摘要：
Recently, the waste water treatment has received a great attention from the scientific community. By considering various harmful dyes, this paper demonstrates the fabrication of a microbial fuel cell (MFC)-microbial electrolysis cell (MEC) coupling system. Herein, nano-zero-valent iron (nZVI) is used as a reinforcing agent for the degradation of wastewater. Degradation experiments of azo dye wastewater were carried out using MFC-MEC coupling system. The results demonstrate that the MFC-MEC coupling system improves the decolorization rate of azo dye by 35% compared with MFC alone. The anode substrate concentration of the biofuel cell has a significant effect on the degradation of the azo dye by the MFC-MEC coupling system. However, the cathode PH has little effect on the degradation of the azo dye by the MFC-MEC coupling system. The current output of the MFC-MEC coupled system is tested. The results show that the coupling system's degradation ability depends on the short-circuit current relationship between MFC-MEC. The MFC-MEC coupling system and nZVI form a system. The nZVI concentration, pH, and initial dyeing wastewater X-3B concentration are used as variables. A large number of experiments confirmed that the decolorization effect of MFC-MEC/nZVI system on printing and dyeing wastewater X-3B is significantly better than that of nZVI treatment alone.
作者机构：
[Huang, Shiyu; Li, Deliang; Sheng, Guojun] College of Environmental Sciences and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[Finch, J.A.] McGill University, 3610University St., Montreal;QC;H3A 2B2, Canada
通讯机构：
College of Environmental Sciences and Engineering, Central South University of Forestry and Technology, Changsha, China
摘要：
A close-looped process based on the membrane separation and electrolysis is proposed to regenerate the copper etchant in-situ, recover copper on-site and reuse it. It is characterized by selective separation of copper from the spent etchant, which is accomplished by the ion exchange membrane-electrowinning, and at the same time the other components useful for etching are reclaimed. The experiments show that at least 90% of electricity efficiency for copper removal can be maintained and the optimum condition for membrane-electrowinning is: cell voltage 2-2.5 V, operating temperature 40 - 50 degrees C and current density 500 - 1500 A/m(2). The regenerated etchant can be successfully reused to etch copper after adjusting its composition to the normal range, and its recycling property is as good as that of the fresh etchant after 50 times of use-disposal-regeneration cycles.
摘要：
A novel nickel stripper using ammonia as the key component was developed to substitute cyanide for removing nickel film from iron substrates. Its compositions are: ammonia 150 g/L, hydrogen peroxide 50 g/L, ammonium chloride 100 g/L, EDTA 7.5 g/L, copper chloride 15 g/L and glucopyrone 1.2 g/L. The optimum operating conditions are: pH 9.5 - 11, temperature 40 - 50 ℃ and stripping time 1 h. It shows many advantages over the traditional cyanide stripper including no toxicity, mild operation, lower cost, larger holding capacity, faster stripping rate and good protection for the base metal, and can meet the technical requirements in industry.
