共查询到20条相似文献,搜索用时 11 毫秒
1.
厌氧氨氧化作为新型生物脱氮技术其关键在于如何实现厌氧氨氧化反应的启动,现有研究多以模拟废水为研究对象,本文以猪场废水为对象的研究,利用ASBR为反应器,接种反硝化污泥培养厌氧氨氧化细菌,在NH+4-N与NO-2-N浓度均为100 mg/L的条件下,运行125 d,经历启动初期、过渡期、系统稳定运行期三个阶段,厌氧氨氧化反应器中NH+4-N的去除率达91.70%,NO-2-N去除率92.0%;NH+4-N的容积负荷为36.90 mg/L.d,NO-2-N的容积负荷为37.55 mg/(L.d),成功实现了厌氧氨氧化反应器的启动。该研究成果对厌氧氨氧化技术在工程实践的应用具有重要的指导意义。 相似文献
2.
A novel laboratory bench-scale sequencing batch biofilm reactor (SBBR) system was developed for the treatment of synthetic domestic strength wastewater, comprising two side-by-side 18 l reactor tanks, each containing a plastic biofilm media module. Aerobic and anoxic conditions in the biofilms were effected by intermittent alternate pumping of wastewater between the two reactors. With a media surface area loading rate of 4.2 g chemical oxygen demand (COD)/m2.d, the average influent COD, total nitrogen (TN) and ammonium-nitrogen (NH4-N) concentrations of 1021 mg/l, 97 mg/l and 54 mg/l, respectively, reduced to average effluent concentrations of 72 mg COD/l, 17.8 mg TN/l, and 5.5 mg NH4-N /l. Using a similar alternating biofilm exposure arrangement, a 16 person equivalent pilot (PE) plant was constructed at a local village treatment works to remove organic carbon from highly variable settled municipal wastewater and comprised two reactors, one positioned above the other, each containing a module of cross-flow plastic media with a surface area of 100 m2. Two different pumping sequences (PS) in the aerobic phase were examined where the average influent COD concentrations were 220 and 237 mg/l for PS1 and PS2, respectively, and the final average effluent COD was consistently less than 125 mg/l--the European Urban Wastewater Treatment Directive limit--with the best performance occurring in PS1. Nitrification was evident during both PS1 and PS2 studies. A 300 PE package treatment plant was designed based on the bench-scale and pilot-scale studies, located at a local wastewater treatment works and treated municipal influent with average COD, suspended solids (SS) and TN concentrations of 295, 183 and 15 mg/l, respectively resulting in average effluent concentrations of 67 mg COD/l, 17 mg SS/l and 9 mg TN/l. The SBBR systems performed well, and were simple to construct and operate. 相似文献
3.
Two methods of surface modification of polyethylene biocarriers, chemical oxidation-surface covering with ferric ion (CO-SCFe) and chemical oxidation-surface grafting with gelatin (CO-SGG), were studied for improving the efficiency of wastewater treatment by moving-bed biofilm reactors. The results showed that two surface modifications caused corrosion pits to increase surface roughness, and brought -(C=O)-/-O-C-O- groups and ferric ions to the biocarrier surface, respectively. The positively charged surface increased the hydrophilicity and biological affinity of the biocarrier. The biofilm formation rate was improved by 37.5 and 60% after surface modifications of CO-SCFe and CO-SGG; the concentration of biomass on the biocarriers was improved by 54.8 and 76.1% and the COD removal efficiencies were increased by 10.63 and 8.64%, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis showed that the microbial populations in the biofilm were almost the same after surface modifications, but the biomass concentration was greatly increased. 相似文献
4.
5.
6.
7.
This paper describes the demonstrative scale application of a membrane biological reactor (MBR) for low loaded domestic wastewater with low attitude to biological treatment (carbon/nitrogen approximately 5). The biological process was managed by the automatically controlled alternate cycles allowing for re-use purposes with a remarkable reduction of the operational costs. The global process evaluation revealed the system capability of obtaining high nitrogen removal (effective nitrogen removal of 69%) thanks to its high flexibility related to the hourly loading fluctuation. Moreover, high removal of heavy metals and polycyclic aromatic hydrocarbons (PAH) was obtained due to the perfect retention capability of the membranes. In-depth studies were conducted to determine the process behaviour for activated sludge over aeration and with addition of exogenous carbon. Limitation of sludge over aeration and energy savings were observed with a gradient air supplying method. The addition of exogenous carbon (acetic acid up to carbon/nitrogen approximately 9) led to complete nitrogen removal (Ed = 96%) and permitted biological phosphorus uptake. In conclusion, it was been found that the coupled process alternated cycles-MBR had the capacity to remove COD, BOD, N, P and suspended solids, as well as heavy metals and organic micropollutants, resulting in high quality effluent suitable for re-use purposes. 相似文献
8.
