苏州河底泥营养物质空间分布及环境风险评价OACSTPCD

In order to study the spatial distribution and environmental risks of nutrients in the sediment of Suzhou River,samples were collected in the Shanghai reach,and the organic index method and nutrient ratio were used to evaluate the environmental risks of nutrients.The results showed that organic matters(OMs),total nitrogen(TN),and total phosphorus(TP)did not exceed the background value.OMs and TN decreased first and then increased along the route,while TP showed a downward trend;in the vertical direction,due to the accumulative effect before closure and the interaction between the sediment and overlying water after closure,OM,TN and TP fluctuated at first,then increased slightly and decreased.According to the evaluation of organic indexes,the river was clean in the 0～22 km section,and slightly polluted in the section after 22 km.In the vertical direction,the river was clean,with zero environmental risk.The C/N value ranged from 14 to 23,and the main source of nutrients was higher plants;the N/P value was much lower than that of eutrophic rivers and lakes.This paper provides a scientific basis for the comprehensive treatment of the environment of the Suzhou River,and provides reference for the assessment of the status quo of nutrients in the river.