Physical And Chemical Properties Of Rice Husk Ash Used For Adsorption Of Organic Pollutant

Power generation from rice husk has a potential industrial value as a mature technology for recycling use. However, the residue of power generation, known as rice husk ash, needs to be carefully handled, or there is certain damage to our environment. The most of studied researches are based on the preparation of rice husk ash from rice husk under experimental condition. The rice husk ash left after the power generation has many differences in the physical and chemical nature with the prepared rice husk ash, because of the high temperature and long heat time in the power generation process.It is studied that the rice husk ash of power generation is used to deal with the deep treatment of water pollutants as absorbent. The removal efficiency of organic pollutants is studied under different experimental conditions, which give a result that the rice husk ash has bad removal efficiency in comparison with the samples treated by alkaline cleaning. The removal efficiency is improved with the increase of alkaline quality used in the alkaline treatment.The instrumental analysis give a series results of that no apparent difference of infrared spectrogram between the alkaline treated samples and the untreated sample. However, the total surface area and total carbon quality of rice husk ash determined by using relative instruments shows that they increased both after the alkaline cleaning. It is found from the scanning transmission electron microscope that the large amount of silicon dioxide particles filled in the pores of rice husk ash. The silicon dioxide decreased after alkaline cleaning for samples, which is supposed to be the result of chemical reaction of silicon dioxide and alkaline. The pH value show a strong influence on the removal results that when pH value is greater than 7 gives a better result than when the pH value less than 7.It was proved in the adsorption study that the absorption model fits Langmuir and Freundlich isotherm model both, which proved that the adsorption belong to the combined action of different effects. It is also known that the adsorption capacity of rice husk ash can reach the highest 15.873 mg/L.The experimental data proved that there were three progresses in the whole adsorption, with quick adsorption first and secondly the slowing down adsorption progress, and the last balance phase. It can be concluded as the phase of adsorption on surface, intra-diffusion phase, and the balance phase. The kinetic study showed that rice husk ash adsorption kinetic model belongs to pseudo second order kinetic model and intra particle diffusion model.