This southern pulp and board mill faced the problem of an aging aeration system in its wastewater treatment lagoon. Maintenance was getting prohibitive on the 50 hp (37 kW) & 100 hp (75 kW) slow speed surface aerators, totaling 1,200 hp. 'New slow speed aerators were very expensive and maintenance was expensive,' said the technical superintendent. 'We looked at high speeds because of price, but they didn’t have the agitation. We had sludge build up problems.'
After reviewing the aeration market, the mill chose the AIRE-O2® system for its mixing capabilities to help suspend the sludge. Four 50 hp (37 kW) units were installed in 1984. Additional purchases were made in 1985 that increased total hp to 900 hp (671 kW). 'We bought the aerators for mixing. They have done very well. The lagoon’s over-all mixing pattern is improved and sludge deposits have been greatly reduced.'
During almost 16 years of AIRE-O2® operation, the mill has enjoyed additional benefits. 'In winter, the lagoon stays at a better operating temperature, providing 95% removal efficiencies. The AIRE-O2® aerators are smaller, more portable, flexible, and maintenance has been definitely easier and less expensive.' And, the mill is still just as pleased with Aeration Industries. 'The company has been a big help over the years.'