Promising New TFR Bioreactor for Wastewater Treatment
As industry continues to embrace technologies that are designed either to save water or to treat process water for multiple uses in industrial applications, new treatment challenges arise. Bowing to stricter regulations and high cost pressures, most industrial users now choose to treat highly loaded effluent in-house before releasing it for further treatment or discharge. A new twist on biological wastewater treatment from German expert DAS Environmental Expert Dresden promises to speed up treatment times and lower investment and operating costs.
Aerobic Biological Wastewater Treatment
According to Dr. Lutz Haldenwang, an expert on biological wastewater treatment based at DAS headquarters in Dresden, Germany, the choice of in-hause treatment systems is no longer the decision it once was. Industry is quickly abandoning high-priced chemical treatment systems in favour of biological treatments that rely on naturally occurring bacteria to degrade and treat influent before it is released or reused. But not all biological systems are created equal, says Haldenwang, referring to the choice between systems using an anaerobic or aerobic approach.
Anaerobic systems use bacteria that require no oxygen to degrade effluent before release. While effective, anaerobic systems can be expensive to use and hard to stabilize. On the other hand, aerobic systems have their own set of issues. Because the biological bed in most aerobic systems is submerged in water, the cost of infusing fresh air or oxygen supplies into the bioreactor usually means prohibitively high design and operating costs.
|Simple principle of aeration|
|Made of Polyethylen|
DAS has solved the aerobic conundrum with a proprietary TFR Bioreactor in which the microorganism bed is now in a reaction space without water. Instead, air is infused upwards from the bottom of the reactor while water trickles down from the top. In this aerosol-like environment, microorganisms quickly thrive on the bed matelial, which is made of low density, finely grained, and highly porous plastic.
In fact, says Haldenwang, by combining the reactor's highly active atmosphere and short mass-transfer paths with an appropriately selected bacterial population, the TFR design achieves very high levels of degradation efficiency. Further, due to the low density (0.02 g/cm3) of the bed's carrier material and the loose, granular layering it provides, pore spaces in the bed condense only slowly, even when microorganisms are present. Compared to other systems, only a small proportion of bio-sludge occurs, and this can removed by simple automatic regeneration and regular rinsing.
Not surprisingly, the DAS TFR Bioreactor made a big splash at several recent trade shows. The most recent of these was TERRATEC 2007, held during March in Leipzig, Germany. The TFR Bioreactor impressed fairgoers not only with its effectiveness but also with its overall low cost profile. The simple operating principle, simple design and the use of modular, wear-free plastic components keep investment costs for the reactor low and ROI high, even for a relatively small plant.
DAS says its TFR Bioreactor is an ideal solution wherever highly contaminated organic wastewater needs to be treated in order to achieve a quality suitable for indirect discharge, direct discharge or multiple uses. Examples include the treatment of municipal wastewater, all sectors of the food industry, as well as all other major industrial and agricultural sectors. The new technology is already implemented at fifty of the reactors at locations in Germany, the Czech Republic, Switzerland, Greece, Vietnam, and Aruba, where the reactors are used to treat effluent before it is released to water purification plants for further treatment or discharged into a water resource.