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污水处理过程中微塑料去除的现状及发展趋势北大核心CSCD 总被引:1,自引:0,他引:1
微塑料(microplastics,MPs)被发现广泛存在于海洋、陆地以及大气等生态系统中。城市污水中的大量微塑料被污水处理厂截留在活性污泥中,但仍有不计其数的微塑料颗粒“逃脱”污水处理厂,排放到自然环境中。与此同时,污水处理过程中绝大部分微塑料会转移到污泥中,伴随着活性污泥的利用过程进入土壤环境,形成微塑料的二次污染。文中基于对国内外文献的调研,对环境中微塑料的来源、分布及危害进行了概述,对活性污泥工艺过程中微塑料的处理情况以及活性污泥中残留微塑料的处理方式进行了梳理;展望了生物技术及合成生物学在活性污泥核心菌群遗传改造,赋予核心菌群微塑料降解能力方面的应用;以期为优化污水处理厂MP的降解提供参考。 相似文献
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城市污水处理厂运行过程中一旦发生活性污泥生物泡沫,就会影响污泥沉降和处理厂运行效能,对出水水质、作业安全和公共健康带来一系列挑战。生物泡沫是自活性污泥法诞生以来长期困扰污水处理厂运行的难题。生物泡沫的形成需要气泡、表面活性物质和疏水物质等3点基本的要素,在其中主要富集了诺卡氏型丝状细菌(Nocardioformfilamentousbacteria)和微丝菌(Candidatus Microthrix parvicella)这两种类型微生物。多种环境和运行因素包括温度、溶解氧、pH、污泥龄、特别是营养物质种类和浓度等均会对这些丝状微生物的生长产生影响。抑制丝状细菌生长的常用控制策略包括选择器、生长动力学控制、投加化学药剂以及噬菌体等方法,通过降低两类丝状细菌在生化池中的浓度以期消除生物泡沫现象。本文总结了生物泡沫的类型、成因、表征生物泡沫程度的指标、影响生物泡沫的环境因素以及常用的调控策略的原理及优缺点等,尽可能全面地介绍活性污泥生物泡沫的研究现状,并探讨未来研究方向和控制策略,期望能够为今后研究活性污泥微生物和污水处理厂运行调控提供有价值的参考。 相似文献
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维生素B_(12)也称氰钴胺素,是首先在动物性蛋白质中被发现的一种促生长因素,后来在城市下水道、污水处理厂的活性污泥和沼气残留物中被发现。无论动物或植物都不能合成维生素B_(12),它只能由某些微生物合成,如灰色链霉菌(Streptomycesgriseus)、巨大芽孢杆菌(Bacillus megaterium)、菲德力丙酸杆菌(Propionibacterium freudereichii)、舒氏丙酸杆菌(P·shermaii)等。在嫌氧发酵过程中,某些甲烷菌如欧氏甲烷杆菌(Methano bacterium omelianski)的生长,也产生维生素B_(12)。日本小野英男于1950年报道了测定酒 相似文献
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原生动物在活性污泥中的作用 总被引:16,自引:1,他引:15
处理污水有三个重要作用 ,保护环境 ,维护生态系统的健康 ;除去污水中的病菌 ,维护人类健康 ;通过中水的回用 ,提高水资源的利用率。 1913年英国的Ardern和Lockett在曼彻斯特建立了世界上第一座活性污泥试验工厂 ,现在活性污泥法已经成为世界各国广泛采用的污水处理方法。在我国城市污水处理厂中 ,采用活性污泥法的占 85 %以上 ,该法的中心环节是曝气形成活性污泥 ,通过生物消耗分解污染物 ,随后活性污泥在沉淀池中沉淀分离 ,从而净化污水。该过程的主要目的是通过微生物的吸收和降解 ,尽量减少污泥的生成量。原生动物是活性污… 相似文献
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污水处理厂污泥膨胀和污泥发泡的比较分析 总被引:1,自引:1,他引:0
活性污泥法由于操作简单、处理效果好被广泛应用于市政污水和工业废水的处理。污泥膨胀和污泥发泡现象影响二次沉淀池的泥水分离过程和生物反应池的微生物量稳定,严重困扰着污水处理厂的正常运行,被称为污水处理厂的"癌症"。本文从污泥膨胀和污泥发泡的定义及分类出发,全面地比较了表征污泥膨胀和污泥发泡的方法、引起污泥膨胀和污泥发泡的丝状细菌种类及控制污泥膨胀和污泥发泡方法的异同,并探讨了污泥膨胀和污泥发泡问题的未来研究方向和控制策略,期望能够为今后污泥膨胀和污泥发泡问题的研究和调控提供有价值的参考。 相似文献
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为了解海口市白沙门污水处理厂活性污泥中细菌抗生素耐性情况,采用平板分离技术分离、纯化细菌,并通过BIOLOG微生物鉴定系统对筛选到的细菌进行鉴定,同时采用Kirby-Bauer纸片琼脂扩散法进行药敏试验并进行抗生素耐性分析。本研究共分离到18株细菌,分属8个属,14个种,其中G+和G-均为9株。抗生素药敏性试验结果表明,所有菌株均耐药,菌株单重耐药率、双重耐药性及多重耐药性分别为50%、38.9%、和11.1%。菌株对9种常用抗生素:头孢他啶、环丙沙星、庆大霉素、链霉素、氨苄西林、红霉素、氯霉素、四环素、卡那霉素的耐药率分别为61.1%、0%、5.6%、16.7%、50%、16.7%、11.1%、0%、5.6%。综上所述,白沙门污水处理厂活性污泥中的细菌耐药性比较严重,存在潜在的环境生态和人畜健康风险。本研究揭示了当前白沙门污水处理厂活性污泥中细菌对常见抗生素耐药的严重现状,为建议污水处理厂加强出水及污泥中抗生素耐药性及耐药基因的检测并评估其生态影响提供基础,避免出水及污泥中的抗性菌和耐药基因可能带来的风险问题。 相似文献
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The main purpose of this paper is to study naphthalene (NAP) biodegradation by acclimated activated sludge, employing the culture-enrichment method in a continuous flow bioreactor of the wastewater treatment process. The effects of various COD loadings and influent flow rates of an artificial wastewater containing 15 mg l−1 NAP on the biodegradation rates of the activated sludge will be investigated, in order to determine the biodegradation kinetics and minimum mean cell residence time of the activated sludge. From the experimental results, it was found that the resulting enriched activated sludge follows the growth rate of the Monod type and can biodegrade those COD and NAP loadings in the influents efficiently, and its bio-treatment efficiency on NAPs increases with the decrease of influent flow rate. The sludge volume index (SVI) of the resulting enriched activated sludge meets the design value required by the convectional activated sludge process for the treatment of wastewater. 相似文献