Two laboratory scale fluidized-bed biofilm reactors (FBBRs) were used to investigate the biomass concentration and the biofilm characteristics in a high performance FBBR used for the denitrification of exceptionally high-nitrate wastewater (1000 mg-N/L). Reported correlations by other workers for predicting the biomass concentration in FBBR were examined for their validity in comparison with the experimental results of this study and the best set of applicable correlations was recommended. The effects of the two main operational parameters, the superficial velocity and nitrogen loading rate on the biomass concentration in the FBBR were also studied. Correlations for the drag coefficient and the expansion index from the literature, together with the biofilm dry density correlation produced from this study were found to produce the best prediction of the FBBR biomass concentration compared to other reported correlations. The average biomass concentration in the FBBR decreased with the increase of the superficial velocity in the range of 45 to 65 m/h at all the applied nitrogen loadings (i.e. 6, 8, 12 and 16 kg-N/m3(bed).d). 相似文献
9.
对《污水再生利用工程设计规范》中氨氮指标的建议 总被引:2,自引:1,他引:1
通过对城市污水处理厂二级出水回用于电厂循环冷却补充水的氨氮指标分析以及与其他相关排放标准的比较,考虑到工业循环水系统冷却塔的处理效果,建议调整《污水再生利用工程设计规范》(GB50335—2002)中的氨氮指标值,以便使污水处理厂出水可作为电厂的循环冷却补充水,实现在满足电厂使用需要的前提下降低工程综合成本的目的。 相似文献
10.
He XW Liu LY Wang H Zhang G Gong JW Lin H Wang JB Qin Q 《Water science and technology》2011,63(11):2732-2736
The electrochemical oxidation of the residual ammonia nitrogen contained in biologically pretreated coking wastewater using three-dimensional electrode system was studied. The results show the Ti/RuO2/IrO2 anode plates and the coke have good surface characteristics for the purpose of this study. In addition, studies also show that the three-dimensional electrode system should be able to give a satisfied solution to the residual bio-refractory ammonia nitrogen in biologically pretreated coking wastewater in comparison to conventional two-dimensional electrodes. At coke size of 10-20 mesh, electrode distance of 1.0 cm and current density of 4.5 mA/cm2, the residual ammonia nitrogen in the three-dimensional electrode system was almost completely removed in 60 min. 相似文献
11.
12.
Recent experiments in our laboratory using both biofilm and suspended biomass reactors have demonstrated high rate nitrification at low pH with known autotrophic nitrifying bacteria originating from wastewater treatment plants refuting previous assumptions that nitrification is significantly inhibited at low pH. Since much of the earlier microbiological work regarding ammonia oxidising bacteria (AOB) physiology was carried out using Nitrosomonas europaea, this model bacterium's capability for high rate nitrification at low pH in a continuous biofilm reactor was tested. A biofilm reactor filled with sintered glass particles was inoculated with a pure culture of N. europaea. The reactor was first operated to high nitrification rates under conditions favourable to N. europaea (pH > 7; high ammonium concentrations). To eliminate inhibitory concentrations of nitrite at low pH, an enriched culture of Nitrospira (a nitrite oxidising bacterium) was then added. The transition from neutral to acidic conditions was attempted by sharply lowering the nitrification rate and by using a feeding solution containing insufficient buffer for complete nitrification. As opposed to other successful transitions, the pH in the N. europaea/Nitrospira reactor initially dropped only slightly and maintained pH > 6 for over two weeks. The reactor reached pH 4.5 only after four weeks. FISH results showed that while the percent of AOB and Nitrospira to eubacteria remained relatively constant at 51.1 +/- 8.2% and 40.8 +/- 6.4%, respectively, the AOB community changed completely in 60 days from 100% N. europaea to 100% Nitrosomonas oligotropha. Even though N. oligotropha was not intentionally introduced into the reactor, it is apparently much better adapted to conditions of low pH. 相似文献
13.
The need for reproducing biofilm processes is undisputable - the quality of biofilm research depends on this reproducibility. However, as many biofilm researchers know, long-term biofilm processes are notoriously difficult to reproduce. To avoid problems related to biofilm reproducibility two strategies are used: (1) to study very young biofilms that have accumulated for a few hours to a few days only, and (2) to run biofilm experiments only once. The first approach trades reproducibility for relevance because natural biofilms are usually older, often much older than a few days. This approach can be applied to answer questions relevant to initial events of biofilm formation but not questions relevant to long-term biofilm accumulation. The second approach conceals the problem of biofilm reproducibility. To assure reproducibility of biofilm processes, we methodically followed a procedure for growing biofilms in terms of microbial makeup, media composition, temperature, surface preparation, etc. Despite all this effort the reproducibility of our results for long term growth is unimpressive. Consequently, the question had to be asked: Are biofilm processes reproducible? The experiments described in this paper address this question. Biofilms grown in two identical and identically operated biofilm reactors had comparable structure only until the first sloughing event. After that, biofilms had different patterns of accumulation. 相似文献
14.
