载铁活性炭固定床对海水养殖尾水中磷的去除

Orthophosphate Removal in Aquaculture Tailwater by Iron-loaded Activated Carbon Fixed Bed

为实现水产养殖尾水中低浓度磷酸盐的快速高效去除,该文构建了基于活性炭负载纳米羟基氧化铁(FeOOH@AC)的固定床吸附除磷装置,探究了盐度、进水磷酸盐浓度和流速对固定床动态吸附除磷效果的影响,并考察了FeOOH@AC固定床对工厂化海水养殖尾水中磷酸盐的吸附去除效果。结果表明,当水中磷酸盐初始浓度为0.75 mg/L时,FeOOH@AC固定床处理90 min后,水中活性磷酸盐浓度可以降到0.05 mg/L以下,去除率可以达到90%以上。FeOOH@AC固定床对水中磷酸盐的去除率随盐度降低而增加,当待处理水的盐度从30降低至5时,水中磷酸盐的去除率可以从69%提高至94%。同时,进水磷酸盐浓度和进水流速减低,使FeOOH@AC固定床到达吸附穿透点和吸附耗竭点的时间会延长。此外,经NaOH再生处理后,FeOOH@AC固定床有良好的重复使用效果。在应用于海水养殖尾水实际处理时,FeOOH@AC固定床可高效去除尾水中的磷,实现磷的达标排放。

A bench-scale experimental nano-ferric-hydroxide loaded activated carbon(FeOOH@AC)fixed bed was set up for the study of efficient removal of low concentration orthophosphate from aquaculture tailwater,which involved investigating the effect of salinity,influent orthophosphate concentration and flow rate on the orthophosphate removal and the performance of the FeOOH@AC fixed bed for orthophosphate removal from the industrial mariculture tailwater.Consequently,the experiment revealed that when the initial orthophosphate concentration of the tailwater was 0.75 mg/L,the orthophosphate can be reduced to below 0.05 mg/L after 90 min,with the orthophosphate removal rate being up to 90%,and the removal rate of orthophosphate increased with the decrease of salinity,as the salinity declined from 30 to 5,the removal rate of orthophosphate increased from 69%to 94%.It was found that reducing influent orthophosphate concentration and slowing down flow rate through the fixed bed would prolong the duration of the adsorption penetration point and the adsorption depletion point.In addition,FeOOH@AC fixed bed had a good feature of reusability after being dealt with the NaOH regeneration treatment.On account of the results,FeOOH@AC fixed bed,when being applied to the practical project of seawater aquaculture tailwater teratment,would be efficiently remove orthophosphate from the wastewater in prospect,meeting the related state discharge standard.