共查询到20条相似文献,搜索用时 15 毫秒
1.
El-Bestawy E Hussein H Baghdadi HH El-Saka MF 《Journal of industrial microbiology & biotechnology》2005,32(5):195-203
The present work compared chemical and biological treatment methods to achieve the most efficient treatment for the reduction or elimination of phosphorus and nitrogen from mixed industrial–domestic wastewaters. Batch chemical precipitation by ferric chloride and aluminum sulfate (alum) and a continuous biological suspended growth system were investigated as well as the optimum operating conditions. Concerning chemical treatment, Alum generally achieved a higher removal efficiency percentage for the investigated pollutants compared with FeCl3 at their optimum pH and dose, especially with chemical oxygen demand (COD). FeCl3 treatment achieved success only with phosphorus removal, while none of the COD, 5-day biochemical oxygen demand (BOD5), total nitrogen (TN) and N–NH3 achieved acceptable treatment and remained above the maximum permissible limits (MPL). Thus, for such wastewaters, alum is more efficient than FeCl3. Biological treatment exhibited higher efficiencies, particularly towards nitrogen. TN removal increased by increasing the flow rate to 30–60 l/day. N–NH3 removal was effective at the slowest flow rate and decreased with increasing flow rate, while an opposite trend was recorded for N–NO3. At all flow rates, phosphorus levels were below the accepted MPL for discharging into natural systems. Moreover, there was a general trend for the proposed biological treatment to achieve a high removal efficiency for BOD5 and COD, bringing them to acceptable levels to be released into watercourses safely, especially at the slowest flow rates. Thus, integration between the proposed chemical and biological treatment is highly recommended, producing high-quality effluents acceptable by the environmental law. 相似文献
2.
Effect of prefermentation on denitrifying phosphorus removal in slaughterhouse wastewater 总被引:12,自引:0,他引:12
An anaerobic-anoxic sequencing batch reactor (A2 SBR) coupled with a fixed-bed nitrification reactor for simultaneous carbon, nitrogen and phosphorus removal was evaluated using slaughterhouse wastewater. Whereas the treatment could not be successfully carried out on the raw wastewater, the process showed very good nutrient removal performances after prefermentation. The removals of COD, N-NH4 and P-PO4 achieved were 99%, 85% and 99%, respectively. The increase in volatile fatty acid (VFA) and phosphate concentrations in the effluent after prefermentation may explain the high levels of biological carbon, nitrogen and phosphorus removal observed. A simple prefermentation is, therefore, necessary but sufficient to ensure good performances of the denitrifying enhanced biological phosphorus removal (EBPR) process. 相似文献
3.
Biotechnology for phosphorus removal during wastewater treatment 总被引:2,自引:0,他引:2
Advanced biological wastewater treatment for the removal of phosphorus in excess of the normal metabolic requirements of activated sludge type processes has been developed as an alternative to chemical addition. Current laboratory and pilot plant investigations have confirmed that a preliminary anaerobic zone and plug-flow type configuration are necessary for good enhanced biological phosphorus removal. Nitrate in the anaerobic stage inhibits the process whereas acetate enhances phosphorus uptake. The bacteria probably responsible are of the Acinetobacter genus and the presence of stored polyphosphate within these bacteria has been demonstrated. It has also been shown that pure cultures of Acinetobacter do not necessarily take up soluble substrate as phosphate is released during the anaerobic phase, in contrast to the current proposed mechanism, and that in certain cases natural chemical precipitation could make a significant contribution towards overall phosphorus removal. Several studies of pilot and full-scale plants have been reported. 相似文献
4.
