污泥同时浓缩消化新型反应器的开发研究

针对污泥厌氧处理的问题，对污泥浓缩消化一体化反应器进行了开发研究，提出了ICSTD、MISTD和TISTD 3套反应器，反应器由内外2个反应室组成，采用沼气搅拌或机械搅拌。3套反应器的试验结果表明：在中温条件下，进泥含水率98.3%～99.8%，VS/TS 0.52～0.69时，排泥含水率87.4%～97.3%，VS/TS 0.23～0.51，产气量8.2～76.6 L/d，其浓缩和消化效果优于其他反应器。     

MBR污泥热水解强化厌氧消化中试研究

针对MBR污泥开展热水解强化厌氧消化中试研究,考察了热水解对污泥性质、厌氧消化效率和污泥脱水性能的影响。结果表明,热水解后污泥中总固体(TS)、挥发性固体(VS)的含量基本不变,但污泥的溶解性总固体(s TS)和溶解性挥发性固体(s VS)含量提高至原泥的10倍左右,总固体解离度(TSDD)和挥发性固体解离度(VSDD)分别为31.7%和51.9%,同时污泥的黏度由927.8 m Pa·s降低至550.4 m Pa·s,污泥流动性显著增强。热水解处理可有效提高污泥厌氧消化反应效率,沼气产量和有机分解率均提高1倍,化学需氧量(COD)消减率由33%上升至44%,但热水解厌氧消化后污泥NH+4-N浓度为传统厌氧消化的2倍。此外热水解能有效改善污泥脱水性能,不添加任何药剂时,热水解污泥经板框压滤机脱水后含水率可降至33.29%。     

卧式厌氧消化反应器处理高含固污泥的特性研究

采用容积为200L的卧式厌氧消化反应器(以下简称卧式反应器),对高含固污泥(总固体(TS)≥10%(质量分数))的厌氧消化特性进行研究。通过序批运行、低负荷半连续运行、提负荷半连续运行逐步提高污泥TS从10.09%至12.58%,并对污泥颗粒的运动轨迹进行了计算机流体力学(CFD)模拟。结果表明,序批运行阶段污泥水解酸化特征显著;在低负荷半连续运行阶段,沼气产率平稳上升,在提负荷半连续运行阶段,沼气产率稳定在(0.359 2±0.011 0)m~3/(m~3·d),挥发性固体(VS)降解率稳定在22.05%±0.52%,高含固污泥在卧式反应器中厌氧消化产气性和稳定性良好。CFD模拟结果显示,污泥颗粒在卧式反应器中得到充分混合,卧式反应器运行稳定后,污泥厌氧消化剩余能量可达2.42MJ/(m~3·d),经济效益明显,具备良好的应用前景。     

有效微生物和多功能复合微生物制剂生物强化提高化粪池粪便污泥减量效率研究

为了考察有效微生物(EM)和多功能复合微生物制剂(MCMP)对化粪池粪便污泥减量的强化效能,以化粪池粪便污泥为研究对象,采用中温(35℃)厌氧消化,研究EM和MCMP不同投加量(0~1.00%)对化粪池粪便污泥厌氧消化总固体(TS)、挥发性固体(VS)和COD的减量效果,考察EM和MCMP投加量与TS、VS和COD去除率间的相关关系。结果表明,投加0.005%~0.10%的EM和MCMP均有利于化粪池粪便污泥TS、VS和COD的去除;其中以投加0.01%的EM(E2处理)和0.01%的MCMP(M2处理)对TS、VS和COD的去除效果最好。E2处理TS、VS和COD的去除率分别为32.51%、42.34%和40.91%,分别比对照(CK)高5.83%、5.29%和7.13%;M2处理TS、VS和COD的去除率分别为33.74%、46.05%和43.33%;分别比CK高7.06%、9%和9.50%。对化粪池粪便污泥厌氧消化TS、VS和COD的减量作用效果表现为:MCMPEM。EM和MCMP的投加量与TS、VS和COD去除率间均存在一定的负相关关系;投加EM和MCMP的各处理的TS、VS和COD去除率两两间均表现为正相关关系。     

