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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.07.002 Byline: Zhao Zhang (a), Fulu Tao (b), Juan Du (a), Peijun Shi (a), Deyong Yu (a), Yaobin Meng (a), Yu Sun (c) Abstract: Surface water quality and its natural and anthropogenic controls in the Xiangjiang River were investigated using multivariate statistical approaches and a comprehensive observation dataset collected from 2004 to 2008. Cluster analysis (CA) grouped the 15 different sampling stations into five clusters with similar hydrochemistry characteristics and pollution levels. Four principal components (PCs), nutrients, heavy metals, natural components, and organic components, were extracted from the entire dataset. Comparison of the different regional characteristics of these four PCs revealed a decreasing trend for heavy metals and an increasing trend for organic factor on an annual scale, and the seasonal trend was only observed for natural factor. We also conducted analysis of variance (ANOVA) in combination with principal component analysis (PCA) to quantify the relative contribution of spatial and temporal variations to each of the four PCs. The results revealed that 62% of the contributions from the spatial sites were responsible for variations in heavy metals, while 83% of the contributions from the sampling time were responsible for natural variations observed. However, no significant spatial or temporal contributions were found to be responsible for the nutrient and organic variations. Finally, some suggestions regarding water management were put forward based on the current status and future trends of surface water quality in the Xiangjiang River. Author Affiliation: (a) State Key Laboratory of Earth Surface Processes and Resource Ecology, Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China (b) Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China (c) The Center of Disaster Relief and Donation, Bureau of Civil Administration in Hebei Province, Shijiazhuang, 050051, China Article History: Received 30 November 2009; Revised 3 June 2010; Accepted 1 July 2010

• Behavior of waterscape park visitors can indicate their perceived water quality. • Mobile phone data allows such quantitative behavioral indicators such as Park visiting hours (PVH) and sub-daily Attendance Probabilities (PVA). • PVH increases with improved water quality, indicating a prolonged enjoyed ecosystem service. • Integration of multisource big data is prospective approach to assist application of behavioral metrics in ecological and environmental issues. The rational evaluation of pollution control measures is crucial for advancing water pollution management, ensuring water quality, and creating high-standard urban environments. Currently the evaluation heavily relies on water quality indicators with little regard to the sense of gain of the people. In this paper, we proposed an objective indicator PVH (Park Visiting Hours) to represent the behavioral response, as a materialized sense of humans, to water quality. We demonstrated the application of PVH in four typical waterscape parks in Beijing with multi-source data, and the results showed that: (1) The Mann-Kendall Test and an independent correlation test utilizing Sina Weibo data (Chinese Twitter) indicated that PVH was significantly negatively correlated with the Satellite image based Sensory Pollution Index (SPI), as corroborated the competence of PVH to appraise the sense of gain from water quality improvement. (2) Multivariate regressions showed that an increase in SPI of 0.1 corresponds to an average 8.8 min reduction in PVH. (3) The relationship between PVH and SPI was consistent across various visitor demographics, and whether visitors were in groups or alone. This study introduced PVH as a novel but concise indicator to represent water quality-related behavior of park visitors and would inspire the use of big multisource data for measuring human perceptions of ecosystem services. [ABSTRACT FROM AUTHOR]

Heavy metal behavior in soil and water requires modeling for a better understanding of the potential adverse impacts on the ecosystem as well as on humans. A heavy metal transport and transformation module is combined with the well-established SWAT (Soil and Water Assessment Tool) model for the purpose of simulating the fate and transport of metals at the watershed scale. The heavy metal module accounts for sorption, complexation and slow reactions among metal species; the heavy metals in the upland are allowed to transport vertically through percolation and evaporation-induced water rising as well as horizontally through soil erosion and surface/subsurface runoff; the heavy metals in the water body, in contrast, are modeled to undergo settling, resuspension, diffusion and burial processes. As a demonstration, the SWAT-laden heavy metal module (SWAT-HM) was calibrated to simulate zinc (Zn) and cadmium (Cd) dynamics in an upstream watershed of the Liuyang River in China, which has been impacted by mining activities for decades. The model simulations were found to agree reasonably well with the monitored results. In particular, the elevation of metal loads in channels with precipitation events was well represented, demonstrating that a considerable amount of Zn and Cd in the waste rock dumps and contaminated soil was released into rivers through rainfall. After a simulation of 6 years (2009–2014), the simulated Zn and Cd concentrations were used as a surrogate for the Predicted Environmental Concentration (PEC), whereby an ecological risk assessment was conducted for the demonstrative mining area. This initiative toward developing a heavy metal module combined with SWAT has high potential for application in environmental risk analysis and pollution control. [ABSTRACT FROM AUTHOR]

