Study On Adsorption Of Pb²⁺ In Wastewater By Waste Incineration Fly Ash Composites

Waste incineration is one of the most important methods of municipal solid waste treatment at present.The harmless treatment of waste incineration fly ash is a difficult point in solid waste treatment.At the same time,pollutants in wastewater,such as refractory organic matter,heavy metals,colored dyes,odorous water bodies,etc.It is harming our health and polluting our living environment in different ways,so it is of great significance to research the treatment of heavy metal ions in wastewater.In this research,after the waste incineration fly ash is harmlessly treated,a low-cost,high-efficiency,easy-recovery and easy-to-handle adsorption material is prepared to adsorb lead ions in wastewater,which has a high study value.The main research has the following contents:(1)The waste incineration fly ash raw material in this research was taken from a waste incineration plant in Shanghai,and the original fly ash was subjected to toxicity leaching test.It was found that the lead ion leaching content was significantly exceeded,the zinc ion content was too high,and in addition,the fly ash have too much inorganic salt ions that affect the later synthesis work.Therefore,the better washing time,liquid-solid ratio and concentration of water washing,alkali washing and pickling in the pretreatment process are investigated.The results showed that the washing liquid-solid ratio is 8 mL/g,the washing time is 55 min,the alkali washing concentration is 4 mol/L,the liquid-solid ratio is 20 mL/g,the washing time is 75 min,the pickling concentration is 1 mol/L,and the liquid-solid ratio is 8 mL/g and washing time is 20 min,the pretreatment conditions were better.After treatment,the lead ion leaching toxicity concentration decreased by 95%,and the zinc ion leaching toxicity concentration decreased by 79%,both are lower than the national standard limit.(2)Using the pretreated waste incineration fly ash,preparing the pore-shaped adsorbing material by high-temperature sintering,and exploring the synthesis factors and environmental factors,that affecting the adsorbing performance of the lead ion in the lead-containing ion wastewater,and the results show that the sintering temperature is 11000 C,fly ash:calcium carbonate:borax mass ratio is 10 g:0.02 g:0.02 g,the simulated wastewater pH is 1.0,the adsorption time is 60 min,the adsorption effect is better,the material adsorption amount is 1.711 mg/g,the adsorption process conforms to the quasi-first order adsorption kinetic model and the Freundlich adsorption isotherm model,which is a heterogeneous monolayer adsorption.(3)In order to improve the adsorption performance of the adsorbing material,adsorbing material was modified by zinc oxide with zinc sulfate and ammonia water,and the better adsorption conditions are explored.It is found that when the better adsorption time is 15 min,the better simulated wastewater pH was 4.0,the adsorption amount is 21.971 mg/g,which is much better than before.