Sulfonamides Effect On The Growth Of Phaeocystis Globosa Scherffel And Prorocentrum Donghaiense With Their Degradation By Fenton

Sulfonamides are synthetic antimicrobial agents,which are used in aquaculture,animal husbandry and human medicines commonly.With the agriculture development in our country, the usage amount of sulfonamides as veterinary and fisher drugs increase every day.Some researches showed that self-decomposition of sulfonamides was slow and a considerable amount of its still remained for a long time in environment.Residue of drugs is harmful to human health and ecosystem by bacterial resistance.The migration conversion and ecosystem influence research of residual drugs was carried out in recent years,but the influence of residual drugs to the harmful algae was not reported,and the treatment of residual drugs in environment is just being in the early stages.This work was aimed to study the effect of SD and SMX on the growth of Phaeocystis globosa Scherffel and Prorocentrum donghaiense.The degradation of trace sulfadiazine and sulfamethoxazole in water by Fenton was investigated too.Results showed that:1,SD and SMX had the same impact on the growth of Phaeocystis globosa Scherffel(P.s) and Prorocentrum donghaiense(P.d).Both of P.s and P.d got little impact when SD and SMX concentration is under 5 mg/L,but obviously forbided while the concentration went over 20 mg/L.The ED₅₀ of SD and SMX on the p.s were 72 mg/L and 55.2 mg/L respectively,while the ED₅₀ of SD and SMX on p.d were 24.1 mg/L and 47.8 mg/L.The algae cell membrane observated by scanning electron microscopy(SEM) at 92 h was destoried strongly in a great measure.2,The optimal degradation condition of SD by Fenton were H₂O₂=30 mg/L,Fe²⁺=1.25 mg/L,pH=3,t=60 min when the initial SD concentration was 2.0 mg/L.The degradation rate reached 99.8%under the optimal condition.3,The optimal degradation condition of SMX by Fenton was H₂O₂=35 mg/L,Fe²⁺=1.2 mg/L,pH=3,t=8 min when the initial SMX concentration was 2.0 mg/L.the degradation rate reached 97.8%under this condition.4,the ED₅₀ of Phaeocystis globosa Scherffel and Prorocentrum donghaiense were larger than some reported algal,so P.s and P.d maybe have advantage in competition on multi-algal ecosystem.A small quantity of Fenton reagents can effectively remove trace sulfonamides in aquatic environments.