Water Pollution Risk Assessment Research Articles

Environmental health risk assessment of urban water sources based on fuzzy set theory

Abstract Water pollution and protection of water resources have become an urgent task for humanity today and are also important components of environmental risk assessment. In response to the problems of high risk level and low risk credibility in the current environmental health risk assessment of urban water sources, this article aims to use fuzzy set theory to comprehensively evaluate the environmental quality and quickly monitor the safety of urban water sources. Therefore, this article analyzed the health factors of the urban water source environment and then studied the content and uncertainty analysis of health risk assessment. Finally, it constructed a health risk assessment system and proposed corresponding water environment protection strategies. In the experimental section, the risk level and risk credibility of the water environment were analyzed. Through comparison, it was found that the risk level in the new water environment health risk assessment was 0.16 lower than that in the traditional water environment health risk assessment, and the risk credibility was 0.11 higher than that in the traditional water environment health risk assessment. The water quality monitoring effect in the new water environment health risk assessment was 7.3% higher than that in the traditional water environment health risk assessment, The health hazard effect is 8.2% lower than traditional water environment health risk assessment. In summary, water environment health risk assessment plays an important role in protecting the water source environment. Health risk assessment of the water environment helps to reduce water pollution, improve water quality, and ultimately improve human health. Moreover, using fuzzy set theory makes it easier to comprehensively and efficiently evaluate the water environment. The innovation of this article lies in paying attention to the importance of fuzzy set theory in water pollution risk assessment and applying fuzzy technology to water pollution control strategies, to better improve water quality and optimize water source environmental health risk assessment methods.

Water pollution risk assessment resulting from leaching organic micropollutants from sewage sludge

Water pollution risk assessment resulting from leaching organic micropollutants from sewage sludge

GIS-based risk assessment of tropical surface water pollution by integrating hydrogeological and anthropogenic parameters

Surface water pollution is a huge issue worldwide that keeps growing in magnitude and complexity which leads to millions of people don’t have access to clean water resource. Numerous studies on vulnerability, hazard and risk assessment of water pollution had been conducted yet most of them only focused on one of the three risk components. Therefore, the objective of this study was to apply a geospatial approach that integrated hydrogeological and anthropogenic parameters to assess the risk of surface water pollution in Selangor River Basin, Malaysia. Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) were applied in hydrogeological vulnerability assessment. WRASTIC index was used in anthropogenic hazard assessment. The risk map showed that high-risk zones were mainly located in areas where development and agricultural activities are extensive. Conversely, low-risk zones were in areas that were mostly covered by forest with few developments, such as the upstream region. The results also revealed that high and very risk levels were dependent on soil media and presence of land use and anthropogenic activity especially agriculture, industry, and wastewater presence. The risk map also showed that developed area with high hydrogeological vulnerability would have higher risk of pollution compared to areas without any anthropogenic hazard. The risk map can assist stakeholders to identify at risk of pollution. This allows for better decision-making in integrated river basin management.

Surface water pollution risk assessment of wadis, Mekerra and Saïda, in the North-Western of Algeria

Considered as the main stream of hydrographic network of Mactaa’s basin, in the west highlands of Algeria, both wadis, Mekerra and Saïda, are affected by pollution which is generated by anthropogenic activities. Makara and Saïda wadis cross the urban areas of Sidi-Bel-Abbes and Saïda respectively, in the west of Algeria, which constitute a real problem of human safety. In order to identify the pollution state on these wadis, samples have been collected during three periods of time (June 2011, July 2012 and April 2013) in the goal to characterize the physico-chemical and bacteriological quality of surface water.Results obtained describe clearly the existence of chemical and organic pollution in both wadis at high levels of calcium, magnesium, chlorides, nitrates, nitrites, phosphate, DBO5 and dissolved oxygen. The evaluation of organic pollution index (OPI) confirmed that there is a high organic pollution, upstream, which increases with high water passage towards urban areas of both cities (OPI).The bacteriological analysis results obtained show presence of high contents of faecal bacteria contamination (total coliforms (TC), faecal coliforms (TC) and faecal streptococci(FS))principally in wadi Saïda. The relationship between FC/FS justifies the predominance of human origin than of animal as source of contamination. While, the determination of microbiological quality index (MQI), for each wadi, confirms degradation of microbiological quality by the faecal pollution, mainly in Saïda urban area.

