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Evolution of shallow fluoride groundwater, in the Lower Liaohe River Plain in northeastern China, a typical coastal area, has been studied to assess the controls of geology, geochemistry and human activity on high-fluoride groundwater. A total of 212 shallow groundwater samples were collected. The range of the measured F– concentration was 0.11–4.9 mg/L with the mean value of 0.71 mg/L. Durov diagram classification, variation function calculation, thermodynamic calculation and factor analysis were used to analyze the distribution, origin and key influencing factors of high-fluoride groundwater. The distribution of high-fluoride samples was mainly concentrated in the southwestern and northeastern Lower Liaohe River Plain. The main origin of high fluoride in shallow groundwater was the lixiviation of fluorine-rich rocks in the northern plain and the alluvial fan of Da Linghe and Xiao Linghe Rivers. Additionally, through the migration and enrichment of fluoride in Xinmin, Linghai, a higher fluoride area was formed. The key influencing factors of fluoride groundwater was the fluoride lixiviation, regional hydraulic gradient, hydrochemical types and ion composition. Meanwhile, human pollution, evaporation and local irrigation were comparatively weak influencing factors. The process of calcite dissolution controlled the regional distribution of high fluoride in shallow groundwater. [ABSTRACT FROM AUTHOR]

Riverbank filtration is a natural water treatment technology that consists of extracting water from rivers by pumping wells located in the adjacent alluvial aquifer. It is vital to choose the most appropriate from multiple potential candidate sites, which is a complex procedure and seldom paid attention to. In this study, a method system including multicriteria evaluation indexes was developed with which the suitability of bank filtration along the Songhua River of China for developing riverside groundwater sources was assessed. The system was comprised of main suitability indexes for water quantity, water quality, interaction intensity between surface water and groundwater, and the exploitation condition of aquifer condition, weights of which were determined by specialist marking methods. Based on this assessment system, the suitability of the study area was divided into five grades. Results show that riversides along Lalin River, Hulan River, and the middle part of Songhua River are suitable for developing riverside groundwater sources. [ABSTRACT FROM AUTHOR]

Pollution risk assessment of a groundwater resource area is instrumental in contributing to groundwater protection. This study considered the evaluation results of source apportionment by combining a principal component analysis (PCA) with a factor analysis (FA) to identify potential risk sources. The vulnerability was evaluated using a DRASTIC model as the main pollution pathway, and groundwater quality as a pollution receptor, in order to validate the risk of pollution in a typical groundwater resource area of northeastern China. Results showed that four principal potential pollution sources were point source pollution such as water-rock interaction, dissolution of iron and manganese bearing minerals due to geological processes, non-point source pollution of nitrogen such as agriculture fertilizers, and organic pollution resulting from domestic and industrial wastewater. A “high” and “relatively high” pollution risk occurred mainly at the northwestern and southeastern edges of the region, respectively, with a widely distributed “moderate” pollution risk over the majority of the study area, and a “relatively low” and “low” pollution risk located mainly in the central of the Limin Groundwater Resources area, which showed that the potential pollution sources, especially due to human activity, have significantly changed the distribution of pollution risk in groundwater resource areas. [ABSTRACT FROM AUTHOR]

An assessment of the presence and health risks of endocrine-disrupting chemicals in the drinking water treatment plant (DWTP) of Wu Chang was performed. A recombinant yeast assay was used to assess the endocrine disrupting activity of the effluents of the DWTP. Agonistic activities of the estrogen receptor and androgen receptor were not detected in any of the effluent samples. However, anti-estrogenic and anti-androgenic activities were observed. In addition, the removal rates of the DWTP for the anti-androgenic activities were limited. A health risk assessment was performed on the basis of the results of the recombinant yeast assay, and the total daily production of hormones was used to evaluate the health risks of these types of endocrine-disrupting chemicals. The predicted effects of the anti-estrogenic and anti-androgenic disrupting activities were below 1.5%. This study suggested that the combined toxicity bioassays with health risk assessment could provide an available method to assess endocrine-disrupting chemicals and to evaluate the potential adverse effects on human health for aquatic environmental samples. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) have become a major type of persistent organic pollutant (POPs) in the world. To well understand the occurrence, spatial distribution and source apportionment of 16 PAHs in different media in Beijing, a comprehensive study was conducted based on 337 obtained and subsequently selected samples in four specific media, including soil, road dust, surface water and atmosphere covering sampling time spanning from 2005 to 2014. Mean concentrations of Σ16 PAHs in soils (878.5 μg/kg) decreased from inner city to exterior areas with different land uses decreased in the order of industrial estate (2510 μg/kg)>educational area (1331 μg/kg)>Park (783 μg/kg)>cultivated (650 μg/kg)>roadside (583 μg/kg)>residential (568 μg/kg)>green area (478 μg/kg)>forest area (125 μg/kg). Meanwhile, PAHs concentrations in branch roads were slightly higher than trunk roads and mainly concentrated in urban areas (1136 μg/kg). Affected by industrial and residential areas, PAHs concentrations in downstream surface rivers were much higher than upstream surface rivers (475 ng/L). Due to strong mobility, PAHs concentrations in atmosphere were not equally distributed around the study area (157.59 ng/m3). The result of source apportionment determined by diagnostic ratios method indicated PAHs in multiple media in Beijing are mainly from coal and biomass combustion. [ABSTRACT FROM PUBLISHER]

