Aqua Clara and Hollow Fiber Membrane Technology
Membranes are useful water filters because the membranes contain “holes” ……intelligently engineered holes…..allowing bacteria and even some viruses to be separated from the water source. At the beginning of the 1990s, hollow fiber membrane filtration cost 3-4 times the price of any basic water filtration system and reverse osmosis desalination cost over 10 times as much. This meant that engineers generally did not often utilize these technologies in water management. However, as with digital technology, costs associated with hollow fiber membranes have decreased significantly, making them highly useful additions to Aqua Clara’s technology array aimed at helping those who live on less than $2/day.
MF [micro-filtration] is a low pressure (10-100 psig) process for separating larger size solutes from aqueous solutions by means of a semi-permeable membrane; the MF process
· retains large suspended solids
· passes some suspended solids and all dissolved material
· pore ranges are available from 0.1 micron to 3 micron
Applications for MF include wastewater treatment, caustic cleaner recovery and clarification of dark juices. For example, in the clarification of wine and dark juices (such as cranberry), MF is employed to separate the suspended solids from the juice to produce a low turbidity juice while allowing the passage of color and flavor.
Today raw sewage water can be transformed into potable quality water more efficiently than alternative filter systems at competitive costs and at significantly lower costs using hollow fiber and RO membranes. Specific classes of membranes can be selected based on performance needs,thus filtering out different contaminants from the water being processed.
Membranes and bacteria
The typical size for all bacteria is 1-3 microns (μ); this structure is the basis for all plants and animals.
MF membranes of at least 0.1 μ permit the passage of salts and minerals to pass thru the membrane wall, yet filter out the bacterial elements that are associated with natural or fouled raw water sources. The resulting output water is microbiologically safe water [free of bacteria] and thus does not support bacteria based disease in consuming humans.
Today, only about 5% of the world’s total water treatment capacity utilizes membranes: this is split, roughly equally, between desalination and MF/Nano- filtration. Further, only about 1% of all the waste water streams are processed or treated using membranes.
Innovations in design and manufacturing cost reduction from scale-up and automation hold the promise of continuing to reduce the costs of membrane technology for sterile use in medical facilities. Many of these innovations will be borrowed from other industries like municipal water treatment and kidney dialysis manufacturing. This will drive the adoption of membranes for sterile point of use applications not only in institutions and homes, but even pocket based systems for emergencies and travel. And perhaps most importantly of all, these innovations could play a critical role in providing cleaner drinking water to the approximately one billion people that still do not have access to safe drinking water today.
Though the transition to membranes for extensive water filtration programs now seems inevitable, the application to global opportunities to serve people within all the markets has only just begun. Likely the initial engineering efforts and applications will clearly continue to be with those who can afford and properly use the technology.
ACI Engineering designs
The ACI engineering designs for our water purifiers include:
1]. Sand filtration units in many applications as the surface water sources available to those in our markets typically have substantial amounts of turbidity, parasites, bio-loads and fecal content;
2] A prefilter for use in applications to clean water provided by municipal water systems that is free of turbidity and parasites but is contaminated by bacteria
3]. The generation of upwards of 10,000 liters per day of bacteria free water utilizing commercially available 0.2 μ hollow fiber, membrane cartridges with special designs to maintain water quality;
4]. The majority of the materials of construction are secured locally;
5]. Storage & delivery of the bacteria free water maintains product quality;
6]. Engineering design flexibility tailored to the local environment;
7]. Projected clean water generation costs of <$ 0.002 per liter; and
8]. These designs are the ACI Sand and Membrane water purifier line.
Community Systems: Sand and membrane units that can remove virtually all turbidity, parasites and bacteria in producing at least 2,000 liters per day of clean water; these units can be designed to produce upwards of 10,000 liters per day, depending on need. These units are intended for use in large applications, such as hospitals, villages, or other entities requiring large volumes of clean water to be available daily.
Facility Systems: Sand and membrane units that produce the same quality of clean water as the larger unit, but at a level of 1,000 to 2,000 liters per day. These units are intended for use in clinics, schools, and similar sized facilities. With the addition of other materials, these units can be modified to provide for simultaneous arsenic removal.
Household Filters: Small sand and membrane units that produce the same quality of clean water as the other, larger hollow membrane-based units but at a level that provides for the daily clean water needs of a family.