生物膜“细菌-藻类”协同系统改良淡水池塘养殖水质与沉积物的效果研究

WATER AND SEDIMENT QUALITY IMPROVEMENT IN FRESHWATER PONDS IN BIOFILM BACTERIA-ALGAE SYSTEM

采用池塘中设置生物膜净水栅对比实验的方法,在8口土池开展生物膜"细菌-藻类"协同系统改良池塘养殖水质与沉积物的效果、对苗种培育效果的影响及其相关机理等的研究。结果表明,在142d的养殖期间,处理组比对照组节水减排达65.1%,具有极显著差异(P<0.01);处理组水质的p H、总氮和亚硝酸盐氮分别极显著低于对照组3.7%、31.3%和38.7%(P<0.01),氨氮、总磷、活性磷和硫化物分别显著低于对照组25.6%、41.6%、37.8%和27.9%(P<0.05);弧菌数和藻类密度极显著低于对照组63.1%和51.3%,硅藻相对密度极显著高于对照组93.7%;细菌总数显著高于对照组50.8%,蓝藻相对密度显著低于对照组16.6%;处理组的藻类生物均匀度指数显著高于对照组8.9%;生物膜上的细菌总数高达1.30×109 CFU/g,而弧菌数为零;处理组池塘沉积物的氧化还原电位显著高于对照组30.5%,硫化物浓度显著低于对照组47.0%;草鱼苗种起捕规格、成活率、产量和生长速度分别显著高于对照组24.6%、4.3%、29.8%和28.6%,饲料系数极显著低于对照组15.6%,处理组每公顷池塘培育草鱼大规格鱼种可增加净利润约1.92万元。

To improve water and sediment quality in freshwater ponds in Ctenopharyngodon idellus fingering culture, an experiment was conducted in biofilm bacteria-algae system. Experiment was conducted in 8 freshwater earthen ponds in 142 days. Biofilm purifying bars were set in the treatment ponds for biofilm development, while the control group set no such bars. At the end of experiment, compared to the control, in the treatment, effluents was significantly reduced by 65.1%(P<0.01); concentrations of p H, TN, and NO2-N significantly fell by 3.7%, 31.3%, and 38.7%, respectively(P<0.01); concentrations of TAN, TP, soluble reactive phosphate, and sulfide significantly dropped by 25.6%, 41.6%, 37.8%, and 27.9%, respectively(P<0.05); the quantity of Vibrio and algae density significantly decreased by 63.1% and 51.3%, respectively(P<0.01); silicon algae relative density significantly increased by 93.7%(P<0.01); the total bacteria and algae evenness index significantly boosted by 50.8% and 8.9%(P<0.05); and blue algae relative density significantly reduced by 16.6%(P<0.05). The total bacteria within biofilm was about 1.30×109 CFU/g; the quantity of Vibrio within biofilm was zero; sediment redox potential significantly hiked by 30.5%(P<0.05); sediment sulfide concentration significantly lowered at 47.0% than the control(P<0.05). At last, the treatment increased fish harvest size, survival rate, yield and growth rate by 24.6%, 4.3%, 29.8%, and 28.6%, respectively(P<0.05), and decreased feed conversion rate by 15.6%(P<0.01). In overall, the treatment gained additional profit of about 19200 Chinese Yuan(~3096 USD currently) per hectare above the control.