Source: Noram Engineering and Constructors Ltd.
The VERTAD sludge digestion system is a state-of-the-art aerobic thermophilic process that converts municipal primary and secondary sludges to Class A Biosolids, as defined by EPA, CFR-503
The VERTAD sludge digestion system is a state-of-the-art aerobic thermophilic process that converts municipal primary and secondary sludges to Class A Biosolids, as defined by EPA, CFR-503. It uses an in-ground hyperbaric aeration reactor; a device that has been proven effective through more than 20 years of commercial operation in biological processes. The VERTAD™ reactor's patented design features gives it the following advantages over conventional ATAD and anaerobic systems:
A treatment plant with a VERTAD™ system and subsequent dewatering will typically produce 50% less sludge volume than a plant with dewatering only.
VS reductions of 40% to 45% are readily obtained with a 4 day detention time, guaranteeing that EPA requirements for Class A biosolids are met.
Overall capital cost is lower than conventional processes in most applications.
Power costs are substantially lower, usually less than half of conventional aeration processes.
The decanted product contains approximately 10% solids and dewaters readily to 30% to 35% solids with minimal polymer addition. The low polymer consumption and the reduced trucking and disposal costs that result from the high solids content, give significant operating cost savings over conventional ATAD processes.
Odor, VOC, and ammonia emissions are minimal compared with those from conventional processes.
The system is very compact and has a low space requirement.
Heat is recovered from the process using inexpensive heat exchangers and can be used to heat buildings without installing the expensive gas cleaning systems and boilers required to recover heat from anaerobic processes.
The system can be economically enclosed in a building in locations where climatic conditions are unfavorable or if it is desirable for the plant to architecturally blend in with the surrounding environment.
The system is uncomplicated, easy to operate and maintain, and well suited to fully automated unattended operation.
The low aeration air requirement significantly reduces foaming.
The leak tight steel and cement grout reactor casing eliminates ground water contamination concerns.
The in-ground aeration reactor is much less likely to sustain damage in an earthquake than above-ground reactors.
Noram Engineering and Constructors Ltd., Granville Square, 400-200 Granville St, Vancouver, BC V6C 1S4. Tel: 604-681-2030; Fax: 604-683-9164.