Source: AirSep
Miami-Dade Water and Sewer Department plant
The Miami-Dade Water and Sewer Department (WASD), which serves more than 2.3 million residents and 20 million visitors annually, is currently mid-way through its multi-billion dollar Capital Improvement Programme, upgrading its sewage treatment plants, pump stations and pipes. Included in the upgrade is the renovation of its current cryogenic oxygen system for wastewater treatment.
The project includes replacing the existing cryogenic oxygen system with two oxygen plants – AirSep ASV97000 VPSA Oxygen Systems (each producing 97,000 SCFH of oxygen), which are the largest systems AirSep has built in the history of the Buffalo, New York-based company.
The AirSep VPSA Oxygen Systems will enable Miami-Dade County to meet new guidelines and regulations set by the US Environmental Protection Agency and the Florida Department of Environmental Protection. With AirSep VPSA technology, oxygen can be produced more cost effectively with an on-stream efficiency of 99%.
“AirSep is honoured to have the opportunity to contribute to the plant’s many improvements that will allow WASD – on behalf of Miami-Dade County to meet new regulatory requirements, as well as increase the plant’s treatment capacity,” said Lawrence Hughes, AirSep Vice-President and General Manager.
The aerobic wastewater treatment method uses oxygen to remove contaminants and pollutants like nitrogen and phosphorus from the wastewater (biological nutrient removal (BNR)). When oxygen is injected into wastewater, it stabilises the sewage sludge and cleans the wastewater, making it odor-free and well-suited for direct discharge or water reuse.
AirSep can customise plant construction to meet a customer’s specifications. In the case of the Miami Dade installation, the AirSep VPSA Plant offers idle time and turndown at 40% of rated capacity without venting product (versus 70-80% with the older system). Molecular sieve adsorbs nitrogen from ambient air to provide the purified oxygen generated by the system. The design of the process switching valves, the adsorber vessels and sieve fluidisation protection controls, provides for extremely long molecular sieve life of all VPSA systems, according to AirSep.
AirSep offers custom-engineered VPSA oxygen systems, with capacities ranging from 2,000 SCFH (52 Nm³/hr) to 120,000 SCFH (3,155 Nm³/hr) and has installations around the world for a variety of applications.