Micro Current Collaborative Experimental Studies Of Chlorine Inactivation Of Enteric Viruses In Water

This study observed synergetic inactivation efficacy for polioviruses I type and coliphage f2 by low amperage direct currenet (DC) and free chlorine (FC), and seek for change of infectivity, antigenicity and ultrastructure after virus was treated, moreover provided envidence for reserching mechanism of synergetic disinfection and desiging installation of synergetic disinfection.There were three groups treated by DC and FC and DC in combination with FC, and each group was divided into different levels. Water samples polluted f2 and PV1 exposed to DC and FC and DC in combination with FC for 5,10 and 30 minutes. Whether DC and FC were synergetic or not was decided by Berenbaum's method, and inactivation efficacy was estimated by comparing inactivation rates K value, meanwhile infectivity and antigenity were detected through Plaque Forming Unit Assay(PFUA) and Virus Enzyme-Linked Cell Immunoassay (VELCIA). Morphologic changes were observed under trasmission electron microscope (TEM). The results indicated:(1) Weak effect of inactivation could be observed on 0.4 mA ?cm-2 or above, and the inactivation efficacy was also enhanced with increasing exposure time or DC density; The effect of inactivation for experimental virus by chlorine containing 0.1-0.3 mg ?L"' could not reach to the sanitation request of disinfection for drinking water.(2) The inactivation rates was higher by 0.4-1.2 mA ?cm-2 DC in combination with 0.2mg ?L-1 than FC alone, and enhanced with increasing DC. The inactivation rates K value of DC reaching to 0.6 mA ?cm-2 for f, or DC reaching to 1.2 mA ?cm-2 for PV1 in combination with FC was significant difference in comparison with FC alone (p<0.05), and inactivation effect of DC in combination FC was synergetic.(3) DC alone or DC in combination with FC producted better effect for water samples of low pH, high hardness and few organism .(4) Inactivation rates for f2 and PV1 treated by DC, FC and DC in combination with FC was samilar, and there were no significant difference.(5) Capsule of virus was not found change after treated by DC, FC and DC in combination with FC under TEM, and inner density of viral grain was partly cut down by FC alone or FC in combination with DC. Viral gathering grain tended to deconcentration after treated by DC.(6) The inactivation of PVI infectivity was increased after synergetic disinfection, but inactivation of PVI antigencity was no change.