into seven areas spanning the shoreline to inland boundary ofLagosState. The study area has a high net recharge of1838 mm/yr and the aquifer media is sand. The intrinsic vulnerability map show areas of highest potential for groundwater pollution based on hydro-geological condition and human impacts. Seven major hydro-geological factors incorporated into DRASTIC model and the geographic information system (GIS) were used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The output map shows that the southeast of the aquifer is under very high vulnerability while central parts of aquifer have high vulnerability. Other parts (north, northwest and south) of the study area have moderate vulnerability to pollution. For testing of the vulnerability assessment, groundwater quality data were collated from literature for the different vulnerability zones of the study area. The chemical analysis results show that both the southeast and northwest west parts of study area aquifer (very high and moderate vulnerability zones) have higher nitrate concentration relative to the rest of aquifer, that are located in high vulnerability zone. The validation of the DRASTIC models was accomplished through pair wise comparison of DRASTIC vulnerability maps (using Pearson’s r correlation coefficient) with a total of 14 layers representing original DRASTIC input data, Land cover (LC) features, and groundwater TDS, Cl- and NO3 data. Results from the correlation analysis indicate a significant association between high groundwater TDS, NO3 concentrations and distances from certain LC types.

Potential Groundwater Pollution Risks by Heavy Metals from Agricultural Soil in Songon Area (Abidjan, Côte d’Ivoire)

The soil samples were collected taking into account the land use in Songon area. The hydraulic conductivity (K) of soils was characterized in-situ when specific yield (Sy), pHw and concentrations of Cooper, Iron, Zinc, Cadmium, Chromium and Lead were measured in the laboratory. Pollution load indices (PLI) were calculated to evaluate the soil contamination levels. The soils were neutral and alkaline (6.7≤ pH ≤ 9.20), permeable (1.9 í 10-5 m·s-1 ≤ K ≤ 8.2 í 10-4 m·s-1), with a high specific yield (13.33% ≤ Sy ≤ 33.33%) which can favor the pollutants transfer. The heavy metals (Fe, Cu, Zn, Cd, Cr and Pb) have very high concentrations in soils. The integrated pollution indices (PLI) indicate that almost 70% of Songon soils are moderately contaminated by the investigated heavy metals, with windows presenting high indices of pollution related to the intensive use of fertilizers and pesticides. The establishment of new boreholes in the Songon area should consider these heavy metals, so as to avoid the risk of groundwater pollution due to the physical properties of soils.

Removal of plant pathogens from recycled greenhouse wastewater using constructed wetlands

Because of the lack of high-quality water and the potential pollution of groundwater by leached nutrients, recirculation of nutrient solutions for greenhouse production is now unavoidable. Although closed growing systems offer several advantages from an environmental standpoint, the risk of pathogen dissemination is a major concern for growers. Constructed wetlands represent an ecological and low-cost alternative method for treating agricultural wastewaters. The objective of this study was to evaluate the effectiveness of three types of constructed wetlands for removing the waterborne plant pathogens, such as Pythium ultimum and Fusarium oxysporum, that can be found in greenhouse wastewater. The experiment was conducted in a greenhouse using three types of horizontal subsurface-flow constructed wetlands in eight replicates. The wetlands were filled with pozzolana, planted with common cattail (Typha latifolia) and supplemented with sucrose or compost carbon sources or left without an external carbon source. The wetland units received reconstituted greenhouse wastewater and were inoculated five times consecutively with P. ultimum and F. oxysporum at 106CFUmL−1. Physical, chemical and biological properties as well as environmental parameters were evaluated during 12 weeks to characterize conditions related to plant pathogen removal efficiency. Even though 99.62–99.99% efficiency for pathogen repression was observed for the constructed wetlands, the compost amendment to the wetland promoted the development of biofilm around the filter media and the production of cell-wall degrading enzymes. Depending on the source of carbon that was provided to promote microbial population growth and wetland activity, different possible modes of action for pathogen removal were predominant but resulted in very high efficiency, considering that the wetlands were inoculated with massive populations of plant pathogens that are not found at the commercial level. This study showed that constructed wetlands can constitute an efficient and safe alternative to treat and then reuse greenhouse wastewater.

