Maciel P M F, Sabogal-Paz L P
Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil E-mail:
J Water Health. 2016 Jun;14(3):369-78. doi: 10.2166/wh.2015.227.
Giardia and Cryptosporidium species are a serious problem if present in water supplies. The removal of these protozoans and the adaptation of existing protocols are essential for supplying drinking water to developing countries. Considering this, the aim of this study is to evaluate, on a bench level, the removal of Giardia spp. cysts and of Cryptosporidium spp. oocysts from water with high turbidity, using polyaluminium chloride as a coagulant. Filtration using mixed cellulose ester membranes, followed, or not, by purification through immunomagnetic separation (IMS) was used for detecting protozoans. By evaluating the adopted protocol, without using IMS, retrievals of 80% of cysts and 5% of oocysts were obtained, whereas by using IMS, recoveries of 31.5% of cysts and 5.75% of oocysts were reached. When analyzing the coagulant performance, a dosage of 65 mg L(-1) showed contamination from protozoans in all the samples of filtered water. A dosage of 25 mg L(-1) presented protozoans in 50% of the filtered water samples. The results showed an improved performance for the 25 mg L(-1) dosage; therefore, the control of coagulation and adaptation of detection protocols must be evaluated according to the features of raw water and availability of local resources.
如果供水系统中存在贾第虫和隐孢子虫物种，那将是一个严重的问题。去除这些原生动物以及调整现有方案对于向发展中国家供应饮用水至关重要。考虑到这一点，本研究的目的是在实验室规模上评估使用聚合氯化铝作为混凝剂从高浊度水中去除贾第虫属包囊和隐孢子虫属卵囊的情况。使用混合纤维素酯膜过滤，之后是否通过免疫磁分离（IMS）进行纯化，用于检测原生动物。通过评估所采用的方案，在不使用IMS的情况下，包囊回收率为80%，卵囊回收率为5%；而使用IMS时，包囊回收率为31.5%，卵囊回收率为5.75%。在分析混凝剂性能时，65 mg L(-1)的剂量在所有过滤水样品中均显示有原生动物污染。25 mg L(-1)的剂量在50%的过滤水样品中存在原生动物。结果表明25 mg L(-1)剂量的性能有所改善；因此，必须根据原水特征和当地资源可用性来评估混凝控制和检测方案的调整。
