What is APF?
APF® is a multi-spectrum coagulant and flocculant that removes pollutants from solution and flocculates fine suspended solids, such as skin cells and bacteria, into large particles that are easily removed by AFM® (Activated Filter Media).
No single flocculant or coagulant can remove everything from the water. APF® is a precise combination of 6 different electrolytes and polyelectrolytes to cover the widest possible range.
Dissolved constituents of water make up 80 % of the oxidation demand and suspended solids around 20%. Everything that is filtered out does not need to be oxidised.
When the correct flocculation is used in combination with AFM®, oxidation demand is reduced and RedOx potential increases. In chlorinated systems unwanted disinfection by-products are reduced by up to 80 %.
Your benefits at a glance:
- For sanitary security
APF® is required to optimise removal of bacteria, parasites such as Cryptosporidiium, Giardia and Mycobacterial parasites (Candida, Aspergillus etc).
- Economic and environmental
Improved filtration reduces oxidation demand by up to 80 %. It also means there will be fewer disinfection by-products formed. Operating costs will be lower and there will be less of an impact on the environment.
- For chlorine-free treatment in biological systems
APF® is an important aid in chlorine-free water treatment of aquatic mammal LSS in combination with AFM® filtration.
What is coagulation and flocculation?
Coagulation; is the process of dragging chemicals out of solution to form colloidal suspensions of small particles. In order to make coagulation work, APF® must be mixed instantly and aggressively with the water, this is why we designed the ZPM. If a ZPM is not used, the coagulation stage is missed, organics will remain in solution and APF® jumps to flocculation.
Flocculation; is the process of bringing colloidal suspensions of small particles (organic detritus, bacteria and parasites) together to form larger flocs that can be easily removed by AFM®.
APF® imparts a positive charge to particles that are then attracted to the negatively charge surface of AFM®. Flocculation takes several minutes and the particle floc is very fragile, so the water must not be subjected to aggressive agitation.
What performance can you get using APF®?
AFM® filter media provides nominal filtration down to 5μ (at 20m/hr filtration velocity). When APF® is used, nominal filtration of 0.1μ is reached, so parasites such as Vibrio, Cryptosporidians, Giardia and Mycobacteria (Candida, Aspergillus) are removed from the water. APF® also contains NoPhos to remove phosphates from the water. If there are no dissolved phosphates, then bacteria and algae simply cannot grow. The improved filtration performance offered by APF® not only makes LSS safer and healthier, it can reduce chemical oxidant demand by up to 80 % and help protect our environment.
How to use APF®?
APF® should be dosed into the water at a constant very slow flow rate. 0.5 - 1ml. of APF® is injected per m3 of water circulated through the filters. Only peristaltic pumps such as the Dryden Aqua flocculation pump should be used. For best results, APF® should be injected directly via a Dryden Aqua ZPM static mixer, located between the pumps and the AFM® filters.
The pH should be neutral, alkalinity should be greater than 30ppm.
Dosage Monitoring and Control
Once commissioned, dosage can be monitored by weekly Aluminium analyses using Al test reagents in a standard spectrophotometer. Drinking water guidelines allow a maximum Al concentration of 0.2 mg/l.