The introduction of lasers as a cutting tool has become an important step in achieving further cost reductions in the multi-functional optical film industry. However, the fumes produced during laser cutting causes an annoying and often unbearable odor in the working environment. To date, little research has been reported in terms of the worker exposure assessment and odorous substances generated in the process of cutting plastics with lasers. This study firstly investigated the worker exposure assessment and the protection efficiency of the carbonyls and phenols when a laser is used to cut polycarbonate (PC) and polyethylene terephthalate (PET), the primary base materials used in optical film industry. Results indicate that the concentrations of these substances increased with the power of the laser. Due to differences in the monomer structures of these materials, a 240 W laser produced a high concentration of phenols (1.56 mg m . However, the result of the masks studies could only reduce concentrations to between 1.88 mg m -3 and 2.2 mg m -3 , which barely meet the related regulatory standards. In contrast, the installation of local ventilation alone can effectively remove as much as 99% of the gaseous substances produced in the laser cutting of plastics.
Alleviation of metal inhibition on BTEX degradation using PVA-immobilized degrader (Mycobacterium sp. CHXY119) was investigated. When BTEX of 29 mg L(-1) [B:T:E:X = 1:1:1:1 (mg)] was used, more than 99 % of BTEX was simultaneously degraded by the free cells within 170 h. In contrast, BTEX of 114-172 mg L(-1) seriously inhibited degradation. High concentrations of metals (Mn(2+): 15, Ni(2+): 10, and Zn(2+): 10 mg L(-1)) also strongly inhibited BTEX degradation by the free cells at BTEX of 29 mg L(-1). Immobilization of degraders alleviated the inhibition of BTEX and heavy metals at high concentrations. A modified non-competitive inhibition model well described the BTEX degradation by the free and immobilized cells in the absence and presence of metal ions (R (2) = 0.92-0.99). The above results provide valuable information on treatment of metal-BTEX co-contaminated wastewater by the immobilized degrader.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.