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Tannins occur commonly in the wastewaters from forestry, plant medicine, paper and leather industries. The treatment of this
kind of wastewaters, including settling and biodegradation, is usually difficult because tannins are highly soluble in water
and would inhibit the growth of microorganisms in activated sludge. The objective of this study is to investigate biodegradability
of tannin-containing wastewaters, so as to characterize the pollution properties of such wastewaters and provide a reference
for their biological treatment in wastewater treatment plants. The research was typified by using the wastewater collected
from vegetable tanning process in leather industry. A model was developed to describe the activated sludge process, and the
biodegradation kinetics of vegetable tanning wastewater (VET wastewater) was studied. It was found that the biodegradability
of tannin-containing wastewater varies heavily with the content of tannins in wastewater. The biodegradation of VET wastewater
with tannin content around 4,900 mg/l occurred inefficiently due to the inhibition of tannins to the activated sludge process,
and only 34.7% of biodegradation extent was reached in 14 days of incubation. The optimal biodegradability of VET wastewater
was observed when its tannin content was diluted to 490 mg/l, where the COD and tannin removals reached 51.3% and 45.1% respectively
in 6 days. Hence, it is suggested that a proper control of tannin content is necessary to achieve an effective biodegradation
of tannin-containing wastewaters in wastewater treatment plants. 相似文献
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Influence of the activated sludge system configuration on heavy metal toxicity reduction 总被引:1,自引:0,他引:1
Ufuk Alkan Sevil Çalışkan Eleren Berrak Erol Nalbur Elif Odabaş 《World journal of microbiology & biotechnology》2008,24(8):1435-1443
The effect of configuration of activated sludge systems on heavy metal toxicity was investigated. Two bench-scale completely
mixed activated sludge systems were operated identically in order to determine the toxic effects of Cr(VI), Zn(II) and industrial
wastewater on the activated sludge biomass. One system was operated with an aerobic selector and the other without. Batch
experiments based on OECD 209 (Organisation for Economic Cooperation and Development) were performed using a respirometer
to find out potential toxicity reduction effect of an aerobic selector. The IC50 (concentration of a chemical that exhibits 50% respiration inhibition) values of Cr(VI), Zn(II) and industrial wastewater
in the activated sludge were determined. Results indicated that the heavy metals and industrial wastewater caused less inhibitory
effect on the selector activated sludge system in comparison to the conventional activated sludge system. Cr(VI) was found
to exert higher inhibition on both systems. 相似文献
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C. Seignez N. Adler J. C. Suard P. Péringer 《Applied microbiology and biotechnology》1996,45(5):719-722
The present work investigates 1-anthraquinone sulphonate (1-AS) biodegradation under (i) aerobic conditions using domestic
activated sludge as inoculum, (ii) anaerobic conditions using sludge from an anaerobic domestic wastewater treatment digestor
in a sulphate-containing or methanogenic environment, (iii) a combination of anaerobic followed by aerobic conditions. The
