分隔式循环水池塘养殖系统设计与试验

为了解决池塘养殖设施化程度低、净化能力不足和排污效果差等问题,设计了分隔式循环水池塘养殖系统。该系统由20%水面的吃食性鱼类养殖区和80%水面的滤杂食性鱼类养殖区构成,配置过水堰、螺旋桨式和水车式推流装置、集污和吸污装置等养殖系统设施和装备。性能测试结果表明:螺旋桨式推流装置提水动力效率为340 m~3/(k W·h),流量为204 m~3/h,空载噪音为60 d B;水车式推流装置提水动力效率为360 m~3/(k W·h),流量为180 m~3/h,空载噪音为67 d B;过水堰过水的总流量约为331 m~3/h,利用水循环装备实现水体流动可实现水体日交换量7 900 m~3,达到养殖池塘水体的50%左右。利用推流装置搅动水体,可实现水体大范围的对流,交替暴晒水体,增加水体中的溶解氧,试验池塘中下层溶解氧水平比对照塘高出59.5%,试验池塘叶绿素a浓度比对照塘低,说明一定程度上限制了浮游植物过渡繁殖。该养殖系统可为池塘健康养殖系统模式构建提供参考。

Design and experiment of partitioned recirculating aquaculture pond system

Abstract: Pond aquaculture plays a very important role in China''s aquaculture industry and is the main source of aquatic product supply. To improve the effect of pond aquaculture, a partitioned recirculating aquaculture pond system (PRAPS) was designed and built based on the characteristics of pond aquaculture in freshwater, which consisted of feeding fish culture zone (20% of water surface) and filter-feeding fish culture zone (80% of water surface). The structure of facilities and equipment of PRAPS was optimized by setting up the overflow weir, propeller flow device, paddlewheel device, and pollutant absorption and collecting device. Tests on the mechanical properties revealed that both propeller flow device and paddlewheel device could achieve the design demand; the energy efficiency of the propeller flow device was about 340 m3/(kW·h), the flow rate was around 204 m3/h, and the no-load running noise was 60 dB; the energy efficiency of the paddlewheel device was about 360 m3/(kW·h), the flow rate was around 180 m3/h, and the no-load running noise was 67 dB; the total flow rate of the overflow weir was about 331 m3/h. The exchange capacity was totally about 7 900 m3/day, accounting for about 50% of the pond water capacity. Additionally, the system could reduce the total energy consumption and farming pollution and effectively improve the pond aquaculture ecological effect, which met the production requirement of energy saving and environmental protection. It was conducive to improve the water quality of the pond though the impeller disturbed the water. The pollutant could be gathered into the middle of bottom by the collecting device, and removed out of system by the pollutant absorption device, in which way the transparency of water was improved, and the content of TN (total nitrogen) and TP (total phosphorus) in the system was decreased. The propeller flow device and paddlewheel impeller stirring water could realize water convection in large scale, so the water was exposed to sunshine and air, which could increase the dissolved oxygen in the water. Tests showed that the dissolved oxygen of the middle and lower layer in the test pond was 59.5% higher than the control pond; the content of TN in the test pond was 21.4% lower than the control pond; the content of TP was 53.1% lower than the control pond; the chlorophyll a concentration in the test pond was lower than the control pond. Because the breeding density in the test pond was higher than the control pond, the content of ammonia nitrogen and nitrite nitrogen in the system was increased. Overall the water quality in the test pond was better than the control pond. For the PRAPS, the one-time investment was big at the beginning and it needed professional and technical personnel to maintain, while the PRAPS had a high economic efficiency. The yield of bream in the test pond was 10 280 kg, and the food coefficient was 1.7; the yield of bream in the control pond was 8 488 kg, and the food coefficient was 2.1. The result showed that the yield of bream increased by 21.1% using the PRAPS, the feed coefficient decreased by more than 23.5%, and the annual output value increased by 6%. The result provides the reference for the model establishment of healthy breeding pond system, which is helpful to make PRAPS become a more mature and reliable novel pond aquaculture system.