APF® - Aquaculture

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%.

• 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.

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.

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.

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.