Alkaline functionalization of granular activated carbon for the removal of Volatile Organo Sulphur Compounds (VOSCs) generated in Sewage Treatment Plants. Issue 2 (April 2018)

• Record Type: Journal Article
• Authors: Jana, Shyamal; Sarkar, Ujjaini
• Is Part Of: Journal of environmental chemical engineering. Volume 6:Issue 2(2018)
• Page Start: 3510
• Page End: 3519
• Publication Date: 2018-04
• Subjects: VOSCs -- Sewage treatment plant -- GAC -- Odour -- Sensory measurement -- GC–MS; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2018.05.022
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Adsorption, using Granular Activated Carbon (GAC), is an effective technique for the removal of mal-odorous Volatile Organo Sulphur Compounds (VOSCs) originating from sewage waste water collected from various Sewage Treatment Plants (STPs). Adsorption capacity of GAC is enhanced by functionalization with various alkaline solution. Alkali functionalized activated carbons (FACs), having higher surface area and pore volume and reduction of oxygen containing functional groups, perform much better in removing VOSCs in comparison to precursor GAC. Different adsorbed odorants (VOSCs), being concentrated and in close proximity to each other on the surface or in the pores of the adsorbent, may interact. The adsorption capacity of GAC and FACs increases in the order FAC-NH3 > FAC-KOH > FAC-NaOH > GAC. FAC-NaOH or FAC-KOH may react with ambient CO2 thereby forming carbonates. This effectively decreases the removal efficiency. Odour concentration is measured simultaneously by two techniques: panel olfactometry (sensory measurement based) and component specific analytical measurement (GC–MS based). Time variant olfactometry based odour concentration data correlated well with the time variant concentration of VOSCs (GC–MS based) for all four malodorous compounds like methyl mercaptan, ethyl mercaptan, dimethyl sulphide and carbon disulphide. Linearization of the percentage removal of overall odour (olfactometry based) versus percentage removal of relative concentrations of the four VOSCs reveals that methyl mercaptan has a very large odour contributing potential ( R 2 = 0.967 ) representing the most obnoxious component of the tested sewage waste water as compared to other three compounds. Simultaneous conversion of methyl mercaptan to dimethyl disulphide leads to its faster removal by FAC-NH3 .