Chemical speciation of phosphorus in surface sediments from a geological phosphorus-rich watershed, South China

Chensheng Wang,Honghan Chen,Qianqian Xue,G.I Rashed,M Kheshti

doi:10.1051/e3sconf/202125203061

Abstract

In order to clarify the distribution characteristics and potentially environmental effect of phosphorus (P) chemical speciation in river sediments from a typical geological P-rich (GPR) watershed, South China. Forty-eight sediment samples collected from the Huangbai River watershed, Yichang city, Hubei province. The levels of TP in Huangbai River wathershed were remarkably higher than those in most Chinese lakes, reservoirs, and river. The Ca-P and Res-P were the two dominant species that accounted for 78.7% and 13.3% of TP, respectively. Based on the sediment quality guideline (SQGs) and background values of Chinese soil and sediment, the majority of the mean TP concentrations in surface sediments were higher than their background values. The unique distribution pattern of P species in the Huangbai River watershed depends on local environment conditions and P sources. These findings improve our understanding of the eutrophication and P cycle in the GPR watershed.

Highlights

The problem of eutrophication of water bodies in China is becoming more and more serious
The forms of P in sediments have been extensively studied, and the results show that the relative amounts of each form of P vary in different regions, and not all forms of P in the sediments can be released to the overlying water [2]
The basic physicochemical characteristics in sediments of Huangbai River is shown in Table1. pH of the sample varied from 7.51 to 8.06 with an average value of 7.71

Summary

Introduction

The problem of eutrophication of water bodies in China is becoming more and more serious. Sediment is an important reservoir of nutrients in rivers and lakes, and the nutrients importing the water bodies will eventually enter the sediment, and under certain conditions, these nutrients will be released into the overlying water again, which in turn impacts the aquatic ecosystem [1]. The analysis of inorganic P is important to study the sorption and release of Р from sediments and the contribution of eutrophication. The forms of P in sediments have been extensively studied, and the results show that the relative amounts of each form of P vary in different regions, and not all forms of P in the sediments can be released to the overlying water [2]. There are two other features about GPR watersheds: (1) large phosphate deposits and intensive mining activities are found; (2) the content of P is relatively high in rock, soil, and sediment. Mining and other human disturbances lead to severe environmental decay, and P is lost to adjacent water from GPR area

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