By means of factor analysis (FA) and positive matrix factorization (PMF) methods, groundwater pollution sources were identified in the Jinji groundwater source area, which is beside the Yellow River and is the only urban water supply source for the city of Wuzhong in Northwestern China. The sources of groundwater were quantified based on 16 samples of shallow groundwater from the source area. The source apportionment with the PMF model identified three dominant groundwater pollution sources. These were anthropogenic activities of agricultural and industrial pollution with a pollution contribution of 53.0%, water–rock interaction of 24.6%, and evaporation and concentration of 22.4%. The source apportionment with the FA model identified four sources which were evaporation and concentration, with the largest contribution (42.6%), followed by anthropogenic activities (29.2%), mineral dissolution and industrial pollution (22.4%), and natural effects (5.8%). Specific attention should be paid to these natural (fluoride, TH,etc.) and anthropogenic sources (NH4+, NO2−, turbidity, total bacterial count,etc.), and pertinent measures should be taken to control local groundwater pollution. The most significant trait of the PMF is its scientific interpretation and physical explanation of the results, depending on non-negative restriction of the pollution source profiles and contributions. [ABSTRACT FROM PUBLISHER]

Groundwater pollution risk assessment is a useful tool to prevent and control groundwater pollution, but its quantitative research is still relatively immature. In this study, a geographic information system based LVF model for a semiquantitative assessment of groundwater pollution risk is established, based on the groundwater pollution source load (L), groundwater vulnerability (V), and groundwater function value (F). Further, the pollution source load is characterized by seven specific pollution sources, the vulnerability is calculated by the modified DRASTIC method, and the groundwater function value is evaluated with the water quality and quantity. The model was used to assess the risk of shallow groundwater pollution in Shenyang city, Northeast China, with an area of 8,263 km2. The results show that highest risk areas account for 16.3% of the study area and are mainly distributed in the east of the study area. High risk areas are significantly affected by a shallow buried depth of groundwater and many types of harmful pollutants from industrial, agricultural, and domestic pollution sources. The evaluation results reflect the risk of groundwater pollution in the Shenyang area, which is relevant to the management and sustainable use of groundwater resources in the area. [ABSTRACT FROM PUBLISHER]

Regional environmental risk assessment has been a significant means of environmental management and decision-making. To assess the regional integrated environmental risk at a nationwide scale, a new index system named the Hazard, Intensity, Vulnerability, and Effectiveness (HIVE) model was designed and evolved from previous researches. The HIVE model consisted of a relatively complete framework with accessible indexes related to environment and social economy, and it considered different risk sources, pathways, and receptors as well as the influence of the risk control. As an important segment of the assessment process, a simple gridding information diffusion method was also proposed to assess the diffusion effect of risk factors in nationwide rivers. Taking China as a case study, this study calculated the environmental risk value of every sub-unit. Through the clustering function of Statistical Package for Social Sciences and the visual representation of a geographic information system, the study area was divided into nine zones that were visualized on maps according to their different risk levels and risk characteristics. This study also identified the dominant factors of each zone, which could provide the foundation for regional environmental management. Moreover, the results implied some significant correlations between risk system components and the regional social economy in China. [ABSTRACT FROM AUTHOR]

Heavy metals are known to have adverse effects on soil ecosystems, while soil enzyme activities are sensitive to soil pollution. This study investigated the combined effects of Cu, Zn and Pb on the activities of invertase (IN), urease (U) and alkaline phosphatase (ALP) in soil obtained from the vicinity of a wellhead protection area via an orthogonal array (OA) design method. The experimental results showed the following: (1) Cu showed higher inhibition on the activities of all three enzymes than Zn and Pb when three metals were all present in the soil sample. IN activity, U activity and ALP activity decreased as the levels of Cu increased, and ranged from 15.9% to 55.7%, 3.57% to 78.6%, and 3.23% to 75.3%, respectively. Their lowest values were found in samples at 35 days with 400 mg/kg Cu. (2) Zn and Pb had different influences on the activities of the three enzymes. The lowest IN activity (the highest reduction 58.0%) and U activity (76.8%) were observed when Zn was at the concentration of 100 mg/kg after 35 days, whereas the highest inhibitory function of Zn on ALP activity (75.3%) was at 300 mg/kg after 7 days. When the concentration of Pb increased from 35 to 350 mg/kg, the activities of IN (62.5%) and U (69.6%) were most inhibited at 35 days and 14 days, respectively. However, when Pb was at the concentration of 500 mg/kg after 14 days, ALP activity (72.0%) showed the lowest value. (3) With respect to the three hydrolases in this study, ALP was the most sensitive to the two-variable interactive effects of Cu, Zn and Pb, especially Cu × Pb. It is concluded that the soil ALP activity may be a sensitive tool for assessing additive toxic effect on soil biochemical parameters. To provide more information about the potential ecological risk of chemicals on soil ecosystems, much more should be done to clearly determine the mechanisms of the combined effects of heavy metals in soil. [ABSTRACT FROM AUTHOR]

This article gives a broad overview about the status and progress of the sulfate radical-based decontamination technologies. Peroxymonosulfate or persulfate can be activated by energy or a catalyzer to form sulfate radical for rapid and effective degradation of contaminants in homogenous systems. Sulfate radical-based heterogeneous catalysis oxidation has been a major research focus since 2005 because solid catalysts are stable, cost-effective, and easy to recover. The application of sulfate radical in other decontamination technologies and the mechanisms involved are also described and discussed. The main points are summarized and the directions of future researches are suggested in the last section. [ABSTRACT FROM PUBLISHER]