堆肥中纤维素和木质素的生物降解研究现状

堆肥是垃圾处理的主要方法之一 ,厨房垃圾、园林垃圾、农村秸秆和日常生活中的废弃纤维产品均可作为堆肥原料 ,这些原料中含有一定量的纤维素和木质素 ,而纤维素和木质素在堆肥过程中较难生物降解。因此 ,国内外学者致力于研究能加速纤维素和木质素降解的高效微生物。研究发现 ,对纤维素和木质素有降解能力的微生物主要是高温放线菌和高温真菌 ,其中有独特降解机制的白腐菌在木质素降解中起着重要作用     

电化学氧化与生物法联合降解木质素的影响因素

采用高效的电化学氧化技术联合低成本的生物降解技术,进行了木质素的降解探索。考察了电流密度、电量、初始pH和电解质浓度对木质素降解效果的影响,结果表明,电流密度和电量影响显著,而初始pH和电解质浓度的影响较小。经过综合比较,得到电化学与生物联合降解木质素的最佳反应条件为:电流密度为5.0 mA/cm2;电量为20 kC;初始pH为7;电解质浓度为0.1 mol/L。在此条件下,碱木质素和木质素磺酸钠的COD去除率分别达到65.97%和59.31%,表征木质素酚羟基结构的UV280分别降低了65.97%和59.77%,色度去除率分别为74.15%和58.32%。总之,电化学前处理可破坏木质素的关键结构,提高木质素的可生化性,从而促进加快后续生物降解。     

Evaluation of biodegradation of nonylphenol ethoxylate and lignin by combining toxicity assessment and chemical characterization

The aerobic biodegradation of commercial nonylphenol ethoxylate (NPE) mixture and alkali lignin was studied using the OECD headspace test accompanied by the simultaneous measurement of ecotoxicity directly from the biodegradation liquors and by the follow-up of the chemical composition of the studied chemicals. NPE degradation was dependent on the inoculum source: approximately 40% of NPE was mineralized into CO₂ during the 4-week experiment when inoculum from Helsinki City wastewater treatment plant (WWTP) was used, and only 12% was mineralized when inoculum from Jyväskylä City WWTP was used. Chemical analyses revealed a shift in the ethoxylate chain length from longer to shorter soon after the beginning of the NPE biodegradation tests. At the same time also toxicity (reverse electron transport assay, RET) and estrogenic activity (human estrogen receptor yeast) measured directly from the biodegradation liquors decreased. In case of alkali lignin, approximately 11% was mineralized in the test and chemical analysis showed in maximum a 30% decrease in lignin concentration. Toxicity of lignin biodegradation liquors started to decrease in the beginning of the test, but became more toxic towards the end of the test again. Especially RET assay proved to be sensitive enough for measuring toxicity changes directly from biodegradation liquors, although a concentrating treatment of the liquors is recommended for a more detailed characterization and identification of toxic metabolites.     

Decolorization and biodegradation of dye wastewaters by a facultative-aerobic process

BACKGROUND: Dye wastewater is one of the main pollution sources of water bodies in China. Conventional biological processes are relatively ineffective for color removal, the development of alternative treatment methods will become important. Our subjective was that of introducing a new biotreatment technology which combined a facultative biofilm reactor (FBR) with an aerobic reactor (AR) to treat a dye wastewater. The efficiencies of color and chemical oxygen demand (COD) removal and the mechanism of dye degradation were investigated. METHODS: The anthraquinone acid dye (acid blue BRLL) concentration, organic loading rate (OLR) and hydraulic retention time (HRT) were varied in the experiments to evaluate the treatment efficiency and process stability. The biodegradation products were detected by infrared (IR) and high performance liquid chromatography and mass spectrometry (HPLC-MS). RESULTS AND DISCUSSION: The results demonstrated that the facultative biofilm process was more effective for decolorization than the anaerobic stage of an anaerobic-aerobic process. Most color removal occurred in the facultative reaction (maximum to 88.5%) and the BOD (biochemical oxygen demand): COD of the FBR effluent increased by 82.2%, thus improving the biodegradability of dyes for further aerobic treatment. The dye concentration, OLR and HRT will be the factors affecting decolorization. Color removal efficiency falls as the influent dye concentration increases, but rises with increased HRT. The infrared and HPLC-MS analyses of the effluents of FBR and AR reveal that the dye parent compound was degraded in each reactor during the process. CONCLUSION: The Facultative-aerobic (F-A) system can effectively remove both color and COD from the dye wastewater. The FBR played an essential role in the process. The average overall color and COD in the system were removed by more than 93.9% and 97.1%, respectively, at an OLR of 1.1 kg COD m(-3) d(-1) and at the HRT of 18-20 hours in the FBR and 4-5 hours in the AR. The color removal mechanism in each reactor was not only a sort of biosorption on the floc materials, but even more an effect of biodegradation, especially in the facultative process. Recommendation and Outlook. In applying the F-A system to treat a dye wastewater, the control of facultative processes and the set up of appropriate operation conditions appear to be critical factors. Also, it is suggested a moderate COD loading rate and about a 24-hour HRT will favor the F-A system.     

