聚磷生物膜法磷回收研究进展

从污水中回收磷已经成为当前污水全面资源化研究领域的重要研究方向之一,聚磷生物膜法磷回收工艺因其在节省碳源、简化回收流程、提高回收效果、污泥减量化等方面的潜力,成为该领域的重要技术手段和研究热点。本文着重介绍了聚磷生物膜法磷回收的基本原理、功能微生物及其代谢特征;详细梳理了生物膜法磷回收工艺不同模式的回收思路,综合分析了不同工艺模式的技术特征和磷回收效果。此外,对聚磷生物膜系统微生物及其代谢的研究方法与技术进行了整理。文章在综合分析聚磷生物膜法磷回收研究现状的基础上,对该技术的应用前景进行了宏观展望,以期为开展聚磷生物膜法磷回收的基础研究和技术开发提供支撑。     

浅谈间歇式活性污泥法

为了防止水体污染的加重,水处理技术得到了深入研究和迅速发展,从而促进了水质净化新工艺的不断出现和广泛应用。间歇式活性污泥法工艺能满足排放要求、处理效果好、运行费用低,作为一种污水处理新技术、新工艺发展迅速。本文从SBR工艺的基本原理出发,介绍了几种SBR的改良工艺,并突出其工艺特征。     

利用水生生物对SBR处理制药废水工艺效果的分析

通过镜检分析运转流程中曝气池污泥中的水生生物,对某药厂污水处理所采用的间歇式活性污泥处理法(SBR)工艺的效果进行分析,寻找出该厂在应用该处理工艺过程中所出现的污水处理效果时好时坏的原因,针对其工艺的不足之处提出改进建议,为改良该类的污水处理工艺提供了一条新思路。     

污染河道治理技术研究进展

河道综合整治已引起人们广泛关注。综述了国内外河道治理常用的物理、化学和生物等方法的原理和工艺。物理法介绍了调水、机械除藻、底泥疏浚等,该法治标不治本;化学法有混凝沉淀,它易造成产生二次污染;生态-生物法是国外近年来发展很快的,借助自然界自身的水体自净能力治理受污水体的一类新技术,包括河道曝气法、生物膜法、生物修复技术,土地处理法等。同时也介绍了目前发展起来的最新河道治理工艺,如悬浮填料移动床、曝气生态净化系统和底泥生物氧化等多种方法,这类工艺是将生物法与其他工艺相结合,具有多功能、高效率等特点。     

渠式生物膜氧化法处理生活污水的技术研究

研究了利用渠式生物膜法进行生活污水处理实验。该法结合了活性污泥法和生物膜法的优点,能有效处理城市生活污水,而且装置不设二沉池,占地面积少,基建投资省。实验测定了不同的水力停留时间(HRT)和进水负荷下的化学需氧量(COD_Cr)及氨氮(NH₃-N)浓度,并分析其对去除率的影响。结果表明,在实验设定的范围内,COD_Cr和NH₃-N去除率随着水力停留时间的增大而增大,而随着进水负荷的增大而相应的减少。在水温25℃,流量0.6L·min^-1,COD_Cr 100mg·L^-1,NH₃-N 15 mg·L^-1的条件下,污染物的去除率较高(COD_Cr为71%、NH3-N为36%),出水水质比较理想,可以达到景观、娱乐和冷却水等的用水标准。     

含苯酚废水生物处理的细菌群落结构初探

本文利用PCR-DGGE技术对苯酚生产污水处理中常用的连续缺氧-好氧工艺、连续好氧工艺和缺氧SBR工艺的微生物的群落变化进行了对比研究。研究结果表明,针对苯酚生产废水的生物处理,与A/O工艺和缺氧SBR相比较,连续好氧工艺处理效果最佳,同时还具有较好的耐冲击力;生物的种群特性与所选择的工艺有密切关系,连续好氧体系中微生物的多样性最高,缺氧SBR的微生物多样性最低;在同一种运行工艺中,随水质或负荷的改变,微生物的种群多样性发生变化,而体系中的优势种群并没发生明显改变。     

ABR结合SBR法处理印染废水的研究*

采用实验室规模的厌氧折流板反应器(ABR)与序批式活性污泥曝气反应器(SBR)结合工艺处理印染废水。通过对ABR-SBR处理系统工艺条件的试验,在ABR段HRT为24~36 h,污泥负荷为0.43~2.46 kg COD/(m³.d),进水pH值为6.5~8.0,温度20℃~35℃;SBR段的溶解氧为2 mg/L,曝气时间为3~10 h,沉淀时间为2 h的条件下,经处理的印染工业废水COD、色度和苯胺去除率分别为32%~95%、89%~99%和50%~98%,其COD为30.0~97     