Long-term net N mineralization potential as an indicator for soil fertility: chances and constraints

The soil capacity to supply nitrogen (N) to crops through decomposition of soil organic matter (SOM) is a main indicator for soil fertility. Assessment of a soil net N mineralization potential via long-term laboratory incubations accounts for many of the influencing factors as it integrates the activity of soil micro-organisms and to some extent, the physical accessibility of SOM. A two-pool first-order kinetic equation was used to fit cumulative net N mineralization data from incubations. It allowed the identification of a fast mineralizable N pool, Nfast (N in fresh residues), and a slow mineralizable N pool, Nslow, which mainly consists of humified SOM. Since the latter represents long-term soil N supply and is a mostly inherent soil property, it could be used as an indicator for soil fertility. We will present results from different studies: • A watershed study (NW-Germany), where reliable pedotransfer functions for site-specific estimates of pool size Nslow were derived. • A study in the Kalahari region, where the approach helped to understand the relevance of the soil net N mineralization potential for groundwater pollution with nitrate. • A study aiming to develop an internet-service for field-specific simulations of current net N mineralization (NW-Germany).

A GIS-based DRASTIC model for assessing groundwater vulnerability in the Ordos Plateau, China

Groundwater plays a key role in arid regions as the majority of water is supplied by it. Groundwater pollution is a major issue, because it is susceptible to contamination from land use and other anthropogenic impacts. A study was carried out to build a vulnerability map for the Ordos Plateau using the DRASTIC model in a GIS environment. The map was designed to show the areas of the highest potential for groundwater pollution based on hydrogeological conditions. Seven environmental parameters, such as depth to water table, net recharge, aquifer media, soil media, topography, impact of the vadose zone media, and hydraulic conductivity of the aquifer, were incorporated into the DRASTIC model and GIS was used to create a groundwater vulnerability map by overlaying the available data. The results of this study show that 24.8 % of the study area has high pollution potential, 24.2 % has moderate pollution potential, 19.7 % has low pollution potential, and the remaining 31.3 % of the area has no risk of groundwater pollution. The regional distribution of nitrate is well correlated with the DRASTIC vulnerability index. In contrast to this, although the DRASTIC model indicated that the western part had no risk, nitrate concentrations were higher in some of these areas. In particular, higher nitrate concentrations were recorded along river valleys and around lakes, such as the Mulin River valley. This is mainly caused by the intensive agricultural development and favorable conditions for recharge along river valleys.

Assessment of the Leaching Potential of 12 Substituted Phenylurea Herbicides in Two Agricultural Soils under Laboratory Conditions

In this study, the potential groundwater pollution of 12 substituted phenylurea herbicides (chlorbromuron, chlorotoluron, diuron, fenuron, fluometuron, isoproturon, linuron, metobromuron, metoxuron, monolinuron, Monuron, and neburon) was investigated under laboratory conditions. For this purpose, leaching studies were conducted using disturbed soil columns filled with two different agricultural soils, one hypercalcic calcisol (HC) and the other endoleptic phaeozem (EP). In the case of the HC, all of the studied herbicides were found in leachates, while for the EP only, chlorbromuron, chlorotoluron, isoproturon, monolinuron, and, especially, fenuron were recovered. For both soils, the groundwater ubiquity score (GUS) index was calculated for each herbicide on the basis of its persistence (as t(1/2)) and mobility (as K(OC)). The half-lives obtained were markedly higher in the EP (217-518 days) than in the HC (71-178 days). As a consequence, higher values of GUS indexes were observed for EP. The ratio of the GUS between the EP and the HC was about 1.3.

