工厂化养殖循环水固液分离特性及处理工艺选择分析

Analysis of the Solid-liquid Separation Characteristics and Treating Process Choice of Industrial Recycled Aquaculture Wastewater

采用固体颗粒去除率累积计算法,以牙鲆(Paralichthys olivaceus)养殖循环水为例,研究了其固液分离特性。结果表明,120min时固体颗粒去除率可达49.3%±0.02%,对应表面负荷为0.39m3·m-2·h-1,与城市污水处理中二次沉淀池设计表面负荷接近。大于100μm的固体颗粒水力粒径占50%左右,此部分颗粒适于用重力沉降或水力旋流工艺去除。小于60μm的颗粒占37%左右,此部分难于水力分离。应基于养殖循环水的固液分离特性选择适合的固液分离工艺处理养殖循环水。

The solid-liquid separating characteristics in the reeirculating aquaculture system （RAS） of Japanese flounder （Paralichthys olivaceus） cultivation was investigated by using the cumulative particle removal rate calculus to process data. From test data the key parameters can be obtained including overflow rate, removal rate and hydraulic particle size. The results showed that the removal rate of solids waste was 49.3%±0.02% at 120 min and 0.39 m^3·m^-2·h^-1 of overflow rate, close to that of the second sedimentation basin used in municipal sewage plant. The distribution of particle size above 100μm varied obviously while that below 60μm varied narrowly. Hydraulic particle size of solid above 100μm made up about 50% of all solids. The processes of gravity settling and swirl separation were suitable for separating this part of solids. Particle size of solid less than 60μm made up about 37% and was difficult to separate by hydraulics. Suitable process of solid-liquid separation should be chosen based on the solid-liquid separating characteristics of recycled aqualeuhure wastewater. Finally foam separating and hollow fibre membrane process were discussed. Fine filters used in industry maybe suit for recycled aquaculture wastewater treatment