Occurrence and Influencing Factors of Odorous Compounds in Reservoirs Used as Drinking Water Resources in Jiangsu Province

Abstract

In order to recognize the risk of odorous compounds and its driving mechanisms in water source reservoirs, the water quality, plankton, and odorous compounds of 17 provincial water source reservoirs in Jiangsu Province were investigated during a high-risk period of odorous compounds. A high eutrophication status, such as high algal biomass and low transparency, were widely observed in our study reservoirs. In addition, 2-methylisoborneol (MIB) exceeded the standard in some water layers of one-third of the reservoirs, of which the average concentration was (13.7±20.7) ng·L-1. Geosmin (GSM) was also detected in several reservoirs, although the maximum concentration of 4.6 ng·L-1 did not exceed the drinking water quality standard. With respect to the relationships between odorous compounds and environmental conditions, significant correlation (P<0.05) was noted between the MIB concentration and eutrophication indicators, including chlorophyll-a, Secchi depth, suspended solids, and comprehensive nutrition state index (TLI), particularly for chlorophyll-a and TLI (P<0.01). These results indicate that the risk of odorous compounds in water source reservoirs depend largely on the eutrophic status. Therefore, nutrient reduction, improvement in vegetation coverage of the reservoir basin, reasonable fishing practices are considered as effective strategies to avoid the risk of the odorous compounds in reservoirs.