Challenge

The Duckwall Pooley Fruit Company is one of the largest fruit packagers in the Hood River Valley in Oregon, packing approximately 1.8 million bushels of pears annually.  To improve their operations and lower their costs, the company implemented new measures to optimize the rinse water usage in the pear packaging line. After packaging of the fruit, collected water is chlorinated for disinfection and treated with coconut shell based activated carbon for residual chlorine removal.

Although reducing the plant‘s water requirement, the water contained residual sediment, pear skin and fruit, which caused bioactivity on the activated carbon media. Sulfur compounds in the water were reduced and formed hydrogen sulfide (H2S), an undesirable “rotten egg“ odor which impacted the packaging plant and facility workers.

Solution

To address the H2S formation issue, the customer contacted Siemens Water Technologies, who recommended the use of their new AquaCarb® 1240CAT catalytic carbon. Catalytic carbon promotes the oxidation of any H2S in water to non odorous, harmless sulfur species.

To pilot test the solution, the customer purchased Siemens‘ AquaScrub® 200 drum adsorber containing 200 pounds of AquaCarb® 1240CAT catlytic carbon for two weeks. A slip stream of effluent water from the existing Siemens‘ PV® 1000 carbon adsorbers was run through the drum adsorber. Based on the results of this study, the customer elected to switch to the catalytic carbon as a final polish step after initial GAC treatment for chlorine reduction.

Results

In July 2010, Siemens Water Technologies performed a turnkey exchange of the existing carbon beds, placing 1000 pounds of AquaCarb® 1230C coconut shell carbon in the lead adsorber for residual chlorine removal, and 1000 pounds of AquaCarb® 1240CAT catalytic carbon in the lag adsorber for treatment of H2S. The results have been exceptional with no H2S issues occurring in their facility, improving the work environment and eliminating worker complaints.

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