Fundamental properties and the factors that influence the distribution of heavy metals of several fly ashes are analyzed. Experiments indicate that the structures are complex and the properties are changeable. The study results show that the chemical composition is Cl, Ca, K, Na, Si, Al, O, etc, and heavy metals are Zn, Pb, Cr, Cu etc. The main structures of fly ash are irregularly amorphous forms and polycrystalline aggregates. Generally, the ieaching toxicity exceeds the identification standard for hazardous wastes. Heavy metals are chiefly in the forms of tiny aerosol particles and aggregates on the surface of fly ash. The properties of fly ash are greatly influenced by the change of incinerators or the variation of incinerating time. The content of Cl ranges from 6.93% to 29.18%, while that of SiO2 does from 4.48% to 24.84%. The leaching toxicity varies between 0 and 163.10 mg x L(-1) (Pb) and between 0.049 and 164.90 mg x L(-1) (Zn).

Chemical composition and toxicity leaching characteristics of fly ash was analyzed. The experiment results show that many heavy metals were contained; leaching concentration of Pb is 67.03 mg/L, which exceeds the limit of identification standard for hazardous wastes. Effect of input mass of H3PO4 on immobilization of heavy metals and its long-term environmental stability was studied. The results show that when input 8% - 14% (H3PO4 mass/ fly ash mass) of H3PO4 sound immobilization effect can be achieved; 8% and 12% of H3PO4 will bring a satisfactory environmental stability of heavy metals, while more H3PO4 led to less buffer capacity to acid conditions. In fly ash treated by 12% H3PO4, a small quantity of crystal Cr2P2O7, ZnP2, Pb3P4O13, Pb3P2O7, NaZnPO4, NaPbP3O9, Ca2ZnSi2O7 can be detected by XRD; many independent fly ash particles and bar-shaped Pb5 (PO4)3Cl with a diameter of 0.3 - 0.5 microm were observed by SEM; concentrated heavy metal materials were not obtained by CHBr3 floatation. Conclusions can be drawn that, through neutralization reaction of H3PO4 with strongly alkaline fly ash, stabilization reaction conditions were improved, entrapped heavy metals were chemically activated and PO4(3-) needed in stabilization was produced. Activated heavy metals combined with PO4(3-) on surface of fly ash,generated phosphates existing as forms of solid solution in SiO2, CaCO3, CaSO4, KCl, NaCl.

Bipolar membrane electrodialysis is uesd to convert sodium p-toluenesulfonate to p-toluenesulfonic acid and sodium hydroxide in the production of d-(-)-p-hydroxyphenylglycine.The two-chamber and three-chamber electrodialysis operations are compared.The optimized operation is found to be the coupling of the conversion with two-chamber electrodialysis and the dissolving of p-hydroxyphenylglycine.Based on the experiment,a modified separation process for the production of d-(-)-p-hydroxyphenylglycine is proposed.

为得到较高通量的手性选择性阴离子交换膜,将β环糊精作为手性选择剂添加在膜相中,制得具有手性选择性的阴离子交换膜。将其用于拆分DL-对羟基苯甘氨酸外消旋混合物的电渗析过程。在碱性条件下L-对羟基苯甘氨酸优先通过手性阴膜,分离因子达1.25,通量达到60.4 g.m-2.h-1,验证了预期的拆分效果。使用普通阴膜,并在电渗析实验中对比了在料液中添加β环糊精以及不添加β环糊精的分离性能,β环糊精添加在料液中有明显的拆分效果,不添加β环糊精的普通电渗析几乎没有拆分效果。结果进一步验证了手性选择性来源于手性膜的β环糊精。