New Margin-Based Biochar for Removing Hydrogen Sulfide Generated during the Anaerobic Wastewater Treatment

Abstract

The present research concerns the development of a new device and process intended for the purification and treatment of sulfurous elements, and more particularly, of hydrogen sulfide (H2S) from the biogas produced at the time of the anaerobic fermentation in the purification stations. The controlled dumps or any other unit are likely to produce biogas with concentrations of H2S harmful to the operation of the machines for the valorization of the produced biogas or deodorization. This device uses new biochar from a mixture of dehydrated digested sludge from sewage treatment plants and margins from traditional crushing units, followed by biological treatment in a liquid medium at a controlled temperature. The liquid medium is based on a margin (nutrient) with culture support (large granules of biochar) in suspension by the injection under the pressure of biogas coming from the biochar filter. Physico-chemical characterization of the biochar and a test practiced on the new device of raw biogas treatment were realized. The results showed that the newly synthesized biochar has a low specific surface and a highly undeveloped porosity. The spectrum corresponding to the images of the biochar reveals the presence of C, O, N, Al, Si, P, and Fe, as significant elements with the following respective percentages: 37.62%, 35.78%, 1.87%, 4.26%, 7.33%, 8.56%, and 4.58%. It is important to note that the C content of the biochar thus synthesized found by EDX is quite comparable to that estimated from ATG. Biogas treatment test results on the prototype object of the invention eliminated 97% of the H2S from the biogas produced.