process was evaluated in terms of primary degradation, i.e. 1-AS elimination and ultimate degradation, as total dissolved
organic carbon removal. It was shown that aerobic conditions lead to the complete primary and ultimate degradation, of 1-AS.
By contrast, neither under sulphato-reductive nor methanogenic conditions does anaerobic digestion lead to the significant
degradation of 1-AS. The use of anaerobic treatment followed by aerobic treatment did not improve degradation. Indeed aerobic
post-treatment resulted in the re-appearance of pollutant in the medium even though this had been partly degraded under anaerobic
conditions.
Received: 12 October 1995/Received revision: 18 December 1995/Accepted: 8 January 1996 相似文献
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Yu. V. Litti V. K. Nekrasova N. I. Kulikov M. V. Siman’kova A. N. Nozhevnikova 《Microbiology》2013,82(6):690-697
Attached activated sludge from the Krasnaya Polyana (Sochi) wastewater treatment plant was studied after the reconstruction by increased aeration and water recycle, as well as by the installation of a bristle carrier for activated sludge immobilization. The activated sludge biofilms developing under conditions of intense aeration were shown to contain both aerobic and anaerobic microorganisms. Activity of a strictly anaerobic methanogenic community was revealed, which degraded organic compounds to methane, further oxidized by aerobic methanotrophs. Volatile fatty acids, the intermediates of anaerobic degradation of complex organic compounds, were used by both aerobic and anaerobic microorganisms. Anaerobic oxidation of ammonium with nitrite (anammox) and the presence of obligate anammox bacteria were revealed in attached activated sludge biofilms. Simultaneous aerobic and anaerobic degradation of organic contaminants by attached activated sludge provides for high rates of water treatment, stability of the activated sludge under variable environmental conditions, and decreased excess sludge formation. 相似文献
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A systematic lab-scale experimental investigation is reported for the external nitrification (EN) biological nutrient removal (BNR) activated sludge (ENBNRAS) system, which is a combined fixed and suspended medium system. The ENBNRAS system was proposed to intensify the treatment capacity of BNR-activated sludge (BNRAS) systems by addressing two difficulties often encountered in practice: (a) the long sludge age for nitrification requirement; and (b) sludge bulking. In the ENBNRAS system, nitrification is transferred from the aerobic reactor in the suspended medium activated sludge system to a fixed medium nitrification system. Thus, the sludge age of the suspended medium activated sludge system can be reduced from 20 to 25 days to 8 to 10 days, resulting in a decrease in reactor volume per ML wastewater treated of about 30%. Furthermore, the aerobic mass fraction can also be reduced from 50% to 60% to <30% and concommitantly the anoxic mass fraction can be increased from 25% to 35% to >55% (if the anaerobic mass fraction is 15%), and thus complete denitrification in the anoxic reactors becomes possible. Research indicates that both the short sludge age and complete denitrification could ameliorate anoxic aerobic (AA) or low food/microorganism (F/M) ratio filamentous bulking, and hence reduce the surface area of secondary settling tanks or increase the treatment capacity of existing systems. The lab-scale experimental investigations indicate that the ENBNRAS system can obtain: (i) very good chemical oxygen demand (COD) removal, even with an aerobic mass fraction as low as 20%; (ii) high nitrogen removal, even for a wastewater with a high total kjeldahl nitrogen (TKN)/COD ratio, up to 0.14; (iii) adequate settling sludge (diluted sludge volume index [DSVI] <100 mL/g); and (iv) a significant reduction in oxygen demand. 相似文献
