Jingling Liu

Spatial distribution and health risk of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in the water of the Luanhe River Basin, China

The objectives of this study were to investigate the contamination levels and dispersion patterns of heavy metals and polycyclic aromatic hydrocarbons (PAHs) and to estimate the risk to health effects within the Luanhe river basin of northern Hebei Province, China. Samples of water were collected from upstream to downstream locations, and also from the main tributaries of Luanhe river. After appropriate preparation, all samples were analyzed for eight metals (As, Hg, Cd, Cr, Pb, Cu, Zn, and Fe) and 16 PAHs. Mean concentrations of As, Cd, Cu, and Zn were within the permissible levels, but Hg, Pb, and Fe concentrations were exceeded at some sites. The results indicated that the metal levels of upriver sites were higher than lower river sites; the metal levels of the main river were higher than ones of the tributaries except for Goutaizi at Xiaoluanhe. Only seven out 16 PAH components, which were mostly three- to four-ring compounds, were detected. Predominance of three- to four-ring PAHs suggests relatively recent local sources of PAHs in the study area. The combined hazard index for all metals and PAHs was from 2.26E − 02 to 1.18E − 01, which was lower than 1, suggesting minimal risk to humans. Only Arsenic (As) was evaluated with potential carcinogenic risks of 7.27E − 06 to 2.50E − 05. The study represents the preliminary implementation of a well-defined methodology into the environmental management process and provides a scientific basis for the pollutant controlment order.

Ecological risk assessment of water environment for Luanhe River Basin based on relative risk model

The relative risk model (RRM) was applied in regional ecological risk assessments successfully. In this study, the RRM was developed through increasing the data of risk source and introducing the source–stressor–habitat exposure filter (SSH), the endpoint–habitat exposure filter (EH) and the stressor–endpoint effect filter (SE) to reflect the meaning of exposure and effect more explicit. Water environment which include water quality, water quantity and aquatic ecosystems was selected as the ecological risk assessment endpoints. The Luanhe River Basin located in the North China was selected as model case. The results showed that there were three low risk regions, one medium risk region and two high risk regions in the Luanhe River Basin. The results also indicated habitat destruction was the largest stressor with the risk scores as high as 11.87 for the Luanhe water environment, the second was oxygen consuming organic pollutants (9.28) and the third was nutrients (7.78). So these three stressors were the main influencing factors of the ecological pressure in the study area. Furthermore, animal husbandry was the biggest source with the risk scores as high as 20.38, the second was domestic sewage (14.00), and the third was polluting industry (9.96). For habitats, waters and farmland were enduring the bigger pressure and should be taken considerable attention. Water deterioration and ecological service values damaged were facing the biggest risk pressure, and secondly was biodiversity decreased and landscape fragmentation.

Development of a relative risk model for evaluating ecological risk of water environment in the Haihe River Basin estuary area.

Ecological risk assessment for water environment is significant to water resource management of basin. Effective environmental management and systems restoration such as the Haihe River Basin require holistic understanding of the relative importance of various stressor-related impacts throughout the basin. As an effective technical tool for evaluating the ecological risk, relative risk model (RRM) was applied in regional scale successfully. In this study, the risk transfer from upstream of basin was considered and the RRM was developed through introducing the source-stressor-habitat exposure filter (SSH), the endpoint-habitat exposure filter (EH) and the stressor-endpoint effect filter (SE) to reflect the meaning of exposure and effect more explicit. Water environment which includes water quality, water quantity and aquatic ecosystems was selected as the assessment endpoints. We created a conceptual model which depicting potential and effect pathways from source to stressor to habitat to endpoint. The Haihe River Basin estuary (HRBE) was selected as the model case. The results showed that there were two low risk regions, one medium risk region and two high risk regions in the HRBE. The results also indicated that urbanization was the biggest source, the second was shipping and the third was industry, their risk scores are 5.65, 4.71 and 3.68 respectively. Furthermore, habitat destruction was the largest stressor with the risk scores (2.66), the second was oxygen consuming organic pollutants (1.75) and the third was pathogens (1.75). So these three stressors were the main influencing factors of the ecological pressure in the study area. For habitats, open waters (9.59) and intertidal mudflat were enduring the bigger pressure and should be taken considerable attention. Ecological service values damaged (30.54) and biodiversity decreased were facing the biggest risk pressure.

