Evaluation of a pilot-scale bio-trickling filter as a VOCs control technology for the chemical fibre wastewater treatment plant.

The performance of lab- and pilot-scale bio-trickling filters (BTFs) for the treatment of emissions from a chemical fibre wastewater treatment plant was investigated. These systems were installed mainly to demonstrate the effectiveness of bio-trickling technologies in purifying exhaust gases containing different kinds of volatile organic compounds (VOCs). Results showed that 12 days more were necessary for the pilot-scale BTF to start up successfully than the lab-scale one. Both the lab- and pilot-scale BTFs exhibited contaminant removal efficiency higher than 90% at an empty bed residence time of 59 s, corresponding to gas flow of 0.2 m3 h-1 and 550 m3 h-1, respectively. The reduction of the microelement in the nutrient solution had little effect on the performance of the pilot-scale BTF. The abundance and diversity of the microorganism analysis showed that the diversity of the contaminants had a significant influence on the microorganism distribution in the BTF. Economic feasibility study showed that BTF might be an efficient solution for VOCs control with a lower cost than adsorption technology and regenerative catalytic oxidation.

Performance and microbial community evolution of toluene degradation using a fungi-based bio-trickling filter.

Fungi have their unique advantages in capturing and degrading hydrophobic VOCs. To study the performance of fungi-based bio-trickling filters (BTFs) with respect to the degradation of toluene, and the succession process of the fungal colony under different operating conditions, a three-layer BTF packed by dominant Fusarium oxysporum immobilized with ceramic particles were set up. The fungal BTF started quickly within 7 days and restarted less than 7 days after starvation; its average RE was higher than 92.5% when the toluene inlet loading rate (ILR) ranging from 7.0 to 100.9 g m-3 h-1 at steady state. Moreover, the maximum elimination capacity (EC) of 98.1 g m-3 h-1 was obtained at a toluene ILR of 100.3 g m-3 h-1. The microorganism analysis of time and space revealed that the dominant fungi Fusarium were replaced by Paramicrosporidium saccamoebae after a certain evolutionary period. The intermediate layer had more microbes and a more complex community than the other two layers, and was more suitable for the survival of the varieties of microbes.

A comparative study of pilot-scale bio-trickling filters with counter- and cross-current flow patterns in the treatment of emissions from chemical fibre wastewater treatment plant.

Two pilot-scale bio-trickling filters (BTFs) with counter-current and cross-current flow modes were constructed, and their performance tested, for purifying chemical fibre waste gas containing H2S, NH3 and VOCs with a maximum gas flow rate of 1008m3h-1. The counter-current type of BTF presented with superior biodegradation results compared to the cross-current type: it could start up quickly, tolerated high transient shock loadings, and possessed an average contaminant removal efficiency higher than 90% with an empty bed residence time of 59s. The contaminant removal efficiency could be increased by 50% during winter due to the addition of pipeline insulation. The abundance and diversity from microorganism analysis showed that Dyella, Bacillus, Candidimonas, Pandoraea and Thiomonas were the main bacterial strains forming the community treating the pollutants. The counter-current type BTF functioned most effectively and is proposed for practical application.