Based on the results of gas flow field, droplet size distribution and droplet initial flow rate distribution on aф300mm rotating stream tray (RST), a three dimensional droplet projection trajectory model and a mass transfer efficiency model were developed. The calculation of the models was carried out by using a finite-difference procedure1 The predicted results of the plate efficiency agreed quite well with the experimental data measured with absorbing NH3 or SO2 on aф300mm RST and the operation data from a commercial ф3600mm RST column1 Meanwhile, the effect of gas-liquid system and RST's structure on plate efficiency was discussed.

通过驯化、筛选和富集培养，从制药厂（Y）和农药厂（N）生化曝气池的活性污泥中分离到2株能以二氯甲烷为唯一碳源和能源而生长的菌株。菌种初步鉴定为假单胞杆菌属和放线菌科分枝杆菌属。由正交试验得出GD11、GD23两株菌的最适培养条件：GD11温度28.5℃，pH值6.0，纱布层数6；GD23温度25℃，pH值7.2，纱布层数4。研究发现NaCl浓度对菌株的降解率有不同程度的抑制作用。

A dual-electronic-probe technique and a multicolor high-speed stroboscopic photographic technique were used to measure the initial projection velocities of droplets on a 300mm diameter sieve tray operating in the spray regime. The experimental results confirmed that both of these techniques can supplement each other for the measurements. A new correlation was obtained to express the relation among projection velocity, droplet size, and gas hole velocity.

汽油添加剂甲基叔丁基醚（MTBE）的污染在国外已引起重视。概述了目前MTBE生物降解的研究现状，着重介绍了国外对MTBE污染地下水的异位和原位生物处理方法。随着汽车的逐步普及和MTBE用量的增加，我国正在或将面临MTBE的污染。指出了开展相关研究的重要性和迫切性，初步提出了这一新课题的研究思路，为我国环境保护领域从事该项研究的人员提供参考。

The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simuhator with 300ram diameter. It has been found that the regime transition occurs as the clear liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.