Development Of Innovative Dual Functional-load Main- Line Filtration And Fisinfection Medium SMZ/ZVI

Taking Escherichia coli, frequently-used referent of Pathogenic microorganism,as the object and Yuanteng’s culture medium as the substrate and adopting the bacteria amount culture method and Yuanteng culture method to determine the amounts, we carry out the experiment using simulative underground water mixed liquor with Escherichia coli of certain concentration.We adopt the methods of ingrafting electropositive surface active agent and flocculent alkali metal hydroxdides and so on to carry out function load modification towards the zeolite surface(SMZ) and then modify zero-valence iron(ZVI) using SMZ to form dual functional load new-type filtration and disinfection medium (SMZ/ZVI).At last,we use this new medium to remove and inactivate pathogenic microorganism efficiently.Through this experiment,we determine every technology condition and other effect factors of developing SMZ/ZVI filtration and disinfection medium and validate its actual apply effect.The result is as follows:(1)As for zeolite, the smaller the grain diameter, the better the effect on filtration and disinfection of E.coli. Lateral thinking,2.0～3.0mm of the grain diameter is suitable and Zeolite can adsorb the maximum E.coli in 30 minutes,about 8.2667x105cfu/g.The surface structure and the superficial area of the zeolite modified by alkali metal hydroxdides and electropositive surface active agent change a lot and the total adsorbance and the irreversible adsorbance of E.coli improve obviously.Besides,the zeolite modified by Aluminum Chlorohydrate and CTAB can remove 1.7、1.8 times the quantity.The removing mechanism shows that the zeolite modified by Aluminum Chlorohydrate and CTAB represents irreversible adsorption.(2)As for zero-valence iron, fine sheet of vortex-type can remove and inactivate E.coli most efficiently because of its large superficial area; medium adsorption isotherm shows that zero-valence iron has durable adsorption and inactivation capacity and it can remove 2.1022×106 cfu/g E.coli in 180 minutes. Zero-valence iron removes E.coli mainly through inactivation.Both the total adsorbance and the irreversible adsorbance of the iron after modified by alkali metal hydroxdides and electropositive surface active agent improve obviously.The iron modified by CTAB improves 2.4 times the quantity and the maximum inactivation quantity can reach 1.955×106cfu/g.Under different water quality conditions(different pH,variou metal cation of different types and different concentrations,different DO, humic acid of different concentrations),iron shows different apply effect.The existence of metal cation and DO of high concentration can help remove E.coli. Humic acid in water environment can reduce the removing of E.col because it competes in adsorption site.(3)When SMZ:ZVI=1:2, the blending agent can remove and inactivate the maximum E.coli,reaching 2.2303×106cfu/g.Water environment conditions influence the apply effect of SMZ/ZV.The apply effect after continuous running shows:filter medium after modified by 0.1mol/L CTAB can remove 97.933% of E.coli (n (cfu)=5.0×105ml-1)when the water sample is 5L,81.20% of E.coli when 100L of the water sample passes and 60.92% of E.coli when 200L of the water sample passes.At this time,the microbiological indicators have reached 8.34×105cfu/g.Among blending filling,zeolite on the upper layer and iron on the underlayer.iron on the upper layer and zeolite on the underlayer,the blending filling has the best effect and it can remove 45.60% of E.coli when 300L of water sample passes continuously.The other two ways can only remove 41.27% and 40.15% of E.coli.Water quality conditions have different effect on removing. If 10mg/L of humic acid is added into the filter column,76.87% of E.coli can’t be removed when 300L of water sample passes in 10.7 days which shows that natural organic matter in water environment can affect the removing of pathogenic microorganism.But on the other hand,it is showed that filtration and disinfection medium can also remove natural organic matter which reduces the forming of chlorination outgrowth.