造孔剂对煤基管状炭膜的结构和性能影响

Effects of pore-forming agent on the structure and properties of coal-based tubular carbon membranes

以粉煤为原料制备管状炭膜,通过添加造孔剂来调控炭膜的孔结构,探讨了造孔剂的形状和添加量对炭膜孔结构、导电性和机械强度的影响,研究了造孔剂添加量对炭膜处理染料废水性能的影响.结果表明,粉末状造孔剂在炭膜中主要形成海绵状孔,纤维状造孔剂主要形成隧道状直通孔;随造孔剂添加量增加,炭膜的孔隙率和孔径增大,但导电性和机械强度下降;在水处理过程中,造孔剂添加量越大的炭膜,其跨膜压越小,渗透通量越高;炭膜对罗丹明B的去除率均达到近100%,但对COD不能完全去除,造孔剂添加量较大的炭膜的COD去除率相对较低;罗丹明B的初步降解产物仍具有一定色度,当被降解至较小的分子或者被完全矿化后,废水才能被完全脱色.

Tubular carbon membranes were prepared by using coal as raw material. The pore structure of coal-based carbon membrane(CCM) was controlled by adding pore-forming agent(PFA). The influences of the shape and amount of PFA on the pore structure, electrical conductivity and mechanical strength of the CCMs were investigated. The effects of the amount of PFA on the dye wastewater treatment performance of CCMs were evaluated. Results illustrate that the powdery PFA mainly forms sponge-like pores in the carbon membrane, and the fibrous PFA mainly produces tunnel-like through-pores. With the increase of adding amount of PFA, the porosity and pore size of CCM increased but the conductivity and the mechanical strength decreased. During the water treatment process, the lower transmembrane pressure and the higher the permeation flux achieved when the adding amount of PFA was higher. The Rhodamine B removal rate of CCM reached nearly 100%. However, the COD could not be completely removed, and the COD removal rate of CCM adding with higher amount of PFA was relatively low.The preliminary degradation products of Rhodamine B still contained color, and the wastewater could be completely decolored when the intermediate products were decomposed into smaller molecules or fully mineralized into H2O and CO2.