Basic Research Of BCMBBR Treating Of Low-concentration Domestic Sewage

According to the character of low concentration domestic sewage of many cities in south China, moving-bed biofilm reactor(MBBR), which possesses the fuction of removing carbon, nitrify, denitrogenation and the feature of low investment, running cost and simple operation, is considered to fit for treating this type of sewage. Therefore, it is very great significance to research and develop the new technology with BCMBBR as main body. So, in this paper, firstly, the key factors of accelerate the rate of biofilm formation and start-up of BCMBBR was suggested. Secondly,running factors were determined, optimize the operating parameters, investigated its resistance capacity, and proven the boundary conditions of operating system. Thirdly, investigated the performance of nitrogen and SND mechanism, determined the influence factors, and proposed the control strategies of treating of low strength, low carbon and high nitrogen effluent.Fourthly, investigated the capacity of phosphorus removal by BCMBBR chemical collaboratively with coagulation method. Finally, completed the new ceramic moving bed biofilm reactor treating domestic sewage in pilot plant and small pilot plant application of dyeing wastewater, in this basis.With bio-ceramic moving bed biofilm reactor in dealing with the low concentration, low carbon high strength ammonia wastewater, it can gradually speed up the start-up speed of hanging film by using of rapid sludge method and gradually increasing the water hydraulic load. Which sludge inoculumis 1 g/L calculations, hydraulic loading from the 0.4 m3/(m2?h) gradually increased to 0.7 m3/(m2?h). When hanging successfuly, the microscopic mature biofilm thickness is about 0.15~0.25 mm and the biofilm is about 33.5 mg/g, which showed a more abundant microbial food chain, including a large number of tired sticks insects, rotifers, insects and small nest of eggs of mantis body clock insects, etc.. Using BCMBBR dealing with low concentrations, low carbon and high nitrogen domestic wastewater of south China, in the middle of the summer heat (25~29℃), with 30% ceramic filling rate should control the influent hydraulic loading under 0.7 m3/(m2?h), which HRT was 6 h, air-water ratio was 5:1, reflux ratio was 150%. COD, BOD5, NH4+-N and SS removal rates were 82% or more; TN and TP removal averaged at 48.7% and 32.3%.Hydrolysis/BCMBBR/sedimentation tank in dealing with the south China low concentration, low carbon and high nitrogen domestic wastewater (COD of about 110~140 mg/L, C/N=3~5), in the middle of the summer high temperature (25~29℃) conditions. The optimum operating parameters were: HRT 6 h, 30% filling ratio, air-water ratio of 5:1, reflux ratio of 150%. BCMBBR was able to adapt to at least 30% of the organic loading of high impact; When the HLR 0.9 m3/(m2?h) the following run-time, water addition to other indicators have reached the outside TP (GB18918-2002) grade A standards.Dealing with low concentrations, low-carbon high-ammonia wastewater of southern China town with BCMBBR can get a better nitrogen removal, which TN average removal rate was 57.1%; and TP removal rates up to 32.3%, with the same plastic MBBR alone, the effluent of biological phosphorus removal difficult to achieve compliance, should be considered chemically coordinated phosphorus; use BCMBBR + enhanced mixed Condensate Removal works well, with the best compound of PAC + AM dosage is 15 mg/L +2 mg/L, TP removal rate reached 90%, water up to standard. Ceramic surface has a good effect of t SND. DO, C/N plays a major role of change of the SND. Improve nitrogen removal efficiency of the control strategy: control of air to water ratio in the low-end (5:1) when the nitrogen effect; increase in organic load (C/N increases), the premise of ensuring low exposure ceramic fluidization gas intensity running, DO control in about 3 mg/L, BCMBBR the SND efficient, effective biological nitrogen removal.BCMBBR biomass, the high biological activity. Normal operation of the biomass was 33.5 mgVS·g ceramic-1, biological activity of (OUR) is 75.3μgO2·g ceramic-1·h-1and specific biological activity (SOUR) is 332.4×10-4μgO2·mgVS-1·h-1. Pilot plant in the 3 Series BCMBBR biomass, OUR, SOUR are increasing as the start process, but along the direction of a decreasing trend; microbial richness increased with the boot process at all levels, reactor types of the same microorganism, but the number showed a decreasing trend along the flow direction; can BCMBBR the emergence of different microbes to determine the operating conditions, which can control the operation of the reactor.Coagulation-BCMBBR dye wash water combined treatment effective. Good control of not only the amount of coagulant (PAC 200 mg/L, PAM 2 mg/L), has greatly improved water stability. System effluent COD, SS and chroma were 46.8 mg/L, 21 mg/L and 27 times, pH was 7.48~7.53, to (GB 4287-92) A standard.Piolt plant combined process hydrolysis + BCMBBR + coagulation treatment process unit operating costs 0.24 yuan/m3. BCMBBR, as a representative technology, is very ideal in dealing with low concentration, low carbon high strength ammonia wastewater of southern China.