Study On Nutrient Pollution In The Surface Sediments Of Jiulong River

Coastal areas are one of the most important sources of economic activity amid rapid urbanization and industrialization. Unfortunately, large amount of industrial wastes are being dumped in the region’s sea basin, resulting in environmental pollution and destruction of the sea ecology. Left unattended, the problem will continue to escalate and pose a serious threat to the eco-system.This paper studies the extent of nutrient pollution in the Jiulong River by analyzing the nutrient level in the surface sediments. The methodology adopted includes: 1) analyzing the content spatial distribution characteristics and chemical speciation of the C, N and P nutrient found in the surface sediments to probe into the environmental impact; 2) conducting preliminary evaluation of the surface sediment contamination level through single factor standard index and organic index analysis; 3) cross-examination of the surface sediment C and N isotopic content analysis to uncover the origin of the organic matter in the surface sediments, and 4) correlation analysis of the acid extracted heavy metals and nutrients found in the surface sediments in the Jiulong River Estuary. Followed by a factor analysis and cluster analysis to probe into its homology.Analysis was conducted in the surface sediments of Jiulong River, including total carbon, total nitrogen, ammonium, total phosphorous and its phosphorous forms such as exchangeable phosphorous, iron aluminum phosphate, calcium phosphate, occluded phosphorous and organic phosphates. It was revealed that compared with the downstream and estuary area, the space distribution of total carbon, total nitrogen, ammonium, total phosphorous in the upstream of Jiulong River varied remarkably;the regression analysis showed that Fe/Al-P(iron aluminum phosphate) was the main chemical speciation among all the deposits with phosphorous content and also the main cause of the phosphate nutrient pollution. The single factor standard index evaluation indicated that the organic and TN(total nitrogen) pollution level were severe, between the range of lowest to serious. Even though the magnitude of TP(total phosphorous) pollution was less alarming, it is still crucial to prevent heavy pollution at the upstream sample collection area, near the Longyan City. Most worrying was the organic index assessment, which placed the organic pollution at level four. This ought to draw the attention of relevant authority.Autocorrelation analysis of the nutrients in the surface sediments of Jiulong River indicated that there was strong correlation for both TN and TP with inorganic phosphorus(P<0.01), which implies that the pollution sources are similar.Applying the isotopic tracer method on the C and N in the surface sediments of Jiulong River, it was discovered that, for the upstream and downstream area, the organic matter embedded in the surface sediments comes from land origin, with the sea origin being more significant in the Jiulong River Estuary, which was in accordance with the result of N isotopic tracer. The correlation isotope ratio analysis of the C isotope with C/N and C/P offered inconclusive results on the origin of the organic matters.The correlation analysis between acid extracted heavy metals and nutrients found in sediments of the Jiulong River Estuary suggested that nutrients and Zn, Cu, Cr and Pb had a strong correlation and possibly share homology. They were effected by the argricultural activities, mining pollution and natural processes.This study systematically analyzed the nutrients within the surface sediments of the upstream, downstream and the estuary of Jiulong River and the correlation between the nutrient and heavy metals found in the surface sediments. The findings will provide a basis for environmental and ecological research in the location, and also serve as advice for environmental protection efforts.