The ALKOTA Sand Filtration Systems are specially designed for use with high pressure washers and steam cleaners. Dirty, oily water is brought into the coalescing tank from the sump. The waste stream twists through the oil-attracting coalescer plates. As the oil droplets and sediment hit the plates, they combine with other droplets forming larger globules and speeding up the separation process. Sediment is heavier than the waste stream so it drops through the plates, collecting in the chamber at the bottom of the coalescing tank. Free oil rises to the top of the tank where it is removed by the adjustable oil skimmer and flows from the coalescer tank into a suitable container. The partially clarified waste stream falls under gravity to the treatment tank.

From the treatment tank, the waste stream is continuously pumped through the sand filter and back to the process tank. As the water circulates, the sand filter removes most of the remaining sediment. As the water in the process tank recirculates through the filter, it becomes cleaner and cleaner. When water is required for cleaning purposes, water is sent from the treatment tank through the final polishing filter. This filter takes out contaminants down to 20 microns in size. As this system does not remove emulsified oils, chemicals, or other solubles it is recommended that fresh water be brought in for rinse operation.

Ultrafiltration or activated carbon canisters are available if emulsified oils and chemicals do need to be removed.