Water quality of reclaimed water from treated urban wastewater in Chaobai River Basin, North China

The utilization of reclaimed water could be an efficient tool to alleviate water scarcity, especially for dry river augmentation. However, it is crucial to monitor water quality to ensure safety to human health and to avoid negative effects on the environment. Reclaimed water samples were collected bimonthly from May to November in 2010 in Chaobai River, and the physiochemical parameters were determined. The main results are as follows: The parameters exceeding the threshold value of the water guidelines are mainly nutrition related to nitrogen and phosphorus, which are known to increase the risk of eutrophication in surface waters. Additionally, nitrite and nitrate can be detrimental to human health. The majority of the parameters have a peaking concentration in May, whereas others either show significant temporal variation over the entire period or remain relatively constant in all four months. Correlation analysis shows that some parameters (pH, T and B) have no significant correlation with others, whereas significant positive correlation was found for Sr with EC and TDS, for Cl with TDS, for SiO2 with TP and for NO3-N with TN and a significant negative correlation between SO4 and Ba. According to principal component analysis, 60.108% of the total data is represented by dominant solutes, and the second principal component with a percentage of 31.876 comprises parameters related to nitrogen. Subsequent cluster analysis of parameters identified four groups, which represent different compositions, and samples in May differ from others.