The Research Of Processing Materials And Method About Heavy Metal Lead In Activated Sludge

The activated sludge is the waste generated by the sewage treatment plant, which itselfis a good organic fertilizer, but as a result of which contain pathogenic microorganisms,heavy metals, and other impurities,cannot be again used effectively. It will not only take up alot of land accumulation, but also pollute the environment seriously.Therefore, that effectivetreatment of activated sludge has important significance in resource utilization andenvironmental protection.The adsorption properties of modified activated carbon, modified wood powder andresin on Pb²⁺were studied and the Pb²⁺were processed that in leaching solution of the heavymetal containing sludge. It has been optimized that the preparation process of the modifiedactivated carbon, modified wood flour, also get the best treatment process and outcome,studies show that:1、The best preparation conditions of modified granular activated carbon by HNO₃is:the concentration of HNO₃is5mol/L, HNO₃: granular carbon=1:1, and the bestadsorption conditions is:pH=4, the adsorption time of60min, the experimentaltemperature of45℃. So the saturation adsorption capacity can be achieved3337.3μg/g, theadsorption rate can reach53.1%. Then the modified granular activated carbon by HNO₃foractivated sludge in leaching solution of Pb²⁺adsorption treatment, Pb²⁺removal rate isabout33.3%.2、The best preparation conditions of modified granular activated carbon by KMnO₄is:the concentration of KMnO₄is0.03mol/L, KMnO₄:granular carbon=1.5:1,and the bestadsorption conditions is:pH=3, the adsorption time of40min, the experimentaltemperature of25℃. So the saturation adsorption capacity can be achieved at2487.1μg/g.3、The adsorption property of modified activated carbon by HNO₃, KMnO₄andnormal activated carbon for Pb²⁺has been studied. The experimental results indicatethat:the modified granular activated carbon by HNO₃has the best adsorption effect onPb²⁺, and it has the advantages of simpler operation, smaller loss and error in experimentalprocess, higher economic benefits than the powder activated carbon. So the modified activated carbon by HNO₃has more experimental and production value.4、The best preparation conditions of modified wood powder amphoteric adsorbent is:with potassium persulfate as initiator （addition of carboxymethylated product quality3%）,AM:wood powder=1:3, Diethylenetriamine:formaldehyde=1.5:1, reaction temperature of50℃, reaction time of1.5h, and the best adsorption conditions is:pH=5, the adsorptiontime of60min, the experimental temperature of25℃. So the saturation adsorptioncapacity can be achieved at3014.3μg/g.5、The best preparation conditions of modified wood powder cationic adsorbent is:first, get etherifying agent with hydrochloric acid:DETA=8:3, epoxy chloropropane:DETA=4:5, reaction temperature of40℃, reaction time of1.5h; second, In the woodpowder with NaOH （NaOH:wood powder=1:2） alkaline of30min, heating up to40℃;third, adding prepared etherifying agent, reaction time of2h, so get the best modification process of cationic sorbent.6、The best preparation conditions of modified wood powder anion adsorbent is:NaOH: wood powder=0.5:1,reaction of40min, then adding chlorine acetic acid（TCA:wood powder=0.5:1）, reaction of1.5h at50℃, so get the best modification processof anion adsorption agent.7、The optimum reaction conditions of modified resin adsorption agent were:the732resin after pretreatment at pH=4, adsorption oscillation at35℃with the time of90min, thesaturation adsorption capacity can be achieved at3533.2μg/g; and chelating resin after thepretreatment at pH=5, adsorption oscillation at35℃with the time of60mins, the saturationadsorption capacity can be achieved at3096.8μg/g. It is showed that732resin has betterabsorption effect than chelating resin under the same experimental conditions.