Removing Surfactants to Decrease Discharge Costs

The Situation:

The wastewater generated by an industrial client was causing problems at the publicly owned treatment works (POTW) where it was being discharged.

This water’s high concentration of surfactants and other organic chemicals was causing intensive foaming in the pump stations and plugging the air relief valves in the force main.

The client was going to be prohibited from discharging to the POTW unless it could pretreat the water to remove the surfactants, chemical oxygen demand (COD), and suspended solids.

The Costly Initial Client Response

The client determined that dissolved air flotation clarification could remove suspended solids and some COD and surfactants from the water.  The pilot study they performed to define the feasibility of the idea revealed that the process might work, but it would be plagued with housekeeping, reliability, and maintenance issues.  A cost estimate indicated that the process would require a capital expenditure of $3.8 million.

The More Affordable Solution

Recognizing the impracticality of the conventional process, Mr. McKinnon researched and identified an alternative process for removing surfactants to decrease discharge costs.  His proposal modified the nature of the wastewater so that it was acceptable to discharge the pretreated effluent to the client’s own wastewater treatment plant and no longer rely on the POTW.  This alternative process used a proprietary adsorbent/polymer product to adsorb the surfactants and remove their foaming tendency.  The client could then remove the solids in their primary clarifier and dewater them with its other wastewater sludge.  They would no longer need to discharge into the POTW at all.

The Result

Following a trial that verified the effectiveness of Mr. McKinnon’s proposal, the client constructed the new system and disconnected from the POTW.

The alternative process cost $1.5 million – a capital savings of $2.3 million as compared to the initial plan.