
A new project by SCHOTT’s partner Clearas Water Recovery is a real big one. The planned 4 million gallon per day wastewater nutrient recovery solution marks this as the first large scale commercialization of photobioreactor technology for nutrient recovery – and uses glass tubing. The customer South Davis Sewer District will apply Clearas’ solution to reduce nutrients that contribute to algae blooms in waterways.
The Advanced Biological Nutrient Recovery (ABNR™) system has already proven its reliability in numerous successful pilot demonstrations. The South David Sewer District is the first commercialization of ABNR™ and is a landmark in the algae and wastewater treatment industries. Current regulations suggest more projects like this may occur – as facilities across the U.S. upgrade their infrastructure to comply with the sophisticated U.S. Clean Water Act requirements. High-end glass tubing and Clearas’ ABNR technology – both establish a working model for addressing the upcoming challenges for municipal wastewater treatment plants – in the U.S. as well as globally.
Traditional wastewater treatment plants rely on chemical flocculation or deposition to remove phosphates and nitrates. In many cases, these methods leave trace amounts. Clearas photobioreactors pump water that has already undergone initial treatment through DURAN® glass tubes. Algae within the tubes feed on the residual amounts of nitrates and phosphates before discharge into public waters. Using Clearas ABNR, phosphate levels typically fall below detectable limits and nitrate levels will fall well below the 1 milligram per liter levels allowed e.g. by the Clean Water Act. In addition to the benefit of cleaner discharges, the user of this new technology will also be able to sell the algae biomass for use in bioplastics.
Closed photobioreactors such as those developed by Clearas – can be made of either plastic or glass tubing. Nevertheless, plastic systems tend to scratch during cleaning and solarize over time. These scratches then allow other microorganisms to gain a foothold in the photobioreactor, making it difficult for algae to grow. Solarized plastic becomes opaque over time, limiting the efficiency of photosynthesis required for algae to grow. Glass, however, is resistant to scratches and does not solarize, meaning that it has a much longer lifespan than plastic and is the perfect material for pioneering technologies in the field of water treatment.