采用连续流生物活性炭(BAC)T艺处理水中挥发性苯系物饵TEX,包括苯、甲苯、乙苯、二甲苯),评价进水负荷、活性炭炭型等因素对于BAC处理性能的影响.研究表明,在40d的处理时间内,除苯之外,其余BTEX的BAC出水中均未检出苯系物(进水为6mg/L).为了检验BAC在高BTEX负荷情况时的处理效果,将进水浓度设定为19~32mg/L左右,在EBCT为1.2min条件下同样只有苯的出水浓度上升至10mg/L(C/Cin为0.45),然后略有下降,最终保持在5-10meCL(C/Cin为0.3以下),其余苯系物出水浓度均一直保持小于5mg/L.这表明BAC可以有效地处理高负荷BTEX(8.68~12.9kgTOC/(m3·d))的进水.生物活性炭对于活性炭吸附容量的恢复有比较明显的作用,煤质炭和椰壳炭的生物再生效率分别为53.6%和26.6%,煤质炭再生效率高的原因可能是其具备更多的大型中孔和大孔.
A series of continuous flow biological activated carbon (BAC) columns were operated for removing benzene, toluene, ethylbenzene and xylene (BTEX) from water to evaluate the effect of high loading and carbon type on the BAC treatment performance. The inoculated granular activated carbon (GAC) columns (EBCT =3.2min) became stable BAC systems quickly; with the exception of benzene, the TEX were totally removed from the 6mg/L single compound influent during the 40d study. The BAC treatment performance was affected for a few days after the increase in loading (8.68-12.9 kg TOC/(m3 · d), BTEX =19-32mg/L, EBCT = 1.2min); the benzene column effluent was affected the most with a peak concentration of 〉 10mg/L before declining to the base level of 5-10mg/L while TEX in effluents from the other columns remained at 〈 5mg/L. Both coal and coconut GAC samples of the respective BAC columns treating the toluene feed exhibited much higher residual toluene capacities relative to the same type GAC of the non-bioactive columns due to bio-regeneration. The BAC function resulted in a more complete recovery of the toluene capacity of the coal GAC than the coconut GAC (53.6% vs. 26.6%) because of its more abundant macropores and large mesopores.