ABR结合SBR法处理印染废水的研究

采用实验室规模的厌氧折流板反应器(ABR)与序批式活性污泥曝气反应器(SBR)结合工艺处理印染废水。通过对ABR-SBR处理系统工艺条件的试验,在ABR段HRT为24~36 h,污泥负荷为0.43~2.46 kg COD/(m3.d),进水pH值为6.5~8.0,温度20℃~35℃;SBR段的溶解氧为2 mg/L,曝气时间为3~10 h,沉淀时间为2 h的条件下,经处理的印染工业废水COD、色度和苯胺去除率分别为32%~95%、89%~99%和50%~98%,其COD为30.0~97.1 mg/L,色度为8~40倍,苯胺浓度为0.20~0.95mg/L,达到了国家一级排放标准。     

白及提取物抗变异链球菌致龋效果的研究

目的研究白及提取物对变异链球菌粘附、生物膜形成及活性的影响,评价其抗龋效果。方法市售白及95%乙醇浸提;纸片法、打孔法测定直接抑菌作用;液体稀释法检测MIC;结晶紫法研究亚抑菌浓度提取物对变异链球菌粘附能力及生物膜总量的影响;采用荧光显微镜和激光共聚焦显微镜观察常态牙菌斑生物膜生长过程中及药物处理后牙菌斑生物膜中死菌和活菌的构成,研究其对牙菌斑生物膜结构和活性的影响;运用扫描电镜观察白及药液对变异链球菌生物膜的影响。结果白及提取物具有一定的抑菌作用,MIC为16~62 mg/m L;结晶紫法定量研究生物膜结果显示白及药液作用4 h对变异链球菌的粘附均有抑制作用,抑制率为28.63%~60.08%;作用20 h对生物膜总量抑制率达77.08%;白及药液作用20 h,荧光染色显示生物膜活性明显被抑制,抑制率达62.03%;梯度浓度白及药液分别作用20 h后,激光共聚焦显微镜下观察到随着药液浓度增加,绿色的活菌、团块状结构减少,生物膜形成明显被抑制;扫描电镜下可见药液作用后细菌间粘性物质减少。结论高浓度白及提取液对变异链球菌有直接抑菌作用,亚抑菌浓度能抑制其粘附和生物膜的形成,进而具有抗龋作用。     

膜生物膜法在水污染控制及资源回收中的研究进展

传统以达标排放为核心目标的废水处理工艺往往以高能耗、高物耗换取污染物削减,形成了"减排污染物、增排温室气体"的尴尬局面,并不符合可持续发展理念。作为一种新型的膜处理技术,膜生物膜法可利用无泡曝气的方式将气态电子供体(甲烷、氢气)或受体(氧气)提供给附着在膜表面的微生物,从而驱动水体中的污染物去除,并产生一些极具回收潜力的物质,最终实现污染物削减、节能减排及资源回收三大目标的有机整合。本文系统介绍了膜生物膜的传质过程及其去除污染物的微观机制,探讨了膜生物膜法在水处理资源回收方面的研究前景,梳理了膜生物膜反应器在水污染控制方面的实验研究和中试应用现状,并总结了膜生物膜法面临的挑战及发展趋势。     

Aerobic Biodegradation of Mononitrotoluenes in Batch and Continuous Reactor Systems

Degradations of nitrotoluenes, individually and in a mixture, were carried out in batch and continuous aerobic reactors by a defined mixed microbial culture. The degradation rates and efficiencies of the isomers were evaluated in batch and continuous reactors. The results demonstrated that all the three-mononitrotoluene isomers were degraded simultaneously and completely in presence of excess oxygen. The nitro group position on the benzene ring influenced the degradation rates of the individual MNT isomers in batch systems. In the continuous biofilm reactor with a sufficient biocatalyst quantity, quality and excessive oxygen supply rate, the degradation rates of the mononitrotoluenes were almost identical as long as the compounds were present individually and their loading did not exceed the capacity of the catabolic master reaction. The microbial composition of the biofilm changed qualitatively and quantitatively during long-term continuous operation under aerobic non-aseptic conditions. This complex investigation resulted in data that can be applied for the scale-up procedure for field experiments.     

The effect of bioaugmentation on the performance of sequencing batch reactor and sludge characteristics in the treatment process of papermaking wastewater

In this paper, the differences between reinforced sequencing batch reactor, which was inoculated with superior mixed flora, and conventional sequencing batch reactor were compared in the process of treating papermaking wastewater under similar conditions. The results showed that the addition of superior mixed flora could not only shorten the sludge acclimation time, but also improve the treatment efficiency of reactor as well as make the reactor have higher ability to withstand high volume loading rate; the phenomenon of aerobic granulation only occurred in reinforced sequencing batch reactor, and superior mixed flora were the key reason that aerobic granular sludge could shape; aerobic granular sludge had many advantages over conventional activated sludge such as it possessed compacter microbial structure, better settling performance, and lower water content.     