Abstract: Membrane separation was employed in a novel photocatalytic oxidation slurry reactor to conserve catalyst. This paper reports some critical operational conditions of this reactor. While fine-bubble aeration served to suspend the catalyst, introducing an intermittent coarse bubbling under the membrane during operation was vital to counteract TiO2 catalyst entrapment on membrane surface. Circulation flow in the reactor was also found to have certain effect on counteracting the dropping out of catalyst. A submerged membrane module with a pore size of 0.1μm successfully conserved the powdered catalysts within the reactor after 2 days’ preluding filtration. As for pollutant removal, membrane filtration and circulation flow had no effect, whereas increase in gas holdup had. Running the reactor to treat model pollutant dissolved in tap water revealed that calcium carbonate both deactivated the catalyst and contributed to membrane fouling, suggesting that water hardness and alkalinity deserves appropriate treatment to warrant a good performance of such a reactor. [Copyright &y& Elsevier]

Abstract: Here we report a structured matrix model for wild Japanese medaka (Oryzias latipes) and the use of the model to predict the population-level effects of 4-nonylphenol (4-NP) using a stochastic simulation approach. In the model, the natural fecundity and mortality rates of wild medaka were considered inhibited by 4-NP, based on Weibull dose–response models estimated from a full life-cycle toxicity test. The matrix model was simulated according to three scenarios: (1) stochastic daily growth under optimal conditions, (2) stochastic annual growth under conditions of seasonal variation and (3) population dynamics over 3 years undergoing density-regulation. Accordingly, a finite population growth rate, λ, was applied as an endpoint in the first and second scenarios and a quasi-extinction risk in the third scenario. The median and 95% confidence interval (CI) of 4-NP concentrations corresponding to λ =1 (C λ=1) in the first and second scenarios were 27.5μg/L (CI: [20.2, 33.0]μg/L) and 17.0μg/L (CI: [16.0, 17.9]μg/L), respectively. The quasi-extinction risks mounted quickly when the exposure concentration approached C λ=1. The influence of uncertainties was analyzed, and the C λ=1 was found to be robust against uncertainties in both the mean and the variation of vital rates, whereas the quasi-extinction risk was moderately sensitive to the mean mortality rate. The ignorance of whether the survival of adult madaka should be considered inhibited by 4-NP or not was found to remarkably affect the population-level effects. This study demonstrates an application of C λ=1 in a stochastic sense as a population-level ecological risk assessment (PLERA) endpoint in chemical risk management. [Copyright &y& Elsevier]

