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With the continuous improvement of the level of urbanization and accelerated process of industrialization, small towns sewage treatment has been put on the agenda, to explore the small town sewage treatment affordable treatment technology has become essential. Small town sewage N ratio is low, the low efficiency of conventional biological treatment processes, it is difficult to achieve discharge standards. Therefore, the search for a set of technical and reasonable economically viable treatment process is to be completed by the Institute of purpose. UASB process is currently the world's the municipal sewage anaerobic treatment is the most widely used process, China has achieved remarkable progress in the use of UASB process high concentrations of organic industrial wastewater, but also in the use of the low concentration of the UASB process sewage basically at the stage of laboratory research. In view of this, on the basis of the research at home and abroad UASB process low concentrations of sewage empirical data collection, to carry out the UASB improvement and innovation: First, to improve the traditional UASB influent, the UASB water from the bottom water, sludge is always in dynamic mode, improved from the central water, the water does not impact the bottom of the sludge, the sludge mixed with water through internal reflux; Second, improve the UASB high aspect ratio, reducing the height to diameter The difference to a small footprint, so as to solve the infrastructure space, infrastructure cost. Transformation and innovative new reactor start-up and small scale test to verify the feasibility of dealing with low concentrations of urban sewage. The results showed that: (1) new reactor for treating low concentrations of urban sewage, domestic sewage directly train the anaerobic activated sludge, will shorten the start-up and acclimatization period, the second start can be completed within 10 days. (2) new reactor treating urban sewage, COD removal rate can reach 77% to 84% when the temperature is between 21 to 29 ° C, influent COD concentration of 234 ~ 366mg / L, HRT = 18 ~ 24h. (3) the use of a new type of reactor for domestic wastewater treatment, wastewater COD is relatively low, and the buffering capacity of water, the reaction does not occur acidification, running in good condition. (4) in the new anaerobic reactor, anaerobic activated sludge rapid enrichment of anammox bacteria successfully the start ANAMMOX process. (5) the use of anaerobic activated sludge as seed sludge of anaerobic ammonia oxidation, control HRT 30d, the initial granular sludge denitrification dominant domesticated 54d, anaerobic ammonium oxidation reactor, denitrification coexistence and anaerobic ammonia oxidation to Section 90d, successfully cultured anammox activity sludge, anammox bacteria grow slowly, in the early stages of domestication, the longer HRT enrichment ANAMMOX microbial is crucial. (6) In the process of anaerobic ammonia oxidation reactor startup, by measuring the NH 4 is -N removal and the NO 2 -N removal the ratio of COD concentration in the reactor and the reactor sludge color changes, we can understand the process of anaerobic ammonia oxidation reactor startup. (7) tests were carried out over five months, during sludge particle size, concentration, sedimentation and color change. Seed sludge (anaerobic granular sludge) gray and black, domesticated 5 months after sludge gradually into red-brown, the formation of the activated sludge of anaerobic ammonium oxidation. After a magnification of 6000 times by the scanning electron microscope can be observed that the the anammox active sludge by a large number of spherical bacteria and coryneform bacteria polymerized particles table and an internal substantially less than was observed the presence of filamentous bacteria. (8) by the influence of the ScS influent ammonia and nitrite in the proportion of the anammox reaction, in this test, a suitable proportion of the influent ammonia and nitrite to 1:1.13, indicating that under anaerobic conditions The novel reactor, the sludge is not only the presence of a large number of anaerobic ammonium oxidizing bacteria, and the presence of small amounts of nitrite bacteria, they coexist in the entire system, co-transformed matrix ammonia, the ANAMMOX contribute. New stable operation of the reactor, there is a relatively strong resistance to impact load, the reactor process is simple, construction costs, low operating costs, operation and management is simple, and complete sets of equipment. Since the reactor studies have reported the structure has not been found, therefore, to study the feasibility of a new reactor for domestic wastewater treatment has some practical value and scientific significance.
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