Experimental Study On Treating Simulative Tannery Wastewater With Fenton-like System Constructed By Fly Ash

We study the modified experiment of fly ash with fly ash of Yangliuqing thermal power plant in Tianjin. Experimental results shows: catalysis of the acid modified fly ash is the best. we get the best modified conditions throught experiment: acid ratio of acid activators is Vsulfuric acid:Vhydrochloric acid=1:2, adding 15mL acid activators to 10g fly ash, agitating at room temperature, the agitating time is 60min.We use the acid modified fly ash to do orthogonal experiment. Experimental results shows: the biggest factors that affects effect of the treatment by Fenton-like system is pH value of reaction. The result of single factor experiment of degradated tannery wastewater by fly ash- EDTA/H₂O₂ system shows that: the reaction pH value is 10, the initial COD value is 110.8mg/L, the hydrogen peroxide concentrations is 200.4mg/L, the concentration of EDTA is 250mmol/L, the dosing quantity of fly ash is 2g/200mL, under this condition the removal rate of COD and coloring are all above 95%, and analysing dynamics of Fenton-like. After useing of fly ash repeatly, removal rate of COD has reached above 97%.We use dipping method for granulation load type catalysts and found the best preparation conditions are as follows: using the mixed pickling liquid of 0.4 mol/L nitric acid of iron/2% oxalic acid and dipping carrier 13h, loading throught roasting under 400℃and 5h. The result of experiment of degradating sulfide by using load type catalysts shows that: the concentration of EDTA is 250mmol/L, the concentration of H₂O₂ is 200.4mg/L, initial concentration of sulfide is 10mg/L, the dosing quantity of granulation load catalyst is 1g/150mL and the reaction pH value is 10, under this condition the removal rate of sulfide reachs 99.85%.