污泥流变学及其厌氧消化混合特性数值模拟研究进展

污泥作为一种非牛顿流体,其流变特性对厌氧消化过程中的传质、传热、搅拌和物料输送等有着重要影响。系统阐述了污泥流变学属性,如流变特性的影响因素、流变模型以及其测试方法。由于污泥在厌氧消化反应器中流场的复杂性及其本身的不透明性,难以对其流场进行高效的实验测试,利用计算流体力学(CFD)技术结合流变学参数对流场进行数值模拟是一种有效工具。因此,综合分析了CFD技术在污泥厌氧消化过程中的研究现状及其搅拌混合过程中旋转桨叶处理方法的选择,并对污泥厌氧消化过程中进行数值模拟存在问题及进一步研究方向进行了展望。随着深入研究,以污泥流变学、计算流体力学为基础结合污泥厌氧消化生化反应过程联合数值模拟研究,将会为控制污泥的厌氧消化工艺提供更加全面和重要的技术措施。     

热水解厌氧消化工艺中污泥胞外聚合物对流变和脱水的影响

为阐明热水解厌氧消化工艺中污泥胞外聚合物对脱水和流变的影响,选取北京市某再生水厂中热水解厌氧消化工艺的污泥为对象,通过测量污泥粒径、三维荧光及各层EPS含量研究了EPS去除对污泥流变和含固率的影响。结果表明,经过热水解预处理后的污泥,粒径相较混合污泥下降66.79%;混合污泥荧光波峰集中出现在酪氨酸类蛋白质区和色氨酸类蛋白质区,经过热水解后可溶性微生物代谢产物的荧光响应值升高,再经过厌氧消化后提升了腐殖酸区域荧光响应值;EPS的去除对于污泥流动性有重要影响。热水解污泥和热水解厌氧消化污泥去除EPS后表观黏度下降幅度较大;此外,不同的脱水方法对污泥含固率的影响也不同。混合污泥和热水解厌氧消化污泥去除S-EPS层后含固率提升366.67%和148.92%,而热水解污泥去除S-EPS层后提升效果不明显。研究结果从污泥组分和流变学角度为污泥脱水提供思路和依据。     

ICSTD反应器处理污泥的启动试验研究

新型内循环污泥浓缩消化反应器（ICSTD）处理污泥的启动运行试验采用某污水处理厂二沉池好氧活性污泥进行驯化培养，使反应器正常启动运行。在日处理量为50 L/d，进泥含水率为99.23％～99.46％，进泥VS/TS为0.65～0.73，进泥COD为4 115～5 780 mg/L，反应器容积负荷为1.31 kg COD/(m³·d)时，排泥含水率在96.2％～97.3％，排泥VS/TS为0.48～0.57，COD去除率在95％以上，出水pH在6.6～7.1，且上清液澄清。试验结果表明： ICSTD反应器处理污泥的启动试验，采用直接培养污泥启动的方式培养厌氧污泥历时66 d，能较快地培养厌氧污泥且运行稳定，对污泥的浓缩消化起到较好的作用，同时对反应器后续运行的消化效果提供了一个良好的条件。     

高含固污泥在热水解-厌氧消化工艺中的流变特性分析

对热水解-中温厌氧消化联合工艺中的高含固率调配污泥、热水解污泥和消化污泥的流变特性进行分析,考察了3种污泥的黏度、屈服应力和触变性等流变特征指标在不同工艺中的变化规律,并讨论了TSS对污泥流变特性的影响。结果表明:调配污泥、热水解污泥和消化污泥均为假塑性非牛顿流体,都可用Herschel-Bulkley模型进行描述;极限黏度与TSS之间呈指数关系;屈服应力在TSS高于7.3%时增长趋势加剧,流动性变差;热水解污泥和消化污泥的触变性与调配污泥相比降低50%以上,使用触变性动力学系数K来表征污泥的触变性较滞后环更适宜。     