氯过氧化物酶对苯酚生物降解的促进作用

氯过氧化物酶是一种底物广泛的手性催化剂,可以催化卤素离子、芳香族化合物和醇类化合物等进行过氧化反应.利用氯过氧化物酶催化氧化苯酚,考察其对苯酚生物降解的促进作用.结果表明,500、1 000 mg/L苯酚在氯过氧化物酶为10 U/mL、pH为6.5、H2 O2投加量为10 mg/L时8h苯酚降解率分别达到86.6％和83.8％,比单纯菌株降解显著提高.说明氯过氧化物酶能快速清除苯酚污染的危害,提高苯酚的生物降解速率.     

非离子型表面活性剂吐温80增溶条件下菲的生物降解

本实验的目的是研究非离子型表面活性剂吐温 80 (Tween 80 )对菲的溶解及生物降解过程的影响。结果表明 ,通过吐温 80促溶 ,菲在水中的溶解度有明显的提高。在与菲共同降解的过程中 ,吐温 80亦能作为碳源被降解微生物利用。但是 ,高浓度的吐温 80对菲的降解有一定的抑制作用 ,同时在菲的降解完成后造成较高的残留表面活性剂量和微生物量     

活性污泥洗涤净化餐饮油烟VOCs及其生物降解过程

将活性污泥驯化25 d后,考察了其性能及其在洗涤净化餐饮油烟VOCs过程中气液组成与微生物群落的变化。结果表明：驯化后活性污泥的MLSS稳定在3.10 g·L^-1,MLVSS稳定在1.60~1.90 g·L^-1,SV、SVI分别稳定在35 %和120 mL·g^-1;在此条件下,洗涤净化系统对油烟的洗涤效率稳定在85%;系统对油烟中烯醛类、醇类、烷烃类、酯类的洗涤效率达到95 %以上,仅对部分直链醛类的洗涤效果较差;驯化前活性污泥中有机物以氯代物和长链烷烃为主,而驯化后酯类成为新增主要成分。此外,活性污泥液相油烟衰减实验共检出18种有机物化合物。其中,14种有机物在第1~3天降解期内被微生物降解完全;在第4~5天内,十五烷、8-十七烷烯、17-三十五碳烯被完全降解,仅剩三氯乙烯仍保持较高的含量。高通量测序分析结果表明：液相油烟VOCs降解过程中起主要代谢作用的微生物为Planctomicrobium、Spartobacteria、Microbacterium、Steroidobacter、Rubinisphaera、Luteolibacter、Phycisphaera细菌属和Nectriaceae、Trichoderma、Saccharomycetes、Cryptococcus、Trichosporonaceae、Archaeorhizomycetaceae、Yarrowia真菌属;微生物种类及相对丰度受液相油烟VOCs组分影响,且随降解反应的进行而变化。本研究可为生物洗涤法处理餐饮油烟的技术应用提供参考。     

共代谢条件下丁基黄药的生物降解实验研究

微生物共代谢是降解废水中难降解有机物的重要方式。通过实验研究,比较了以丁基黄药作为唯一碳源和能源以及有共代谢基质存在下丁基黄药的降解过程。结果表明,共代谢显著提高了丁基黄药的降解率。在25℃条件下,以丁基黄药为唯一碳源和能源时,其降解率仅为43.1%;而利用葡萄糖作为共代谢基质,当葡萄糖质量浓度为0.20g/L时,振荡培养72h后丁基黄药的降解率可达65.2%;再加入微量的蛋白胨作为氮源后,丁基黄药的降解率可提高到73.5%;加入共代谢基质后微生物的适应期由原来的36h缩短至24h。共代谢是提高丁基黄药生物降解性能的一条有效途径。     

白腐菌S.commune降解微囊藻毒素-LR的研究

为研究真菌对微囊藻毒素的降解作用,以白腐菌S.commune为降解菌,微囊藻毒素-LR(MC-LR)为降解目标进行生物降解,考察了白腐菌预培养方式及降解过程中的培养方式、充氧方式、温度、初始pH以及MC-LR初始浓度对降解效果的影响.结果表明,白腐菌可有效降解MC-LR,经液体预培养白腐菌对MC-LR的降解效果好于固体预培养,白腐菌静置培养过程中每天充入纯氧1min有助于MC-LR的降解,白腐菌降解MC-LR的最佳初始pH为4.5,适宜温度为30～35℃.白腐菌对MC-LR的降解能力随MC-LR初始浓度的增加而降低.在最佳条件下,当MC-LR初始质量浓度为1 mg/L时,其完全降解需要2d;当MC-LR初始质量浓度为15 mg/L时,其完全降解需要7d.高浓度MC-LR(30 mg/L以上)会对白腐菌生长产生抑制作用.MC-LR降解中间产物的具体结构尚不清楚,有待未来深入分析研究.     

