Biotechnology as an alternative for carbon disulfide treatment in air pollution control

摘要

Biotechnology has emerged as an affordable, effective, and eco-friendly alternative to treat carbon disulfide (CS_2) containing waste gases. Carbon disulfide is a chemical of widespread use both in the past and in the present. Its industry demand hasdramatically changed over the last two decades and is expected to grow in future in step with those industries involving fibre, mining, rubber products, and the agro-chemical sector. This compound, classified as a hazardous air pollutant about 20 yearsago, has been re-appraised, as increasingly restrictive pollution standards are expected to be introduced. An array of physical–chemical technologies for treating CS_2 containing air are already in use, but they have a series of drawbacks, such as highenergy consumption (incineration, thermal oxidation), the immobilization of the contaminant solely from one phase to another (adsorption), and the generation of secondary by-products that require additional treatment (hydrolysis). Thus, technological research on affordable processing alternatives is of considerable interest for related industries using or producing CS_2. The biological technologies whose efficiency is based on the activity of microorganisms to biodegrade air pollutants overcome many ofthe disadvantages of conventional techniques and are especially useful for the removal of relatively low concentrations of pollutants. In this paper, the main properties, sources, and uses of CS_2 are summarized, and alternative biotreatments for CS_2 are reviewed. Several applications of the technical and economical feasibility of biofilters and biotrickling filters are shown, although their widespread industrial application still requires further research.