Technological Reconstruction Of The Municipal Wastewater Treatment Station Of Kunming Shipping Company

The wastewater treatment station of Kunming ship company was first built in 1996,and reconstructed in Mar.1999,the designed flow is 3000m~3/d, and treat with biological contact oxidation process which use the jet flow aeration method,and uses the slope tube sedimentation pond, the non-valve filter tank to further treat. Starts from 2006, the effluent starts not to attain a designated standard, In order to cause effluent to satisfy the emissions standard, and use some of effluent as gray water,so needs to reconstrut the station.Before reconstruction,the original processing condition of the staion was careful investigated, including all equipment and constructions, and monitored the quality of influent and effluent,in order to discover the bottleneck question of the station.The inspection discovered that, primary treatment is not enough and the only grating has no function,the filter in the biological contact oxidation tank was blocked up because of no clean and change and the jet flow aeration was deformation,the slope tube of sedimentation pond has slumped so cannot be used,and the filter of the non-valve filter tank was blocked up, these all influence the treatment.Considering the reconstraction demands and some limiting factor,the improved A/A/O craft was adopted, only an advection sand collector and a grill are added to increase the primary treatment; a sludge desiccation field was built to make the sludge reduction.And the use of the perforation eddy pond was changed,only one pond was used as transition pond.For reconstruct, the equalization pond was transformated as anaerobic pond and anoxic pond, the TP of pond and influent were compared,the former was higher,this indicate that gathered the phosphorus fungus release the phosphorus in the pond.For reconstruct, the biological contact oxidation pond was transformated as aerobic pond ,while the jet flow was transformated as pore aeration,and increases the backflow: a part of intermixture of the aerobic pond backflow to the front of the anaerobic pond.The sludge was raised by intermittent rasie method,and a fast raise and effective way was seledted,which is a part of slope tube sedimentation pond sludge was backflowed aerobic pond;during operation the BOD of the effluent for the aerobic pond can maintain below 20 mg/L, the elimination rate about 60%, TP below 2 mg/L, NH3-N in the aerobic pond reduces obviously, the effluent is about 15 mg/L.For reconstruct, the original collapse slope tube was replaced,the aperture is change as 80mm by 50mm, and the slope tube installment was enhanced by 0.5m.The treat effection was analysis during the normal operation:the BOD of the effluent for the slope tube sedimentation pond was lower 10 mg/L than the effluent of aerobic pond,the turbidity of the effluent was approximately 12NTU.The non-valve filter tank was cleaned and inspected,and the turbidity of effluent for non-valve filter tank was 1NTU~5 NTU during operation.During the normal operation, the effluent can arrived the B of Grade I for municipal wastewater treatment plant.The reconstrction cost and the operation cost have analysised, calculated the cost is 0.51 Yuan /m3; around the energy consumption expenseof operation unit to compare, after the reconstrction is 0.2389 Yuan /m~3, before is 0.3223 Yuan /m~3.