Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2011;23(5):711-7. doi: 10.1016/s1001-0742(10)60466-4.
Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 microm. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.
废水和废水处理过程中的生物气溶胶是大气气溶胶的一个重要亚组。大多数先前的工作都集中在评估它们的生物风险上。然而，在这项研究中，应用吸附法来减少来自氧化沟中试规模污水处理厂的空气中微生物。结果表明，颗粒活性炭（GAC）的吸附是净化空气中微生物的有效方法。GAC 本身对空气中的细菌具有最大吸附容量为 2217CFU/g，真菌为 225CFU/g，流速为 1.50m3/hr。在连续运行 80 小时内，氧化沟中排放的 85%以上的空气中细菌和真菌被吸附。它们的大多数粒径为 0.65-4.7 微米。那些粒径较小的空气中微生物更容易被吸附。SEM/EDAX、BET 和 Boehm 滴定法被用于分析 GAC 的物理化学特性。GAC 表面特性与其吸附性能之间的关系表明，多孔结构、大表面积和疏水性使 GAC 成为空气中微生物的有效吸附剂。比较了两种再生方法，即紫外线照射和高压蒸汽，用于再生用过的活性炭。由于高压蒸汽完全破坏了附着在活性炭上的微生物，因此是一种有效的技术。还进行了微观观察，以研究原始和使用的吸附剂。
