Research On High Ammonia Nitrogen Content And Low C/N Sewage By Self-forming Bio-dynamic Membrane Reactor

A study on high ammonia nitrogen and low C/N ratio sewage reclamation using Self-forming Dynamic Membrane Bioreactor was presented in this thesis. More emphases were put on the nitrification of this system.The reactor was equipped with a plate membrane that was made of a 0.1mm nylon mesh as filter material instead of a micro-filtration membrane or an ultra-filtration membrane. The nitrification behavior was investigated under aerobic condition and intermittent aeration.The filterability of dynamic bio-membrane sheet was firstly studied. The tap water permeation and gel-layer attaching permeation were investigated. The result illustrated that, the tap water filtration resistance of the fresh dynamic bio-membrane sheet was about 2.20×108m-1, while the filtration resistance for gel-layer attached membrane was about 0.96×107m-1.In the process of aerobic treatment, the DMBR was used for the treatment of wastewater from septic tank at HRT=5h, the membrane flux=17~19L/(m2·h) and the COD/NH4+-N= 0.56~2.22. The removal efficiency of COD was 70% initially and decreased to 40% later. The degradation of NH4+-N was about 60%. At the same time, the nitrite accumulation appeared in the reactor.In the process of intermittent aeration, the removal of ammonia-nitrogen was optimized by an intermittent aeration of the reactor, furthermore the anoxic phase and aeration time of a cycle was adjusted. The experiment was conducted with three different time patterns of an anoxic-aerobic cycle. In aerobic phase and anoxic phase, 66.5% and 49.1% of COD could be removed respectively. The removal efficiency of NH4+-N was 70% in aerobic stage. In anoxic stage, the ammonia nitrogen degradation decreased gradually.