Effects Of Copper Zine And Chromium On Aerobic Activated Sludge In Swine Wastewater

Aerobic activated sludge treatment is widely used in swine wastewater treatment process.The experiment used the batch activated sludge culture,Eventually,cultivated a stable with good activity aerobic activated sludge.Experimental study of different concentration of heavy metal ions on aerobic activated sludge independent inhibit and join inhibit to organic matter degradation rection, nitrification and the concentration of activated sludge.The main result as follows:(1)Ascertain by measuring concentration of heavy metals in the swine wastewater,The results show that the swine wastewater contains higher concentration Cu2+(2.32mg/L),Zn2+(5.11mg/L),Cr+(2.65mg/L).The experiment of activated sludge inhibition showed that the simulate wastewater1.36times the swine wastewater on the average rate of sludge production in the20-day test cycle.(2) Study on the inhibitory effect of heavy metal,Cu2+is minimum critical concentration,only0.5mg/L. That is, the relative toxicity largest.The critical concentration of Zn2+is1.0mg/L,the critical concentration of Cr3+is5.0mg/L,the relative toxicity is the weakest,the order of heavy metals toxicity was Cu2+>Zn2+Cr3+.Swine wastewater Cu2+(2.32mg/L)50.81%,66.78%and67.39%; Zn2+(5.11mg/L)of CODcr, NH3-N and sludge concentration relative inhibition rates were5.04%,33.11%and15.54%; Cr3+(2.65mg/L) of CODcr, NH3-N and sludge concentration relative inhibition rates were2.85%,3.73%and11.20%.(3)Study on the joint inhibitory effect of heavy metals, The different levels of heavy metals had inhibitory effects on activated sludge.The mixing Cu2+and Zn2+of CODcr, NH3-N and sludge concentration relative inhibition rates were6.89%-32.25%,14.50%～63.40%and19.85%～60.42%; The mixing Cu2+and Cr3+of CODcr, NH3-N and sludge concentration relative inhibition rates were7.41%～35.73%,14.91%～63.30%and22.23%～44.76%; The mixing Zn2+and Cr3+of CODcr, NH3-N and sludge concentration relative inhibition rates were5.55%13.07%,9.90%～39.50%and24.36%～37.12%.(4)through range analysis to orthogonal test data and the level interaction analysis of mixing heavy metals showed that,the Cu2+/Zn2+mixed showed additive,the Cu2+/Cr3+mixed and Zn2+/Cr3+mixed showed antagonistic.