Separation Technologies

Membrane Technologies

Reverse Osmosis (RO)

This is a process used to remove dissolved ions from water. When designing RO systems a complete analysis of should be done in advance. In RO, pressure forces the water through a semi-permeable membrane element. The membrane will freely pass water but rejects most of the dissolved materials as well as any small particles in the feed water. Thus the permeate water which has passed the membrane contains a relatively low concentration of ions compared to the reject (or concentrate) which contains all of the ions which did not pass the membrane in a reduced quantity of water. More detailed information can be found at and sample RO specifications.

Ultrafiltration (UF)

Ultrafiltration is a membrane process with the ability to separate molecules in solution based on size. It is a pressure driven process with a typical nominal pore size of 0.01 micron (100,000MWCO), and configurations are either cross flow or dead end. UF removes bacteria and protozoa, including giardia and cryptosporidium. Reduces turbidity to < 0.1 NTU and removes 6 log of viruses. UF is used as pretreatment, final membrane treatment in the pharmaceutical industry, and in the municipal market for potable water applications. More information can be found in this .

Ultraviolet Light (UV)

Ultraviolet sterilization uses radiation to destroy biological activity. Radiation at a specific wavelength is generated by a lamp, penetrates cells, and is absorbed, causing either cell death or preventing replication. Because the UV radiation must reach cells through the water, the water must be relatively free of turbidity or the distance across which the radiation can be transmitted is greatly reduced. Radiation is usually provided by mercury arc lamps, which provide most of their light at a wavelength within the optimal range for disinfection, TOC destruction or most recently in chlorine destruction.

Electrochemical Technologies

Electrodeionization (EDI)

Electrodeionization (EDI) - process that removes ionized and ionizable species from liquids using electrically active media and using an electrical potential to influence ion transport.

Since the introduction of a commercial EDI in the late ‘80’s many new EDI products have entered the market, i.e. thin cell, thick cell, spiral, plate and frame, homogeneous membrane vs. heterogeneous membrane, single bed technology vs. mixed bed technology etc. Let AWS ‘clear the turbid waters of technology’ in explaining the differences in EDI stacks and what that means to your EDI system maintenance and care. We’ve worked with all the major suppliers and specialize in EDI. We consider this one of our many core competencies.

Electrodialysis (ED)

Electrodialysis Reversal (EDR)

Electrodialysis Reversal is a continuous self-cleaning Electrodialysis process by means of periodic reversal of the DC polarity, switching concentrating and diluting flow streams. EDR systems are constructed symmetrically so that when the current is reversed the respective diluting and concentrating compartments are also reversed.

Media Filtration Technologies

Pretreatment is key in the design of any water treatment system. Below are some standard specifications of media filtration. Correctly sizing your pretreatment and knowing your feed water will minimize maintenance and allow for better operation of all down stream equipment.

Multimedia Filtration

The filter body shall be constructed of reinforced, lined fiberglass; epoxy coated steel or other such materials of sufficient thickness as required by operating conditions to insure a five-year minimum operational life. The vessel shall be designed for a working pressure of 150 PSIG and shall be provided with manholes for loading and inspection of media. The unit shall incorporate a central bottom distributor designed to insure even flow distribution over the entire media bed. The media shall consist of layers of anthracite, quartz or silica sand and garnet, graded in density. Unit backwash shall be initiated by a central microprocessor and controlled automatically using a multi-port valve. The filter shall automatically cycle through the positions of backwash, rinse and return to service.

Water Softener

The filter body shall be constructed of reinforced, lined fiberglass; epoxy coated steel or other such materials of sufficient thickness as required by operating conditions to insure a five-year minimum operational life. The vessel shall be designed for a working pressure of 150 PSIG and shall be provided with manholes for loading and inspection of media. The unit shall incorporate a central bottom distributor designed to insure even flow distribution over the entire media bed. The unit shall be provided with high-capacity, non-phenolic ion exchange resin having a minimum exchange capacity of 30,000 grains/ft3. Unit regeneration shall be initiated on totalized process flow by a central microprocessor and controlled automatically using a multi-port valve. The filter shall automatically cycle through the positions of backwash, brine draw, slow and fast rinse, brine tank refill and return to service. The unit shall be provided with a brine tank of sufficient capacity to provide for seven days of continuous service without refilling.

Activated Carbon

The filter body shall be constructed of reinforced, lined fiberglass; epoxy coated steel or other such materials of sufficient thickness as required by operating conditions, to ensure a ten-year minimum operational life. The vessel shall be designed for a working pressure of 150 PSIG and shall be provided with access ports for loading and inspection of media. The unit shall incorporate a central distributor designed to insure even flow distribution through the activated carbon elements. The unit shall also monitor total processed gallons and indicate when carbon replacement is required.