PTA²O工藝是在傳統(tǒng)A²O工藝基礎(chǔ)上的改進工藝，它將曝氣、污泥回流、污泥沉淀集約在一個構(gòu)筑物內(nèi)，占地小，投資省。某養(yǎng)豬廢水處理項目規(guī)模為1 500 m³/d，原采用AO工藝，針對其廢水高COD、高氨氮的特點，改造工程采用水解酸化+PTA²O工藝，出水執(zhí)行《畜禽養(yǎng)殖業(yè)污染物排放標準》（GB 18596—2001）。工程運行100多天后生物池自發(fā)產(chǎn)生厭氧氨氧化現(xiàn)象，之后進行生產(chǎn)性厭氧氨氧化調(diào)試5個月，生物池運行功率由143 kW降為37 kW，節(jié)能74.1%，堿液及碳源基本停止投加，處理成本（不包括人工費）由9.49元/m³降為1.38元/m³，COD去除率達80%左右，總氮去除率維持在90%水平。厭氧氨氧化運行一年多來，從未發(fā)生崩潰，一直穩(wěn)定運行，出水達標，節(jié)能顯著。本案例證明，PTA²O工藝采用的曝氣、沉淀、污泥回流及水力循環(huán)方式在適宜的水質(zhì)條件下易于自發(fā)產(chǎn)生厭氧氨氧化現(xiàn)象，且有較強生命力。

PTA²O process is an improved process on the basis of traditional A²O process, which integrates aeration, sludge reflux and sludge sedimentation in one structure, occupies small area and saves investment. The capacity of a swine wastewater treatment project was 1 500 m³/d under the originally AO process. Swine wastewater has the characteristics of high COD and high�瞫trength ammonium, so the transformation project adopts hydrolysis acidification and PTA²O process. The effluent after transformation is required to meet the Discharge Standard of Pollutants for Livestock and Poultry Breeding (GB 18596-2001). Anammox occurred spontaneously after about 100 days’ operation of the project. Afterwards, full�瞫cale Anammox was carried out for 5 months. The power consumption of the biological tank was reduced by 74.1％ from 143 kW to 37 kW; alkali and carbon source were basically stopped addition. The treatment cost excluding labor decreased from 9.49 yuan/m³ to 1.38 yuan/m³; the removal rate of COD was about 80%; the removal rate of total nitrogen was maintained at the level of 90%. Anaerobic ammonia oxidation process operated for more than a year, with no collapse, stable operating, effluent up to standard, energy saving remarkable. This case showed that the aeration, sedimentation, sludge reflux and hydraulic circulation that PTA²O process adopted could easily produce spontaneous anaerobic ammonium oxidation under suitable water quality conditions, and had strong sustainability.