Electrocoagulation Technology Keeps Site In Operation, Meets Regulatory Requirements
An oily water treatment facility on the Sabine River near Port Arthur, Texas, was not in compliance and had a large inventory of wastewater on site. Gulf Coast Environmental, LP had been operating a chemical/biological based water treatment facility. The plant received water from barge washout, bilge pump-out, tank truck washout, petroleum production, and oily water from spill cleanup. Over 900,000 gallons of wastewater were on hand and regulatory agencies were threatening when the facility contacted Ecoloquip, Inc. of Houston to assist.
Samples from eight of the 23 storage tanks were collected for evaluation at Ecoloquip's treatability lab. Each sample was different in appearance and chemical composition. The facility did not control acceptance and wastewater was mixed into a number of holding tanks. Each sample was tested for treatability using the bench scale JOULE EC» electrocoagulation device.
All eight samples displayed a positive reaction to the electrocoagulation technology. The JOULE EC was effective at releasing the organic material and the suspended solids, leaving a clear aqueous layer. Subsequent chemical analysis indicated >90% reduction in organic contamination and >95% reduction in the concentration of toxic metals.
The water quality from the treatability tests was beyond expectations and personnel from the facility and the regulatory agencies were skeptical. Ecoloquip provided a trailer-mounted pilot test unit to process wastewater on site. After several delays due to schedule conflicts from the interested parties, the unit began processing wastewater within 30 minutes of arrival. Storage tanks were selected at random and 1,000 gallons were treated from each tank. The processing rate was between 15 and 20 gallons per minute.
Only two tanks were tested per day due to the need for free-oil skimming, coarse solids removal and pH adjustment prior to treatment. On-site testing confirmed that the JOULE EC technology was meeting or exceeding the target quality limits for COD, TSS, oil and grease, and turbidity. Laboratory testing confirmed the efficiency and effectiveness of the technology on the ten tanks sampled and processed. For future processing, the COD, pH, and turbidity were selected as indicator parameters by the owner, operator, regulators, and Ecoloquip.
The owner contracted with Ecoloquip and its agent ENSERCO, Inc. for the use of a portable JOULE EC electrocoagulation unit. Ecoloquip also provided a portable bench-scale testing unit to evaluate each storage tank prior to treatment. In addition to the electrocoagulation unit, two API separators, an oil water separator, an inclined plate clarifier and a pH controller were used to produce treated water. ENSERCO provided trained technicians and operators for the project. One technician and two operators were necessary to provide 24-hour operation of the JOULE EC-based system.
The equipment was mounted on a 28-ft. trailer and delivered to the site. The owner provided electrical power through a 220VAC, 60 amps circuit. Within one hour, the treatment plant was operational and wastewater was processed from the first storage tank.
Continuous sampling and testing verified the effectiveness of treatment. Treated water was to be discharged to the biological treatment unit at the facility. The added treatment was necessary for removal of the remaining organic compounds. This unit was not operational at the time due to the loading of waste material prior to the arrival of Ecoloquip.
In order to maintain the schedule, an Ecoloquip Bioreactor was provided that was able to breakdown the remaining organic materials within the 12-hour retention time. The product was discharge quality water significantly below the permit requirements. Standard facility operation required as much as 18 days for complete processing of wastewater through the chemical/biological treatment units. Ecoloquip had a complete, continuous flow treatment plant on site within one week of mobilization. Wastewater was processed at the average rate of 25 gallons per minute.
During the third week of operation, the owner declared bankruptcy and the project was terminated. Ecoloquip had processed and discharged over 300,000 gallons of wastewater at a cost to the client of $0.05 per gallon plus electricity. Alternatives for wastewater disposal were priced from $0.08 to $0.18 per gallon. After Ecoloquip moved off site, the U.S. Coast Guard and the Texas Natural Resources Conservation Commission pressured the responsible parties and the Bankruptcy Court to remove additional wastewater from several tanks. The wastewater was transported to another facility at the cost of $0.25 per gallon plus transportation. Sludge also was removed for disposal at a RCRA TSDF at a cost of $400 per ton plus transportation, and storage tanks were dismantled or removed.
The facility was later purchased from bankruptcy with permits intact by EcoWater, L.L.P. Michael Laws, president of EcoWater, said, "The facility came with hundreds of thousands of gallons of contaminated water ranging from extremely contaminated to fairly clean. There was no inventory, no records of origin, and no information of contamination. After we acquired the site, several individuals expressed concern, stating that their knowledge of the site lead them to believe that it would wind up under Superfund. I was informed by a representative of the TNRCC that the TNRCC had anticipated a cleanup cost of between one and two million dollars."
EcoWater became aware of Ecoloquip due to ongoing operations in the United Kingdom and from the site history. Ecoloquip was contracted to provide the treatment unit for remediation and to design a full-scale treatment system capable of processing 100,000 gallons per day, expandable to 300,000 gallons per day. Ecoloquip immediately returned the trailer-mounted JOULE EC treatment system. Staff and associates of Ecoloquip devised a cleanup protocol and reconfigured the available facility equipment to optimize on-going treatment.
Ecoloquip provided training for EcoWater personnel and they operated the transportable unit with the assistance of a technician. The biological treatment unit at the facility was restructured and made operational as a bioreactor. Using the electrocoagulation technology and the equipment available, inventoried wastewater was processed at rates of up to 50 gallons per minute. The results of treatment were significantly better than required by permit. Laws wrote, "These impossible circumstances may have created the best testimony of your technology. The [JOULE] EC, in reality, acted as an equalizer, removing 70Ü99%+ of the contaminants and creating a clean, stable, safe flow of water very treatable with a biological system for polishing."
Ecoloquip delivered a permanent electrocoagulation unit to the EcoWater facility last month. In addition, EcoWater has selected the URRICHEM¬ chemical fixation technology, offered through Ecoloquip, to process the solids removed from the wastewater - rendering them a nonhazardous industrial waste.