The Project
Theia was contacted by a longtime customer about a site that they were operating. This customer, an environmental consultant, had been operating a gas station remediation site in central NJ for a number of years. The customer already had a dual phase extraction system on site with groundwater treatment to remove BTEX compounds and some of the MTBE
Recently, the customer had been informed that, in addition to the GRO compounds it had been treating for, they would now have to start treating for TBA ( tert butyl alcohol) as well as zinc. As with most systems operating in the northeastern US, iron was also an issue. This iron was creating maintenance issues for the existing treatment system which had an air stripper and carbon treatment. The air stripper needed constant maintenance and was hard to clean.
System Specifications
Theia designed and implemented a treatment system that meshed with the existing treatment system to provide both pretreatment as well as post treatment.
- Iron Oxidation and removal was added – this design utilized an existing inlet tank and Theia’s Oxygenator system to directly oxidize the iron in the water.
- A dual pH adjustment system was added to allow the system to operate within the correct range for metals removal as well as for the MTBE/TBA treatment
- A precipitating agent was added to take any zinc out of solution.
- The filtration system was upgraded to include automated sand filters. Water from the oxidation step ( put inside the container) was pumped over to the filter system installed in one of the skid buildings. A polishing step of cartridge filters was installed as polymer injection was not permitted on the site.
- From the filter system, water was pumped back to the air stripper system and carbon vessels in the existing container.
- A media vessel filled with Theia Water’s ZM media was added to assure removal of any remaining zinc.
- The final step of the process is a two stage biological treatment process designed specifically for the site.
- Stage one is a MMBR which utilizes the Oxygenator aeration system for high efficiency aeration as well as the right amount of mixing and turning of the packing to maximize efficiency. Stage one is intended to remove the mass of the TBA with any existing MTBE.
- Stage two is a biotrickling filter utilizing a unique structured growth media. This stage was selected for a polishing step
Many challenges faced the design and implementation of the upgrades. The system had to be tied into an existing container system in different locations and also had to mesh with the existing ( older) control system. Space was also very tight on the site and moving any large structure into the existing space was not possible. Thus, the system had to be built in multiple parts and designed to be tied together quickly and easily in the field. Influent levels of MTBE were as high as 30 mg/l and TBA as high as 45 mg/l.
The system was installed into two(2) small skid buildings and shipped to the site along with three(3) Polyethylene tanks. Theia worked with the customer, supplying design drawings and installation oversight as well as start up. Together, we were able to get the system up and running and performing. Continued difficulties with the existing system and operator issues created more downtime than was typical but the Theia provided system ran well and exceeded the performance goals for the site.
Results
The system removed the iron, increasing the run time for the existing system. additionally, the zinc and the TBA was brought to within acceptable discharge levels.
