Research On The Removal Of Organic Compounds And Heavy Metals Concomitantly From Micro-Polluted Water Using Potassium Ferrate

In recent years, the drinking water treatment has faced enormous challenges due to the deteriorating of drinking water sources quality and the continuous improvement of drinking water quality requirements. So that seek cost-effective, green water treatment chemicals and methods become an important research topic. Ferrate has a great potential for application in water treatment because of its unique chemical properties and superior efficiency. However, because of some limitations (such as preparation is difficult, high cost, the product break down easily) existing, it has not used in water treatment widely, research work in this area is still very limited. The type of pollutants have been studied is limited and the study on the mechanism is lack, specially on removal of organic compounds and heavy metals from micro-polluted water.This paper prepared solution in the laboratory, did the following three sub-experiments in turn:⑴Studied the effect factors and performance on removal of phenol and Cu(II) concomitantly from the stock solution(the concentration of phenol is 13.29mg/L,the concentration of Cu (II) is 1.0 mg/L), explored its removal mechanism and analysised the effect of Cu (II) on the removal of phenol and COD_Mn.⑵Studied the effect factors and performance on removal of phenol and Cr(Ⅵ) concomitantly from the stock solution(the concentration of phenol is 13.29mg/L,the concentration of Cr(Ⅵ) is 0.05 mg/L), explored its removal mechanism and analysised the effect of Cr(Ⅵ) on the removal of phenol and COD_Mn.⑶Studied the effect factors and performance on removal of phenol, Cu(II)and Cr(Ⅵ) concomitantly from the stock solution(the concentration of phenol is 13.29mg/L,the concentration of Cu (II) is 1.0 mg/L , the concentration of Cr(Ⅵ) is 0.05 mg/L), explored its removal mechanism and analysised the mutual influence among phenol, COD_Mn, Cu (II) and Cr (Ⅵ) in this process.The main conclusions of this paper are as follows:⑴The optimum conditions of phenol, COD_Mn and Cu(II) removal concomitantly from micro-polluted water in sub-experiment 1 by potassium ferrate are as follows: the best rate of ferrate to phenol is 15:1, oxidation segment pH is 9.0, oxidation time is 10min, flocculation segment pH is 8.0, flocculation time is 30min. The removal efficiency of COD_Mn can be achieved 51.58 % and the residue can meetⅢtype surface water(GB3838-2002)(Permanganate index≤6 mg/ L). The removal efficiency of of Cu(Ⅱ) can be achieved 99.07 %,and the residue can meetⅠtype(Copper≤0.01 mg/ L).⑵The optimum conditions of phenol, COD_Mn and Cr(Ⅵ) removal concomitantly from micro-polluted water in sub-experiment 2 by potassium ferrate are as follows: the best rate of ferrate to phenol is 15:1, oxidation segment pH is 4.0, oxidation time is 20min, flocculation segment pH is 7.0, flocculation time is 30min. The removal efficiency of COD_Mn can be achieved 56.77 % and the residue can meetⅢtype surface water(GB3838-2002)(Permanganate index≤6 mg/ L). The removal efficiency of Cr(Ⅵ) can be achieved 88.47 %. ⑶The optimum conditions of phenol, COD_Mn, Cu(II)and Cr(Ⅵ) removal concomitantly from micro-polluted water in sub-experiment 3 by potassium ferrate are as follows: the best rate of ferrate to phenol is 15:1, oxidation segment pH is 4.0, oxidation time is 20min, flocculation segment pH is 9.0, flocculation time is 30min, the removal efficiency of COD_Mn can be achieved 51.39 % , and the residue can meetⅢtype surface water(GB3838-2002)(Permanganate index≤6 mg/ L), the removal rate of Cu (II), Cr (Ⅵ) are 76.33% and 61.36% respectively;The removal of phenol, COD_Mn, Cu(II)and Cr(Ⅵ) concomitantly by potassium ferrate is a processes including competitive adsorption, coordination adsorption, precipitation, complexation and so on. Because of the adsorbent competition, the removal rate of Cu (II) and Cr (Ⅵ) is lower than that in single removal. The removal rate of phenol and COD_Mn unchanged basically.Because of China's water shortage and pollution, to research ferrate and promot in micro-polluted raw water treatment will have a good environmental,economic and social benefits.