L.-H. Zhang’s scientific contributions

In order to dispose of H3S odor pollution, a long-term lab-scale deodorization experiment is carried out continuously by bio-trickling filter packed with ZX01 stuffing. The results show that the removal efficiency of H2S is nearly 100% and the optimum gas retention time is 30 s when inlet concentration of H2S is 300 mg/m3. Metabolism product of H2S is mainly composed of SO42-. The bio-reactor is not blocked in the experiment in which the resistance is maintained at lower value. The bio-trickling filter needs not carry out a back washing frequently, and it can be operated steadily for a long term.

Two autotrophic rod sulfur-oxidizing strains (zw1 and zw2) were isolated from Pharmaceutical wastewater containing hydrogen sulfide gas, and were streaked and purified by repeated transfer to fresh solid medium on the plate. Shape, physiological and biochemical characteristic of chemolithoautroph zw1 and zw2 was checked, and removal capacity of hydrogen sulfide gas from hydrolyzation tank in wastewater treatment plant was investigated by the inoculated biofilter with zw1 and zw2. The results suggested that the optimal temperature of zwl (aerobic bacilli, short rod and Gram-positive) was between 22°C and 32°C and the optimal pH was between 5.0 and 7.0. And the optimal temperature of zw2 (facultatively-aerobic bacilli, long rod and Gram-negative) was between 22°C and 25°C and the optimal pH was between 4.0 and 6.5. Furthermore, the inoculated biofilter with zw1 and zw2 had stronger ability to resist shock of high inlet loading. Removal efficiency of hydrogen sulfide was close to 100% when the maximum volumetric loading achieved 192 g/(m·h). Metabolism products of zwl and zw2 were mainly composed of SO42- and the biofilter was not blocked during the experiment of more than three months. Therefore, the biofilter need not carry out a back washing frequently and it can be operated steadily for long-term. It is a potential industrialization method that can be fulfilled easily.

It is difficult to solve the pollution of volatile organic compound (VOCs) from the production and purification of penicillin. In this study, biotrickling filter was used to treat waste gases (VOCs) which were made up of Butyl acetate, n-Butyl alcohol and Phenylacetic acid and were volatilized from the raffinate in the penicillin workshop. The field pilot experiment was carried out continuously for more than three months. The results showed that when waste gases were discharged normally and inlet flow was monitored to 7.5 m/h, removal efficiency of Butyl acetate, n-Butyl alcohol and Phenylacetic acid were 95%, 92% and 100% in the case of their maximum inlet concentrations of 2000 mg/m3, 2400 mg/m3 and 370mg/m3, respectively. And meanwhile, the concentration of VOCs was less than 6800 mg/m3 and its removal efficiency was more than 94%. Furthermore, when pollution materials were appended factitiously in order to achieve higher loading, removal efficiency of Butyl acetate, n-Butyl alcohol and Phenylacetic acid were all more than 90% in the case of their maximum inlet loading of 373.4 g/(m · h), 317.2 g/(m · h) and 209.5 g/(m · h), respectively. The biotrickling filter had abundant microorganism colony and stronger ability to resist shock of high inlet loading. Therefore, the biotrickling filter could be operated easily and steadily for long-term. It was a potential technology for removing VOCs and easy to realize industrialization.