Advanced start-up of anaerobic attached film expanded bed reactor by pre-aeration of biofilm carrier

The start-up and performance of the anaerobic attached film expanded bed (AAFEB) reactor with pre-aeration of carrier were investigated. The carriers of the reactors had been aerated for 10 days before they were put into the AAFEB reactors. The results indicated that the reactors advance the start-up by 15 days, and maintain higher efficiency when they were subjected to organic and hydraulic loading shock, but during steady-state operation, the reactors did not show better performance than the control reactors without pre-aeration of carrier. The thicker biofilm and higher biomass concentration of the reactors with pre-aeration were observed during the start-up period, but the difference between two types of reactors tapered with the time course, and at the steady-state operation, the difference between two types of reactors on these two parameters was not obvious. Maximum specific methane or acids production rates, dehydrogenase activity and coenzyme F(420) content were continuously higher than those of the control reactors. After running 30 days, filamentous bacteria dominated in the reactors with pre-aeration, whereas the cocci were predominant species in the control reactors. It was suggested that the action of the biofilm is strongly dependent on the biofilm thickness or the biomass concentration in normal circumstances, but under adverse circumstances, such as organic or hydraulic loading shock, the characteristics and activity of the anaerobic granular sludge play key roles on the reactor performance. These results clearly indicated that pre-aeration of carrier favor to enhance the start-up and performance of AAFEB reactor.     

Small-scale domestic wastewater treatment using an alternating pumped sequencing batch biofilm reactor system

An alternating pumped sequencing batch biofilm reactor (APSBBR) system was developed to treat small-scale domestic wastewater. This laboratory system had two reactor tanks, Reactor 1 and Reactor 2, with two identical plastic biofilm modules in each reactor. Reactor 1 of the APSBBR had five operational phases—fill, anoxic, aerobic, settle and draw. In the aerobic phase, the wastewater was circulated between the two reactor tanks with centrifugal pumps and aeration was mainly achieved through oxygen absorption by microorganisms in the biofilms when they were exposed to the air. This paper details the performance of the APSBBR system in treating synthetic domestic wastewater over 18 months. The effluent from the APSBBR system satisfied the European Wastewater Treatment Directive requirements, with respect to COD, ammonium-nitrogen and suspended solids. The biofilm growth in the two reactor tanks was different due to the difference in substrate loadings and growth conditions.     

Quantitative comparison of stability of ANAMMOX process in different reactor configurations

A new stability evaluating system for ANAMMOX comprising three instability indices i.e. coefficient of variation ratio, coefficient of range ratio and coefficient of regression function derivative was established. Three lab-scale ANAMMOX reactors viz upflow anaerobic sludge blanket (UASB) reactor, upflow stationary fixed film (USFF) reactor and anaerobic sequencing batch reactor (ASBR) were compared for their stability based on the established criterion against the hydraulic and substrate concentration shocks. The results showed that all ANAMMOX reactors under investigation were more tolerant to the hydraulic shock than substrate concentration shock. The UASB reactor was the most stable reactor configuration towards substrate concentration shock, followed by the USFF reactor and ASBR. However, the ASBR proved the most tolerant to hydraulic shock, followed by the UASB reactor and USFF reactor. In terms of stability, UASB reactor was more suitable configuration compared with USFF reactor. The instability indices proved to be effective and explicit for the evaluation of ANAMMOX systems.     

Properties of phenol-removal aerobic granules during normal operation and shock loading

The physical structure and activity of aerobic granules, and the succession of bacterial community within aerobic granules under constant operational conditions and shock loading were investigated in one sequencing batch reactor over ten months. While the maturation phase of the granulation process began on day 30, the structure of microbial community changed markedly until after three months of reactor operation under constant conditions with a loading rate of 1.5 g phenol L⁻¹ day⁻¹. A shock loading of 6.0 g phenol L⁻¹ day⁻¹ from days 182–192 led to divergence of bacterial community, an inhibition of the biomass activity, and a decrease in phenol removal rate in the reactor. However, phenol was still completely removed under this disturbance. After the shock loading, the mean sizes of aerobic granules increased, and the activity of the microbial population within the granules decreased, although there appeared highly resilient for the dominant bacterial community of aerobic granules which mainly included β-Proteobacteria. Correlation analysis suggested that biomass concentration and biomass loading were significantly related to the community composition of aerobic granules during the whole operational period. The development of a relatively stable bacterial community in aerobic granules implied that those distinct dominant microbes in aerobic granules were favorably selected and proliferated under the operational conditions.     

