Converting Sugar-Bearing Wastewater Into A Usable and Profitable Product Cuts Water Usage

Management at L&S Sweeteners, Leola, PA, knew what they were doing when they approved the installation of a 6500 gpd distillation system designed to convert their sugar-laden wastewater into reusable and saleable products. Instead of dumping their wastewater into the sewer system and paying the high county surcharge, they are conserving water, cutting costs and helping to improve the environment.

Installation Photo of Castion 6500 gpd system at L&S Sweeteners showing tanks, piping and Vanton ANSI thermoplastic pump that has been operating trouble-free for the past two years.

The unique wastewater recovery system they chose was custom designed, engineered and installed by Castion Corp. of Ludlow, MA, a firm actively involved in developing environmentally sound systems that minimize or eliminate manufacturing and process industry wastes by recovering valuable components, restoring depleted elements or converting the waste into usable products.

The award winning system conserves 6,000 gallons of water per day, recovers close to 100% of the sugar, and provides a liquid/solids product that is sold to farmers for use with animal feed mixes.

Schematic of Flash Distillation Process

At the start of the recovery distillation process, the wastewater is preheated in a concentration tank to reduce biological activity and degas carbon dioxide, then drawn by vacuum into a process vessel for further degassing.

The heated and degassed wastewater is pressurized and heated to 140F, then sprayed into the process vessel. The flashed vapor is condensed, the distillate is extracted and treated to remove organic carryover or odor. The final distillate is pumped to a cooling tower tank and consumed as make-up.

Nonflashed portions are mixed with new feed wastewater and recirculated through the process, then discharged to storage for sale as animal feedstock enhancement.

Clean distillate water is also recycled to the company's truck-washing facility, thus eliminating BOD sewer discharge fees.

As with most fluid handling systems, particularly those requiring dependable transfer and recirculation of aggressive solutions, pump selection was critical.

In writing the specifications for pumping systems, Castion designers called for a pump that conformed to ANSI B73.1 process pump standards with all wetted components of corrosion resistant nonmetallic thermoplastic materials suitable for handling the acidic and abrasive sugar-laden wastewater at temperatures of 120F at a flow rate of 100 gpm against a 100' TDH.

Vanton's ANSI thermoplastic pumps were selected for the project.

The pumps feature casings, casing covers and flanges that are injection molded homogeneous polypropylene. The semi-open keyed impeller is of the same material, injection molded with an embedded dynamically balanced stainless steel insert.

The stainless steel shaft is isolated from the fluid by a thick-sectioned thermoplastic sleeve made of Kynar polyvinylidene (PVDF). And, the double mechanical arrangement uses a Viton 0-ring for the inner seal and silicon carbide for the rotating and stationary components.

The pump's casing and flanges are metal armored so that the pump can sustain the same nozzle loadings as metal pumps.

"We are pleased that this waste recovery system received special 'Good neighbor' recognition from the Lancaster County Emergency Management Agency, and our personnel take pride in the fact that we are conserving about 6000 gallons of water per day, cutting costs and helping the environment," said Shawn Sensensig, Operations Manager, L&S Sweeteners.