牙鲆养殖循环系统中固体废物的粒径分布与沉降特征

Particle size distribution and settling characteristics of solids waste settled in the recirculating aquaculture system for Japanese flounder culture

沉淀槽是收集系统中固体废物的最简单装置,其设计参数与其沉淀的颗粒物特性有关。通过研究牙鲆（Paralichthys olivaceus）养殖循环系统产生固体废物的粒径分布和沉降特征,得到了牙鲆养殖固体废物去除的沉淀槽设计参数——溢流率与颗粒物去除效率间的关系,可作为设计沉淀槽时参考。结果表明：系统产生固体废物量为0.13-0.27 kg TSS/kg饲料,平均为（0.22±0.06）kg TSS/kg饲料。沉淀槽中固体废物主要为粒径〈200μm的颗粒,占51.5%,其粒径分布符合双曲线型分布。在给定溢流率的情况下,沉淀槽的固体废物理论去除效率可采用颗粒物的沉降曲线估算。溢流率为1/16 m3/（m2.s）时计算的颗粒物理论去除效率为81%。

The settling basin is simplest equipment for capturing solids waste from recirculating aquaculture system. Knowledge of particle properties is essential to the design of effective solids removal systems. The particle size distribution and settling characteristics of solids from recirculating aquaculture system for Japanese flounder （Paralichthys olivaceus） culture were investigated. The relationship between design parameter over-flow rates and removal efficiencies of sedimentation basin for removal of solids waste was obtained. The results show that the contents of solids waste generated from per kg of food per day at three different feed levels was 0. 22±0.06 kg of dry weight ranging from 0.13 to 0.27 kg of dry weight. In the particles settled in sedimentation basin, the majority of the particles were found to be in the size less than 200 μm, percentage is 51.5%. The particle size distribution settled in the sedimentation basin could be described using hyperbolic function. The theoretical removal efficiencies were estimated according to settling curve of particles at given overflow rates （OFR） for the reference of sedimentation design.