Study On Advanced Treatment Of Printed Circuit Board Wastewater By Aeration Biological Fluidized Tank

In this study, base on the adequate investigation of the manufacturing technique of circuit board and blowdown situation, the circuit board production wastewater was classified reasonably. According to the feature of different kinds of wastewater, the removal of the main organic pollutants for various treatment techniques was studied, the optimal parameter was determined, and the techno-economic analysis and feasibility of selected technique was estimated combining with engineering example. The main research contents and results in this study are listed as followed:(1) A comparison of the traditional circuit board wastewater treatment technique, recently, the methods for circuit board wastewater treatment consisted of chemical precipitation, micro-electrolysis using the mixture of scrap iron, biochemical, ion exchange, chemical oxidation and so on. Combining with the way of aeration biological fluidized tank technology, the feasibility of aeration biological fluidized tank technology in advanced treatment of circuit board wastewater was analyzed from two aspects of technology and economy. The aeration biological fluidized tank technology had a good removal for NH3-N, CODCr, Cu2+ and total phosphorus, and the removal efficiency of NH3-N, CODCr, Cu2+ and total phosphorus were 98%、76%、79% and 87%, respectively. In addition, the cost of aeration biological fluidized tank technology was 0.45 RMB/m3.(2) By the technical research of advanced treatment of printed circuit board wastewater by aeration biological fluidized tank, the application of aeration fluidized tank was studied, and the operational control parameters, stacking proportion, hydraulic retention time, gas water ratio, and aeration intensity were determined. The results showed that the optimum stacking proportion, hydraulic retention time, gas water ratio, and aeration intensity were 20%, 8.5 h, 10~20:1 and 10~20 m3/m2?h.(3) Based on the principles of integration device application, processing equipment and electric auto-control system were designed to match the site conditions. From the practice application, the operating parameter and working conditions were analyzed, the technology, the stability of equipment, and economic indicators were examined and improved. Finally, the industrialization production of reclaimed water reuse advanced treatment and device of circuit board wastewater was realized.