剩余污泥混合对絮凝污泥厌氧消化的强化

为了考察絮凝污泥与剩余活性污泥混合中温(35℃)厌氧消化效果,分析了不同混合比例、不同投配率下的总化学需氧量(TCOD)去除率、挥发性固体(VS)降解效果,通过p H值与氨氮浓度的变化来分析各反应器的稳定性。结果表明:污泥混合后消化效果明显得到提高,且污泥消化效率随着投配率的增加先提高后下降。5%投配率时,絮凝污泥/剩余污泥(VS比)为1∶2时厌氧消化效果最好,TCOD去除率达到47.8%,VS降解率达到46.8%,分解单位VS产气量达到了435 m L/g,p H值与氨氮浓度分别保持在7.4和269 mg/L左右,混合污泥厌氧消化系统较稳定。这说明与剩余污泥的混合消化能有效提高絮凝污泥的厌氧消化性能。污泥絮体的显微分析表明:厌氧消化过程中絮体面积百分比逐步减小,污泥结构逐步解体,可以解释污泥消化的微观过程。     

基于猪粪流变特性的厌氧消化反应器内的数值模拟

采用流变仪对不同含固率猪粪的流变性质进行测量,分析其流变特性,将流变数据与非牛顿流体模型进行拟合,得到用于描述猪粪流变特性的最佳流变方程。结果表明:猪粪是一种非牛顿流体,黏度随剪切速率的增加而减小并趋于稳定。基于其流变特性,运用计算流体力学(computational fluid dynamics,CFD)模拟技术,对猪粪厌氧消化反应器内的流场进行研究。模拟结果显示:反应器内速度最大值出现在桨叶末端,猪粪流体在其反应器内的宏观循环运动状态为沿着搅拌轴径向的绕流运动;壁面及顶部和底部区域速度几乎为零,形成死区,容积比率为29.85%。     

Enhanced sludge granulation in upflow anaerobic sludge blanket (UASB) reactors by aluminum chloride.

Two upflow anaerobic sludge blanket (UASB) reactors were concurrently operated for 146 days to examine the effects of aluminum chloride (AlCl3) on the sludge granulation process during start-up. Sludge granulation (defined as that over 10% of granules were larger than 2.0 mm) was achieved in the control reactor (R1) in approximate three months. Introduction of Al3+ at a concentration of 300 mg/l reduced the sludge granulation time by approximate one month. Throughout the experiment the AlCl3-added reactor (R2) had a higher biomass concentration, e.g., 13.8 g-MLVSS/l versus 12.8 g-MLVSS/l on Day 146. Granules became visible earlier in R2 compared with R1 (35 days versus 65 days). The average size of granules from R2 was larger than that from R1. The results demonstrated that AlCl3 enhanced the sludge granulation process in the UASB reactors.     

剩余污泥发酵产酸特征及基质释放规律研究

剩余污泥发酵既能实现污泥减量,又能获得污水生物脱氮除磷所需的挥发性脂肪酸VFAs等。采用序批式污泥发酵实验,在(30±1)℃的条件下,研究剩余污泥投配比对序批式污泥发酵系统污泥减量、产酸以及基质释放过程的影响,探索VFAs生成最大化的条件。实验结果表明:投加接种污泥不能明显提高序批式污泥发酵系统剩余污泥的减量效果,但可以改善污泥的产酸特性;当污泥投配比大于50%时,发酵过程中将出现2个VFAs浓度峰,且第二次峰浓度更大;较为理想的序批式污泥发酵投配比是60%~80%、发酵时间为5 d或25 d,前者VFAs表观转化率最大(约24%),后者发酵液中VFAs浓度最高(约600 mg/L);发酵过程中,NH4+-N总体呈上升趋势,磷浓度发酵5 d时达到最大值。     

Harnessing dark fermentative hydrogen from pretreated mixture of food waste and sewage sludge under sequencing batch mode