生物净化甲苯气体的中间产物控制研究

为了提高生物法净化甲苯气体的去除能力,对甲苯降解过程中的中间产物控制问题进行了研究.以甲苯为碳源,驯化分离出甲苯降解菌 Pseudomonas putida,通过封闭系统的反应器试验,测定降解菌体的生长特性和中间代谢产物对甲苯矿化的影响,在生物滴滤实验系统(φ40 mm×H 500 mm)上,研究甲苯降解的中间产物产生、积累和控制问题.结果表明,甲苯的降解中主要有中间产物邻苯二酚的积累,中间产物邻苯二酚的氧化反应支持了 Pseudomonas putida 菌的生物合成.当气体流量 60～100 L/h,甲苯入口浓度0.14～1.71 S/m3时,邻苯二酚最大累积量为0.045 mg/L;采用白天运行12 h,夜间停运12 h的模拟工况运行方式,停止有机废气基质供应时,生物降解积累的中间产物邻苯二酚在 6～10 h 内完全矿化,邻苯二酚继续氧化可转化为生物量,维持系统的稳定性.     

共基质对白腐菌降解喹啉的影响

选用吲哚、苯酚和氨氮作为喹啉降解的共基质.通过白腐菌BP对共基质的降解,研究了白腐菌BP对不同共基质降解体系中喹啉的降解过程及其反应动力学,同时研究了共基质物质对白腐菌BP漆酶活力、生物量增长速率和降解体系pH的影响.结果显示,白腐菌BP对不同共基质降解体系中的喹啉均具有较高的降解率,共基质物质苯酚、吲哚和氨氮对喹啉的降解有一定的抑制作用;共基质降解体系使白腐菌BP漆酶系统启动更加迅速,漆酶活力峰值提前出现;共基质降解体系能促进白腐菌BP的生长,缩短白腐菌BP的生长周期;秸秆滤出液培养基中,pH为6.00～8.00时,白腐菌BP对喹啉均具有较强的降解能力.     

草浆碱木素过氧化氢氧化氨解制备氨化木质素缓释肥料的研究

研究了草浆碱木素的过氧化氢氧化氨解的工艺过程,研究了各种工艺参数对过氧化氢氧化氨解的影响。在最佳的工艺条件,120℃, 90 min 反应时间, 20%过氧化氢用量和20% 氨水用量下,得到的氨化木质素总氮11.62%,氨态氮4.12%。研究表明过氧化氢完全可以替代氧气作为木质素氧化剂,为草浆碱木素转化成有机肥料提供依据。     

不同共代谢基质对四氯乙烯的厌氧生物降解研究

用驯化好的厌氧污泥对葡萄糖、乳酸盐和醋酸盐作为电子供体时四氯乙烯（PCE）的降解进行研究.实验结果表明,PCE是通过还原脱氯发生生物降解的.实验的回归结果表明,反应均符合一级动力学反应速率,常数的大小依次为k乳酸＞k葡萄糖＞k醋酸.表明乳酸盐作为电子供体时PCE的降解速率较快,说明在实验条件下乳酸盐是最合适的电子供体.并且在整个实验过程中由共代谢基质提供的电子供体不是PCE降解的限制因素.     

氟苯胺好氧生物降解性能的研究

利用驯化污泥研究了邻氟苯胺、对氟苯胺、2,4-二氟苯胺的好氧生物降解性能.结果表明,3种氟苯胺的好氧生物降解性能从高到低依次为对氟苯胺、邻氟苯胺和2,4-二氟苯胺.降解动力学分析表明,除2,4-二氟苯胺在实验质量浓度8.56 mg/L时为一级反应,其他为零级反应;且它们的降解规律都符合Monod方程;30 ℃、振荡速率140 r/min为氟苯胺的最佳降解条件.同时研究了共基质条件下葡萄糖和苯胺对2,4-二氟苯胺的好氧降解的影响,葡萄糖的引入有促进作用,而苯胺只在一定浓度范围内有促进作用.氟苯胺的生产废水与生活污水合并处理以及多种组分混合废水处理是可行的.     

