Fiber Filter for Pectin Recovery

July 26, 2005

An interesting application for the Fiber Filter has evolved over the last few years. The project started as a rental at a plant whose wastewater treatment plant (WWTP) was causing excessive odor.

The customer's operation involves receiving fresh lemon peel as a raw material, washing the dissolved solids (sugars) from the peel, and then extracting pectin from the washed peel. The precipitated pectin is dried and sold, in powder form, as a food ingredient.

The WWTP load came principally from the dirty water from the peel washing system. This water contains both dissolved solids and suspended particles of lemon peel. The initial project involved using a Model FF-12, with coarse 190 micron sleeves, to filter this wastewater.

The project was a success. Odor from the WWTP noticeably decreased after filtering out the suspended solids. This is true even though most of the solids are dissolved, so they pass through the Fiber Filter.

At first, the solids sludge from the Fiber Filter were trucked to a remote site. Soon, however, it was determined that this sludge contained valuable pectin of good quality.

For the next season, a second Fiber Filter was added, and the sludge from the machines was pumped back to the peel wash system. In this manner the pectin was recovered.

Today, a third Fiber Filter has been added. The system has been further refined by pumping the sludge from the three machines directly to the acid/alcohol plant. There it is mixed with the washed peel, and the pectin is extracted. (They found that if this sludge was added back to the washing system, the screw presses did not seem to work correctly.)

Issue 163