Evaluation of Nutrient and Heavy Metal Pollution in Maozhou River in Shenzhen City

The sediment of Shenzhen Mazhou River was collected and sieved with different particle sizes to determine the physicochemical properties, nutrient contents and heavy metal contents of sediment, interstitial water and oversize mud. At the same time, the single factor evaluation and potential ecological risk assessment of heavy metals were carried out on the sediment of Mazhou River. The experimental results show that the screening of different particle size has little influence on the physicochemical properties and nutrient content of sediment. Mazhou River nitrogen and phosphorus nutrients pose little ecological risk effect on the environment. The ecological risk ranking of heavy metals is Hg> Cd> Cu> Ni> As> Zn = Cr> Pb. Mazhou river sediment comprehensive potential risk index RI values are greater than 1200, indicating that Maozhou river was in extremely high risk. Among them, Hg contributes the most, which is the most important factor controlling the risk of heavy metal pollution in sediment.