Experimental Research On The Treatment Of Electroplating Wastewater With FeS Reactor

In this paper, trying to find a flexible and easy, low cost, suitable for electroplating wastewater treatment for small and medium reactors and the corresponding process for the costs of our existing electroplating wastewater treatment are high, the low level of pollution control, as well as the FeS fluidized bed reactor our predecessors studied have some problems in the process. This paper mainly in three aspects: First, the traditional fixed bed reactor and the S-type fixed bed reactor as a test reactor to low-cost easy to get the FeS as the remover of mixed Chromium, copper, zinc, cadmium removal efficiency and the impact of factors were studied, and second, it was studied that the traditional fixed bed of mixed waste water treatment backwash cycle, solid-liquid separation process parameters; third compared the reactor from the removal, the actual operation and management aspects. Papers obtained through a large number of tests:â‘ t raditional fixed bed reactor and the S-type fixed bed reactor have high removal efficiency to the Cr6+, Cu2+, Zn2+, Cd2+ in mixed electroplating wastewater. The best combination of fixed-bed reaction conditions, namely: FeS fill height 40cm, water flow rate 1.6L/h, FeS particle size of 5-7mm; Cr6+, the average removal rate was 99.96%, Cu2+, the average removal rate of close to 100% , Zn2+, the average removal rate was close to 100%, Cd2+, the average removal rate was 99.52%. S-type fixed-bed combination of the best reaction conditions, namely: inner packing the reactor height 30cm, Outer packing height of 30cm, the inner packing size 5~7mm, outer packing size 7~10mm, water flow 1.6L /h; Cu2+ and Zn2+, the average removal rate is almost 100%, Cr6+, the average removal rate reached 99.97%, close to 100%, Cd2+, the average removal rate was 99.86%;â‘¡backwash cycle was 160min ,the optimal dosage of Ca(OH)2 is 60mg;â‘¢fluidized bed have large power consumption, but easy to operate, easy to achieve in the industry; traditional fixed bed need backwashing, but the manufacture of the reactor is simple; S-type fixed-bed backwashing too much trouble, is not easily achieved in industry.By XRD, XRF and XPS detection, combined with the fore research achievement, this paper thinks that the removal mechanism of electroplating wastewater's heavy metal ion with FeS is oxidation-reduction reaction, chemical deposition reaction, adsorption coprecipitation, oagulation and flocculations'combined action. Under the acidity condition, the removal of Cd2+, Cu2+ and Zn2+ mainly dues to hardly dissolved metal sulfide's generation. The removal f Cr6+ is that Cr6+ is reduced firstly, and then removed in the hydroxide and coprecipitation form. Fe2+ and S2- are all powerful reducing agent.