ON-SITE ACTIVATION OF SLUDGES, ORGANIC COMPOUNDS AND WASTEWATER FOR MICROBIAL DIGESTION USING PEROXODISULPHATE DERIVED FROM TOXIC SULFUR COMPOUNDS

摘要

The Invention described herein is a method of chemically activating sludges,wastewater containing organic compounds,and other organic matter (generally referred to herein as "organics" unless itis necessary to distinguish between them)using a potent chemical oxidizer, peroxodisulfate ("persulfate", S2O8 2-),typically derived from toxic sulfur-containinggases, e.g. hydrogen sulfide or methyl mercaptan, or other sulfur compounds,preferably on-site. The activation oforganics with persulfate can be accelerated through the use of heat, catalysts(such a ferrous ion, Fe2+), radiation, orultraviolet light. The chemical activation Is controlled to limit the amountof oxidation of the organics to a level sufficientto accelerate subsequent microbial digestion, presumably Including chemicaldisruption of cell walls, but significantly lessthan the amount required to completely oxidize (mineralize) the organicspresent. This moderate but sufficient level ofoxidation, will facilitate digestion of the remaining organics present butlimit the oxidation to less than the amount thatwould eliminate or nearly eliminate the organics present, thus preventing thembeing available for digestion. Afteroxidative treatment with persulfate, the said organic compounds will contain agreater proportion of oxidized groups,such as carboxylic acids or alcohols, which will increase the water solubilityof the organic matter, rendering it more readilydigestible by microbial activity for subsequent biofuel production or otheruseful processing. Sulfur-containing gases, suchas hydrogen sulfide and methyl mercaptan, can be converted to persulfatedirectly at an organics processing site througha variety of processes including combustion and electrochemical oxidationtogether, or by electrochemistry alone,preferably on a boron-doped diamond anode. The process can be applied to manytypes of organic matter and wastesIncluding cellulosic, lignocellulosic, and cellular residues for theproduction of many types of biofuels, Including biogas(mostly methane and CO2), and ethanol. Such activated (oxidized) organicmatter may also be used as a feedstock forother chemical and biological processing.