CONTENT 3 Transition metal and transition metal ions as activator - PowerPoint PPT Presentation

The Influence Factors of Phenol Wastewater Treatment Using Persulfate Activated by Fe 0 Bing Wang, Jiani Li, Lan Fang, Jia Fu Municipal & Environmental Engineering College, Shenyang Jianzhu University Email: wangbing8835829@163.com

CONTENT

3 Transition metal and transition metal ions as activator for persulfate have become a hot. Heavy metal ions could cause secondary pollution. Fe 2+ has obvious advantages, but many problems also exist inevitably. Fe 0 whose principle is similar to Fe 2+ became the first choice of replacement as activator. The reaction time, activator dosing quantity, K 2 S 2 O 8 dosing quantity, pH value, and phenol initial concentration on the effect of phenol wastewater treatment were discussed in detail. The optimum operation parameters were obtained. A small-scale phenol wastewater treatment will be implemented.

Raw water Artificial wastewater was used to simulate the phenol wastewater in this experiment. Methods The COD value and phenol value could be measured respectively, and the corresponding removal rate could be calculated. Ascertain the main factors for phenol wastewater treatment using orthogonal test of 5 factors and 4 levels with the variables of reaction time, activator dosing quantity, K 2 S 2 O 8 dosing quantity, pH value and phenol initial concentration. Use 4-AAP direct photometric method to determine the phenol concentration, and the fast airtight catalytic decomposition method for COD.

RESULTS AND DISCUSSION A B C D E 5

m(K 2 S 2 O 8 ):m(C 6 H 6 O)=1 C K2S2O8 = 0.05 mol/L n(K 2 S 2 O 8 ):n(Fe 0 )=1 C phenol 200mg L pH= 3 T= 35 ℃ The Fe 0 played a good activated role, and when reaction time was around 200 min, the degradation of phenol wastewater was basically completed.

m(K 2 S 2 O 8 ):m(C 6 H 6 O)=1 C K2S2O8 = 0.05 mol/L C phenol 200mg L pH= 3 T= 35 ℃ n(Fe 0 ):n(K 2 S 2 O 8 )=0.2-2 When Fe 0 dosing quantity reached a certain value, the quantity of Fe 2+ produced by Fe 0 was enough to activate the potassium persulfate, furthermore, adding more Fe0 was not benefit to the phenol and COD removal. Therefore, set the reasonable ratio of metal activator and oxidant about 1:1.

8 n(Fe 0 ):n(K 2 S 2 O 8 )=1 C K2S2O8 = 0.05 mol/L C phenol 200mg L pH= 3 T= 35 ℃ m(K 2 S 2 O 8 ):m(C 6 H 6 O)=0.2-2 Considering the economy and the treatment effect, m (K 2 S 2 O 8 ):m (C 6 H 6 O) = 1.0 as a reference type dosing ratio was more appropriate.

m(K 2 S 2 O 8 ):m(C 6 H 6 O)=1 n(Fe 0 ):n(K 2 S 2 O 8 )=1 C K2S2O8 = 0.05 mol/L C phenol 200mg L T= 35 ℃ pH= 1-10.6 When pH value is equal to 3.0, phenol wastewater treatment experiment achieved the best effect, and the phenol and the COD removal rate reached the maximum of 78.66% and 68.61% at the same time, so 3.0 was the optimum pH value.

10 m(K 2 S 2 O 8 ):m(C 6 H 6 O)=1 n(Fe 0 ):n(K 2 S 2 O 8 )=1 C K2S2O8 = 0.05 mol/L T= 35 ℃ pH= 3 C phenol 50-300mg L With the increase of the initial concentration of phenol, the quantity of oxidant gradually can not meet the needs of pollutants consumption quantity, so that the degradation of phenol wastewater effect gradually declined.

11 B(time/min) C(Fe 0 /mg/L)D(K 2 S 2 O 8 /mg/L)E(C 6 H 6 O/mg/L) Factorlevel A(pH) Level 1 1 120 50 50 50 level 2 2 140 100 100 100 level 3 3 160 150 150 150 level 4 4 180 200 200 200

A B C D E C 6 H 6 O C 6 H 6 O Fe 0 NO. Time K 2 S 2 O 8 pH (initial) removal (min ) (mg/L) (mg/L) (mg/L) rate(%) 1 1 120 50 50 50 70.52 2 1 140 100 100 100 72.11 3 1 160 150 150 150 72.74 4 1 180 200 200 200 73.18 5 2 120 100 150 200 70.45 6 2 140 50 200 150 68.87 7 2 160 200 50 100 59.69 8 2 180 150 100 50 76.54 9 3 120 150 200 100 74.04 10 3 140 200 150 50 73.38 11 3 160 50 100 200 61.57 12 3 180 100 50 150 70.78 13 4 120 200 100 150 69.65 14 4 140 150 50 200 56.24 15 4 160 100 200 50 75.41 16 4 180 50 150 100 69.88

A B C D E Factor Fe 0 (mg/L) pH Time(min) K 2 S 2 O 8 (mg/L) C 6 H 6 O(mg/L)  K 72.17 71.17 67.71 69.10 73.96 1  68.89 67.65 72.19 69.97 68.93 K 2  K 69.94 67.35 69.89 71.61 70.51 3  K 67.80 72.60 68.98 72.88 65.36 4 R 4.34 5.25 4.48 3.78 8.60 Primary and EBCAD secondary factors

14 (1) Under the medium temperature (35 ℃ ) , influence factors of phenol wastewater treatment using persulfate activated by Fe 0 were studied. Discuss the reaction time, the activator dosing amount, the K 2 S 2 O 8 dosing quantity, the pH value, and the initial concentration of phenol in detail for the research of phenol wastewater treatment, and obtain the best operating conditions through orthogonal test. (2) When the initial phenol concentration was 200 mg/L, the reaction time lasted 180 min, the pH value was 3.0, m (K 2 S 2 O 8 ) : m (C 6 H 6 O) = 1, and n(K 2 S 2 O 8 ):n(Fe 0 )=1, the phenol and the COD removal efficiency were the highest, which reached 78.66% and 68.61%. (3) Analyze the L 16 (4 5 ) orthogonal experiment with the varieties of the reaction time, activator dosing amount (Fe 0 ), K 2 S 2 O 8 dosing quantity, pH value and initial phenol concentration. The phenol wastewater treatment using persulfate activated by Fe 0 effect was more ideal, when the reaction temperature was 35 ℃ , the pH value was equal to 3.0, the reaction time lasted 180 min, the Fe 0 activator dosing quantity was 200 mg/L, the K 2 S 2 O 8 dosing quantity is 200 mg/L, and the phenol initial concentration was 150 mg/L.