实验模拟条件下不同粒径海泡石对渔业环境中重金属镉的去除效果研究

Sepiolite with Different Particle Sizes: Effects on Removing Heavy Metal Cadmium in Aquaculture Environment Under Experimental Simulation

为了研究纳米级别的海泡石是否可用于去除渔业环境中的重金属镉。本研究在实验室模拟条件下,构建了暴露有2种环境浓度镉(50μg/L和100μg/L)的渔业水生生态系统,并比较了普通粒径和纳米粒径2种海泡石对渔业水体和水产品中重金属镉的去除效果。结果表明,在该生态系统运行的10天,镉从水体向鱼体产生生物浓缩过程;试验接下来利用0.03 g/L浓度的海泡石粉末对水体进行泼洒,发现纳米粒径的海泡石对镉的吸附去除能力优于普通粒径,吸附的稳定性也更好;经过吸附去除作用,鱼体可食部位肌肉中镉含量虽然与处理前(10天时)相比数值有所下降,但不显著,且高浓度处理组数值仍超过相关标准。虽然利用海泡石,特别是纳米粒径的海泡石可有效去除渔业水体中的镉,但由于生物浓缩和积累效应,镉在鱼体中的含量并不会显著得到降低。建议在渔业养殖开始前就对镉的污染水体进行修复,以期达到渔业水质标准,从而保证水产品上市时的质量安全。

The paper aims to study whether nanometer-grade sepiolite could be used to remove heavy metal cadmium in aquatic environment. Under the condition of a laboratory simulation, we constructed 2 aquatic ecosystems with the exposure levels of Cd 50 μg/L and 100 μg/L respectively, and compared the effects of 2 kinds of sepiolite(common particle size and nanometer size) on the removal of heavy metal cadmium in fishery water and aquatic products. The results showed that: within 10 days, Cd had a bio-concentration process from water body to fish body;we then used the sepiolite powder of 0.03 g/L to sprinkle the water body, and discovered the adsorption removal ability of nanometer sepiolite to Cd was superior to that of common particle size, the adsorption stability was also better;after adsorption removal, the content of Cd in the muscle of edible parts of fish body was lower than that before the treatment(on the 10 thday), but it was not significant, and the high concentration treatment group still exceeded the relative standard;although sepiolite especially the nanoparticle size sepiolite could effectively remove Cd in the fishery water, but the bio-concentration and accumulation effect resulted in the non-significant decrease of the Cd content in the fish body. The study suggests that: the Cd polluted water body should be remedied before the start of fishery aquaculture in order to meet the fishery water quality standard, so as to ensure the quality and safety of aquatic products for marketing.