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     

实验室模拟高负荷SPAC厌氧反应器运行

采用模拟废水, 对新型高负荷螺旋式自循环(Spiral automatic circulation, SPAC)厌氧反应器的运行性能进行了实验室模拟研究。结果表明: 在30oC, 水力停留时间(HRT)为12 h, 进水COD浓度从8000 mg/L升至20 000 mg/L的条件下, 反应器的COD去除率为91.1%~95.7%, 平均去除率为93.6％。在进水浓度为20 000 mg/L, HRT由5.95 h缩短至1.57 h的工况下, COD去除率从96.0%降低至78.7%, 反应器达到最高容积负荷率306 g COD/(L·d), 最大容积COD去除率240 g/(L·d), 最高容积产气率131 L/(L·d)。该反应器对基质浓度的连续提升具有良好的适应能力。进水COD浓度由8000 mg/L提升至20 000 mg/L时, 出水COD浓度一直处在较低水平(平均为852?mg/L), 容积COD去除率和容积产气率分别提高162%和119%。该反应器对HRT的连续缩短也有良好的适应能力。HRT由5.95 h缩短至1.57 h时,反应器容积COD去除率和容积产气率分别升高191%和195%。     

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。     

木质纤维素燃料乙醇蒸馏废水的高温厌氧处理及菌群结构分析

【目的】为开发高效的高浓度木质纤维素燃料乙醇蒸馏废水厌氧处理及资源化利用工艺,以活性炭为载体,在实验室规模上对高温厌氧流化床反应器处理木质纤维素燃料乙醇蒸馏废水进行研究。【方法】反应器经65 d梯度驯化后启动,对工艺参数进行一系列优化,并通过基于16S rRNA基因的分子生态学技术分析厌氧污泥中的优势菌群。【结果】实验获得了最优的反应条件和处理效果:厌氧流化床反应器(Anaerobic fluidized bed reactor,AFBR)在温度55±1°C、有机负荷率(OLR)13.8 g COD/(L·d)及水力停留时间(HRT)48 h操作时,COD去除率达到90%以上,同时甲烷产率达到290 mL/g COD;菌群鉴定分析结果显示高温厌氧活性污泥中Clostridia所占比例最大,产甲烷菌属以Methanoculleus和Methanosarcina为主,其它功能菌群主要为Alphaproteobacteria等。【结论】AFBR反应器可高效降解木质纤维素燃料乙醇蒸馏废水并产生生物能源甲烷,其反应体系内微生物种类丰富。     

中试厌氧氨氧化反应器的启动与调控

研究了中试厌氧氨氧化(Anaerobic ammonium oxidation,Anammox)反应器的启动性能。结果表明,以硝化反硝化污泥、短程硝化污泥、厌氧絮体污泥和厌氧颗粒污泥混合接种,经过255d的运行,可在常温下(5oC～27oC)成功启动中试Anammox反应器,反应器的基质氮去除速率可达1.30kg/(m3·d)。厌氧氨氧化是致碱反应,厌氧氨氧化成为反应器内的主导反应后,进水pH宜控制在厌氧氨氧化适宜范围的偏低水平(6.8左右)。亚硝酸盐既是Anammox菌的基质,也是抑制剂,控制进水亚硝酸盐浓度(13～36mg/L)有助于厌氧氨氧化反应。菌种是生物反应器的功能之源,向中试装置投加少量厌氧氨氧化污泥(投加比2%),可大大加速中试Anammox反应器的启动进程。     

流加菌种对厌氧氨氧化工艺的影响

厌氧氨氧化工艺具有很高的容积氮去除速率,现已成功应用于污泥压滤液等含氨废水的脱氮处理,容积氮去除速率高达9.5 kg/(m3·d)。但由于厌氧氨氧化菌为自养型细菌,生长缓慢,对环境条件敏感,致使厌氧氨氧化工艺启动时间过长,运行容易失稳,并且不适合处理有机含氨废水和毒性含氨废水,极大地限制了该工艺的进一步推广应用。为了克服厌氧氨氧化工艺实际应用中存在的问题,结合发酵工业中常用的菌种流加技术,提出了一种新型的菌种流加式厌氧氨氧化工艺,研究了该新型工艺在厌氧氨氧化工艺的启动过程、稳定运行以及处理有机含氨废水和毒性含氨废水等方面的应用情况。结果表明,通过向反应器内补加优质厌氧氨氧化菌种,可提高厌氧氨氧化菌数量及其在菌群中的比例,强化厌氧氨氧化功能。据此研发的菌种流加式厌氧氨氧化工艺不仅可以实现快速启动,而且可以稳定运行,并突破了有机物和毒物所致的运行障碍,拓展了厌氧氨氧化工艺的应用范围。     