A lab-scale anaerobic-anoxic-aerobic (A(2)O) process was operated to investigate denitrifying phosphorus removal and nitritation-denitritation from domestic wastewater, especially regarding the impact of nitrite accumulation caused by nitritation on phosphorus removal. The results showed that mean total nitrogen (TN) removal was only about 47% and phosphorus removal was almost zero without the pre-anoxic zone and additional carbon source. Contrastively, with configuration of pre-anoxic zone, TN and phosphorus removal was increased to 75% and 98%, respectively, as well as denitrifying phosphorus removal of 66-91% occurred in the anoxic zone. Nitritation-denitritation was achieved through a combination of short aerobic actual hydraulic retention time and low dissolved oxygen levels (0.3-0.5 mg/L); however, phosphorus removal deteriorated with increase of nitrite accumulation rates. The free nitrous acid (FNA) concentration of 0.002-0.003 mg HNO(2)-N/L in the aerobic zone inhibited phosphorus uptake, which was major cause of phosphorus removal deterioration. Through supplying the carbon sources to enhance denitrification and anaerobic phosphorus release, nitrite and FNA concentrations in the aerobic zone were reduced, and phosphorus removal was improved. Compared with nitrification-denitrification, nitritation-denitritation reduced the carbon requirement by 30% and performed biological nutrients removal well with mean TN and phosphorus removal of 85% and 96%, respectively. 相似文献
5.
This study investigated the effects of internal recycling time mode and hydraulic retention time (HRT) on nutrient removal
in the sequencing anoxic/anaerobic membrane bioreactor process. Denitrification and phosphorus release were reciprocally dependent
on the anoxic/anaerobic time ratio (Ax/An). As Ax/An increased, nitrogen removal rate increased but phosphorus removal rate
decreased. The increasing Ax/An provided the longer denitrification period so that the organic substrate were consumed more
for denitrification rather than phosphorus release in the limited condition of readily biodegradable substrate. Decreasing
HRT increased both nitrogen and phosphorus removal efficiency because as HRT decreased, food-to-microorganism loading ratio
increased and thus enhanced the biological capacity and activity of denitrifying bacteria. This could be verified from the
observation mixed liquor suspended solids concentration and specific denitrification rate. The change of Ax/An and HRT affected
phosphorus removal more than nitrogen removal due to the limitation of favourable carbon source for phosphorus accumulating
organisms. 相似文献
6.
The effect of an anoxic zone on biological phosphorus removal by a sequential batch reactor 总被引:7,自引:0,他引:7
Nitrate can affect phosphate release and lead to reduced efficiency of biological phosphorus removal process. The inhibition effect of remaining nitrate at the anaerobic/anoxic phases was investigated in a lab scale sequencing batch reactor. In this study the influence of denitrification process on reactor performance and phosphorus removal was examined. The experiments were carried out through simultaneous filling and decanting, mixing, mixing-aeration and settling modes. Glucose and acetate were used as carbon sources. The proposed treatment system was capable of removing approximately 80% of the influent PO4-P, 98% NH4-N and 97% COD at a SRT of 25 days. In the fill/decant phase, anoxic and anaerobic conditions prevailed and a large quantity of nitrate was removed in this stage. In the anoxic phase the remaining nitrate concentration was quickly reduced and a considerable amount of phosphate was released. This was attributed to the availability of acetate in this stage. For effective nitrogen and phosphate removal, a short anoxic phase was beneficial before an aerobic phase. 相似文献
7.
Hua Zou Guo-Cheng Du Wen-Quan Ruan Jian Chen 《World journal of microbiology & biotechnology》2006,22(7):701-706
Summary The effects of nitrate on phosphorus release and uptake in a sequencing batch reactor for biological phosphorus removal was
investigated. The addition of nitrate decreased phosphorus release in the anaerobic stage. The synthesis of poly(hydroxyalkanoates)
was decreased with the presence of nitrate, possibly due to the competitive utilization of the carbon source by PHA synthesis
and denitrification of nitrate. Instead of oxygen, nitrate could be used as an electron acceptor for phosphorus removal. However,
the simultaneous addition of nitrate and acetate greatly reduced the phosphorus removal rate. Phosphate and nitrate could
be removed simultaneously with nitrate as the electron acceptor, and the continuous and steady feeding of nitrate was beneficial
to phosphate removal. 相似文献
8.
