AWWA WQTC58844

Small drinking water systems using surface water sources will soon have to comply with theStage I Disinfectants/Disinfection Byproducts (D/DBP1) Rule (January 1st, 2004). Smallsystems have the most difficulty meeting federal compliance standards for drinking water,because the treatment technology that may be affordable to large-scale operations may not beaffordable for small-scale operations. Therefore, small system compliance problemsare the most difficult problems to solve in the water industry. The overall objective of this researchwas to study the treatment of a variety of Missouri surface waters using techniques applicableto small systems such as powdered activated carbon (PAC), aluminum sulfate (alum),polyaluminum chloride (PACl), and anion exchange resin (MIEX) for removal of NOM andminimization of DBPs by single and sequential treatments. This study demonstrated thatPAC treatment is unlikely to be a sole remedy to DBP problems because it cannot remove asufficient amount of NOM at reasonable doses (30 mg/L). MIEX treated water had thehighest ultraviolet absorbance (UVA) and Total trihalomethanes (TTHM) removal at 88 %and 86 %, respectively. For alum treatment, a minimum dose of 20 mg/L was required todestabilize the particles, causing a decline in UVA254. Lower pH improved alum and PAClperformance. Sequential treatment clearly showed better UVA removal than single PAC oralum treatments. Sequential treatment for alum/PAC is at least 42 % to 47 % higher thanPAC treatment alone and 6 % to 26 % higher than alum treatment alone, whereas sequentialtreatment for PACl/MIEX is at least 10 % to 26 % higher than PACl alone and 5 % to 33 %higher than MIEX alone. TTHM versus UVA and UFC chlorine dose (C24) correlationanalysis showed that the UVA was better than C24 and dissolved organic carbon (DOC) for predicting TTHM for mostwaters. Includes 13 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

22

File Size:

1 file , 410 KB