The Engineering Design And Treatment Efficiency Of The Constructed Wetlands Of Aquaculture Wastewater

With the economic development of Jiangxi Province and the rapid expansion of population around Poyang Lake, the environment and ecosystems of Poyang Lake are facing enormous pressure. While point source pollution, such as industrial and domestic pollution, had been under effective control, the area source pollution has become the main factor of water pollution.This study is designed to plan a vertical flow constructed wetland sewage treatment system for the reclamation of aquaculture waste water. We selected the prefect filler for wetland through comparing their decontamination capability. Also, hydraulic loading, residence time and some parameters were studied to determine the optimal ratio. All the factors which may affect the operation of vertical flow artificial wetland were analyzed, results are as follows:1,Combined with the aquaculture experience both at home and abroad in wastewater treatment model, a set of parallel vertical flow constructed wetland system was designed. Two sets of vertical flow wetland system, including wetland construction and designing of engineering parameters, selection for wetland site, plant and matrix, were also used.2,Selection of filling materials. In this study, for the selected six kinds of fillers, the adsorption potential of the nitrogen and phosphorus corresponds well with the Freundlich and Langmui linear isotherm equation. The following is the Absorption capacity for nitrogen from strong to weak:Zeolite>sand>gravel>vermiculite> limestone>blast furnace slag. The following is the absorption capacity for total phosphorus from strong to weak:vermiculite>slag>sand>zeolite>Gravel>limestone. In this study, gravel, as a local material, was used for its economic and practical effect.3,Operation management and effectiveness analysis on the Parallel vertical flow constructed wetland system.We detected the best hydraulic loading as 485 mm/d, HRT as24h, through moderating the hydraulic loading and HRT (Hydraulic Retention Time) from September 2009 to October 2010. Based on the sampling every two weeks, results showed that the water quality of the effluent water for 14 months had reached the quality standard of Fisheries (GB11607-89) as well as eutrophic criteria of lakes, namely:TSS(?)10mg/ L; BOD5(?)5.0mg/L; TN(?)0.3 mg/L; non-ionic ammonia(?)0.02 mg/L; TP(?)0.1 mg/ L. Therefore, the aquaculture wastewater can be recycled.