A quality-assured ecological risk assessment (ERA) requires enormous resources (time and labor) in collection/assessment of hazard data, as well as considerable expertise to interpret the risk. The ERA of chemicals is thereby considered difficult or impossible for those with little assessment experience and cumbersome or complicated for practitioners. To meet the concerns regarding ERA and accelerate the risk assessment and management of chemicals, we developed an all-in-one free tool for multi-purpose ecological risk assessment management (MeRAM) of chemical substances in aquatic environment called the AIST-MeRAM Ver. 2.0.0 (Copyright No: H28PRO-2007). It allows users from beginners to experts to conduct ERA without any preparation because all the necessary ecotoxicity test data and methodologies are available in the system. Approximately 270,000 ecotoxicity test data points for 3900 chemical substances together with the scientific methodologies from traditional simple hazard quotient (HQ) to more ecologically relevant complicated assessments such as species sensitivity distribution (SSD) and population-level assessment are embedded in the AIST-MeRAM. In addition, users can easily understand the Japanese regulatory RA and management of chemical substances due to a special function based on the Japanese Chemical Substance Control Law (CSCL). Here, we demonstrate a tiered ERA using the embedded sample data to evaluate and ensure the functions of AIST-MERAM. We show that the AIST-MeRAM can provide a comprehensive and accurate ERA, suggesting that it is a powerful IT solution for cumbersome ERA. Image 1 • A free IT solution for ecological risk assessment (ERA) called AIST-MeRAM was developed. • Database (e.g., ecotoxicity data) and available ERA methods were embedded for saving required labor and time. • Perform the ERA by an intuitive mouse click right after installation on your Windows PC. • AIST-MeRAM affords point/probabilistic risk estimations and auto-setting of uncertainty factors. • As a legal template referring to the scheme of Chemical Substances Control Law for developing countries. [ABSTRACT FROM AUTHOR]

• Zn input and output fluxes with uncertainties were quantified at a watershed level. • In the upland, Zn fluxes with soil erosion and lateral flow dominated Zn export. • In the river channel, bed sediment was identified as the most important Zn sink. Heavy metal (HM) pollution is a serious and urgent issue in integrated watershed management in China and worldwide. Determining effective management strategies for pollution control requires quantification of input and output metal fluxes and the inherent uncertainties. Process-based metal models can simulate the metal movement on a watershed scale providing essential information for metal budget. However, there has been little effort to quantify the uncertainties in metal flux simulations. In this work, we modified the previously developed SWAT-HM (Soil and Water Assessment Tool – Heavy Metal) model by adding two external model inputs (atmospheric deposition and agricultural-source input) and one process-based module (plant uptake). We then linked the modified model with the SWAT Calibration and Uncertainty Programs SWAT-CUP for stochastic calibration and uncertainty analysis. The modified SWAT-HM was used to model the fluxes of primary inputs and outputs of zinc (Zn) in both uplands (soil) and channel (bed sediment) in the upper Liuyang River watershed in south-central China. To calibrate the model with uncertainty analysis, we used six-years of daily streamflow, daily sediment load, and daily Zn load at monthly frequency at the watershed outlet. In the upland phase, we identified Zn input from atmospheric deposition and Zn output through soil erosion as the most significant fluxes. In the channel phase, bed sediment was the critical Zn sink receiving 5,100 to 42,000 kg yr−1 Zn. The method used in SWAT-HM calibration and uncertainty analysis is general with potential application to similar settings in the world. [ABSTRACT FROM AUTHOR]

Fluoride (F) exhibits toxicity in excess but provides health benefits in moderate concentrations. While extensive research has focused on elevated F levels in groundwater, studies are scarce on F concentrations in surface water, a crucial drinking water source. In this study, we compiled a comprehensive database encompassing three decades of oral epidemiological data from over 140,000 Chinese children (6–17 years) and F concentrations in 160 freshwater lakes and reservoirs across China to investigate the health risks, environmental drivers, and future evolution of F in surface water. We found that insufficient F intake through surface water does not cause dental fluorosis but rather dental caries in children. East and South China regions bear the highest health burdens, quantified in Disability-adjusted life years (DALYs), reflecting the extensive use of surface water for drinking purposes. Multiple linear regression analysis indicated that soil & geology largely control F concentrations, with precipitation exerting a significant negative effect, accounting for 16.5% of the explained variance. As China anticipates increased precipitation in the future, a potentially elevated risk of fluorine deficiency in South and East China demands vigilant attention. [Display omitted] • The dose-response curve based on fluoride intake via drinking water was developed. • Fluorine deficiency was prevalent in Chinese residents with surface water sources. • More than half of the attributable DALYs were concentrated in South and East China. • A regression model attributed national-scale lake F variability to 5 key predictors. • Climate change may exacerbate fluorine deficiency in children of South and East China. [ABSTRACT FROM AUTHOR]