Speciation and spatial distribution of nitrogen in surface sediments of in Ming Lake

Yu Li,Qi-Yu Kuang,Chao Din,Z.B Xu,D.Q Chen,J.Y Liu

doi:10.1051/e3sconf/201913101047

Abstract

To reveal the diverse occurrence forms and spatial distribution characteristics of nitrogen in the surface sediments of Ming Lake, a sequential leaching method was employed to determine the nitrogen in the surface sediments of Ming Lake. The results show that the total Nitrogen (TN) of the surface sediments of Ming Lake are between 383.23 and 3270.38 ug/g, and the spatial distribution is generally shown as southwest>middle>southeast>west of the lake. The results indicate the nutrient level of the whole lake is not very high. However, for some local areas a risk of high eutrophication pollution may exist due to excessive content; the average TTN is 638.77 ug/g which occupying 36 % of the lake; the spatial distribution is the same with TN; the average (NTN) is 928.61 ug/g that occupied 61 % of TN. With the exception of SAEF-N, every occurrence form of nitrogen was positive with TOM, indicating that the content and spatial distribution of organic matter in the surface sediments of Minghu Lake are the main controlling factors for the content and spatial distribution characteristics of various forms of nitrogen in the sediments.

Highlights

In recent years, measurements such as harnessing the surrounding environment of lakes, cutting off the import of exogenous pollution into lakes were taken to reduce eutrophication of lakes
When blocking the influx of exogenous N and P nutrients, the endogenous N and P salts deposited in the sediments are dissolved into the water again through the concentration gradient formed by the Sediment-Overlying water body in the form of desorption, dissolution, release and diffusion, which aggravates the risk of secondary eutrophication pollution in the lake water body [6,7]
The surface sediment of Minghu Lake was taken as the research object, and the continuous extraction method of sediment N proposed by Ma Hongbo et al [10,11] was used to study the occurrence form and spatial distribution characteristics of N in Minghu Lake sediment and its correlation with total organic matter (TOM) in sediment

Summary

Introduction

Measurements such as harnessing the surrounding environment of lakes, cutting off the import of exogenous pollution into lakes were taken to reduce eutrophication of lakes. This method has achieved good results in the early stage, with the passage of time scale, lake water eutrophication again highlighted. When blocking the influx of exogenous N and P nutrients, the endogenous N and P salts deposited in the sediments are dissolved into the water again through the concentration gradient formed by the Sediment-Overlying water body in the form of desorption, dissolution, release and diffusion, which aggravates the risk of secondary eutrophication pollution in the lake water body [6,7]. To control the release of endogenous nitrogen in the sediments of Minghu Lake and control the blooms in the water body of Minghu Lake, the corresponding theoretical basis was provided

Methods

Results

Conclusion