TOMATO YIELD, NITROGEN UPTAKE AND USE EFFICIENCY IN RELATION TO NITROGEN FERTILIZATION LEVELS

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Greenhouse 2010 and Soilless Cultivation TOMATO YIELD, NITROGEN UPTAKE AND USE EFFICIENCY IN RELATION TO NITROGEN FERTILIZATION LEVELS

지하수 오염방지를 위한 산업폐기물 관리평가 모델(IWEM)의 국내 적용성 분석

Selection of appropriate liner type would be the most important factor to prevent groundwater contamination by leachate from waste management site. This report introduces the IWEM (Industrial Waste Management Evaluation Model) developed by US EPA to evaluate the potential pollution of groundwater under the waste management unit and to suggest an appropriate type of liner, and provides with the results of IWEM application to a coal-ash landfill site in Korea as a case study. IWEM uses a standard method using a database, a decision-making process based on site characteristics, and the user-friendly input-and-output system. Authors evaluate this model to be applicable in Korea provided that the database is replaced into local data.

Physio-Chemical Properties and Hydraulic Characteristics of Reconstruction Soil Filling with Fly Ash

Abstract. Efficient full use of fly ash is still an important issue which has been troubled by the developing countries like China, and a large area subsidence as a result of coal mining also give rise to serious damage for agricultural soils. The agricultural soil profile reconstruction is great significance with fly ash as a substrate because of combining the two problems. In this paper, the feasibility of soil reconstruction is discussed through studying the physio-chemical properties and hydraulic characteristics of fly ash. The results show that the physio-chemical properties of fly ash layer in reconstruction soil profile tend to healthy development with rehabilitation time increasing. Though fly ash layer has a higher water content and poor ability of water vertical upward movement compared to surface soil, but the parameters values are basically appropriate to crop production and not evidently decreasing yields. As for potential groundwater pollution due to solute downward transport of reconstruction soil, we will start further research and draw up solution.

Evaluating and managing potential groundwater pollution from leaking USTs at a coastal city in saudi arabia

Leaking underground fuel storage tanks (USTs) are the main source of petroleum hydrocarbon contamination of soil and groundwater. The distribution and fl ow of the leaked hydrocarbon is infl uenced by capillary and gravity forces. Depending on the leaked volume and the soil properties, the hydrocarbon could exist as a residual phase completely held in the soil above the water table or as both free phase product and residual. Various components of gasoline will affect the groundwater quality and each will spread according to its own characteristics. The pollution processes are studied through the development of a combination of two models: a compositional and a potential fl ow model. The former was developed using the mass balance principle and is capable of using the organic compound and the subsurface properties to predict the concentration of the various components of benzene, toluene and xylene (BTX) mixture in a leachate from a site contaminated by a residual mixture. Potential fl ow theory was utilized to model the advective transport of contaminants towards municipal wells. Capture zones were defi ned and travel times for different municipal wells were estimated for a sample study area at a coastal city in eastern Saudi Arabia. Modeling and fi eld survey indicated the high potential for groundwater pollution and concluding that more effort should be directed to promote leak prevention through management strategies that include developing proper design regulations and installation requirements like monitoring wells for new and existing service stations.

Nitrate pollution of Neogene alluvium aquifer in Morogoro municipality, Tanzania

Concern over nitrate pollution of groundwater in integrated water quality management has been growing recently. The levels of nitrate in wells from septic tanks and urban agriculture with nitrogen fertilizers application may increase the potential groundwater pollution by nitrate. The purpose of this study was to determine the concentrations and spatial distribution of nitrate (NO3 -) in groundwater in Morogoro municipality. Groundwater samples were collected from 20 wells during wet season period in March-April 2010 in 6 wards namely Kihonda, Mji Mpya, Mafisa, Saba Saba, Boma and Kilakala. The spectrophotometer was used to measure the NO3 - concentration in water samples. The minimum and maximum nitrate levels were 1.4 and 32.5 mg/L respectively in the wards studied with an average of 7.76 mg/L. These results showed that all of the groundwater samples have NO3 - concentration below the Tanzania Bureau of Standards upper limit value and World Health Organization guideline of 75 mg/l and 50 mg/l respectively. Also, the level of nitrate concentration tends to decrease with depth for most of the places due to the anoxic condition that is available at the higher depth which facilitates the utilization of nitrate by anaerobic microorganisms.