Spatial distribution and ecological risk assessment of metals in sediments of Baiyangdian wetland ecosystem

Although there are many studies of heavy metal contaminations of sediments, attention has seldom been paid to the problem in developing countries. The purpose of this article is to find the distribution and ecological risk of As, Hg, Cr, Cd, Pb, Cu, and Zn in surface sediment of Baiyangdian which is the biggest wetland in Northeast China. We apply three methodologies. The first is literature analysis comparing total concentrations of heavy metals with other water bodies around world. The second is Chinese Environmental Quality Standard for Soils (EQSS), National Environmental Protection Agency of China 1995, and the third is Soil and Aquatic Sediment Guidelines and Standards issued by New York Department of Environmental Conservation (NYSDEC). The results show that compared to other water bodies around the world, the seven heavy metals are low. However, Cd was found in the most polluting level of EQSS near a village and was second grade some distance from it. The village was also the most polluted site of Zn, which was in the second grade. When assessed by NYSDEC, Cu, Cr, and As contaminated the sediment and with moderate impacts on benthic life while Pb, Hg, and Zn were found at tolerable levels throughout Baiyangdian. The centre of Cu and Cr contamination was also near the village. As is the most polluting heavy metals with a major occurrence in the middle of the wetland. There were no heavy metals creating severe disturbance to the benthic communities. Based on the assessment, this article proposes different options for more sustainable management.

Polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries of China: Distribution, seasonal variations and ecological risk assessment.

The distribution, seasonal variations and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries in Hai River Basin of China, which has been suffering from different anthropogenic pressures, were investigated. In three estuaries, the average concentration of ΣPAHs was the lowest in Luan River estuary, followed by Hai River estuary, and the highest in Zhangweixin River estuary. There were significant seasonal variations in ΣPAHs, the concentrations of ΣPAHs were higher in November than in May and August. The composition profiles of PAHs in different sites were significantly different, and illustrated seasonal variations. Generally, 2-ring (Nap) and 3-ring PAHs (Acp, Fl and Phe) were the most abundant components at most sampling sites in three estuaries. The PAHs in three estuaries were mainly originated from pyrogenic sources. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) was proposed to assess the ecological risk of ΣPAHs, with the ecological risk of individual PAHs being considered separately. The results showed that the ecological risks caused by ΣPAHs were high in Hai River estuary and Zhangweixin River estuary, and moderate in Luan River estuary. The mean values of ecological risk in August were lower than those in November. The contributions of individual PAHs to ecological risk were different in May, August and November. 3-ring and 4-ring PAHs accounted for much more ecological risk than 2-ring, 5-ring and 6-ring, although the contributions of 5-ring and 6-ring to ecological risk were higher than these to PAHs concentrations.

Distribution and potential ecological risk of heavy metals in the typical eco-units of Haihe River Basin

The distribution and characteristics of seven heavy metals in sediments located in the typical ecological units (eco-units) (e.g., rivers, lakes, and estuaries) of Haihe River Basin were analyzed. The Hakanson potential ecological risk index was used for ecological risk assessment. The results indicated that the concentration scales of As, Hg, Cr, Cd, Pb, Cu, and Zn in the eco-units were 2.08 to 24.80 mg·g−1, 0.01 to 1135.50 mg·g−1, 28.70 to 152.73 mg·g−1, 0.03 to 195765.83 mg·g−1, 8.65 to 157.82 mg·g−1, 6.47 to 178.61 mg·g−1, and 21.09 to 1076.25 mg·g−1, respectively. The maximum concentrations of Hg, Cd, and Zn showed higher levels than other water bodies around the world. Hg and Cd have high concentrations in Zhangweinanhe River (1135.50 and 195765.83 mg·g−1, respectively) and Haihe Estuary (790.50 and 548.47 mg·g−1, respectively). According to the ecological factor, Cd and Hg showed very strong ecological risks. The seven heavy metals, namely, Cd, Hg, As, Cr, Pb, Cu, and Zn, exhibited ecological risk levels in descending order. Based on the potential ecological risk index, Luanhe River and Baiyangdian Lake had moderate ecological risks, whereas every site in Zhangweinanhe River and Haihe Estuary had substantial risk levels. The risk order of the typical eco-units are as follows: Zhangweinan River (2278345.68) > Estuary (161914.74) > Luanhe River (191.54)>Baiyangdian Lake (120.95). These results provided a scientific basis for water environment improvement and risk management of the Haihe River Basin.

