木屑型香菇菌菌渣活性炭及其制备方法

A new method for preparing activated carbon with the spent shiitake substrates

以木屑型香菇菌菌渣为原料,采用微波辐照碳酸钾（K2CO3）活化法制备菌渣活性炭。探讨了活化时间、K2CO3与菌渣质量比、活化功率对活性炭得率及吸附性能的影响,得到适宜的制备条件为：活化时间16 min,K2CO3与菌渣质量比0.8∶1,活化功率520 W。该制备条件下所得活性炭碘值为729.94 mg/g,亚甲基蓝吸附值为163.47mg/g,得率为23.4%。SEM、N2吸附、零点电荷p H值的表征结果表明,微波辐照K2CO3活化起到了很好的造孔作用,菌渣活性炭的孔大多为直径介于3~6 nm的中孔。根据BET方程计算的菌渣活性炭比表面积（SBET）为674.2 m2/g,孔容为0.54 m L/g,平均孔径为3.7 nm,菌渣活性炭的p HZPC为5.23。

The paper is intended to introduce a new method for preparing activated carbon from the consumed shiitake substrates （SSSs） via the microwave assisted K2CO3 activation. The said SSSs we have adopted in our experiments are mainly made of sawdust. For our research purpose, we have made an investigation over the effects of the three main factors （i. e. the activation time, the K2CO3/SSS ratio and the microwave power） on the adsorptive capacity and the yield of the activated carbon （denoted as SSS- AC） with the method of single factor variance analysis in a series of experiments. In so doing, we have first of all made an assessment of the effects of the activation time and the way for fixing the K2CO3/SSS ratio at 0.8/1 and the microwave power at 520 W. The resuhs of our experiments show that the adsorption of SSS - AC for the amount of iodine and methy- lene blue （MB） tends to increase first and then decrease with the prolonging of the activation time from 10 to 18 rain, with the turning point taking place at the point of 16 min. In addition, the yield of SSS- AC has been found reversely related to the activation time. Secondly, we have also investigated the effects of K2C03/SSS ratio, the fix of the microwave power at 520 W and the maximum point of the activation time at 16 min. The results of our tests demonstrate that K2C03 is essential as an activation agent and the iodine amount whereas that of MB adsorption of SSS - AC tends to increase and reach its peak value with the ratio between the K2CO3 and SSS being 0.8 to 1. And from that point on, the ratio would begin to decline. What is more, we have found that the yield of SSS - AC is in a nega- tive proportion to the K2CO3 to SSS. Thirdly, we have made an ex- ploration of the effects of the microwave power, confirming the activa- tion time （16 min） and the ratio of KzCO3 to SSS （0.8 to 1）. The results we have gained indicate that the iodine amount and the amount of MB adsorption of SSS - AC tend to first increase then decrease with the increase of the microwave power from 360 W to 560 W, with the turning point being 520 W. Thus, as is expected, the yield of SSS - AC is also in a reverse relation to the strength of the microwave power. However, on the whole, the rational preparation conditions should be stated as follows： the activation time： 16 min; the K2CO3/ SSS ratio： 0.8/1; and the microwave power： 520 W. Under the above said conditions, the iodine amount, the amount of MB adsorption and the yield of SSS AC are： 729.94 mg/g, 163.47 mg/g and 23.4 %, respectively. What is more, the SSS- AC can be characterized by the scanning of the electronic microscopy, the nitrogen adsorption and pH-zero point of charge （pHzpc ）. The characterization results show that the microwave-assistant K2CO3 activation performs well in producing pores, in which the main part of the mesopores is in a diameter sphere of 3 - 6 nm. As to the SSS - AC, it is possible to work out their surface area according the BET equation （SBET） of 674.2 m2/g, whereas the total volume of the pores is 0.54 mL/g with the average pore diameter being 3.7 nm and the pHzec being 5.23. Thus, it can be seen that our work can be thought to have laid out a new promising approach to the resource utilization of SSSs.