Research on Simultaneous Removal of Cyclohexane and Methyl Acetate in Biotrickling Filters

Abstract

-In order to further purify two kinds of organic waste gases, methyl acetate and cyclohexane, which were difficult to be biodegraded in refinery wastewater treatment process, a new scheme for purifying mixed waste gas by bio-film construction with dominant bacteria was put forward. Because of the packing has a great influence on the performance of the bio-trickling filter (BTF) for purifying exhaust gas, the effect of two kinds of packing, namely ceramsite and volcanic rock, on cyclohexane purification was investigated. The results indicated that the filter efficiencies with two different packing were equivalent under the same conditions, but ceramsite was finally chosen as the next experimental packing because of its low weight. With activated sludge in secondary sedimentation tank from wastewater treatment plant as the original strain, the dominant degrading bacteria of methyl acetate and cyclohexane were obtained. After initial identification, a vertical BTF was startup with membrane of the dominant cyclohexane degradation bacteria Ochrobactrum intermedium. The tower can be startup quickly in 10 days, and the removal efficiency can reach over 95%. Moreover, the maximum eliminate capacity of cyclohexane was achieve 58.59 g·m -3 ·h -1 . When the reactor entered in stable phase, two kinds of methyl acetate predominant degrading bacteria, Bacillus velezensis and Ochrobactrum anthropi, were added and the methyl acetate gas was injected into the BTF. The performance of purify the mixture of cyclohexane and methyl acetate in the BTF was investigated in different operating conditions. The results showed that when the empty bed residence time was 176.6 s and 83.3 s, for cyclohexane concentration in the inlet air ranging from 50 mg·m -3 to 300 mg·m -3 , the removal efficiency was above 90%. Meanwhile, for methyl acetate concentration ranging from 300 mg·m -3 to 800 mg·m -3 , the removal efficiency was achieve 100%. The maximum eliminate capacity of the two kinds of pollutions was attain 72.99 g·m-3·h-1. In addition, the BTF was strongly resistant to impact load, and the pressure drop was remained at 5~100 pa over the entire operation time, no blockage appeared in the tower.

A review on biofiltration techniques: recent advancements in the removal of volatile organic compounds and heavy metals in the treatment of polluted water

“…and Hyphomicrobium sp. 12.68 g m −3 h −1 n -hexane and 30.28 g m −3 h −1 dichloromethane [ 135 ] n -Hexane Biofiltration Fungal biomass 3000 CFU/ml (optimum biomass) [ 136 ] Benzene Biofiltration Aspergillus 151.67 g m −3 h −1 [ 137 ] Cyclo hexane and methyl acetate Biotrickling filtration Ochrobactrum intermedium 100% [ 138 ] Hydrogen sulfide (H 2 S), methanethiol, dimethyl sulfide, and dimethyl disulfide Biotrickling filtration Acidithiobacillus , Metallibacterium , and Thionomas 90.1%, 88.4%, 85.8%, and 61.8% [ 139 ] 2,5-Dimethylpyrazine Biofiltration Fusarium solani 8.5 g m −3 h −1 [ 140 ] Toluene Biofiltration Scedosporium apiospermum 258 g m −3 h −1 [ 141 ] Phenol Biofilter Anaerobic microorganisms >85% [ 142 ] Phenol Biodegradation Acinetobacter sp., Pseudomonas sp., Nitrospira sp., Rubrivivax sp. ~100% [ …”

Archives of Environmental Protection

“…Hydrophobic cyclohexane and hydrophilic ethanol were used as model compounds. These compounds are found in post-processing gases from, e.g., paint, petroleum and food industries (Avalos Ramirez et al 2007;Zhanga et al 2018). Biotrickling filtration of air containing single cyclohexane or ethanol was previously investigated (Avalos Ramirez et al 2007;Cox et al 2001;Salamanca et al 2017).…”

Effect of Metal Cations on the Kinetics of Formation and Structure of Gels Formed during the Acid Hydrolysis of Tetraethoxysilane

“…Tetraethyl ester of orthosilicic acid (tetraethoxysilane or TEOS) is often used as a precursor in the solgel production of silicate materials. It is possible to obtain various materials via its hydrolysis with subsequent polycondensation [5][6][7][8], where the dopants are introduced directly into the initial solution. The pH value and the hydrolysis catalyst strongly affect the structure of the final product.…”