Fine grain bed decontamination - by using suspension with nutrient salts for microorganisms in a bio-reactor to degrade toxic organic matter

摘要

To decontaminate fine grain beds, soiled by toxic organic matter, a suspension is formed from the bed material and water. The water contains the nutrient salts for the metabolic activity of the micro organisms, in the form of phosphates, trace elements, co-substrates e.g. sugar, ethanol or lactic acid. The bed/water suspension, at a rate of up to 50 wt.%, is agitated in a mixer or directly in a bioreactor. As an oxidising agent, nitrate is used alone or combined with other oxidising agents e.g. sulphate, bivalent Fe or Mn and CO2. When all the components for the bio process have been added, the suspension is stirred in the bioreactor at 10-20 deg.C with air exclusion. USE/ADVANTAGE - The process is for the decontamination of masses contaminated by toxic organic matter with a high fine grain content, e.g. loose or overgrown beds, sludge, harbour slick, or the fine grain fraction pptd. from earlier chemical/physical bed cleaning stages, and inert carriers soiled such as by aliphatic and aromatic hydrocarbons, polycyclic and halogenised hydrocarbons and cyanides. The technique gives an effective cleaning action to fine grain and clogged bed material, under controlled conditions, in a cost-effective action and economic time scales.