AlumCAS™ is a coagulant aid for water and wastewater treatment. It improves conventional water treatment plants performance to:
- Achieve filter effluent turbidity limits of less than 0.10 NTU all the time;
- Reduce alum consumption;
- Comply to drinking water aluminum residuals of less than 0.100 mg/L all the time;
- Improve clarifier effluent turbidities;
- Increase the removal of DBP precursors, thereby lower chlorine demand when pre-chlorination is not used.
The coagulant aid AlumCAS™ is a cationic aluminum-silica (CAS) nanopolymer. It is a “bridging-type” polymer that increases the size and density of the flocs to make the flocs settle faster and produce a low turbidity clarifier effluent.
AlumCAS™ can be used with any aluminum or iron based coagulant, and it works best with alum (aluminum sulfate) as the primary coagulant. AlumCAS™ is usually made as a 2% SiO2 (silica) solution. Presently, it is not advisable to make a more concentrated form due to its high reactivity towards itself (self-polymerization), impurities in water and aluminum.
As a coagulant aid, inorganic silica is safer health-wise than synthetic organic polymers for drinking water production. In the process of finding an optimum dose of AlumCAS™ for the plant, it is recommended that the dose is express as a volume ratio of the as-received products (coagulant or coagulant aid).
This technique will simplify the transfer of the optimum dose found in a “jar” test to the plant. For example: if the optimum dose found in the jar tests are: 250 uL of AlumCAS™ and 50 uL of Alum, then the dose ratio is 250/50 = 5. Usually, the optimum ratio lies between 3 and 5.
In the above example, the dose of alum is 32 mg/L dry alum, and that of AlumCAS™ (2% SiO2) is 5 mg/L SiO2.
- Improves the coagulation and flocculation process forming large and heavy flocs.
- Filtered Water Turbidity less than 0.100 NTU similar to that achieved using membrane filters but without its disadvantages.
- Compliance to regulatory guidelines for aluminum residuals in drinking water.
- DOC removal.
AlumCAS™ is a coagulant aid for water and wastewater treatment. It improves conventional activated sludge plant performance by providing:
a consistent way of controlling the removal of Phosphorus, BOD, and Suspended Solids in the primary and/or secondary clarifiers;
a means of preventing “bulking” events at the secondary clarifier, and;
a means of upgrading secondary clarifier effluent water quality to tertiary quality.
Unlike iron coagulants, the performance of AlumCAS™ is consistent and predictable. Plant operators would be able to run the primary clarifier in NORMAL mode or on Chemically Enhanced Primary Treatment (CEPT) mode or in-between mode by increasing or decreasing the dose of AlumCAS™ added to the raw sewage. Automating or Real Time Control of chemical addition is simplified. The same is true when AlumCAS™ is used at the secondary clarifier. Increasing or decreasing the dose will control the quality of clarifier effluent up to tertiary effluent quality.
The coagulant AlumCAS™ is a cationic aluminum-silica (CAS) nano-polymer. It is a “bridging-type” polymer that increases the size and density of the flocs to make the flocs settle faster and produce a low turbidity clarifier effluent.
Improves the coagulation and flocculation process forming large and heavy flocs.
Consistent and predictable performance.