Food waste and sewage sludge are the most abundant and problematic organic wastes in any society. Mixture of these two wastes may provide appropriate substrate condition for dark fermentative biohydrogen production based on synergistic mutual benefits. This work evaluates continuous hydrogen production from the cosubstrate of food waste and sewage sludge to verify mechanisms of performance improvement in anaerobic sequencing batch reactors. Volatile solid concentration and mixing ratio of food waste and sludge were adjusted to 5 % and 80:20, respectively. Five different hydraulic retention times (HRT) of 36, 42, 48, 72, and 108 h were tested using anaerobic sequencing batch reactors to find out optimal operating condition. Results show that the best performance was achieved at HRT 72 h, where the hydrogen yield, the hydrogen production rate, and hydrogen content were 62.0 mL H₂/g VS, 1.0 L H₂/L/day, and ~50 %, respectively. Sufficient solid retention time (143 h) and proper loading rate (8.2 g COD/L/day as carbohydrate) at HRT 72h led to the enhanced performance with better hydrogen production showing appropriate n-butyrate/acetate (B/A) ratio of 2.6. Analytical result of terminal-restriction fragment length polymorphism revealed that specific peaks associated with Clostridium sp. and Bacillus sp. were strongly related to enhanced hydrogen production from the cosubstrate of food waste and sewage sludge.     

絮凝剂对高速厌氧反应器污泥颗粒化的强化作用

以考察絮凝剂对厌氧反应器中活性污泥性能的影响为目的,将聚合氯化铝(PAC)、聚丙稀酰胺(PAM)、聚季铵盐3种不同类型絮凝剂以不同投加量添加到反应器中,采用生物化学甲烷势(BMP)和厌氧毒性测定(ATA)分析方法,评价了3种絮凝剂的厌氧生物可降解性以及3种絮凝剂对厌氧污泥产甲烷活性、沉降性能等方面的促进或抑制作用。确定以聚季铵盐作为厌氧污泥颗粒化促进剂,建议采用多次投加方式,反应器中聚季铵盐质量浓度以10-50mg／L为宜。     

Coagulant recovery from water treatment plant sludge and reuse in post-treatment of UASB reactor effluent treating municipal wastewater

In the present study, feasibility of recovering the coagulant from water treatment plant sludge with sulphuric acid and reusing it in post-treatment of upflow anaerobic sludge blanket (UASB) reactor effluent treating municipal wastewater were studied. The optimum conditions for coagulant recovery from water treatment plant sludge were investigated using response surface methodology (RSM). Sludge obtained from plants that use polyaluminium chloride (PACl) and alum coagulant was utilised for the study. Effect of three variables, pH, solid content and mixing time was studied using a Box–Behnken statistical experimental design. RSM model was developed based on the experimental aluminium recovery, and the response plots were developed. Results of the study showed significant effects of all the three variables and their interactions in the recovery process. The optimum aluminium recovery of 73.26 and 62.73 % from PACl sludge and alum sludge, respectively, was obtained at pH of 2.0, solid content of 0.5 % and mixing time of 30 min. The recovered coagulant solution had elevated concentrations of certain metals and chemical oxygen demand (COD) which raised concern about its reuse potential in water treatment. Hence, the coagulant recovered from PACl sludge was reused as coagulant for post-treatment of UASB reactor effluent treating municipal wastewater. The recovered coagulant gave 71 % COD, 80 % turbidity, 89 % phosphate, 77 % suspended solids and 99.5 % total coliform removal at 25 mg Al/L. Fresh PACl also gave similar performance but at higher dose of 40 mg Al/L. The results suggest that coagulant can be recovered from water treatment plant sludge and can be used to treat UASB reactor effluent treating municipal wastewater which can reduce the consumption of fresh coagulant in wastewater treatment.     

