Promotion Effects Of PDC On Removal Of Heavy Metals With Hydrous PDE

Heavy metal pollution incidents have occurred frequently in recent years,and heavy metal content in surface waters in many regions of China has seriously exceeded the standard.Heavy metal pollution has caused constant concern in the academic and social circles.Heavy metals are highly toxic and nonbiodegradable,causing long-term damage to the ecological environment and animals and plants.Therefore,it is of great significance to research and develop materials and technologies that are highly efficient and cost-effective to remove heavy metal contaminants from water.In this thesis,we synthesized cheap and efficient hydrated PDE water purification materials using PDC and PDF to remove Pb(II),Cd(II)and Ni(II)in water.The hydrated PDE material was characterized by means of SEM,FT-IR,XPS and BET.The deep removal of heavy metals was achieved by combining PDC and under acidic conditions.The mechanism of PDC promoting removal of heavy metals was investigated,and was regenerated by acidic PDC.The main research contents and conclusions are as follows:(1)Different hydrated PDEs were synthesized at different pHs,namely a(pHa = 1.5),b(pHb = 3.5)and c(pHc = 5.5).The experimental results show that a has the higher Zeta potential,the larger specific surface area,the clearer surface petal shape and the higher hydroxyl content of the surface than the b and c.And the heavy metal removal ability of a also exceled b and c.(2)The ability of a to remove different heavy metals under acidic conditions follows as: Pb(II)>Cd(II)>Ni(II).The adsorption process can be balanced in 25 minutes.The adsorption process conforms to the quasi-secondary kinetic model and the Langmuir model.The adsorption process belongs to chemisorption and monolayer adsorption.PDC can promote the removal of heavy metals by a under acidic conditions,especially in the effect of deep removal of heavy metals,which can effectively reduce the amount of a added.During the removal of Pb(II),Cd(II)and Ni(II)by a,when the input amounts were 42 mg,54 mg and 78 mg,respectively,the residual concentration of the treated heavy metal solution was 0.02 mg/L,0.01 mg/L and 0.02 mg/L.After adding 3 mL of PDC solution,the same residual concentration was achieved,and the dosage of a was only 30 mg,36 mg and 66 mg,respectively.Through a series of characterizations such as TEM,XPS and UV,it is found that the reason for the promotion may be that a releases PDE ions during the process of adsorbing metals,and PDC reacts with the released PDE to form a small amount of active in situ,promoting heavy metal removal.