Water District No. 1 of Johnson County, Kansas (WaterOne), is a large utility that
supplies water to approximately 340,000 people in the Kansas City metropolitan area.
WaterOne has two facilities (55 and 125 mgd) that treat water from the Missouri and
Kansas Rivers by presedimentation, preoxidation and disinfection with chlorine dioxide,
two-stage lime softening, dual media filtration, and disinfection with chlorine. Currently,
WaterOne is planning a new 30 mgd treatment facility that will treat Missouri River
water withdrawn through horizontal collector wells. One proposed treatment process
would include lime softening and filtration by microfiltration (MF)/ultrafiltration (UF) membranes. WaterOne and Black
& Veatch performed a 6 month pilot study to evaluate the potential effects of lime-softened
water, specifically water with pH of 9.5 and calcium carbonate precipitation
potential greater than 20 mg/L as CaCO<sub>3</sub>, on the MF/UF membranes.
The membrane system suppliers were allowed to specify the flux and other operating
setpoints, but were required to meet water recovery, membrane cleaning, and specific
flux recovery following CIP values outlined in the pilot testing protocol. The pilot
testing extended over several seasons, so the impact of water temperature, TOC increases
with spring runoff, and process changes upstream of the membrane systems were
investigated. An on-line alkalinity, total hardness, and TOC analyzer were also used to
determine the effects of calcium carbonate precipitation potential and TOC on the
membrane fouling rate.
The paper discusses the results of the pilot study and fouling rates as a function of TOC
concentration, upstream treatment with polymer, and calcium carbonate precipitation potential. The paper also provides practical guidance for other softening plants that are
considering MF/UF membranes. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 3.4 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 03/01/2007 |
