Erosion Control supply a number of different products for coagulation and flocculation of suspended solids. We have expertise in all areas of flocculation ranging from sediment retention ponds and common clays to peats and other nasties you may wish to remove from your water.
Polyaluminium chloride (PAC) is the go to chemical in New Zealand currently for use in rainfall activated systems on earthworks sites. PAC is a strong coagulant which uses aluminium ions as its active ingredient. Clays are generally negatively charged with clay particles repelling other particles (two negative charges will repel each other like two magnets) preventing settling. Aluminium ions are positively charged. When the aluminium reacts with the clay these charges neutralise each other leading to a electrically neutral particle. The particles will no longer repel each other and will therefore settle. Mixing is useful to get efficient settling as the particles will collide and bind to each other, causing flocculation to occur with the generation of "flocs" which are larger and heavier than the individual particles.
Alternative chemicals such as PolyDADMAC have also proven useful on difficult to treat clays and soils. PolyDADMAC is an organic polymer which acts as both a coagulant (it carries a positive charge) and a flocculant with its long polymeric chains able to bind multiple particles together.
Erosion Control has recently teamed up with Vital Industries to bring a new alternative flocculation product to the market. EcoSuperfloc is a Chitosan based flocculant and is a greener and more environmentally friendly alternative to PAC. Chitosan is produced from Chitin which is found in the shells of crustaceans and as such is produced from a renewable resource.
Erosion Control is also able to offer any support in regards to chemical flocculation in any industry. Give us a ring if you have any questions.