Potable Water Treatment
Today the potable water industry uses polyacrylamides, polyamines and polydadmacs in clarifying and dewatering processes. Several years ago only inorganic coagulants were used in the clarifying processes although today the use of organic coagulants such as polyamines and polydadmacs often in conjunction with flocculants have totally or partially replaced the organics. The advantages of the organic coagulants against the inorganics are as follows:
Improved performance at dosages of 5 to 10 times lower than organic coagulants
Minimises the volume of sludge generated saving on sludge dewatering and deposal costs.
Improvements in solid / liquid separation times therefore demanding less thickening capacity and reduced capital investment.
No effect on the pH of the treated water.
Operates over a broader pH range.
No addition of soluble metals such as Al and Fe.
The clarifying processes will include thickening /settling, flotation and filtration.
In most cases the addition of a flocculant after a coagulant is desired ensuring the flocs produced are much larger increasing the rate of solid / liquid separation and clarity of the supernatant. Adding a coagulant (organic / inorganic or a blend of the two) to destabilise colloidal suspensions followed by the addition of a flocculant to bridge the colloidal particles creates larger "flocs" which will then settle rapidly leaving a clear supernatant. Following settling, dewatering of the sludge is normally carried out by use of a belt filter, filter press or a centrifuge. Laboratory test work is recommended for product selection before progressing to plant trials. Please see your TianFloc representative for assistance with lab testing procedures and product selection.
