Investigation on polluted water quality of the typical tidal urban river
典型感潮内河涌水质污染特征调查研究

The hydrology and water quality of a tidal-gated urban river in the Pearl River Delta (PRD) region were consecutively monitored for three months. The results indicated that the investigated water body was overall inferior to water quality standard V grade of surface water, and the concentrations of each pollution indicator exceeded the standard V grade by 0.5 to 7.2 times. Water quality and the pollutant concentrations changed accordingly as the change of the water level, and the ratios of maximum-to-minimum concentrations of each pollutant fluctuated between 8.3 and 49.4. Trend of pollutant concentrations showed significant negative correlation to those of the water level, and the pollutant concentration ratio of low-to-high water level was 1.2 to 2.2. The complex composition of pollutants suggested they are of low biodegradability. This investigation revealed a common feature of the urban river in the PRD region and provided important information for the pollution control and ecological restoration technology.