畜禽粪便和粪水厌氧消化技术分析与展望

随着我国畜禽养殖集约化程度的不断提高,畜禽粪污导致的环境污染已成为畜禽养殖业发展面临的重要制约因素。粪污通过厌氧消化可回收能源、生产沼肥和消灭病原菌,避免对环境产生危害,是畜禽粪污处理和资源利用技术链条的核心环节。根据原料性质的差异,将粪污区分为畜禽粪便与养殖废水,分别探讨了这两种处理对象厌氧消化处理的不同技术难点和发展方向。针对畜禽粪便,重点探讨了高含氮粪便厌氧消化过程中存在的氨抑制问题及解除氨抑制的方法;针对养殖废水,介绍了废水处理与回用标准,比较分析了升流式厌氧污泥床、厌氧膜生物反应器、厌氧折流板反应器和自搅拌厌氧折流板反应器等几种代表性的和新型的废水厌氧处理工艺,并展望了技术的创新发展,旨在为畜禽粪便和养殖废水的厌氧消化及废水回用技术的发展提供参考。     

UASBF反应器处理垃圾渗滤液的试验研究

研究了上流式厌氧复合床反应器(UASBF)处理垃圾渗滤液的启动期、负荷提高期、运行期的处理效果及COD_Cr负荷、pH、碱度对反应器运行的影响.结果表明,启动期最佳启动温度在35±1℃,进水pH6.8,COD_Cr浓度1000～1200 mg·L^-1,水力停留时间(HRT)48h,容积负荷为0.5kgCOD_Cr·m^-3·d^-1.提高期和运行期容积负荷为10kg COD_Cr·m^-3·d^-1,COD_Cr去除率为71.5%,氨氮去除率为57.5%,总磷去除率为64.8%,悬浮物达到去除率为55%.     

厌氧氨氧化膨胀床反应器的运行性能

试验研究了以竹炭为载体的厌氧氨氧化膨胀床反应器的运行性能.接种反硝化污泥,用模拟废水可成功启动该反应器:运行至144 d时,容积总氮去除率达到3.02 kg N/m3/d.这是国内文献报道的最高水平.动力学分析表明.这种反应器的最大容积总氮去除率可迭12.77 kg N/m3/d.具有很大的脱氮潜能.反应器的启动过程可分为菌体自溶、活性延滞和活性提高三个阶段.与此相应,污泥性状也从黄褐色絮状污泥变为棕灰色颗粒污泥和红色颗粒污泥.红色颗粒污泥以杆茵和球菌为主.厌氧氨氧化活性可达0.56mg TN/(mgprotein)/h,它们是反应器厌氧氨氧化功能的主要承载者.     

UASB-化学混凝技术处理草浆造纸废水的研究

采用UASB-化学混凝技术组合对草浆造纸废水进行处理。结果表明,接种颗粒污泥的二级启动,大大缩短了反应器的启动时间。在水力停留时间(HRT)6 h,进水COD逐渐提高的情况下对颗粒污泥进行驯化,20 d后pH、COD去除率趋于稳定。另外,通过L9(34)正交试验,研究了混凝中4因子影响大小的排序,并在最优条件下对UASB反应器出水进行混凝处理。组合技术处理的出水水质指标符合国家造纸工业污水排放标准。     

Hydrogen bio-production through anaerobic microorganism fermentation using kitchen wastes as substrate

