Pall Aria Systems for Surface Water Treatment

Remove bacteria, viruses, organic matter, and turbidity to produce consistent effluent.

The quality of surface water entering your treatment system from rivers, lakes, streams, and reservoirs varies with seasonal conditions. The Pall Aria™ microfiltration membrane system produces effluent that remains consistent regardless of your source water quality.

Raw water
Raw water treatment removes chlorine-resistant Giardia and Cryptosporidium to meet the requirements of the Surface Water Treatment Rule. The Pall Aria system’s 0.1 μm membranes eliminate the need for you to add chemicals to coagulate these contaminants.

Performance data shows that the Pall Aria system achieves a 6 log reduction of Giardia and Cryptosporidium, with recovery rates that vary from 90-97%, depending on the quality of your influent water. (Refer to the following table.)

Typical Performance Data for Pall Aria Systems Processing Raw Surface Water

Avg turbidity (NTU) TOC avg mg/L Flux (gal/day/ft²) Recovery (%)

<20 <3 75 97

<50 <5 53 94

Up to 100 >5 32 90

Nephelometric turbidity unit (NTU) is the unit of measure for the size or concentration of suspended particles based on the scattering of light transmitted or reflected by the medium.
Total organic carbon (TOC)represents the average number of organic particles per liter of water processed.
Fluxis a measure of the flow rate in gallons per day per square foot of membrane.

Process flow using Pall Aria system to treat surface water

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Direct coagulated water
With microfiltration membranes, coagulation can improve the removal efficiency of harmful contaminants such as arsenic, natural organic matter, and phosphorous.

When you add coagulant and establish the proper pH, the Pall Aria system can reduce arsenic to well below the maximum level (10 μg/L) specified by the US EPA’s Arsenic Rule. This is the case even if your source water contains more than 50 mg/L arsenic.

Disinfection byproducts such as trihalomethanes and haloacetic acids are formed when chlorine reacts with natural organic matter in the feed water. Removal of organic matter reduces these byproducts.

Coagulant injected upstream of a Pall Aria system can eliminate 30-60% of the organic matter and attain a recovery rate of approximately 90-95%. It is more cost-effective than nanofiltration or reverse osmosis (RO) for this purpose.

Typical Performance Data for Pall Aria Systems Processing Direct Coagulated Surface Water

Avg turbidity (NTU) TOC avg mg/L Flux (GFD) Recovery (%)

<50 <5 75 97

<50 >5 51 95

Up to 100 >5 35 93

Process flow using Pall Aria system to treat direct coagulated water

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Coagulated and settled water
If you use low-quality source waters, an option for increasing flux rates is to allow coagulated materials to settle before feeding the clarified supernatant to the Pall Aria system. This has immediate financial benefits if you have settling equipment in place, but it is still cost-effective if you purchase the equipment. Fewer microfiltration modules are needed when settling is part of the treatment process, so the expense of the settling equipment is offset by what you save on the modules.

The following table presents performance data for the processing of coagulated and settled water. The data shows that settling equipment enables Pall Aria system performance to remain relatively stable despite changes in water quality.

Typical Performance Data for Pall Aria Systems Processing Coagulated and Settled Water

Avg turbidity (NTU) TOC avg mg/L Flux (GFD) Recovery (%)

<50 <5 75 97

<50 >5 75 97

Up to 100 >5 75 97

Process flow using Pall Aria system to treat coagulated and settled water

Articles and Success Stories

Pall Aria Installations for Surface Water Treatment

Pall Aria Systems for Water Treatment Applications Guide

Municipal Water Treatment homepage