home > why choose koi? > about us > our products > our services > partners & customers > technical info > warranty > jobs & careers > contact


  The Koi wastewater treatment system is a specially designed recirculating trickling filter (RTF) utilizing a fixed film biological process. The filter consists of random packed plastic media which provides void space and surface area for a zoological slime (composed of bacteria and other biota) to develop on the stationary surfaces. The void space allows air and wastewater to pass and trickle through the media and come in contact with the slime. The microorganisms utilize the dissolved oxygen and the organic material in the wastewater for metabolism.

The Koi RTF can be considered as either a standard-rate or a high-rate biological filter. It is used to reduce the BOD in septic tank effluent wastewaters. It is generally recognized that a properly designed “Biological Filter” is more capable of coping with highly variable loads and the operation and control is simpler than with most other processes.

A standard-rate or a high-rate trickling filter is described as a packed media bed covered with biological growth called slime or biomass over which wastewater is passed. As wastewater flows over the slime some biosorption and coagulation of suspended and colloidal matter occurs. Soluble organic matter and oxygen diffuse into the slime where biological oxidation results in the production of carbon dioxide, water and metabolic by-products. Additional new slime material is synthesized. An anaerobic film layer is established which depends on the depth of oxygen penetration. Reduction of BOD is related to the available biologically active slime and its time in contact with the wastewater.

Plastic filter media such as those used in the Koi RTF are designed to promote efficient laminar flow across a large specific surface area. This enhances the contact time and ensures a greater slime surface area per unit volume. A high void area is provided for adequate oxygen transfer and alleviation of plugging problems.

It can be concluded that the Koi RTF is considered and/or can be compared to an “aerobic attached-growth or fixed film biological nutrient removal” treatment process. Further it should be recognized that the efficiency of the biological treatment process to promote decomposition of wastes is based on the control of the environment within the Koi for optimum growth of the microorganisms involved.

Although the Koi is a biological filter performing biological treatment by well-known processes, the Koi is unique in that the parameters that affect performance have been designed to be adjustable. This ability to optimize the operation of the Koi ensures an economical, efficient and reliable wastewater treatment facility.




Terms of Use •  Privacy Policy  •   © Koi Environmental Inc. 2009