In order to treat the kitchen wastes and produce hydrogen, anaerobic fermentation technology was used in this experiment. The results showed that the fermentation type changed from mixed acid fermentation to ethanol fermentation in a continuous stirred tank reactor (CSTR) 22 days after start-up. The maximum efficiency of hydrogen bio-production in the CSTR was 4.77 LH₂/(L reactor d) under the following conditions: organic loading rate (OLR) of 32–50 kg COD/(m³ d), oxidation reduction potential (ORP) of −450 to −400 mV, influent pH value of 5.0–6.0, effluent pH value of 4.0–4.5, influent alkalinity of 300–600 mg/l, temperature of 35 ± 1°C and hydraulic retention time (HRT) of 7 h. An artificial neural network (ANN) model was established, and each parameter influencing the performance of the reactor was compared using the method of partitioning connection weights (PCW). The results showed that OLR, pH, ORP and alkalinity could influence the fermentation characteristics and hydrogen yield of the anaerobic activated sludge; with an influence hierarchy: OLR > pH values > ORP > alkalinity. An economic analysis showed that the cost of producing hydrogen in this experiment was less than the cost of electrolysis of water.     

Anaerobic treatment of highly concentrated aniline wastewater using packed-bed biofilm reactor

The performance of packed-bed biofilm reactor (PBBR) with self-floating bio-carriers was investigated to treat highly concentrated organic nitrogenous aniline wastewater with a COD value as high as 24,000 mg/L. With 45 vol% of carrier charge inside the reactor, the aniline wastewater can be effectively treated with 94% of COD removal efficiency at a low organic loading rate (OLR) of 0.9 kg COD/(m³ d). The removal efficiency decreased gradually down to 75% when OLR increased to 12.27 kg COD/(m³ d) that corresponded to 1 day of HRT. Separate tests with biofilm alone showed that the conversion contribution of the biofilm was about half of the overall COD conversion by the biofilm plus sludge system at the same OLRs of 3–4 kg COD/(m³ d), and that the biofilm had higher activity than suspended sludge. Ammonium released from decomposed aniline was increased gradually from 500 to 1700 mg/L with the OLR increase from 0.9 to 12.27 kg COD/(m³ d), which resulted in inhibitory effect to the microorganism due to the toxicity of free ammonia. Batch anaerobic toxicity tests showed that the biofilm was less sensitive to toxic compounds than suspended sludge and could tolerate higher concentration of free ammonia.     

Start-up of an anaerobic hybrid (UASB/filter) reactor treating wastewater from a coffee processing plant

The ability of an anaerobic hybrid reactor, treating coffee wastewater, to achieve a quick start-up was tested at pilot scale. The unacclimatized seed sludge used showed a low specific methanogenic activity of 26.47 g CH4 as chemical oxygen demand (COD)/kg volatile suspended solids (VSS) x day. This strongly limited the reactor performance. After a few days of operation, a COD removal of 77.2% was obtained at an organic loading rate (OLR) of 1.89 kg COD/m3 x day and a hydraulic retention time (HRT) of 22 h. However, suddenly increasing OLR above 2.4 kg COD/m3 x day resulted in a deterioration in treatment efficiency. The reactor recovered from shock loads after shutdowns of 1 week. The hybrid design of the anaerobic reactor prevented the biomass from washing-out but gas clogging in the packing material was also observed. Wide variations in wastewater strength and flow rates prevented stable reactor operation in the short period of the study.     

Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process

The present study investigated a two-stage anaerobic hydrogen and methane process for increasing bioenergy production from organic wastes. A two-stage process with hydraulic retention time (HRT) 3 d for hydrogen reactor and 12 d for methane reactor, obtained 11% higher energy compared to a single-stage methanogenic process (HRT 15 d) under organic loading rate (OLR) 3 gVS/(L d). The two-stage process was still stable when the OLR was increased to 4.5 gVS/(L d), while the single-stage process failed. The study further revealed that by changing the HRT_hydrogen:HRT_methane ratio of the two-stage process from 3:12 to 1:14, 6.7%, more energy could be obtained. Microbial community analysis indicated that the dominant bacterial species were different in the hydrogen reactors (Thermoanaerobacterium thermosaccharolyticum-like species) and methane reactors (Clostridiumthermocellum-like species). The changes of substrates and HRT did not change the dominant species. The archaeal community structures in methane reactors were similar both in single- and two- stage reactors, with acetoclastic methanogens Methanosarcina acetivorans-like organisms as the dominant species.     

