New Media Key in Wastewater Plant Rehab

NSW Environmental Systems and the company's PVC sheet media are helping one Mexican city put a stalled wastewater treatment plant on line.

The Tuxtla Gutierrez Wastewater Treatment Plant in the state of Chiapas, Mexico, was originally designed to work with two rock trickling filters but was never placed on line. The Mexican government approved rehabilitation and upgrade of the plant, to include a new trickling filter, for a total of three trickling filters. The complete treatment layout includes screening, followed by two primary clarifiers, followed by three trickling filters, followed by two intermediate clarifiers. Total throughput of the upgraded plant will be 14 mgd.

The NSW Dura-Pac PVC Sheet Media is designed for trickling filters, submerged fixed beds and oil/water separators. The media is supplied in crossflow or vertical flow modules, with specific surface areas of 30, 42 and 60 ft2/ft3. Dura-Pac systems are capable of producing effluents able to meet more stringent BOD and nitrogen limits. The average influent BOD at the Chiapas site is 300 mg/L. It is estimated that, with the upgrade, the plant will meet effluent limitations currently at 60 mg/L of total BOD.

The Dura-Pac media may be shipped as sheets or preformed modules. To save freight cost for the Chiapas client, NSW will ship the media in sheets to be assembled into modules at or near the job site. The entire 106,685 ft3 of XF30 crossflow media for this installation will be shipped in four trailer loads. An estimated 37 loads would have been required to ship the media in preformed modules.

In addition to providing the media, NSW staff will train the project contractor's personnel, so they may properly assemble the sheets into modules. Training will be provided at the production plant for the media, located in North Carolina. NSW offers training and other technical assistance for projects like the Chiapas installation. During its 20 years of service to the wastewater industry, the company's Environmental Systems division has provided products and technical support for more than 300 trickling filter installations worldwide.

Dura-Pac is one of four plastic trickling filter media systems available from NSW. The company's complete product line includes Sessil® Polyethylene Strip Media, Bio-Pac SF#30 Polypropylene Random Media, Kompakt extruded tubular block media, Nor-Pac tower packings, Copasacs screening systems and N-Dec underdrains. A new NSW Vertical PVC media for trickling filter applications is expected soon.

Booth 1449