Desalination of agricultural drainage return water. Part I: Operational experiences with Conventional and nonconventional pretreatment methods
✍ Scribed by Arthur C. Molseed; James R. Hunt; Mark W. Cowin
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- English
- Weight
- 656 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0011-9164
No coin nor oath required. For personal study only.
✦ Synopsis
The State of California Department of Water Resources is currently operating a demonstration reverse osmosis facility at Los Banos, California, which is treating agricultural drainage water. The pretreatment system at this plant at the time of this study consisted of marsh ponds and an upflow reactor clarifier which were operated in parallel, followed by gravity filtration, ion exchange, and cartridge filters. This system was monitored using conventional turbidity and silt density index measurements. Since neither of these parameters provides an adequate characterization of suspended particles, the techniques were supplemented with measurements of direct particle size distributions throughout the pretreatment system.
During the summer and fall of 1985, the Demonstration Facility successfully removed particles from drainage waters. The reactor clarifier, operating at alum doses of 50-75 rag/1 and cationic polymer doses of 4 rag/l, was able to consistently lower drainage water turbidities from the 1-10 NTU range down to 1.0 NTU and could dampen out fluctuations in turbidities observed in drainage waters during high winds. Filtered reactor clarifier effluent was typically 0.1 NTU and its silt density index was usually below 5.0. Particle size distribution data confirmed that micrometer and larger sized particles were effectively removed.