Anaerobic treatment of winery wastewater using laboratory-scale multi- and single-fed filters at ambient temperatures

A lab-scale investigation was conducted to examine the effectiveness of a multi-fed upflow anaerobic filter process for the methane production from a rice winery effluent at ambient temperatures. The experiment was carried in two identical 3.0-l upflow filters, a single-fed reactor and a multi-fed reactor. The results showed that the multi-fed reactor, operated at the ambient temperatures of 19–27 °C and influent chemical oxygen demand (COD) of 8.34–25.76 g/l, could remove over 82% of COD even at an organic loading rate (OLR) of 37.68 g-COD/l d and a short hydraulic retention time (HRT) of 8 h. This reactor produced biogas with a methane yield of 0.30–0.35 l-CH₄/g-COD_removed. The multi-fed upflow anaerobic filter was proved to be more efficient than the single-fed reactor in terms of COD removal efficiency and stability against hydraulic loading shocks. A linear-regression model with influent COD concentration and HRT terms adequately described the multi-fed upflow anaerobic filter system for the treatment of rice winery wastewater at ambient temperatures.     

The effect of pretreatment on anaerobic activity of olive mill wastewater using batch and continuous systems

This study was focused on several physico-chemical and biological treatment methods that may affect the reduction of the organic load in olive mill wastewater (OMW). In this study, removal of 95% of the phenolic compounds present in OMW was achieved using sand filtration and subsequent treatment with powdered activated carbon in a batch system. This pretreatment for OMW was found to enhance the anaerobic activity of the sludge in the batch system significantly. The efficiency of organic load removal achieved by the anaerobic treatment of untreated OMW in batch reactors with tap water dilution factors below 1:10, reached approximately 65% chemical oxygen demand (COD) removal. However, in the up-flow sludge anaerobic blanket (UASB) reactor, COD removal efficiency of 80–85% was reached at a hydraulic retention time (HRT) of 5 days with an influent COD concentration of 40 g l⁻¹ and organic loading rate (OLR)=8 g⁻¹ COD l⁻¹ per day.     

Treatment of low strength industrial cluster wastewater by anaerobic hybrid reactor

The study was aimed at treating the complex, combined wastewater generated in Mangolpuri industrial cluster. It was considered as a low strength wastewater with respect to its organic content. Anaerobic treatment of this wastewater was studied using an anaerobic hybrid reactor (AHR) which combined the best features of both the upflow anaerobic sludge blanket (UASB) reactor and anaerobic fluidized bed rector (AFBR). The performance of the reactor under different organic and hydraulic loading rates were studied. The COD removal reached 94% at an organic loading rate (OLR) of 2.08 kg COD m(-3)d(-1) at an hydraulic retention time (HRT) of 6.0 h. The granules developed were characterized in terms of their diameter and terminal settling velocity.     

Biodegradation of high phenol containing synthetic wastewater by an aerobic fixed bed reactor

The continuous aerobic degradation of phenol, mixed with readily degradable synthetic wastewater was studied over a period of 400 days at 25+/-5 degrees C temperature in a fixed bed biofilm reactor using 'Liapor' clay beads as packing material. The phenol concentration added to the reactor ranged from 0.19 to 5.17g/l and was achieved by a gradual increase of phenol in wastewater, thus adapting the microbial flora to high contaminant concentrations. A maximal removal rate of 2.92g phenol/(ld) at a hydraulic retention time (HRT) of 0.95 days and a total organic loading rate (OLR) of 15.3g COD/(ld) with a phenol concentration of 4.9g/l was observed. However, this was not a stable rate at such high phenol loading. At the end of reactor operation on day 405, the phenol removal rate was 2.3g/(ld) at a influent phenol concentration of 4.9g/l. There were no phenol intermediates present in the reactor, as evident from corresponding COD, phenol removal and the absence of fatty acids. Omission of organic nitrogen compounds or of urea in influent feed was not favourable for optimal phenol removal. The phenol degradation profile that was studied in shake flasks indicated that the presence of a acetate which represent as an intermediate of phenol degradation retarded the phenol degradation. The highest phenol degradation rate observed in batch assays was 3.54g/(ld).