Effects of different carbon supplements on phosphorus removal in low C/P ratio industrial wastewater
This study focuses on the effects of different carbon supplements on biological phosphorus removal in the optonics and semiconductor industrial wastewater treatment. Experimental results demonstrate that the addition of a carbon source (glucose, acetate, and digester supernatant) improved phosphorus removal effectively. When the COD/P ratios were controlled in the range of 18-20 (using glucose and supernatant as supplement), the acclimated sludge showed more than 98% removal of phosphorus. In addition, different organic carbons induce dissimilar behavior in anaerobic release and aerobic uptake of phosphorus. The glucose supplement induces significant phosphorus release in anaerobic phase and then an increased phosphorus uptake in aerobic phase. The released phosphorus descended in anaerobic phase when acetate and supernatant were added. There was a good linear relationship of first order reaction between initial COD concentration and specific substrate utilization rate in anaerobic phase. 相似文献
9.
The purpose of this study was the development of an alternative coagulant supply device intended to replace the conventional chemical dosing system used for phosphorus removal. Bench-scale, multi-stage, upflow anaerobic fixed bed reactors (UAFBRs) were packed with iron nuts and domestic wastewater was fed continuously to enhance microbially influenced corrosion under anaerobic conditions. Total iron concentration in the effluent varied between 7.8 and 13.0 mg/l over the 120-day testing period ensuring sustained corrosion of iron in the reactors. A hybrid process consisting of the UAFBRs and an anoxic/oxic (A/O) process was tested to investigate the removal efficiencies of organic substances, nitrogen and phosphorus from domestic wastewater. Two types of systems were operated in parallel with different return sludge ratios. One was the hybrid process and the other was the A/O process. In comparing the hybrid process with the A/O process with respect to phosphorus removal efficiency, the performance of the hybrid process was much better than that of the A/O process alone, since phosphate ions in wastewater combined with iron cations from UAFBR. Nitrogen removal efficiency of the hybrid process was lower than that of the A/O process because the chemical oxygen demand/total Kjeldal nitrogen ratio of influent to the anoxic and aeration tank was decreased as organics in the domestic wastewater were removed by the UAFBR. 相似文献
10.
The effect of propionic to acetic acid ratio on anaerobic-aerobic (low dissolved oxygen) biological phosphorus and nitrogen removal 总被引:5,自引:0,他引:5
In this paper, three lab-scale sequencing batch reactors (SBR-A, B, and C) operated with anaerobic/aerobic (low dissolved oxygen, 0.15-0.45 mg L(-1)) configuration were long-term cultured, respectively with single acetic acid and propionic/acetic acid of 1/1 and 2/1 (carbon molar ratio), and the comparisons of anaerobic and aerobic transformations of phosphorus and nitrogen among them were made. With the increase of propionic/acetic acid, lower anaerobic phosphorus release and higher phosphorus release to short-chain fatty acids uptake ratio were observed, and less anaerobic and aerobic transformations of glycogen and poly-3-hydroxybutyrate as well as total polyhydroxyalkanoates occurred, but the transformations of poly-3-hydroxyvalerate and poly-3-hydroxy-2-methyvalerate increased. The phosphorus removal efficiency was respectively 81, 94 and 97% in SBR-A, B and C. Almost all ammonium was removed and no significant nitrite was accumulated at different propionic/acetic acid ratios. However, the nitrate accumulation and total nitrogen removal were observed to be affected by propionic/acetic acid ratio. The total nitrogen removal efficiency was 61, 68 and 82%, and the aerobic end nitrate concentration was 8.05, 6.40 and 3.54 mg L(-1) in three SBRs, respectively. All the above studies indicated that the sole acetic acid caused more nitrate accumulation than propionic and acetic acids mixture, and a pertinent increase of wastewater propionic/acetic acid ratio was of benefit to both nitrogen and phosphorus removal in an anaerobic/aerobic (low dissolved oxygen) biological wastewater treatment process. 相似文献
11.