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A sequential anaerobic–aerobic biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was studied. The results demonstrated
that: (i) a complete degradation of RDX was achieved within 20 days using a consortium of bacteria from a wastewater activated
sludge, (ii) RDX degradation did not occur under aerobic conditions alone, (iii) RDX-degrading bacterial strain that was isolated
from the activated sludge completely degraded RDX within 2 days, and (iv) RDX- induced protein expressions were observed in
the RDX-degrading bacterial strain. Based on fatty acid composition and a confirmation with a 16S rRNA analysis, the RDX-degrading
bacterial strain was identified as a Bacillus pumilus—GC subgroup B. 相似文献
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The aim of this study was to determine the impact of a static magnetic field (MF) of 7 mT on formaldehyde (FA) biodegradation by activated sludge in synthetic wastewater. The MF had a positive effect on activated sludge biomass growth and dehydrogenase activity. The influence of the MF on the degradation process was observed with a FA concentration of 2400-2880 mg/l. Decreases in FA concentration and chemical oxygen demand (COD) were greater, by 30% and 26% respectively, than those in the control sample. At initial FA concentrations in raw wastewater of 2400 and 2880 mg/l, a decrease in the wastewater biodegradation efficiency was observed. This resulted in an increase of the ecotoxicity of the effluent to Daphnia magna. The value of the sludge biotic index (SBI) was dependent on the FA concentration in raw wastewater and the induction of the MF. 相似文献
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《Process Biochemistry》2010,45(6):919-928
2-Methylquinoline is a common organic contaminant in environment. Its degradation in wastewater treatment system has not been fully explored. In this study, batch experiments were conducted to investigate the biodegradation of 2-methylquinoline by activated sludge under both aerobic and denitrifying conditions. The results showed that 2-methylquinoline was degraded under both conditions, but the degradation under aerobic condition was significantly faster than that under denitrifying condition. Total organic carbon (TOC) residues were detected in the final effluent under both conditions, indicating the formation of recalcitrant metabolites. Further analysis identified 1,2,3,4-tetrahydro-2-methylquinoline, N,N-diethyl-benzenamine, and 4-ethyl-benzenamine as common metabolites under both conditions. 4-Butyl-benzenamine and 2,6-diethyl-benzenamine were additional metabolites under the aerobic condition, whereas 2-methyl-4-quinolinol was exclusive to the denitrifying condition. Most of these metabolites were further degraded during the treatment process. 1,2,3,4-Tetrahydro-2-methylquinoline, however, remained in the final effluent under both conditions, implying its persistence in the environment. It can be concluded that 2-methylquinoline undergoes the similar degradation pathway under both treatment conditions. 相似文献