Anammox start-up in sequencing batch biofilm reactors using different inoculating sludge

In this study, anammox bacteria were rapidly enriched in sequencing batch biofilm reactors (SBBRs) with different inoculations. The activated sludge taken from a sequencing batch reactor was used and inoculated to SBBR1, while SBBR2 was seeded with stored anaerobic sludge from an upflow anaerobic fixed bed (2-year stored at 5–15 °C). Nitrogen removal performance, anammox activity, biofilm characteristics and variation of the microbial community were evaluated. The maximum total nitrogen loading rate (NLR) of SBBR1 gradually reached to 1.62 kg?N/(m³/day) with a removal efficiency higher than 88 % and the NLR of SBBR2 reached to 1.43 kg?N/(m³/day) with a removal efficiency of 86 %. SBBR2 was more stable compared to SBBR1. These results, combined with molecular techniques such as scanning electron microscope, fluorescence in situ hybridization, and terminal restriction fragment length polymorphism, indicated that different genera of anammox bacteria became dominant. This research also demonstrates that SBBR is a promising bioreactor for starting up and enriching anammox bacteria.     

High efficiency of a coupled aerobic-anaerobic recycling biofilm reactor system in the degradation of recalcitrant chloroaromatic xenobiotic compounds

Chloroaromatic compounds are xenobiotics that cause great concern. The degradation of a model molecule, 3,4-dichlorobenzoate (3,4-DCB), was studied using three aerobic (AE)-anaerobic (AN) biofilm reactor systems: a coupled aerobic-anaerobic recycle biofilm reactor (CAR) system, an in-series anaerobic-aerobic biofilm reactor (SAR) system; and an independent aerobic and anaerobic biofilm reactor (IAR) system. In all three systems the inlet substrate concentration was 2.0 g/l and the dilution rates ranged from 0.045 to 0.142 per hour. The results show that the degradation efficiency of the CAR system (expressed as dechlorination and xenobiotic disappearance efficiencies, and biomass yield), was higher at all dilution rates tested than in both SAR and IAR systems. Moreover, dechlorination and xenobiotic disappearance efficiencies for resting suspended aerobic and anaerobic cells or mixed aerobic-anaerobic growing cells under anaerobic conditions were higher than under aerobic conditions. These results suggest that a “cooperative metabolism” between aerobic and anaerobic bacteria (caused by an exchange of cells and metabolites between AE and AN reactors) in the CAR system overcame the metabolic and kinetic limitations of aerobic and anaerobic bacteria in the AE and AN reactors of IAR and SAR systems. Therefore, the degradation efficiency of persistent and recalcitrant chloroaromatic xenobiotic compounds could be enhanced by using a CAR system. Received: 1 March 1999 / Received revision: 11 May 1999 / Accepted: 16 May 1999     

Performance and Microbial Structure of a Combined Biofilm Reactor

A novel combined biofilm reactor was established and applied as a single treatment unit for carbon and nitrogen removal of wastewater. The nitrogen removal performance of the reactor at different levels of organic carbon (COD) loading was investigated when the influent total nitrogen (TN) loading was 0.74 g TN/m² day. Continuous experimental results demonstrated that 80% nitrogen was eliminated when the influent COD loading ranged between 2.06 g and 3.92 g COD/m² day. Microbial composition in the reactor was analyzed using fluorescent in situ hybridization (FISH) and conventional batch tests. The relative abundance of ammonia-oxidizing bacteria in the aerobic zone of the reactor measured by FISH was consistent with the result from conventional batch tests.     

Influence of detachment,substrate loading and reactor scale on the formation of biofilms in airlift reactors

 For a stable and reliable operation of the biofilm airlift suspension reactor (BAS reactor) means to control biomass concentration, biofilm thickness and biofilm morphology are required. For this reason, the influence of applied detachment forces and surface substrate loading on the formation of heterotrophic biofilms in laboratory-scale BAS reactors was studied. Detachment forces were altered by variation of the initial bare carrier concentration or the superficial air velocity. In addition, the dynamics of biofilm formation during start-up of a full scale BAS reactor (300 m³) was monitored and compared with the laboratory-scale start-up (3 l). This study shows that the biofilm morphology and strength were influenced to a large extent by the surface substrate loading and applied detachment forces. A moderate surface substrate loading and a high detachment force yielded smooth and strong biofilms. The combination of a high surface substrate loading and low detachment forces did lead to rough biofilms, but did not lead to the expected high amount of biomass on the carrier, apparently because of the formation of weaker biofilms. The strength of the bio-films appeared to be related to the detachment forces applied during biofilm formation, in combination with the surface substrate loading. The biofilm morphology and biomass on carrier in the BAS reactor can be controlled using the carrier concentration, substrate loading rate and the superficial air velocity as parameters. The dynamics of biofilm formation during the start-up of a full-scale BAS reactor proved to be similar to heterotrophic biofilm formation in laboratory-scale reactors. This indicates that a model system on the laboratory scale can successfully be applied to predict dynamic phenomena in the full-scale reactor. Received: 31 March 1995/Received revision: 11 August 1995/Accepted: 22 August 1995