Assessment of Water Quality and Identification of Pollution Risk Locations in Tiaoxi River (Taihu Watershed), China

Abstract

Taihu Lake is the third largest freshwater lake in China and serves as a drinking water source for~30 million residents. Tiaoxi River is one of the main rivers connected to this lake and contributes >60% of the source water. Taihu Lake has been facing various environmental issues; therefore, it is important to study the water quality of its inflow rivers. This study aimed to evaluate the physico-chemical and microbiological characteristics of Tiaoxi River and to determine the spatial and seasonal variations in the water quality. Water samples were collected from 25 locations across the Tiaoxi River in three seasons in 2014-2015. Fourteen water quality parameters including multiple nutrients and indicator bacteria were assessed, and the data analyzed by multivariate statistical analyses. The physico-chemical analysis showed high levels (>1 mg/L) of total nitrogen (TN) in all locations for all seasons. Total phosphorus (TP), nitrite-N (NO 2 -N), and ammonium-N (NH 4 -N) exceeded the acceptable limits in some locations and fecal coliform counts were high (>250 CFU/100 mL) in 15 locations. Hierarchical cluster analysis showed that the sampling sites could be grouped into three clusters based on water quality, which were categorized as low, moderate, and high pollution areas. Principal component analysis (PCA) applied to the entire dataset identified four principal components which explained 83% of the variation; pH, conductivity, TP, and NO 3 -N were found to be the key parameters responsible for variations in water quality. The overall results indicated that some of the sampling locations in the Tiaoxi River are heavily contaminated with pollutants from various sources which can be correlated with land use patterns and anthropogenic activities.

Assessment of Water Quality of Odor River, Anambra State

“…The study emphasized the importance of the microbiological parameters in determining the water quality index for groundwater regarding its role in ascertaining actual condition of water quality for different purposes. A similar study by Vedde et al [8] also examined the physicochemical and microbiological parameters from 25 locations of Tiaoxi River, China. The objective of the study was to determine the spatial and seasonal variations in water quality.…”

“…into groups or clusters. The resulting clusters of objects should exhibit high internal homogeneity (within clusters) and high external heterogeneity (between clusters) [8].…”

Assessment of Water Quality Evolution in the Pearl River Estuary (South Guangzhou) from 2008 to 2017

“…A total of 11 water quality parameters were selected for analysis, including a microbiological parameter: fecal coliform (F. Coli); physiochemical parameters: T, pH, dissolved oxygen (DO), potassium permanganate index (BOD 5 ), COD Cr , potassium permanganate index (COD Mn ), and petroleum; and nutrients: total nitrogen (TN), NH 3 -N, and TP. The physicochemical parameters, DO, BOD 5 , COD Cr and COD Mn , are common indicators of organic pollution in water [26,27]. Petroleum was selected as a representative local organic pollutant because the petrochemical industry is a pillar industry of Guangzhou [28].…”

Evaluation of Spatial and Temporal Variations of Surface Water Quality in the Nile River Damietta Branch

“…Throughout this study, the EC values ranged from 398 to 1434 µS•cm -1 with an average 830 µS•cm -1 . These high values may indicate the high impact of land runoff where wastewater could increase the conductivity due to the presence of chloride, and nutrient salts [26]. Moreover, they also suggest a potential irrigation problem in Damietta branch due to salinity hazards where the EC values exceed on an average the level set by national guidelines [27] for agricultural use and other purposes.…”