Risk Assessment of Water Pollution in Urban Rivers of Northwest China

As the main carrier of regional residential sewage, industrial wastewater and surface runoff emissions, urban rivers are most vulnerable to pollution and destruction. Taking the Dongsha River in the city of Baoji in Northwest China as an example, four river pollutants were monitored, and the improved Nemero index and factor information model were established to for risk assessment of river water pollution. While compared with other methods, the method is verified, and it is believed that this method is a good tool to evaluate the water pollution of urban rivers. Moreover, the source load mechanism of urban river pollution is discussed. Evaluation results show that for TP, risk of upstream is highest, and for COD and NH3N, risks of the middle are highest, while for PH, risk of downstream is highest. Overall, COD and ammonia nitrogen are a major pollutant in urban rivers, which pollutants originate from industry and agricultural wastewater discharge. The domestic sewage, solid waste and agricultural wastewater overflows also play an important role in the change of river water quality. These studies provide the basis for urban environmental planning and pollution control.

The risk assessment of water pollution in the Gorgan Bay catchment using the WRASTIC index

The WRASTIC model is one of the most practical methods to assess the risk and an advanced method to evaluate the potential for the pollution in a catchment basin. In order to assess the risk of pollution in the Gorgan Bay catchment, six sub-basins of the study area were extracted using the elevation map in QGIS and TerrSet software. The risks have been detected by field visits, library studies, and asking experts and related organizations. Finally, the WRASTIC index was provided as seven informational layers and the index number for each sub-basin was calculated by weighting, ranking, and integrating the layers. The results showed that three sub-basins have a high risk and three others have a medium risk. According to the level of risk, this catchment is exposed to pollution and has vulnerability mainly due to human activities including a high volume of sewage discharged into the catchment, a high amount of agricultural and entertainment activities in the region, transport pathways and railways, as well as the vastness of the catchment. Therefore, supervising and controlling human activities in the catchment is necessary to improve the ecological conditions of water resources in the area.

A Bayesian Network-based risk dynamic simulation model for accidental water pollution discharge of mine tailings ponds at watershed-scale

Mine tailings ponds that contain heavy metals are sources of potential risk to human security and ecosystem health. China particularly faces challenge of accidental water pollution risk from more than 8869 mine tailings ponds in serve by 2015, some of which are close to residential areas and other important infrastructures within 1 km downstream. To address watershed-scale risk assessment of accidental water pollution from mine tailings ponds, a Bayesian Network-based Risk Dynamic Simulation (BN-RDS) model was proposed to simulate “sources/stressors-receptors-endpoints” risk routes. An accidental water pollution convection-diffusion simulation was coupled to Bayesian Networks to perform the risk dynamic simulation and risk evolution quantification at watershed-scale. This method was applied to the risk assessment of 23 tailings dams in 12 sub-watersheds covering the Guanting Reservoir basin (the major backup drinking water source for Beijing) in Zhangjiakou City, China. The result indicated that ecosystem health and property security were the endpoints at the highest risk in the overall watershed. Spatially, the combined risk distribution map showed the risk was higher in the downstream of the Guanting Reservoir Watershed and in its two tributary basins (the Qingshui River and the Longyang River). This research highlighted a probabilistic approach to accidental water pollution risk assessment of tailings ponds with verifiable and tangible results for risk managers and stakeholders.

