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In this study, we analyzed the concentration distributions of 20 polycyclic aromatic hydrocarbons (PAHs) in 41 water samples which were collected from the northern part of Taihu Lake during 4 field campaigns (201511, 201606, 201702 and 201709). The concentrations were determined with GC–MS, and their spatial and seasonal distribution characteristics were interpreted. The results show that 2-ring PAHs present considerably higher concentrations in warm seasons than cold seasons, but the concentrations of the other higher-ring PAHs are rather stable in warm and cold seasons. The distribution patterns of these PAHs might be mainly attributed to ambient temperature effects on the PAH solubility in the water body. Meanwhile, the spatial distributions of the PAH concentrations in cold seasons were rather various in the sampling area, while the distributions in the warm seasons were homogeneous. The different distributions could result from the water recharge from the Yangtze River during cold seasons, which diluted PAH concentrations in the northeastern part of the lake. Furthermore, via literature review on PAH concentrations in water body, PAHs are in a wide range of levels and their patterns are different among the studies, which should be more effected by local factors instead of general PAH properties. The results from this study also present special characteristics of PAHs in Taihu Lake, which exhibit more insight on PAHs existence in water bodies. [ABSTRACT FROM AUTHOR]

Taihu (Tai Lake) is China´s third largest freshwater lake and serves as drinking water resources for several million people. Located in a densely populated region close to Shanghai, Taihu is a drastic example of water pollution. Organic contaminants, heavy metals and the excess of nutrients from urban areas, industry and agricultural run-off not only pose a risk for the environment but also endanger a safe drinking water quality. Therefore, the SIno-German SIGN project aims to adapt proven technologies and management concepts from Germany to the conditions in China in order to improve lake management and guarantee a long-term safe drinking water supply.This study presents and discusses the results of the first project (2015-2018) with respect to occurrences of organic pollutants, their toxicity and impact on drinking water. Moreover, it presents first results of the second project (2018-2021) focusing on organic contamination of sediment as potential source of raw water pollution and on elimination rates of 200 organic contaminants during different treatment steps in drinking water plants.During the first project, multiple sampling campaigns in the Northern Taihu, artificial wetlands, drinking water and wastewater treatment plants have been conducted. More than 80 samples have been collected and analysed for pesticides, industrial chemicals, pharmaceuticals, PAHs, VOCs and THMs. Here, 70 different organic pollutants have been detected, whereas spatial patterns indicate multiple sources within the various catchment areas of the major inflowing rivers. The results further show that the artificial wetlands, which are used as pollution control for water fluxes entering Taihu, are able to substantially lower pollution loads. Also, several pollutants have been detected in the drinking water. In order to evaluate mixture effects regarding endocrine disruption and genotoxicity, in vitro bioassays have been conducted. Estrogenic activity up to 2.1 ng EEQ / L could be determined in 18 samples while no androgenic effect and no genotoxic potential were observed. Furthermore, a potential environmental and human risk was assessed, identifying spatial and temporal exceedances of 19 parameters like the analgetic Ibuprofen, the herbicide Bentazone and the x-ray contrast agent Iohexol.Based on the results of the study, several recommendations for drinking water treatment facilities have been derived. For example, the dosage of ozone for water purification should be adjusted according to online measured physico-chemical parameters in order to avoid the generation of transformation products. [ABSTRACT FROM AUTHOR]

In the present work, we analyzed the concentration patterns of 20 Polycyclic Aromatic Hydrocarbons (PAHs) in 25 surface sediments and 11 sediment cores from the northern part of Taihu Lake, China. Three of the cores were dated based on 137 Cs activity for the deposition age of the sediment. The spatial distributions of the PAH concentrations show that the inflow rivers into Zhushan Bay and Meiliang Bay were the main pathway for PAHs and sediment input to the northern part of the lake. This results in substantially higher PAH concentrations (up to 5000 ng/g) and sedimentation rates (higher than the average of 3-4 mm/a) in the area close to the river outlets. In addition, results also show that PAH concentrations in the sediments considerably increased from the early 1960s, but the decreasing concentrations in the upper layers of the sediment could be attributed to the introduction of measures on environmental improvement from ca. 2000. There were both anthropogenic and biogenic origins of perylene in the lake sediments, which were distinguished based on spatial distribution patterns and also the concentration proportions of perylene to the sum of the 20 PAHs. In the cores collected close to river outlets, the concentration proportions of perylene typically range from 0.02 to 0.18 and there are significant positive linear correlations between the concentration of perylene and three anthropogenic PAHs (Benzo[a]pyrene, Benzo[e]pyrene, Pyrene), suggesting that perylene was dominated by anthropogenic input. However, the cores collected further away from the river outlets show the concentration proportions between 0.13 and 0.96, and present significant negative correlations or no correlations between perylene and the three PAHs, suggesting that perylene was mainly formed by biogenic activities. Furthermore, the different perylene sources accompanied with the location distributions imply that anthropogenic activities could inhibit its biogenic formation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)