The Mobile Organic Biofilm System, MOB System is an innovative new patented treatment system developed by RF WasteWater.

This system uses a mobile organic biofilm carrier which allows operators to achieve target effluent objectives with lower capital costs, shorter start-up time and lower operating costs resulting in an economically and environmentally superior treatment option.

The Mobile Organic Biofilm (MOB) process provides wastewater treatment plant (WWTP) owners and operators with an economical means of expanding the biological wastewater treatment capacity of a facility by means of:

a) Enacting additional treatment capacity within existing bioreactor volume.

b) Allowing for the implementation of a hybrid process while using fine-bubble air diffusers.

c) Providing an operational platform that is essentially the same as suspended growth processes (e.g., conventional activated sludge and biological nutrient removal). Contemporary hybrid systems, such as the integrated fixed-film activated sludge (IFAS) process, make use of submerged free-moving plastic biofilm carriers. These systems require the replacement of diffuser grids with stainless steel medium-bubble diffusers and construction of a wall that integrates stainless steel screens for retention of the plastic biofilm carriers. The plastic biofilm carrier volume can approach 65% of the empty bioreactor and with its high cost and massive volume, can become an operational challenge when maintenance is required in the bioreactor.

The MOB process functions under the premise that hydraulic retention time, solids residence time, and submerged free-moving biofilm carrier retention time are independent and subject to operator control. The biofilm carriers are separated from waste activated sludge (WAS) prior to being reintroduced to a sidestream treatment reactor or to the head of the secondary treatment system. The organic biofilm carrier has been selected to create a biofilm that is robust, resilient, and acts as an effective base for the development of the biological community that drives this technology. Storage of replacement carriers, the biofilm carrier/WAS separation units and units for pumping the carriers back to the treatment system can be modular and are external to the bioreactor. Therefore, construction is inexpensive and non-disruptive to existing operations. The process dynamics create niche biofilms that are uniquely composed to treat the site-specific contaminated water stream.

Our MOB process developers have created a market-ready process subjected to extensive research and development efforts. This multi-year research includes data from exhaustive laboratory studies and 2016 will yield data from our initial full-scale installations. We have also developed – along with a team of global leaders – a new mathematical model capable of modeling the MOB process which has been incorporated into leading commercially available WWTP simulation software.


  • Capacity upgrades in existing footprint
  • Quick upgrade timelines
  • For new plants, especially those requiring a small footprint and easy operation
  • For BOD/COD and nitrogen removal
  • As a high loading system in front of existing biological treatment
  • To increase the amount of nitrifying bacteria in existing activated sludge systems using the unique natural biofilm carrier in a hybrid plant to meet ammonia limits
  • To implement post-treatment at existing plants for process improvements
  • To greatly improve shock-loading capabilities

Technology Advantages

  • Stable Process
    • Resistant to incoming toxic compounds
    • Able to withstand lower temperatures
  • Increased nitrification
    • Increased autotroph population on high surface area media allows indigenous nitrifiers within the MLSS to increase overall nitrogen removal capacity
  • Improved sludge quality
    • Low suspended sludge age along with large floc sizes developed on the natural biofilm create increased settlabilty and reduced filamentous growth
  • Biological phosphorus removal
    • Media being circulated throughout anoxic, anaerobic and aerated zones allows for diverse growth of biological populations on the bio media resulting in increased bio-p removal

End User Benefits

  • Cost Effective
    • Low media cost and reduced capital equipment requirements provide the most cost-effective fixed film media system on the market
    • Lower DO environment results in lower operating costs
  • Small Footprint
    • High surface area media results in minimal space to implement the MOB technology
  • Low Maintenance
    • Self-regulating robust process requires minimal adjustments to variations of incoming contaminants resulting in minimal operator supervision and adjustments. The lightweight, and cost effective media also makes servicing mixers and blowers much simpler than competing MBBR and IFAS technologies
  • Expandable
    • Progressive addition of media can easily grow with increased incoming substrate without the need for additional tankage and equipment
  • Environmental Impact
    • Replaces plastic media with an inexpensive natural, renewable, biofilm carrier material
    • Reduces electrical consumption and negative environmental impact from plant operations

“After a full on-site evaluation, RF WasteWater changed my full chemical program, eliminating several chemicals, lowering cost, reducing operator headaches, and increasing my plant’s treatment efficiency.”

Operator Testimonials