Fuzzy synthetic model for risk assessment on Haihe River basin

A comprehensive indicator model for risk assessment and a multiple-level theoretical indicator system of the water quality–quantity-ecosystem (WQQE) for the Haihe River basin were constructed in this research. A fuzzy optimization model was used to assess risks for the four water systems of the Haihe River basin, and their risk order from high to lower risk was southern Haihe River system (SH), northern Haihe River system (NH), Tuhaimajiahe River system (TH) and Luanjiyanhai River system (LJ). The highest risk value (SH) was 0.8737. In terms of the WQQE, the secondary parameters for assessment of the four water system risks were 0.3579, 0.7226, 0.9547, and 0.5428 respectively. The results indicated that the main control factors for pollution for LJ, TH, SH and NH differed from each other and involved pollutant level, development of water resources, water flow and quality, ecosystem health and the hydrologic structure.

Biologic risk and source diagnose of 16 PAHs from Haihe River Basin, China

Surface sediments of rivers can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations. As to pollution control and remediation of watershed, large-scale and further background data on PAHs in China were required urgently. Spatial distribution and compositional characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Haihe River Basin were investigated. A method based on effects range (ER) was used to assess ecosystem risk of ΣPAHs (the total of 16 PAH) sensitively and accurately. The results indicated that ΣPAHs content levels ranged from 257 to 16901 μg·kg−1 dry weight. The lower rings predominated in the samples, and 2-, 3-, 4-, 5- and 6-ring PAHs accounted for 12%, 21%, 30%, 30%, and 7% respectively in total PAHs. The ratio of Fl / (Fl + Py) uniformly distributed in the interval 0.20–0.80, indicating that it may be affected by petroleum origin, oil combustion, biomass and coal combustion jointly. ΣPAHs in Cetian (S6), Dongwushi (S19), Handan (S20), Aixinzhuang (S21) and Tianjin (S37) exceeded effects range low (ERL), in which biologic effects were in a medium level with an adverse effect on biologic organisms. Thus, it is necessary to strengthen the PAHs monitoring and research of the Haihe River Basin.

Role of dams in the phase transfer of antibiotics in an urban river receiving wastewater treatment plant effluent

Dams are universally constructed to change hydrodynamic forces and impound water in urban rivers, but few efforts have been made to expound the impact of dams on the transport of antibiotics in rivers. In this study, the main object and focus was to elucidate the intercept effect of rubber dam and the gate dam on the sediment-water phase redistribution of eight typical antibiotics along an urban river with the water replenished from wastewater treatment plants (WWTPs). The results show that the eight antibiotics were widely detected in the whole river segment, and the WWTPs were found to be the main sources. Among the eight antibiotics, fluoroquinolones had the highest concentrations in the surface water, while tetracyclines constituted the dominant composition in the sediments. Due to the retention effect, the rubber dam encouraged the enrichment and degradation of the antibiotics in the river. However, the role of gate dams depended mainly on the opening and closing of the sluice gate. For all eight antibiotics, each dam or WWTP exhibited a generally consistent impact on the changes (e.g., an increase or decrease) of the sediment-water partitioning coefficients, although obvious differences existed between effect degree. Moreover, the changes in the coefficients caused by the rubber dam were completely opposite to those affected by gate dams. Contrary to the other six antibiotics, the two sulfonamides showed significant relationships with the dissolved organic matter in the surface water but had no significant relationships with the organic matter in the sediments.

Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAH) in water and sediments of the Luan River, China

The distribution of polycyclic aromatic hydrocarbons (PAH) was studied by determining the levels of 16 PAH in the water and sediment samples of the Luan River; a very important drinking water source for Tianjin and Tangshan in Hebei province, China. A total of 11 water samples and 11 sediment samples were collected in April 2008. The total PAH concentrations in water varied from 9.8 to 310 ng L−1, and those in surficial sediments ranged from not detected (ND) to 478 ng g−1 dry weight. The results showed that the upstream and downstream areas were low-polluted and high-polluted sites concentrated in the middle reaches of the river, respectively. The concentrations of PAH in rural areas (5 sites), which could be considered as the “background” levels, were lower than those near city zones (6 sites), which could be regarded as the “maximum” values. The PAH were dominated by 3- (38.4%) and 4-ring (60.7%) components in water samples and by 3- (27.4%), 4- (38.5%), and 5-ring (15.8%) compounds in sediments. High molecular weight PAH were inclined to be absorbed into sediments. The 3- and 4-ring PAH were the most common components in the Luan River. The molecular indices and the distribution of different rings were used to infer the sources of PAH, and the results suggested that anthropogenic heavy fuel combustion was likely to be the main source. The petroleum PAH had a high contribution to the PAH pollution at Baohekou and Daheiting.