For example, mimicking a cell membrane's efficient gatekeeping could result in water purifying membranes that don't require a lot of pressure or energy to push the water through. (pnnl.gov)
The Black Berkey Purification Elements can be classified as water purifiers because they remove 99.9999999 % of pathogenic bacteria and 99.999 % of viruses, which greatly exceeds the standard. (theberkey.com)
The 22 Oz Sport Berkey Portable Water Purifier is durable, made from safe non-leaching LDPE # 4 that is BPA - Free and offers a convenient and portable filtration system using medical grade technology. (theberkey.com)