Groundwater Dynamics and Quality Assessment in an Agricultural Area

Problem statement: The analysis of the relationships among the different hydrogeological Units and the assessment of groundwater quality are fundamental to adopt suitable territorial planning measures aimed to reduce the potential groundwater pollution especially in agricultural regions. In this study, the characteristics of groundwater dynamics and the assessment of its quality in the Cuneo Plain (NW Italy) were examined. Approach: In order to define the geological setting an intense bibliographic analysis has been performed by the authors. This analysis was implemented by several correlated land controls and specific surveys that have permitted to analyze to certain reliability the Quaternary evolution of the entire plain sector and the current relationships among the different geological bodies that strongly affect the groundwater dynamics. Results: The Quaternary alluvial deposits overlap a Tertiary sedimentary succession through a series of erosional unconformity surfaces. These Quaternary deposits highlight a variable thickness ranging from 80-100 m in the foothills of the mountains up to a few meters in the more distal portion of the plain. In these deposits there are several unconfined aquifers which are not hydraulically interconnected due to the deep fluvial incisions that reach the underlying tertiary substrate. The Cuneo plain is intensively populated and lot of villages and farms characterize the landscape. In the overall area it is present an intensive agricultural and livestock activity predominantly represented by crops of wheat and corn and farms of cattle and pigs. All these activities represent point and diffuse groundwater pollution sources and require a considerable amount of groundwater which is withdrawn from the Quaternary aquifers by means of thousands of water wells. The groundwater quality is strongly influenced by the content of nitrates and manganese. The nitrates are linked to pollution due to agricultural activities and livestock and increase along the groundwater flow lines. The manganese content is quite high in the foothills of the mountains and in some restricted areas of the plain and appears to be linked to the natural litho logical composition of the aquifers. Conclusion: Due to high degree of intrinsic aquifers vulnerability over the entire Cuneo plain sector in order to reduce the actual groundwater pollution and the risk for human health it has to be planned several territorial suitable planning actions aimed to limit nitrates effluents and livestock untreated discharges according with the European rules.

An investigation of heavy metal and migration through groundwater from the landfill area of Eskisehir in Turkey

This paper was conducted in order to determine the groundwater and soil pollution within and around the landfill of Eskisehir, Turkey. In this paper, mud, leachate and groundwater samples were collected seasonally a year from near Eskisehir landfill-site to investigate the possible impact of leachate which affects soil and groundwater quality. Concentrations of various heavy metals (Fe, Cu, Zn, Mn, Co, Pb, Cr, Ni and Mo) were determined in mud, leachate and groundwater samples. In addition, the heavy metal transportation infiltrated from landfill through a porous medium into the groundwater was modelled in order to determine the potential groundwater pollution caused by the leachate of the landfill. The modelling of the contaminant transportation was carried out by using a multiflow computer programme which simulates the distribution of heavy metal concentrations. As a result of this study, the distribution of the contaminant concentration was modelled and determined with respect to time and distance. Hence, the contaminant concentrations were determined at any time interval according to distance. The heavy metal contamination in groundwater does not affect the wells found at far points from the source in a short time, e.g. 10, 20 and 30 days according to the obtained experimental results. When the time intervals extended more than 1 year, heavy metal concentrations decrease with distance but the concentration of the contamination increases when it gets closer to the pollution source. In this study, the potential contamination of groundwater was effectively estimated.