不同共代谢基质对四氯乙烯的厌氧生物降解研究

用驯化好的厌氧污泥对葡萄糖、乳酸盐和醋酸盐作为电子供体时四氯乙烯(PCE)的降解进行研究。实验结果表明,PCE是通过还原脱氯发生生物降解的。实验的回归结果表明,反应均符合一级动力学反应速率,常数的大小依次为k乳酸>k葡萄糖>k醋酸。表明乳酸盐作为电子供体时PCE的降解速率较快,说明在实验条件下乳酸盐是最合适的电子供体。并且在整个实验过程中由共代谢基质提供的电子供体不是PCE降解的限制因素。     

Determination of naturally occurring MTBE biodegradation by analysing metabolites and biodegradation by-products

Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline. Its degradation is known to be difficult in natural environments. In this study, significant MTBE degradation is demonstrated at a contaminated site in Leuna (eastern Germany). Since the extent of the plume appeared to be constant over the last 5 years, an extended study was performed to elucidate the degradation processes. Special attention was paid to the production, accumulation and degradation of metabolites and by-products. Groundwater samples from 105 monitoring wells were used to measure 20 different substances. During the degradation process, several intermediates such as tert-butyl alcohol (TBA), tert-butyl formate, formate and lactate were produced. However, the potentially carcinogenic by-product methacrylate was not detected in several hundred samples. At the Leuna site, MTBE degradation occurred under microaerobic conditions. In contrast to hydrocarbons and BTEX, there was no evidence for anaerobic MTBE degradation. Among the degradation products, TBA was found to be a useful intermediate to identify MTBE degradation, at least under microaerobic conditions. TBA accumulation was strongly correlated to MTBE degradation according to the kinetic properties of both degradation processes. Since maximum degradation rates (v(max)) and k(m) values were higher for MTBE (v(max)=2.3 mg/l/d and k(m)=3.2 mg/l) than for TBA (v(max)=1.35 mg/l/d and k(m)=0.05 mg/l), TBA significantly accumulated as an intermediate by-product. The field results were supported by bench scale model aquifer experiments.     

Study of the biodegradation process of polychlorinated biphenyls in liquid medium and soil by a new isolated aerobic bacterium (Janibacter sp.)

We have isolated and characterised a novel aerobic bacterial strain, designated MS3-02, belonging to the genus Janibacter sp. The capability of this new strain to degrade polychlorinated biphenyls (PCBs) in a commercial mixture (Aroclor 1242) in liquid medium and in soil (sterile and non sterile soil), under laboratory scale, has been evaluated. MS3-02 was isolated from the soil around of an incinerator, located in the east of Madrid (Spain). Gas-chromatographic analysis showed that MS3-02 was able to reduce most peaks observed in the chromatogram between 70% and 100% after seven days of incubation in a culture mineral medium containing yeast extract, but without the addition of biphenyl. The presence of biphenyl in the culture medium decreased the rate of PCB degradation by this bacterium. Comparing the performance of the MS3-02 in liquid culture medium and in soil, degradation was less efficient in sterile soil and still less efficient in non sterile soil. Under the best conditions (sterile soil and 20 weeks of incubation) MS3-02 was able to reduce, between 50% and 100%, nine of the main gas-chromatographic peaks in Aroclor 1242.     

污水处理过程中BTEX迁移降解与去除途径研究

以某涂料废水为研究对象,采用实验检测废水中BTEX浓度和模式计算挥发量相结合的研究方法,对BTEX污染物在污水处理过程中的迁移降解与去除途径进行研究,分析隔油、气浮、氧化沟工艺对苯系物去除效果,同时研究了吸附、挥发和生物降解3大去除途径对苯系物去除的影响。研究表明,该工艺对BTEX的去除效率高,苯的总去除效率为88.11%,甲苯、乙苯、邻二甲苯和间、对二甲苯总去除率分别高达98.14%、98.09%、97.45%和97.68%。其中苯、甲苯、乙苯、邻二甲苯主要都是在氧化沟中去除,间、对二甲苯在气浮池和氧化沟都有较高的去除率,隔油池工艺对BTEX的去除率较低。去除途径方面,苯以挥发为主,甲苯、乙苯和邻二甲苯都以生物降解为主要去除途径,而挥发和生物降解对间、对二甲苯的去除作用相当。     

甲苯在硝酸盐还原条件下的生物降解性能研究

通过对长期受石油污染的土著微生物进行培养驯化,得到适于降解甲苯的优势混合菌,并对其在硝酸盐还原条件下降解甲苯的件能进行研究.结果表明,驯化所得甲苯降解菌的最适降解条件为:温度25℃,pH值7.5,C/N值15,接种量1%.混合降解菌对硝态氮的去除符合一级动力学特征,其降解速率常数为0.0021 mg/(L·h).采用非...