The 65 AIRE-O2® aerators create a 'flow linkage' in the gigantic 44 acre (75 MG) oxidation-like oval lagoon and operate 24 hours/day
This southwestern city’s experienced overloading problems with its huge 44-acre (75 MG) aerated lagoon. The plant serves a population of 225,000 and also, treats industrial wastewater from petroleum refinery, food processing, and garment manufacturing wastes. The existing aeration system could not meet the oxygen demands in the plant’s overloaded condition. Daily flow was 26.2 MG (99167m 3). Effluent BOD was exceeding the permit limit of 30 mg/l.
The city called on its consulting engineers for help. The firm recommended using Aeration Industries’ AIRE-O2® aspirator aeration system to convert the plant’s lagoon system to an oxidation-like oval with a three-day detention time. The engineer said, 'the aeration system provided a means to quickly add a large amount of aeration capacity (1600 hp) to a shallow lagoon (5.5 ft).' A total of 65 - 25 hp (18.5 kW) AIRE-O2® aerators were installed. Also, key to the aeration layout was the directional pumping (flow) ability of the AIRE-O2® units. The anchoring system was unique too. Five aerators were anchored from a single cable spanning 550 ft. 'No other product was located that could, on a stand-alone basis, meet the criteria of the above,' said the engineer.
After the AIRE-O2® system’s installation, 'the dissolved oxygen (DO) values in the lagoon’s effluent increased from 0.5 to a DO residual of 3.0 mg/l at all times,' reports the city. 'The aerators have eliminated bad odors and have lowered chlorine consumption from 2302 lbs/day to 750 lbs/day. The greatest result from the new aeration system is no more non-compliance fines! Since the aerators’ installation, the city is in compliance with both its BOD and TSS. That makes everyone very pleased with the system.