The chemical treatment is a simple two phase process. During the first chemical phase thickened WAS is dosed with chlorine dioxide and held for one hour. Next, the pH of the process tank is lowered in preparation for the second chemical phase, nitrous acid dosing. The nitrous acid phase is maintained for six hours. At the conclusion of the nitrous acid phase the pH is restored to the pH level desired by the end user of the treated product.
Ferric chloride can be added to the process tank during the process to aid in phosphorus removal from the wastewater treatment plant. After treatment, the process tank is evacuated and the biosolids dewatered by any preferred means of dewatering.
The Neutralizer® process produces a Class A/AA biosolid that may be registered as a commercial fertilizer. The system is designed to have minimal impact on local environmental conditions. It is a "zero-emission" process that takes place within a climate controlled building. The resulting treated biosolids are disinfected and deodorized without exposure to the surrounding environment. Many of BCR's current installations are in close proximity (<300 feet) to residential neighborhoods.
BCR's system relies on simple chemistry rather than on energy intensive treatments such as digesters, dryers, incinerators or gasifiers. The entire process has been designed using individual energy efficient (fractional horsepower) equipment to minimize the need for electricity.
Many WWTPs are having difficulty meeting strict regulatory requirements for phosphorus levels in effluent. By eliminating digestion, the nitrogen and phosphorus return and ammonia loading to the plant is greatly reduced. Additionally, the chemistry of the process binds phosphorus in the biosolid and has proven to be extremely effective at reducing phosphorus levels in the return effluent from dewatering.
Biosolids produced by the Neutralizer process have an extremely low P index (measurement of phosphorous leach-ability). In testing by Penn State University, the Phosphorus Source Coefficient of processed biosolids is 0.1.
System equipment includes a chemical dosing system, disk thickener, batch process tank, SCADA equipment and process control sensors.
The Neutralizer system has been in operation at three facilities in Florida for 3+ years. Two additional facilities are currently under construction. The PFRP recommendation opens the doors for broad adoption of the system throughout the U.S. and provides a basis for worldwide acceptance of BCR Environmental's technologies.
For more information on the system, visit BCR's website at: www.bcrenvironmental.com. WW
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