The Southern California Water Company has conducted testing to simultaneously remove
arsenic and manganese from groundwater at its Centralia plant south of Los Angeles. The
testing was funded in part by the AWWA Research Foundation as a Tailored Collaboration. The
project included bench- and pilot-scale process testing, design and construction of full-scale
improvements, and full-scale trials to investigate the potential for chlorine and ferric chloride
addition followed by filtration to simultaneously remove arsenic and manganese.
Many wells in Southern California have been equipped with pressurized filters for
manganese removal. However, the manganese removal process (oxidation/direct filtration) is
not very effective for arsenic removal especially when iron concentration in the groundwater is
low. There are several known treatment technologies for arsenic removal, including both
conventional processes (e.g., coagulation/filtration and softening) and emerging technologies
(e.g., coagulation assisted membrane processes and proprietary adsorbents). However, most all
of them are not feasible for urban groundwater wells to address the particular arsenic/
manganese concern due to larger space requirements, multiple chemical handling, and high costs.
Since many well sites in Southern California are adjacent to residential areas, a small footprint
and minimum chemical usage are often required.
The specific goals of the research were to answer the following key questions:
will chlorine and ferric chloride addition followed by filtration simultaneously
remove arsenic and manganese;
what is the relationship between ferric chloride dose and filtered water arsenic
concentration;
how effectively will bench-testing estimate the required ferric chloride dose to
achieve the target filtered water arsenic concentration;
how effectively will pilot-testing estimate filtration design and operating
parameters including filter run time; and,
what are the optimal design and operating parameters to achieve the target
finished water arsenic concentration with minimum water waste and sludge
production?
The following major tasks were performed to investigate arsenic and manganese removal:
analysis of existing conditions;
bench-scale testing;
pilot-scale testing;
design and construction of full-scale improvements;
full-scale testing; and,
data management and reports. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 990 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 17 |
| Published : | 06/15/2003 |
