三种国产活性炭吸附去除水中病毒能力的比较

Comparison of Several Domestic Products of Activated Carbon in Virus Adsorption in Water

目的开展饮用水的深度处理,比较几种常用的国产活性炭在不同条件下吸附去除水中病毒的能力。方法采用三角瓶实验比较了两种国产椰壳颗粒活性炭和一种国产粘胶基纤维活性炭毡在设定条件下(磷酸盐缓冲液,pH=7.3,25℃)去除病毒的能力以及其中一种椰壳颗粒活性炭在不同条件下(预处理前后,温度15～35℃,pH=6.0～8.4,钙离子浓度为0～500mg/L,离子强度为0～0.1mol/L)去除病毒的能力。实验病毒为从污水中富集的大肠杆菌(Escherichia coli 285)噬菌体指示病毒。结果颗粒活性炭去除病毒的过程较好地符合一级反应动力学(R2=0.83～0.99),而纤维活性炭的符合程度较差(R2=0.44～0.64),速率常数为0.5053～2.6068(颗粒炭)和0.2192～0.4138(纤维炭);预处理活性炭(用去离子水煮沸2h后冲洗)即可增强又可减弱病毒的去除效果,取决于活性炭来源;两个厂家生产的椰壳颗粒炭在去除病毒的效果上有较大差异,其相对强弱取决于有无预处理;较高的温度和钙离子浓度或离子强度以及偏酸偏碱条件通常加快颗粒炭对病毒的去除。一级动力学模拟计算表明,15min内去除率约为30%,最高为40%,最低为5%;在实验5h内的最大去除数量为5个对数。实际测定结果显示,虽然颗粒炭的实验用量(1g)是纤维炭(0.1g)的10倍,但是后者比前者有更快的初始去除速率。结论三种国产活性炭在吸附去除水中病毒的效果上有较大差异,其相对强弱取决于实验条件。如果考虑目前水处理技术中较短的活性炭滤池处理时间(大约15min),研究能进一步提高本实验所用的国产活性炭材料在吸附去除病毒方面的能力十分必要。

Objective For drinking water deep treatment,this study compared the abilities of several common domestic products of activated carbon in virus removal from water through adsorption. Methods This study compared the abilities in virus removal of two types of granular activated carbon （GAC） materials （domestic product made of coconut shell） and one type of activated carbon fiber （ACF） material （domestic product made of mucilage glue-based ACF felt） under a fixed condition （phosphate buffered saline-PBS solution,pH =7.3,25 ℃） and the abilities of one of the above two GAC types under various conditions （before and after pretreatment,15-35 ℃,pH= 6.0-8.4,concentration of Ca^2＋ 0-500 mg/L,ionic strength 0-0.1 mol/L）. The tested virus was the indicator phages obtained from sewage with an enterobacterium （Escherichia coli 285）. Results The removal process with the GACs followed the first order kinetic model （R^2： 0.83-0.99）,whereas that of the ACF did not （R^2： 0.44-0.64）,with the rate constants of 0.505 3-2.606 8 （GACs） and 0.219 2-0.413 8 （ACF）. Pretreatment （boiling for 2 h and then washing in deionized water） could both increase and decrease the removal effects,depending on the GAC sources. Different abilities in virus removal were found between the two GACs with their comparative outcomes depending on if they were subject to the pretreatment; higher levels of temperature,Ca^2＋ concentration,and ionic strength,and slight acidic and alkaline conditions favored virus removal. Calculation from the first order kinetic simulation showed that： the removal percentage within 15 min was around 30% with the highest 40% and the lowest 5%; and the maximum removal during the experimental period of 5 h reached 5-log. Although the amount （1 g） of the GACs used was ten times of that of the ACF （0.1 g）,the measured values showed that the latter had faster initial removal rates than the former. Conclusion The three domestic products of activated carbon showed a large difference in their abilities to remove the viruses from water through adsorption with their comparative outcomes depending on the experimental conditions. If the short duration （about 15 min） currently employed in activated carbon treatment process is considered,it will be necessary to study the ways in promoting virus removal through adsorption onto the activated carbon materials of domestic products used in this experiment.