Assessment of Groundwater Pollution Potential of the Datong Basin, Northern China

Groundwater is water present below the surface of the earth in underground streams and aquifers. It is the main source of water supply in arid and semi-arid regions of northwestern China. Studies, in recent years have reported increased cases of aquifer contamination due to different factors such as rapid urbanization and industrialization. Using DRASTIC model, this study attempts to measure vulnerability of ground water to contamination in the Datong Basin, located in Northern China. To reduce subjectivity, a sensitivity analysis was performed to evaluate the influence of a single parameter on aquifer vulnerability.The results show that 32.5% of the total study area is under a “highly vulnerable zone”. In addition the most sensitive parameter to contamination is aquifer media (A), followed in importance by hydraulic conductivity (C), topography (T), depth to water (D), soil media (S), and impact of vadose zone (I). Net recharge (R) is the least sensitive parameter to pollution. Aquifer vulnerability maps developed in this study are valuable tools for environmental planning and predictive groundwater management.

Review of vadose zone soil solution sampling techniques

Understanding the composition and fluxes of vadose zone soil water is extremely important to many environmental studies, and hence the monitoring of soil solution is of basic interest for different scientific and practical fields, including pedologic studies, water-use management, fate and transport of environmentally consequential pollutants, monitoring of disposal from mining and industries, nutrient management of agricultural and forest ecosystems, ecology, and environmental protection. Soil solution sampling techniques for effectively monitoring the quality and quantity of vadose zone soil pore water have been used to assess the persistence and transport of potential groundwater pollutants, assess the ecological and human health impact of such pollutants, and develope appropriate remediation strategies. However, there is still no consensus as to best techniques for soil solution collection at most field or laboratory soil conditions. The purpose of this review is to evaluate different laboratory and in-situ techniques of vadose zone soil solution sampling. This comprehensive review presents and discusses advantages and disadvantages of these techniques, problems and limitations of some of these techniques, proper installation, operation and pretreatment of samplers, interaction of pollutants with sampler materials, and proper selection of samplers under a wide range of potential pollutants measurements to provide a background and guidelines for the evaluation of recent developments.

TRASH OR TREASURE?: Putting Coal Combustion Waste to Work

Even as public debate rages over the question of whether coal should continue to provide the majority of U.S. electric power needs, the U.S. Energy Information Administration predicts in International Energy Outlook 2009 that, absent new policies to the contrary, the United States—along with China and India—is expected to account for 88% of the projected net increase in coal consumption between 2006 and 2030. Meanwhile, coal combustion waste (CCW)—the noncombustible remains from coal burning—continues to pile up at the rate of about 131 million tons per year in the United States alone, and electric utilities are looking to recycle a larger proportion of this material.

Improvement of N fertilization by using the nitrification inhibitor DMPP [3,4-dimethylpirazole phosphate] in drip-irrigated citrus trees

Nitrogen management in orchards should tend to improve the fertilizer N use efficiency for a sustainable agriculture where productivity, fruit quality and environment are reconciled. The use of specific nitrification inhibitors could increase the N fertilizer uptake and decrease the potential groundwater pollution by nitrate leaching. The aim of this experiment was to assess the effect of application frequency of the ammonium sulphate (AS) and the nitrification inhibitor (NI), 3,4-dimethylpirazole phosphate (DMPP) supply on: nitrate-N and ammonium-N seasonal changes in soil; N and Fe concentrations in the spring-flush leaves; and yield and fruit quality. The experiment was carried out with clementine cv. Nules (Citrus clementine Hort. Tanaka x Citrus reticulate Blanco) mandarins grafted on Troyer citrange (Citrus sinensis x Poncirus trifoliata) rootstock under field conditions during three consecutive years. The trees were fertilized with 324 Kg N/ha from which 192 Kg N/ha were applied as AS (21% NH4+ -N) either with or without NI, and the remainder N came from irrigation water. The AS and AS+NI were split into 1, 2 or 4 applications per month by drip irrigation. The NH4+ -N concentration in the 0-20 and 20-40 cm soil layers was significantly higher in the AS+NI treatment. By contrast, the NO3- -N concentration was significantly higher in the soil treated only with AS. Moreover, the addition of NI to AS originated a significantly higher N and Fe concentrations in the spring-flush leaves. The yield was higher and some fruit quality parameters improved in trees fertilized with AS+NI compared to those fertilized only with AS.