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Subject: Activated carbon purifies polluted sludge
Content: Urban sludge is a carbon material rich in organic matter. The preparation of activated carbon can not only solve the disposal problem of sludge, but also generate efficient and cheap adsorbent, which conforms to the scientific concept of circular economy and sustainable development. In this paper, the sludge of the municipal sewage plant was used as raw material, and the activated carbon was prepared by chemical activation method, and the adsorption of lead and cadmium was studied with it, so as to realize the use of waste for waste control. The conclusions are as follows:(1) According to the relevant national standards, the sludge of Liede Sewage Treatment Plant is mainly composed of volatile organic compounds, with a volatile content of 64.86%, which can be used as the main raw material for the preparation of activated carbon. (2) Without adding additives to the sludge, the concentration of sulfuric acid and zinc chloride is 4 mol · L' and the volume ratio is 2:1. The activated carbon prepared has the maximum iodine adsorption value of 549.6 mg · g 'and the yield of 51.3%, which is the better carbon sample prepared by pure sludge and is recorded as SAC.(3) Adding 8% peanut shell, the iodine value of activated carbon of sludge reached 789.6mg · g', which was recorded as PAC By single factor experiment, the optimal conditions of carbon production were obtained as follows: pyrolysis temperature 600 ℃ , activator concentration 4 mol · L', pyrolysis time 1.5h, solid-liquid ratio 1:2.5.Orthogonal experiment showed that the influence of each factor was as follows: pyrolysis temperatureIs the activator concentration Pyrolysis time >Solid-liquid ratio.(4) the main performance of PAC is basically equivalent to 8818 type activated carbon; www.powdered-activated-carbon.com The concentrations of heavy metals in activated carbon leaching solution of sludge were all qualified.Compared with domestic and foreign research reports, the quality of PAC is in the middle level.(5) Compared with SAC, the specific surface area of PAC is larger, up to 636.8m2 · g'. PAC is mainly mesoporous, but also contains some micropores. The adsorption/desorption isotherm shows that PAC is activated carbon with parallel wall slit pore structure. imagitarium activated carbon pellets