Polycyclic Aromatic Hydrocarbons in Sediments from Typical Algae, Macrophyte Lake Bay and Adjoining River of Taihu Lake, China: Distribution, Sources, and Risk Assessment

Yibo Dong,Zaisheng Yan,Mingzhong Yang,Haichen Zhang,Huifang Wu,Guoqing Zhang

doi:10.3390/w13040470

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants in sediments and pose a serious risk for freshwater ecosystems. In this study, sediment samples from 24 sites were collected from the cyanobacterial bloom-occurring, macrophyte-growing lake bay and adjoining river of Taihu Lake. Here, the concentration levels, sources, and risk assessment of 16 priority PAHs in the surface sediments from typical algae, macrophyte lake bay and adjoining river of Taihu Lake, were investigated, and the results were compared with those of previous studies. The total PAH (ΣPAH) concentrations ranged from 4900 to 16,800 ng·g−1 in sediments of the Taihu Lake bay and from 5736.2 to 69,362.8 ng·g−1 in sediments of the adjoining river. The level of PAHs in riverine sediments was significantly higher than those of the Taihu Lake bay, and that of the Dongshan River was significantly higher than that of the Mashan River, while there was no significant difference in the concentrations of PAHs between the cyanobacterial bloom-occurring and macrophyte-growing lake zone. The results indicated petroleum contamination was dominated in the cyanobacterial bloom-occurring, macrophyte-growing lake bay, while PAHs of the riverine sediments derived from petroleum contamination and the combined combustion including wood, coal combustion, and petroleum combustion according to the identification by the molecular diagnostic ratio and principal component analysis (PCA). Sediment risk assessment based on sediment quality guidelines (SQGs) suggested that partial regions of the Taihu Lake bay were subjected to the potential ecological risk of the 3-ring and 5-ring PAHs, and there existed negative effects related to naphthalene pollutant in all survey regions. The adjoining riverine sediments showed a high ecological risk.

Highlights

Introduction iationsPolycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants that are prevalent in the environment, which could be transported to the lakes and rivers through surface runoff, sewage discharge, atmospheric deposition, and some other means, such as oil leaks [1,2,3,4]
16 priority PAHs in sediments from the macrophyte-growing, cyanobacterial bloom-occurring lake bay and adjoining rivers in Taihu Lake were investigated, and possible source contributions were estimated based on the isomer ratios diagnoses and principal component analysis (PCA)
The distribution of PAHs concentration in sediments was more dependent on specific pollutant sources than lake-zone type or other environmental factors

Summary

Introduction

Introduction iationsPolycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants that are prevalent in the environment, which could be transported to the lakes and rivers through surface runoff, sewage discharge, atmospheric deposition, and some other means, such as oil leaks [1,2,3,4]. PAHs entering the water body are adsorbed on the particles and tend to accumulate in the sediments [5]. Sediment is one of the important environmental reservoirs for PAHs [6,7]. Due to their mutagenicity, carcinogenicity, and toxicity, PAHs pollution raises great concerns worldwide [8,9]. Sources, and risk assessment of PAHs in sediments from typical macrophyte, algae lake bays and adjoining rivers is crucial for effective abatement of pollution and risk [10,11,12]. Previous studies have found that the sedimentwater interfaces in the cyanobacterial bloom-occurring, macrophyte-growing lake zone

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