Simultaneous nitrification,denitrification, and phosphorus removal in a lab-scale sequencing batch reactor 总被引:18,自引:0,他引:18
Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHAs), accompanied by phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to <0.5 mg/L by the end of the cycle. Ammonia was also oxidized during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis showed that the final denitrification product was mainly nitrous oxide (N(2)O), not N(2). Further experimental results demonstrated that nitrogen removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms (DGAOs), rather than denitrifying polyphosphate-accumulating organisms (DPAOs), were responsible for the denitrification activity. 相似文献
12.
传统厌氧/好氧生物除磷与厌氧/缺氧反硝化除磷效能的比较 总被引:1,自引:0,他引:1
采用序批式反应器(SBR),对比厌氧/好氧(A/O)和厌氧/缺氧(A/A)2种运行模式对模拟生活和工业混合污水同时脱氮除磷的效能。结果表明:反硝化聚磷菌完全可以在厌氧/缺氧交替运行条件下得到富集,稳定运行的2种模式对有机物和P的去除率分别保持在90%和85%以上,且A/A SBR具有更强的释磷能力,其释磷量比A/O SBR高出1.2倍。进一步试验表明:磷的释放在有无硝酸盐的情况下效果是不同的。2个系统内污泥均有反硝化除磷能力,A/A SBR中所含反硝化聚磷菌(DPAO)的比例是A/O SBR的4.56倍。2种模式出水水质都能取得较好的效果,且能实现同步除磷脱氮,而反硝化除磷在生物除磷方面更具优势。 相似文献
13.
Ilaria Di Termini Annalisa Prassone Claudia Cattaneo Mauro Rovatti 《Ecological Engineering》2011,37(6):976-980
This study shows results of nitrogen and phosphorus removal by microalgae (tertiary treatment) in a prototype of tubular photobioreactor tested under controlled and uncontrolled conditions. The wastewater was the supernatant coming from a secondary settler of a municipal wastewater activated sludge treatment plant without nitrification and denitrification units. The algal biomass was directly selected from the supernatant and it was principally composed of genus Scenedesmus (autochthonous algae). All the experiments evaluated both nitrogen and phosphorus removal and biomass and lipid production. A satisfactory nutrients removal - about 99.9% for the nitrogen and phosphorus - and a specific biomass productivity of 0.25 g/l d have been obtained in the indoor photobioreactor; less satisfactory results have been reached in the outdoor photobioreactor because of ambient condition instability and limiting nutrients concentration. 相似文献
14.
Lee N Nielsen PH Aspegren H Henze M Schleifer KH la Cour Jansen J 《Systematic and applied microbiology》2003,26(2):211-227
Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added to the influent wastewater. Rhodocyclus-related bacteria were present in both systems in significant numbers (ranging from 4 to 28%) throughout the whole period. This supports the hypothesis that these bacteria occur in significant numbers in different types of well-operating EBPR activated sludge processes. However, we observed a lower correlation (< 0.5) for the amount of Rhodocyclus-related bacteria to the P content in activated sludge than previous studies (> 0.9). The Actinobacteria were the only additional group of bacteria which showed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria--but only for the system without nitrogen removal. Significant amounts (< or = 12%) of glycogen-accumulating bacteria (GAOs) were detected in the system with nitrogen removal (but not in the other system), but had no, in contrast to previous observations, apparent negative effect on the overall EBPR performance. FISH-MAR indicated that a significant part of the Betaproteobacteria (part of them identified as Rhodocyclus-related bacteria) as well as the Actinobacteria were able to take up 33Pi, [3H]-acetate and [3H]-glucose under anaerobic-aerobic conditions. The contribution of anoxic 33Pi uptake under alternating anaerobic-anoxic conditions was significantly lower. Interestingly, not all Rhodocyclus-related bacteria showed uptake of these three radioactive substrates. This may be due to differences in metabolic state, physiological potential or genotype, not detectable by the present probe set for Rhodocyclus-related bacteria. Comparison of the 33Pi, [3H]-acetate and [3H]-glucose uptake by activated sludge after different fixation and incubation procedures showed that a part of the observed 33Pi uptake may have been caused by a combination of a biological and chemical or biologically induced chemical P adsorption. 相似文献
15.
