The innovative BIOZONE-AD® process
Watair has developed the innovative BIOZONE-AD® process for higher level of sewage sludge stabilization. This process supplements standard anaerobic sludge stabilization with an additional phase and involves the injection of pre-digested sludge with ozone, which results in the further oxidative decomposition of the sludge and thus increases its suitability for biological use. This "activated" sludge is returned to the digesters and intensifies the degradation process. The organic dry substance is further reduced and at the same time, biogas production is increased.
The process allows for an increase in biogas yield by 40 percent as well as for further sludge digestion and a decrease in the sludge volume in order to save landfill space. In addition, micro-pollutants (e.g. polycyclic aromatic hydrocarbons) are degraded. This can be of relevance for agricultural use when parameters such as that for benzo(a)pyrene exceeds the statutory limits.