3种污泥对磺胺二甲基嘧啶的吸附性能

研究了厌氧颗粒污泥、厌氧污泥及好氧污泥对磺胺二甲基嘧啶(SM2)的吸附性能。当SM2初始浓度为50μg/L时,采用活性污泥灭活吸附,考察了吸附平衡时间、吸附等温线及温度对污泥吸附的影响,并比较了失活污泥与活性污泥的吸附性能。结果表明,3种污泥对SM2的吸附均在1 h内达到吸附平衡;3种失活污泥对SM2的吸附都可用Freundl-ich和Langmuir吸附模型来描述,并且Freundlich吸附模型的拟合效果要好于Langmuir模型(R2F>R2L);温度对3种污泥吸附影响规律一致,并且吸附常数KF(15℃)>KF(25℃)>KF(35℃),这说明吸附为放热反应,低温有利于吸附反应的进行。活性污泥对SM2的吸附与失活污泥吸附规律一致,都符合Freundlich模型。3种活性污泥对SM2的去除是吸附和降解的共同作用,并且都是降解占主导地位,降解效率为厌氧污泥>好氧污泥>厌氧颗粒污泥。     

Effects of sludge recirculation rate and mixing time on performance of a prototype single-stage anaerobic digester for conversion of food wastes to biogas and energy recovery

Food wastes have been recognized as the largest waste stream and accounts for 39.25 % of total municipal solid waste in Thailand. Chulalongkorn University has participated in the program of in situ energy recovery from food wastes under the Ministry of Energy (MOE), Thailand. This research aims to develop a prototype single-stage anaerobic digestion system for biogas production and energy recovery from food wastes inside Chulalongkorn University. Here, the effects of sludge recirculation rate and mixing time were investigated as the main key parameters for the system design and operation. From the results obtained in this study, it was found that the sludge recirculation rate of 100 % and the mixing time of 60 min per day were the most suitable design parameters to achieve high efficiencies in terms of chemical oxygen demand (COD), total solids (TS), and total volatile solid (TVS) removal and also biogas production by this prototype anaerobic digester. The obtained biogas production was found to be 0.71 m³/kg COD and the composition of methane was 61.6 %. Moreover, the efficiencies of COD removal were as high as 82.9 % and TVS removal could reach 83.9 % at the optimal condition. Therefore, the developed prototype single-stage anaerobic digester can be highly promising for university canteen application to recover energy from food wastes via biogas production.     

Applications of two-phase anaerobic degradation in industrial wastewater treatment

Prospects for the phased anaerobic treatment of wastewater are extremely promising. With the variety of reactor designs available and the amenability of reactors to modification, existing treatment systems may be replaced or upgraded as required to achieve increased stability, higher loading capacities and greater process efficiencies than single-stage systems. In recent times, various reactor configurations and substrates are applied to two-phase anaerobic process. This paper reviews applications and studies of two-phase anaerobic degradation for wastewater treatment, sums up the performance of application to treating waste from distillery, landfill leachate, coffee, cheese whey and dairy, food, pulp and paper, sludge and solid, etc., and summarises reactor configurations, environmental and operational conditions, and comparisons of two-phase anaerobic digestion with other anaerobic reactors.     

搅拌对污泥厌氧消化过程中污泥形态及微生物活性的影响

搅拌对污泥厌氧消化过程中的物料传质具有非常重要的作用,为进一步了解搅拌对厌氧消化微观环境的影响,考察了污泥厌氧消化过程中搅拌和无搅拌条件下污泥形态、微生物活性及分布的变化。采用吖啶橙染色法对微生物中的RNA、DNA染色,通过染色情况分析微生物活性的空间分布。结果表明,搅拌系统中污泥絮体结构松散,粒径细小,但具有良好的沉降性能;搅拌系统中RNA/DNA(以荧光的相对面积表征)和脱氢酶活性均高于无搅拌系统,说明适度搅拌可以提高污泥厌氧消化系统中微生物活性。RNA/DNA与传统脱氢酶的测试结果基本一致,但前者测试过程简单、结果直观且可获得微生物活性的空间分布特性,因此可用于微生物活性的评估。