Effect of constructed wetland system on aquaculture wastewater by ecological treatment

Ruohan Tang,Ruohan Tang,Yuling Ou,Xiang Chen,Zhi Chen,Yeqin Xu,A.E.-F Abomohra

doi:10.1051/e3sconf/202126902002

Abstract

In this study, an integrated ecological system was constructed to treat small scattered aquaculture wastewater in southern rural areas of China. The water outlet of 4 level wetlands was continuously monitored from July to December in 2017. Results showed the average concentrations of total nitrogen (TN), ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3-N), total phosphorus (TP) and chemical oxygen demand (COD) were 43.64mg/L, 17.53mg/L, 1.71mg/L, 1.66mg/L and 51.39mg/L in the average effluent concentration of grade I wetland, respectively, and 8.35mg/L, 4.42mg/L, 0.24mg/L, 0.26mg/L, 21.32mg/L in the average effluent concentration of grade IV wetland, respectively. The removal rates were 81%, 75%, 86%, 85% and 59% for TN, NH4+-N, NO3-N, TP and COD in the integrated ecological system, respectively. The effluents from the integrated ecological system met the requirements of “Discharge Standard of Pollutants for Livestock and Poultry Breeding” (GB 18596-2001) and achieved “Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant” (GB 18918-2002) the center two levels to discharge the standard. Obviously, the integrated ecological system could work efficiently in treating the rural scattered aquaculture wastewater, and also possess merits of low construction and operation costs and simple management method, which will be benefited to its application in the southern rural regions of China.

Highlights

At present, seven major water systems have been polluted to varying degrees in China, and the problem of water eutrophication has become increasingly prominent [1]
This paper introduces an ecological combination treatment technology for sewage treatment in small-scale farms in rural areas, in order to provide technical support for solving pollution control of livestock and poultry breeding in rural areas in China
The total nitrogen (TN) concentration of the left of wetland I outlet and the right of wetland I outlet is 3.69 - 115.71mg/L, 4.22 256.12mg/L, respectively, and the TN concentration at the outlet treated by wetland II, III, and IV is 1.46 47.32mg/L, 1.39 - 44.47mg/L, 0.17 - 32.79mg/L, respectively, the corresponding TN removal rate is 54%, 25%, 45%, respectively

Summary

Introduction

Seven major water systems have been polluted to varying degrees in China, and the problem of water eutrophication has become increasingly prominent [1]. The environmental pollution caused by the poultry breeding industry has exceeded the industrial pollution, and the environmental problems caused by it have attracted great attention in China [2]. Farming sewage has the characteristics of high content of organic matter, nitrogen, phosphorus and other pollutants, and direct discharge will pollute the water source and pose a certain threat to the safety of drinking water [3]. The results of constructed wetlands for rural sewage treatment have achieved certain effects [4,5,6,7,8,9,10]. Farms are built in suburbs or rural areas, and their topography and

Methods

Results

Discussion

Conclusion