Study On In-situ Adsorption And Monitoring Methodology For Microcystins By Resins

In recent years, the eutrophication is becoming to a serious issue ofenvironmental pollution with rapid development of economy. Both ecologicalenvironment and human health have been seriously affected by cyanobacterial blooms,especially cyanobacterial toxins produced by toxic species of cyanobacteria.Microcystins directly affect the safety of drinking water because they are the mostuniversal cyanobacterial toxins and very toxic to human health. So it is very urgent tomonitor microcystins in water resource.Firstly, the intra-cellular and extra-cellular distribution of MC-LR and [Dha7]MC-LR toxins were analyzed using the Microcystis aeruginosa905cultures in thepresent study. Secondly, the adsorption and desorption of MC-LR and [Dha7] MC-LRtoxins by HP20and SP700resins were characterized, and the adsorption mechanismwas explored according to the porosity structures of resins. Finally, the in-situadsorption and monitoring for microcystins were simulated by cyanobacterial cultureswith different density in order to obtain the theoretical basis and data for the newmonitoring technology.The results demonstrated that both intra-cellular and extra-cellular amount ofMC-LR and [Dha7] MC-LR toxins in average cyanobacterial cell gradually declinedwith growth in the initial phase, exponential phase, and stationary phase. However,the total intra-cellular and extra-cellular amount of both toxins increased gradually inthe experimental term, and ratio of extra-cellular amount to intra-cellular amount alsogradually rised. The behaviors of adsorption of microcystins by HP20and SP700resins were corresponding with Freundlich equation. Although both HP20and SP700resins could fastly adsorpt microcystins in the range of experimental concentrations,HP20resin was better for monitoring method because it was more advantageousdesorptin in toxins solution with low concentration. Both resin bags could adsorpt and monitor microcystins in the cultures of Microcystis aeruginosa905producingMC-LR and [Dha7] MC-LR toxins. However, the results indicated that the HP20resinhad better behavior in cultures with low cyanobacterial density. Therefore, the HP20resin was recommended as an effective tool combined with the HPLC method tomonitor and forecast the microcystins pollution in water resource.The study provided theoretical basis and primiary data for the mornitoring andforecasting methodology of microcystins in water resource, which was verysignificative and valuable to protect the driking water safety and human health.