| In recent years, large numbers of sludge are produced during the disposal of wastewater, and it may pollute the environment without stabilization or safe disposal because it is huge, vertiginous, putrid, and toxic. Proper treatment and resource utilization are needed for sludge final disposal. The residual sewage sludge produced during the biological treatment process contains plenty of organic substances, nuisances and even harmful pathogenic microorganisms and parasitic ovum. The properties of the sludge are unstable, and easily to be septic. It will become a secondary pollution if it was not disposed carefully during the wastewater disposal. Making the sludge into adsorbent is a new way of utilizing the sewage sludge, which can handle the sewage sludge and reuse the material produced from sewage sludge at the same time.The residual sewage sludge produced through biologic method treatment domestic sewage is taken as raw material, and the chemical activation method is applied to paralysis sewage to obtain porous adsorption material. Utilized the orthogonal experiment and single factor experiment to research correlation effect factors of production of sewage sludge-based adsorbent derived from sewage sludge and activor, which including pyrolysis temperature, pyrolysis dwell time and the conceration of activation reagent. The experiment results show that the most feasible condition to produced adsorbrnt is the concentration of activor 3mol·L-1, pyrolysis temperature 650℃and pyrolysis dwell time 30min. The characteristics of the sewage sludge-based adsorbent are the SBET area 270.08 m2·g-1, the total porous volume 0.27 cm3·g-1 and the microporous volume 0.05 cm3·g-1.It was found that pyrolysis makes the formation of the pore configuration and functional groups on SBA surface by scanning electron microscope (SEM), specific surface area analysis, Fourier infrared spectroscopic (FT-IR), X-ray photoelectron spectroscope (XPS) and etc. Final pyrolysis temperature affected surface chemical structure of SBA greatly. The higher the final pyrolysis temperature, the higher carbon content of SBA surface, the lower content of functional groups, though SBAs obtained at different final pyrolysis temperature had similar pore structures. The surface oxygen-containing functional groups affect the surface chemistry of SBA, and they act as active site for the adsorption. In addition, heavy metals arsenic, cadmium, mercury, nickel and copper in SBA seem not leach in the environment pH of 1-12; chromium, lead and zinc leaching concentration are less than the maximum allowable value. Therefore, SBA seems not damage the water environment.The removal efficiencies of lipid on SBA are stable with the solution pH of 2-10, which are 85-96%. The removal efficiencies of lipid on SBA with the adsorbent dosage of 4.0g·L-1 is 97%, which is 1.15 times that of PAC. Most of the adsorptions on SBA and PAC from pure solutions fit better in Freundlich model than in Langmuir model. Adsorption mechanism of lipid on SBA mainly is the reactions between the surface oxygen-containing function groups of SBA and organic substance molecules, as well as the reactions between the surface Si, Ca and Fe elements of SBA and organic substance molecules. |
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