【背景】投加微生物菌剂是强化生物处理效能的重要手段,反硝化是污水脱氮除磷的关键步骤,但目前对于反硝化微生物菌剂相关的研究报道较少。【目的】驯化高效反硝化聚磷菌菌剂,并对系统进行生物强化。【方法】采用两阶段法快速富集反硝化聚磷菌,筛选高效脱氮除磷功能菌株NC1-1并进行鉴定,以NC1-1为菌种来源制备干粉菌剂,研究菌剂强化A2SBR系统污水处理效果。【结果】历经36 d后反硝化聚磷菌富集成功,菌株NC1-1经鉴定属于戈登氏菌属,其脱氮除磷率分别为89.46%和91.68%。麦麸、玉米粉配比为85%:15%、NC1-1投菌量为20 mL、发酵液用量20 mL的条件下成功制得干粉菌剂,干粉菌剂最佳投加量为10%的A2SBR系统总磷(total phosphorus,TP)和NO3--N去除率比未投加菌剂的A2SBR系统提高12.06%和11.52%。【结论】菌剂NC1-1的投加使A2SBR系统的污染物去除效能进一步提高,研究结果为进一步研究反硝化聚磷菌菌剂提供了... 相似文献
16.
In this research, investigations were made on material transfer mechanisms and optimum operation mode for sequencing batch reactor system removing phosphorus and nitrogen simultaneously. Phosphorus release characteristics were expressed in the Monod equation, in which the reaction rate was replaced with specific phosphorus release (SPR) rate. The rate of SPR was increased during the first 80 days, but increased sharply to reach 0.003 hr-1 afterwards. Phosphorus removal efficiencies were about 60% in the first 80 days, 75% after 80 days, and above 95% after 120 days. After 120 days, phosphorus concentration in effluent was below 0.5 mgl-1 when 8 mgl-1 was in the influent and the released phosphorus after 3-hour-anaerobic period was 60 mgl-1. In the proposed optimum operation strategy (2-hour anaerobic react, 3-hour aerobic react, 4-hour anoxic react, and 3-hour settle and draw), phosphorus reappeared if the oxidized nitrogen was completely denitrified. In order to prevent this undesirable phosphorus release, anoxic period should be reduced to the extent of which the minimal concentration of the oxidized nitrogen existed. Phosphorus removal efficiency was stable under shock load as 5 times high as normal phosphorus concentration.Abbreviations dP/dt
Phosphorus release rate (mgl-1 hr-1)
- K
Phosphorus release yield constant (mg P mg TOC-1)
- dS/dt
Substrate utilization rate (mgl-1 hr-1)
- X
Mixed liquor suspended solid (MLSS, mgl-1)
- S
Soluble TOC (mgl-1)
- k-qmax (Ymax)-1
Maximum substrate utilization rate
- Y
Yield coefficient (mg mg-1)
- Ks
Saturation constant (mgl-1)
- Pmax
kK-Maximum phosphorus release rate (hr-1)
- Prel
Total released phosphorus (mgl-1)
- Po
Phosphorus in influent (mgl-1)
- Pe
phosphorus in effluent (mgl-1)
- t
Anaerobic period (hr) 相似文献
17.
