GET Surface Water Purification Systems

GET Surface Water Purification Systems

GET manufactures river & surface water purification systems for high & low volume usage, from small portable systems, to whole house systems, to medium & larger size systems for commercial & industrial use, to very large systems for municipal applications. These systems remove solids, turbidity, parasites, bacterial & viral pathogens, giardia & cryptosporidium cysts, and other undesirables from surface water to provide a safe, healthful potable water supply.

The Challenge

Today’s world is chronically short of good potable water, but many regions have abundant surface water, usually fouled by parasites, bacteria, viruses, silt, and many other un-drinkables. To solve these water treatment requirements, we at GET, Inc., provide standard & customized system design and packaged water treatment systems which effectively remove any type of unpleasant or unhealthful contaminants. These optimized systems provide the best operational characteristics with the highest efficiencies. To achieve these aims, pilot testing and detailed engineering is done to guarantee the long-term success of your plant, and to obtain the lowest overall cost of producing good water.

The Benefits of Pilot Testing

In most cases the water analyses can be reviewed to prepare preliminary designs prior to a site visit or a pilot test. Yet, by running a well engineered & monitored pilot study, we refine the design to optimize the system performance and to ensure longest possible system and component life. This practice has been developed to ensure that the heart of the system (membrane life) meets or exceeds industry standards, resulting in optimum performance, maximum reliability, and lowest operating cost.

Site inspection and study are also highly recommended prior to final plant design for best results, and is required for any performance guarantee from GET and for any BOO or BOOT project operated by GET.

GET HFUF Pilot System

Membrane Selection

By piloting the membranes on site, the membrane selection can be done to insure proper system performance and optimum membrane life. Membranes are provided with NSF 61 approvals for Municipal Water suppliers and Industrial membranes of various styles can be provided depending on our customer’s individual needs.

PESM polymer membranes provide high efficiencies at very low operating pressures. Typical start-up pressure is less than 10 psig. Flows are maintained at constant production using Variable Frequency Drive (VFD) pumps. Backwash is done based on pre-programmed PLC and when upsets to the feed supply occur the unit can automatically adjust backwash frequency to ensure that membranes are not prematurely fouled. The membranes can be set up for barrier or crossflow filtration as required by feed conditions.

Membranes used are HFUF or hollow fiber ultra-filtration and are the very durable based on their construction and design. The GET HFUF membrane incorporates 7 fibers in a single large fiber for added strength without compromising production. Membrane surface area is 500 square feet per module. The unique backwash construction of the membrane design provides proper flow velocity during feed, flush and backwash modes. Membranes using PESM single bore 1.5 mm can be used for industrial or municipal where there are high TSS levels in the feed water supply. Large bore membranes benefit is typically in cross-flow operation.

Membrane manufacturing and local stock are designed to ensure fast delivery and all membranes are wet tested to ensure quality. Membranes are easily removed and fast opening device ensures ease of use by plant personnel.

The outer annular gap between the membrane bundle and the pressure vessel which is used for the filtrate collection is built by a perforated tube. To optimize the distribution of the water within the annular gap, the upper part located at the permeate connection is not perforated. Thus, a radial flow distribution can be guaranteed which is especially important for a backwash that is conducted with higher volumes. The perforation underneath then provides an optimal axial distribution. Small openings right under the potting material allow a complete de-aeration of the vertically installed module also on the permeate side.

To minimize the pressure loss between the capillaries, the flow velocity of the water should be constant at every position in the module. These modules enable this by means of special module housing as well as the unique arrangement of the capillary fibers.

The construction of the module permits a space-saving, cost-efficient assembly of the rack. As can be seen from the example below, the modules are mounted separately and vertically – thus providing numerous advantages:

Due to the fact that a complete aeration and de-aeration is easy possible, an integrity testing can be done within a few minutes. Also, the complete de-aeration guarantees that neither on the feed side nor on the permeate side air cushions may arise. Therefore, each capillary contributes to filtration and backwash. (Air on the feed or permeate side of the module might either be attained through out-gassings of supersaturated water, e.g. some ground waters, dam waters and biologically active waters or during the integrity testing)

The complete dewatering of the modules that are vertically installed on the rack provides the possibility of a “dry” mounting and dismounting of the modules that can be done by one person only. Each module can be mounted / dismounted separately without having to remove others modules first.

The parallel inflow of the modules provides a constant flux through the capillaries. In addition, the transportation distance for removing the layer cake out of the module is very short. Between the racks, a space of far less than 36” is sufficient for a comfortable mounting and dismounting.

Racks can be quickly installed and start-up can typically be done on existing plants without interruption of service to the process or Municipal Distribution.

The GET Surface Water Purification System is a low-pressure-driven separation process that uses semi-permeable membranes to separate macromolecules in a solution. GET systems use a membrane element consisting of hollow-fiber capillary membranes housed in a PVC shell. The membranes are hydrophilic polyether sulfone. These membrane elements are 40 or 60 inches in length and are arranged together in modules designed and fabricated to specific plant requirements, along with treat ability study data.

Feed water enters from the ends of the module and flows along and through the inside of the hollow-fiber capillary membranes. The semi-permeable membranes block passage of particulates larger than 0.01 µm but allow passage of pure water through to the central core tube

The filter membranes are periodically cleaned by back flushing. The water flow is reversed back through the central core tube and passes through the walls of the hollow-fiber capillary membranes to dislodge material trapped inside the lumens and flush it away through the concentrate tube.

The GET Surface Water Purification System is designed to address a variety of water treatment applications.

The GET system can be used to treat surface waters in the same manner that a gravity filter would be used. It can be used directly on some surface waters where the turbidity is relatively low (<20 NTU). Above this level of turbidity, the system design would probably incorporate settling/precipitation or automatic filters prior to the membrane system to minimize the overall loads on the membrane system and offer the most cost-effective solution.

The GET system is ideal for this type of water. The hollow-fiber membrane provides a barrier against giardia and cryptosporidium in the water. This type of an application usually demonstrates a very high flux rate with this membrane.

The GET system can eliminate the potential for recycling cryptosporidium or giardia around a conventional granular filter system during backwash water recovery operations. When the backwash water is filtered using the Ultra-Filtration membrane, the treated water will have less than 0.1 NTU of turbidity.

GET HFUF systems can be used for pretreatment to other membrane systems. The hollow-fiber membrane produces permeate that is free of any suspended solids. This minimizes the potential for fouling of spiral membranes. Typically spiral membrane systems operate at a lower trans-membrane pressure with our systems as a pretreatment. The spiral system will also operate longer between cleanings due to the elimination of suspended solids from the feed water.