The Current Pollution Status And Ecological Risk Assessment Of Nonylphenol In Domestic Water Environment

Nonylphenol is a persistent organic pollutant, belonging to the typical phenolsendocrine disrupting chemicals. As one of the stable degradation products ofNonylphenol Ethoxylate, which is a kind of nonionic surfactant widely used aroundthe world at present, Nonylphenol is toxic, resistant to degradation, biologicalaccumulating and estrogenic active. As a synthetic chemical with high emulsification,high moisture, hard water resistance, oxidative resistance and low temperaturedetergency, Nonylphenol Ethoxylates is widely used in many industries such as textile,plastics, papermaking, chemical fertilizer, pesticides, food, medicine and etc. Aroundsixty percent of the Nonylphenol Ethoxylates used in these industries will bedischarged into sewage treatment station as waste water, and finally enter the aquaticenvironment. After entering the environment, Nonylphenol Ethoxylates is easilydegraded under the action of microorganisms and ultraviolet rays, resultingNonylphenol at last. Compared with the parent compound, Nonylphenol has anincreased stability, enhanced water-solubility and obviously increased biologicaltoxicity. The United Nations Environment Protection (UNEP) puts the Nonylphenolinto the list of27priority persistent toxic substances. European Union WaterFramework Directive put the Nonylphenol and its short chains of the parentcompounds as Priority Hazardous Substances.The Nonylphenol can generate some extent damage to aquatic organism. Thoughthe concentration of Nonylphenol is low in the water environment, it can enrich in thebiological body. The research of environment distribution in our country has begun,however, none of them comprehensively assess the pollution status and ecologicalrisk of Nonylphenol in domestic water environment combined with the environment characteristics in all regions. Compared with foreign research of ecological riskassessment, the domestic research of ecological risk theory and method started late,and the ecological risk assessment related to Nonylphenol pollution. As a result, basedon the mass data, this article firstly analyzes and summaries the Nonylphenoldistribution in domestic water environment, analyzes and compares the Nonylphenolpollution in different levels such as offshore, river and ocean, and analyzes andconcludes the Nonylphenol allocation pattern in different environmental medias.Based on existing toxicology research data and Predicted Non-effect Concentration(PNEC) determined by Nonylphenol ecological risk assessment model, the articlecomprehensively assesses the Nonylphenol ecological risk in researched regions’water environment using risk office, suggests a series of risk control solutionsincluding source control, process control, and decomposition of the degradation, andprovides scientific evidence to establish related laws and regulations, criterion orreference and adopts corresponding environmental regulation and control.The research results prove that the river basins with maximum risk office above1in surface water are some positions in Daliao River basin, Yellow River in Lanzhouand Hai River basin and Hongkong Mipu wet land. This indicates that theNonylphenol pollution in these river basins has threatened regional ecosystem anddamaged the growth of aquatic animals and plants, and it will badly affect humanhealth without artificial regulation and control. The river basins with surface waterrisk office between0.1and1are north Yellow Sea in Liaoning inner sublittoral zone,Bohai Gulf, Hai River basin, Yellow River Estuary, Yangzi River Estuary and adjacentocean areas, Daliao River basin, Jiaozhou Gulf River basin and Zhujiang Delta. TheNonylphenol content in surface water of the river basins has not directly damaged theacquatic animals and plants, but the potential risk has lead the attention of relateddepartments, and corresponding protection and measures of remediation need to beadopted to avoid greater degree damage of local river basin ecosystem. LingdingyangBay has a Nonylphenol risk office in surface water less than0.1, whick can notthreaten the local ecosystem. For the sediment in water environment, Yellow RiverEstuary has a risk office below0.1which is in the safe range. Yangzi River Estuary and adjacent ocean areas has a Nonylphenol risk office of0.347, slide over the criticalvalue of0.1, indicating that Nonylphenol has potential threat to benthos, which shouldbring attention to related departments, and be controled. The river basins that have aNonylphenol risk office far above critical value of0.1are Jiaozhou Gulf, YellowRiver in Lanzhou section, Lingdingyang Bay, Zhujiang Delta, Wenyu River andJiaozhou Gulf and adjacent rivers.According to the water quality standard published by the EnvironmentalProtection Agency of United States, the concentration of Nonylphenol in JiaozhouGulf, Yellow River Estuary, Yangzi River Estuary are all below the chronic thresholdconcentration of the sea, which is keeped as1.7μg/l; According to the datas used inthis article, we can draw the conclusion that the concentration of Nonylphenol inDaliao River, Hai River basin, Jiaozhou Gulf and adjacent rivers, Yellow River inLanzhou section, Zhujiang Delta, Wenyu River and Hongkong Mipu wet land are allbelow the chronic threshold concentration of the freshwater system, which is keepedas6.6μg/l.