Nitrogen and phosphorus removal from wastewater is now considered essential for the protection of our waterways. Biological nutrient removal processes are generally the most efficient and cost-effective solution to achieve this. While the principles of these processes are well known, intriguing and useful details are being discovered with the recent advances in bio-process engineering and microbial sciences. Phosphorus accumulating organisms have only been identified in recent years, and there are now competing glycogen accumulating organisms being found in biological phosphorus removal systems. These can possibly explain the reasons for the variable phosphorus removal performance of certain systems, and their control can help in the development of more stable and better performing processes. Detailed investigations of the traditional nitrification-denitrification systems, but also of novel developments for nitrogen removal, reveal a more complex and diverse range of processes involved in these transformations. Increasingly, linked phosphorus and nitrogen removal processes are being developed, creating further opportunities to optimise the technologies. However, this might also bring certain risks such as the potential to produce the greenhouse-gas nitrous oxide (N2O) rather than nitrogen gas as the final denitrification product. A range of recent developments in these areas is covered in this paper. 相似文献
18.
Simultaneous nitrification, denitrification, and phosphorus removal from nutrient-rich industrial wastewater using granular sludge 总被引:2,自引:0,他引:2
The biological removal of nitrogen and phosphorus from nutrient-rich abattoir wastewater using granular sludge has been investigated. A lab-scale sequencing batch reactor, seeded with granular sludge developed using synthetic wastewater, was operated for 13 months under alternating anaerobic and aerobic conditions. It is demonstrated that the granules could be sustained and indeed further developed with the use of abattoir wastewater. The organic, nitrogen, and phosphorus loading rates applied were 2.7 gCOD L(-1) day(-1), 0.43 gN L(-1) day(-1), and 0.06 gP L(-1) day(-1), respectively. The removal efficiency of soluble COD, soluble nitrogen and soluble phosphorus were 85%, 93%, and 89%, respectively. However, the high suspended solids in the effluent limited the overall removal efficiency to 68%, 86%, and 74% for total COD, TN, and TP, respectively. This good nutrient removal was achieved through the process known as simultaneous nitrification, denitrification, and phosphorus removal, likely facilitated by the presence of large anoxic zones in the center of the granules. The removal of nitrogen was likely via nitrite optimizing the use of the limited COD available in the wastewater. Accumulibacter spp. were found to be responsible for most of the denitrification, further reducing the COD requirement for nitrogen and phosphorus removal. Mineral precipitation was evaluated and was not found to significantly contribute to the overall nutrient removal. It is also shown that the minimum HRT in a granular sludge system is not governed by the sludge settleability, as is the case with floccular sludge systems, but likely by the limitations associated with the transfer of substrates in granules. 相似文献
19.
反硝化除磷菌筛选及其特性研究 总被引:1,自引:0,他引:1
【目的】研究反硝化除磷菌特性。【方法】通过微生物筛选和生物学特性研究方法,从对虾养殖池塘中筛选出多株可在有氧条件下同时具有反硝化除磷功能的菌种。【结果】菌株LY-1可在18 h内将初始量为10 mg/L的亚硝酸盐氮降低至0.04 mg/L,PO43?-P降低至0.05 mg/L。在DO浓度为5.0?5.9 mg/L时,该菌反硝化除磷率近100%。试验选取具有反硝化除磷功能的枯草芽孢杆菌为阳性对照菌,大肠杆菌为阴性对照菌,比较研究了菌株LY-1在不同pH、温度、盐度、PO43?-P浓度、亚硝酸盐浓度时反硝化除磷的强弱,在pH为5?9范围时,该菌亚硝酸盐氮去除率近99%,PO43?-P去除率86%;温度为30°C时,该菌反硝化除磷率近100%;盐度为5‰?15‰、PO43?-P浓度为10 mg/L、亚硝酸盐氮浓度为20 mg/L时,该菌亚硝酸盐氮和PO43?-P去除率均可达99%。【结论】菌株LY-1反硝化除磷性能显著高于对照菌(P<0.05)。通过菌株LY-1形态学观察、生理生化及16S rRNA基因序列分析,初步鉴定为蜡样芽孢杆菌(Bacillus cereus)。 相似文献