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

ZHANG Qinxin; WANG Shihui; GU Jing; YANG Guojun; GUO Yue; LI Hechong; WANG Hua

doi:10.19672/j.cnki.1003-6504.1620.23.338

Abstract：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 investi-gating the effect of salinity,influent orthophosphate concentration and flow rate on the orthophosphate removal and the perfor-mance 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 regener-ation 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.