Study On Preparation Of TiO₂/sludge Activated Carbon And Its Photocatalytic Purification Of Acetone Gas

Activated carbon prepared by sludge as the carrier of Ti O2 photocatalyst, not only to achieve sludge recycling, but also synergies adsorption and photocatalytic provide a new composite photocatalytic material. In this paper, using the refinery sewage sludge and city sewage sludge as the raw materials respectively, using ZnCl2 as the activating agent, and prepared two kinds of activated sludge carbon, then characterized with the help of the DTA-TG, BET, SEM and other means, investigated the adsorption properties by adsorbed iodine value of two categories sludge activated carbon. Using the two kinds of activated carbon as raw material, by "one-step" and "two-step" two load method loading TiO2 on sludge carbon to prepared four composite photocatalytic materials, with acetone as the target pollutant. The performance of TiO2 / sludge AC of photocatalytic degradation of organic pollutants and purifying mechanism. The results were as follows:1) Through the analysis of the sludge, heavy metal content of industrial analysis, show that the sludge preparation of activated carbon is feasible.2) The iodine adsorption of activated carbon obtained in 300mg/g or more. The surface area of urban sludge activated carbon is 453.6m2/g, refinery sludge carbon is 490.6m2/g. The activated carbon surface and inner holes are relatively rich in uniform. The pore of urban sludge activated carbon are mainly distributed in 4~7nm, refinery sludge activated carbon pore are mainly distributed at 3.8nm, two kinds of sludge carbon are mainly micro pore and medium pore. The surface area of the composite photocatalytic material was less than 100m2/g after two sludge carbon load TiO2, but the surface distribution of Ti O2 was more uniform.3) By controlling the UV intensity, the concentration of acetone atmosphere and when the UV light turn on to compare the effect of the catalytic material handling acetone, and the mechanism of the photocatalytic reaction was obtained by the product analysis. It shows that:Photocatalytic materials prepared by two step method than the one step method was good in treatment effect of acetone, lasted for much longer time, the results are consistent with the front part of photocatalytic materials characterization;The acetone gas concentration is lower, the photocatalytic duration lasted longer, but in a certain range of concentration, acetone atmosphere concentration is higher, the degradation rate is higher too;The intensity of the light is proportional to the degradation rate, but the higher the temperature is, the degradation rate is lower, the temperature is the disadvantage factor for the photocatalysis;The results show that the products were ethanol and propionic acid. Based on this, the reaction mechanism of acetone photocatalytic degradation is preliminarily given.