Risk Assessment of Water Pollution in Mountainous Industrial Parks

Water system security is the basic condition and important factor to promote the stable development of mountain industrial parks. The purpose of this study is to scientifically evaluate the water pollution risks that mountain industrial parks may face. To this end, in this paper a water pollution risk assessment index system was constructed in four aspects such as water supply, water use, drainage and flood control. Then, the analytic hierarchy process (AHP) was applied to calculate the weight of each factor. Finally, based on expert scoring, few water pollution risks in the mountain industrial park were found, of which the flood control facilities, chemical pollution, ground seepage capacity and water pipeline system are potential unsafe factors with high risk, and especially various chemical pollution poses a risk for the water source safety, water supply quality and drainage in the park, which needs to be strictly controlled.

The Risk Assessment of River Water Pollution Based on a Modified Non-Linear Model

The water resource system is a non-linear system, featuring variability and randomness. Its risk assessment is very different from that of a linear system. Considering the effects of river flow on the pollutant diffusion, migration, and maximum tolerable concentration, a modified non-linear model (MNLM) was established, while the forcing terms were introduced to model functions for water pollution risk assessment. Taking the Weihe River Basin in China as an example, the risk assessment values were divided into five levels: negligible risk, acceptable risk, marginal risk, unacceptable risk, and catastrophic risk. As such, the risk variation of the river pollution interval was analyzed. The results showed that the BOD5, COD, and nitrite nitrogen are the main pollutants, leading to great risks of river water pollution. Moreover, it was found that the risk in the dry season is higher than that in the flood season, while the risk based on MNLM is 10.9% higher than that of linear methods. Verification indicates that MNLM is considered more suitable for risk assessment of complex river water pollution. However, the forcing term coefficient should be corrected for actual situations in different river water systems. The explored MNLM is expected to give insights into regional river water environment management.

Water renewal and risk assessment of water pollution in semi-enclosed domains: Application to Bilbao Harbour (Bay of Biscay)

The inclusion of water renewal behaviour in the risk assessment of water pollution for Bilbao harbour (located within the Nervión estuary, southeastern Bay of Biscay) is analysed. Several parameterisations of water renewal (integral and local perspectives), obtained from the numerical evolution analysis of a Eulerian tracer, were used. The local characterisation of water renewal confirmed a strong horizontal spatial variability. In addition, vertical variability on water renewal patterns, due to the 3-dimensional structure of the flow was also appreciated. For the period analysed (August 2008) the water renewal was less effective at the surface, than in deeper waters, because marine breezes counteracted water renewal at the surface, during the observed period. The incidence of this vertical variability, on harbour environmental management, was analysed in implementing a recently developed methodology to evaluate the risk of water pollution. Since this methodology takes into account water renewal, the values of risk of water pollution in Bilbao harbour differed considerably, as a function of the renewal pattern at the surface or within deeper waters. In conclusion, it was found that the water renewal should be parameterised properly, in order to improve environmental management strategies in semi-enclosed water bodies in coastal areas. The findings permitted knowledge to be gained on water renewal behaviour within Bilbao harbour, advancing the framework for the environmental management of harbour waters.

Investigation and integrative modelling of xenobiotics discharged from urban drainage systems

The urban aquatic environment is increasingly polluted by low concentrated but potentially harmful compounds such as pharmaceuticals and endocrine disruptors - so-called xenobiotics. These substances are mainly carried by waste water. Up to now information with regard to their impact on the urban ecosystem and human health exist for only few of them. Within an interdisciplinary project on risk assessment of water pollution, we work on the identification of the fluxes of these substances. In a first step, we used a runoff formation model representing the city of Halle (Germany) and the Saale river. The Saale river acts as surface water system collecting slope inputs along the city traverse and sewer outflows. We investigated the anthropogenic effect on the urban water system using indicators such as hydrological parameters, selected complex organic substances, isotopic signatures and dissolved substances (sulphate, nitrate). A first balance modelling showed that main ions are not very sensitive concerning the diffuse urban input into the river. However, the concentration pattern of fragrances (tonalid, galaxolid), rare earth elements (gadolinium) and endocrine disrupters (t-nonylphenol) point to a different pollution along the city traverse: downstream of the sewage plant a higher load was observed in comparison to the upstream passage. Various substance concentrations in groundwater along the city traverse showed increasing trends.