科學(xué)家弄清了一種常見的可以食用的仙人掌如何凈水的原因,，這為它在發(fā)展中國家的使用鋪平了道路,。該研究成果發(fā)表在《環(huán)境科學(xué)與技術(shù)》（Environmental Science & Technology）上,。
胭脂仙人掌原產(chǎn)于美國，而且在非洲大陸,、墨西哥和其他發(fā)展中國家廣泛種植,。這組科學(xué)家說，它如今可以成為發(fā)展中國家的農(nóng)村地區(qū)的一種可持續(xù)和可負擔(dān)得起的凈水方法,。
科學(xué)家已經(jīng)知道胭脂仙人掌能夠凈水,，但是他們對于這種機制的理解仍然不夠充分。
他們在被污染的水中測試了兩種粘液——仙人掌分泌的膠狀物質(zhì),。仙人掌通過讓沉淀物和細菌聚集成小的絮狀物從而在15分鐘內(nèi)去除了98%的細菌,，這些絮狀物可以很容易地過濾掉。
這組科學(xué)家說,，這些發(fā)現(xiàn)為使用多少仙人掌用于凈水的指南鋪平了道路?，F(xiàn)在已經(jīng)有了用辣木種子凈水的指南，這是另一種天然凈水劑,。
“我們設(shè)想社區(qū)可以在使用仙人掌填飽肚子的同時用它清潔水,。”該研究的第一作者、美國佛羅里達大學(xué)的Norma Alcantar說,。
她說,，當(dāng)她在一個墨西哥農(nóng)村社區(qū)測試這些仙人掌的時候，“人們?nèi)冀邮苁褂孟扇苏频淖龇?rdquo;。
但是墨西哥水技術(shù)研究所（IMTA）水凈化項目的負責(zé)人Alejandra Martín認為,，最大的挑戰(zhàn)在于教育人們凈化水的重要性,。“我們看來這是必要的，但是他們卻不這樣認為”,，她說,，“一些當(dāng)?shù)厣鐓^(qū)并不凈化水，”IMTA的社會參與項目負責(zé)人Daniel Murillo說,，“胃腸感染被認為是清潔身體的一種方式,，而不被認為是一種疾病”。
Alcantar的研究組如今正在與墨西哥的非營利組織和大學(xué)一起組織教育項目,。她預(yù)計將在6月啟動一個類似的項目,，從而幫助最近海地地震引起的水問題。
瑞典Uppsala 大學(xué)的材料物理學(xué)家Adrian Rennie的研究包括利用辣木種子凈水,，他說很樂意看到關(guān)于天然聚合物凈水的更詳細的研究,，因為不同的環(huán)境適合不同的生物聚合物。（生物谷Bioon.com）
Nature Nanotechnology ：凈水芯片可分離出99的污染物
生物谷推薦原文出處：
Environ. Sci. Technol. DOI: 10.1021/es9030744
Removal of Sediment and Bacteria from Water Using Green Chemistry
Audrey L. Buttice?, Joyce M. Stroot?, Daniel V. Lim?, Peter G. Stroot§ and Norma A. Alcantar*?
Department of Chemical and Biomedical Engineering, Department of Cell Biology, Microbiology, and Molecular Biology, and Department of Civil and Environmental Engineering, University of South Florida, Tampa, Florida 33620
Although nearly all newly derived water purification methods have improved the water quality in developing countries, few have been accepted and maintained for long-term use. Field studies indicate that the most beneficial methods use indigenous resources, as they are both accessible and accepted by communities they help. In an effort to implement a material that will meet community needs, two fractions of mucilage gum were extracted from the Opuntia ficus-indica cactus and tested as flocculation agents against sediment and bacterial contamination. As diatomic ions are known to affect both mucilage and promote cell aggregation, CaCl2 was studied in conjunction and compared with mucilage as a bacteria removal method. To evaluate performance, ion-rich waters that mimic natural water bodies were prepared. Column tests containing suspensions of the sediment kaolin exhibited particle flocculation and settling rates up to 13.2 cm/min with mucilage versus control settling rates of 0.5 cm/min. Bacillus cereus tests displayed flocculation and improved settling times with mucilage concentrations lower than 5 ppm and removal rates between 97 and 98% were observed for high bacteria concentration tests (>108 cells/ml). This natural material not only displays water purification abilities, but it is also affordable, renewable and readily available.
