Preparation Of Rice Hull Adsorbent And Its Treatment Efficiency Of Marine Petroleum Pollution

Activated carbon is a kind of common adsorbent which has been widely used in industry. It has developed pore structure and a large number of superior surface functional groups. With the widening of the application area of activated carbon, a variety of new activated carbon materials have been developed both in China and abroad in recent years. Among them, high specific surface area activated carbon (HSAC) arouses extensive attention due to its centralized pore distribution and good adsorption performance. However, preparation of high specific surface area activated carbon is a complex process, the differences in raw material and processing technology can have significant impacts on the pore distribution and surface characteristics and other performance indicators of activated carbon.This study applied agricultural waste rice husk as raw material to prepare high specific surface area activated carbon through carbonization, KOH activation method. During the process of preparation, we investigated the influence of carbonization temperature, activation temperature, alkali carbon ratio and activation time on the pore structure of rice husk carbon.This research adopted the Autosorb-iQ-MP-VP automatic physical adsorption apparatus and transmission electron microscopy (TEM) to characterize and analyze the self-made rice husk carbon. The experimental results show that we could get comparatively black and complete carbonized rice husk particles when the carbonization temperature was set at350℃for20min, which is advantageous to the subsequent activating reaction; when the alkali carbon ratio was4:1, alkali activation time of1h and the activation temperature of750℃, the specific surface area of the rice husk carbon sample S2was the biggest, up to2627m2/g. Through using SLD method to analyze the pore distribution of sample S2, the aperture of the rice husk carbon is mainly concentrated in1.8nm, the micropore content ratio is high and its structure is developed while the mesopore content ratio is low. TEM analysis of sample S2showed that the graphite crystallite in the surface of the microscopic structure of the rice husk carbon had an inconstant and amorphous structure, but in short-range order.In addition, we did research on oil-contaminated seawater purification effect and adsorption kinetics model by using self-made rice husk carbon; we also made rice husk carbon adsorption bags, in order to compare the adsorption efficiency between rice husk carbon and rice husk adsorption bags. The results showed that the original concentration of petroleum substance in the sea water dropped respectively from3.655mg/L,3.794mg/L to1.268mg/L and0.966mg/L, and the highest removal efficiency reached65.3%and74.5%respectively. The experiment of the adsorption time indicated that the adsorption reached a maximum (278μg/g) after3h, to equilibrium. Experiment of different specification of rice husk adsorption bag showed that50#bag got the highest adsorption amount after3h (278ug/g), the60#and40#are relatively low, getting261,253ug/g respectively. This difference may relate to density and eyelet size of the non-woven fabrics.