螺、蚌对污水处理厂再生水环境的改善稳定作用

Role of snails and mussels in improving and stabilizing reclaimed water environment of sewage treatment plants

通过选用昆明市第五污水处理厂的一级A标出水和水处理厂外排污泥作为静态实验环境,研究不同混养密度下铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的净化性能,筛选出净化效果较好的放养密度。结果表明:放养30 d,铜锈环棱螺、椭圆背角无齿蚌对污水处理厂再生水环境的水质、底质均有一定的净化作用,扣减空白对照影响,水中COD、TP、NH3-N及底泥有机质平均去除率分别为22.26%、26.10%、25.60%和25.69%,底泥厚度平均减少3.8 cm;与对照相比,放养螺蚌45 d内水均能清澈见底,透明度均>70 cm,能明显稳定水体透明度,改善水环境。综合螺蚌生长适应性和净化效果考虑:污水处理厂再生水静态环境中,螺蚌混养密度应≤3 000 g/m3,在2 000～2 500 g/m3为宜,其中铜锈环棱螺的最适放养密度在400 g/m3,椭圆背角无齿蚌为1 600～2 100 g/m3。

By using the effluent（Grade A marked）and sludge of the Kunming Fifth Sewage Treatment Plant as a static test,it researched the purification effect on the reclaimed water environment of sewage treatment plant between Bellamya Aeruginosa and Anodontawoodianaelliptica in different stocking density,and selected the best stocking density of purifying effect.The results showed that breeding Bellamya aeruginosa and Anodontawoodianaelliptica in 30 d had certain purification effect on water quality,sediment in the reclaimed water environment of Kunming fifth sewage treatment plant,deduction of the blank,the average removal rates of COD,TP,NH3-N,sediment organic were 22.26%,26.10%,25.60%,25.69%,respectively,and the sediment average thickness reduced by 3.8 cm.Compared with the control,breeding Bellamya aeruginosa and Anodontawoodianalliptica in 45 d could clean the water with its transparency more than 70 cm,apparently stabilize water transparency,and improve the water environment.Taking the growth adaptation and purifying effect of the snails and mussels into consideration,in this static environment,the mixed breeding density of Bellamya aeruginosa and Anodontawoodianaelliptica shall be ≤ 3 000 g/m3,preferably in the 2 000～2 500 g/m3,while Bellamya aeruginosa optimal breeding density is 400 g/m3,and Anodontawoodianaelliptica is 1 600～2 100 g/m3.