Green process for supercritical water oxidation of sewage sludge with red mud as CO2 absorbent

摘要: Abstract To mineralize CO 2 produced in situ and other acidic substances originating from organic components sewage sludge, we developed a green SCWO system involving the treatment of sludge with red mud as an alkaline absorbent. In this new system, two steps mineralization were covered. Primary occurred inside reaction vessels part situ. By primary treatment, total inorganic carbon solid residue increased rapidly, predominantly form calcite. Moreover, S P content by more than ten times compared that pure sludge. The pH drained water 5.16 to about 7.7 addition 2% mud. second step involved exhausts cleaning using slurry. With 2.5 h reactions at pressures 0.1, 1, 3, 5 MPa, approximately 4.49, 5.30, 6.06, 7.52 g, respectively, per 100 g bound high absorption capacity was ascribed pressure reaction, which conveniently achieved just simple adjustment back-pressure valve. disposal, level cut below 800 ppm (mg/L); SO nitrogen oxides (NO, NO ) diminished 15 ppm 12 ppm, respectively. Due comparative stability residues obtained, they can easily be handled conventional methods or recycled for range industrial applications including building materials, special ceramics, silicate cements.