采用曝气生物滤地(BAF)工艺处理某污水处理厂模拟二级出水,研究了水力负荷及滤料层高度对NH_3-N去除效果的影响.试验结果表明,当进水NH_3-N≤25 mg/L时,平均NH_3-N去除率达到93.12%,出水NH_3-N可降至3 mg/L以下.当水力负荷为1.44 m~3/(m~2·h),HRT为1.8 h时,氨氮的去除效果最好,去除率达到95.32%,出水NH_3-N在1.5 mg/L以下.BAF对NH_3-N的去除作用主要发生在滤料的中上层. 相似文献
15.
The influence of temperature (5-35 C) and salinity (up to 20 g/l NaCl) on the wastewater purification process in completely mixed and aerated submerged fixed bed biofilm reactors (SFBBRs) was studied. C- and N-conversion in SFBBRs designed according to the DWA (German Association for Water, Wastewater and Waste) rules for carbon removal was investigated for several months on synthetic wastewater. The DOC degradation rate was even at, according to the DWA, high DOC/BOD loading rates not much affected by temperatures between 5-35 degrees C and salt contents up to 20 g/L NaCl. At these high DOC loadings an appreciable ammonium conversion could also be observed. The ammonium conversion proved to be sensitive to temperature and salinity. At 5 degrees C the ammonium removal rate decreased by a factor of five compared to 25-35 degrees C. Under many operation conditions investigated more than 50% of the converted ammonium was transformed into gaseous nitrogen. The addition of 20 g/L NaCl caused a strong inhibition of the ammonium removal rate over the whole temperature range investigated. 相似文献
16.
E Melin T Leiknes H Helness V Rasmussen H Odegaard 《Water science and technology》2005,51(6-7):421-430
The effect of moving bed biofilm reactor (MBBR) loading rate on membrane fouling rate was studied in two parallel units combining MBBR and membrane reactor. Hollow fiber membranes with molecular weight cut-off of 30 kD were used. The HRTs of the MBBRs varied from 45 min to 4 h and the COD loading rates ranged from 4.1 to 26.6 g COD m(-2) d(-1). The trans-membrane pressure (TMP) was very sensitive to fluxes for the used membranes and the experiments were carried out at relatively low fluxes (3.3-5.6 l m(-2) h(-1)). Beside the test with the highest flux, there were no consistent differences in fouling rate between the low- and high-rate reactors. Also, the removal efficiencies were quite similar in both systems. The average COD removal efficiencies in the total process were 87% at 3-4 h HRT and 83% at 0.75-1 h HRT. At high loading rates, there was a shift in particle size distribution towards smaller particles in the MBBR effluents. However, 79-81% of the COD was in particles that were separated by membranes, explaining the relatively small differences in the removal efficiencies at different loading rates. The COD fractionation also indicated that the choice of membrane pore size within the range of 30 kD to 0.1 microm has very small effect on the COD removal in the MBBR/membrane process, especially with low-rate MBBRs. 相似文献
17.
Garcia GP Souza CL Glória RM Silva SQ Chernicharo CA 《Water science and technology》2012,66(9):1871-1878
This study aimed at the identification of microorganisms present in the scum layer of the settler compartment of upflow anaerobic sludge blanket (UASB) reactors, and to evaluate their role in the biological oxidation of sulphides. The experiments were conducted using scum samples taken from two pilot-scale UASB reactors, both treating domestic wastewater. Microorganisms similar to Beggiatoa sp., Thiotrix sp. and species of cyanobacteria were identified based on their morphology, and most of them have been shown to be capable of carrying out sulphur oxidation. Tests of biological oxidation of sulphides using scum and cultures of the cyanobacteria Phormidium and Pseudoanabaena showed a significant decrease in the concentrations of the sulphides, suggesting that the microorganisms present in the scum layer can play a role in the minimization of odour emissions. 相似文献
18.
AOMBR处理高氨氮废水的效能稳定性及影响因素研究 总被引:1,自引:0,他引:1
对AOMBR(缺氧-好氧膜生物反应器)处理高氨氮废水的脱氮效能进行了研究,着重考察了硝化效能的稳定性及影响系统稳定运行的因素.研究结果表明:在适宜的pH、DO和温度下,容积负荷<1.5 kgNH3-N/(m3·d)时,硝化率可保持在99%以上;好氧池中DO>1.5 mg/L能满足硝化需要;好氧池pH维持在6.8~7.2时可稳定高效地去除氨氮;碱度、污泥龄等也会对硝化效率产生影响.在好氧池中硝化率较高的情况下,影响反硝化效果主要是回流比和碳源. 相似文献
19.