Meng, J; Xiao, X; Lu, Z; Zou, K; Wang, X; Zhai, Z
The rubber industry has caused concerns of residents and the government because of the serious odor pollution in the production processes. For in-depth study of the causes of odor pollution, this work confirmed the main characteristics of mixing, vulcanizing and devulcanizing of 8 rubber companies by instrument and sensory analysis. In addition, the work gave specific substances of three processes by odor activity value, sifting through 20 precedence-controlled pollutants by cluster analysis, principal component analysis and fuzzy synthetic system. The control and strategy will be improved by analyzing emission characteristics. The results show that: (1) The average TVOCs (Total Volatile Organic Compounds) released from mixing, vulcanizing and devulcanizing were 15.7235, 4.6609, 98.8165 mg/m3, respectively. (2) 150 kinds of VOCs (Volatile Organic Compounds) and odor substances were identified, mainly including alkenes (e.g. n-hexane, n-heptane, methylcyclohexane), aromatic compounds (e.g. benzene, toluene, styrene), oxygenated compounds (e.g. acetone, methyl isobutyl ketone, ethanol) and sulfides (e.g. methyl sulfide, dimethyl disulfide, carbon sulfide). (3) The odor concentration in desulfurization process and plant boundary exceeded the standard of Emission Standarads for Odor Pollutants (GB 14554-1993). (4) The main odorants in the rubber industry were aldehydes (e.g. isobutyraldehyde, isovaleraldehyde), sulfides (e.g. hexylmercaptan, butylmercaptan), styrene and trimethylamine. (5) The industry's top 20 control VOC pollutants included styrene, methylcyclohexane, trimethylamine, carbon disulfide, 1, 2, 4-trimethylbenzene, methyl isobutyl ketone, p-xylene, acetaldehyde, carbonyl sulfide, ethylbenzene, and so on. In conclusion, the average TVOCs released by the rubber industry is less than other key industries, except devulcanizing and refining. The types of odorants were basically similar between mixing and vulcanizing. It is important to adjust industrial structure, improve production technology and strengthen standard management for abating VOC and odor pollution in waste tire rubber recycling. © 2021, Editorial Board, Research of Environmental Sciences. All right reserved.