ASBR处理食品废水中DOM转化过程的荧光光谱

利用厌氧序批式反应器(ASBR)处理食品废水,结合三维荧光光谱技术考察不同反应时段废水中溶解性有机物(DOM)的光谱特征和物质来源,并建立DOM特征峰荧光强度与氨氮浓度的关系.工艺运行结果表明:食品废水经过ASBR处理后,进水的COD从1100mg/L降至91mg/L,COD去除率达到91.73%,说明ASBR反应器可有效降解食品废水中的有机物质.三维荧光光谱显示,5种物质的特征荧光峰,即高激发波长色氨酸(峰A)、低激发波长色氨酸(峰B)、可见光区富里酸(峰C)、紫外光区富里酸(峰D)、类腐殖酸(峰E).随着厌氧生物处理的进行,峰A、峰B和峰C的荧光强度表现为先增加后减少的趋势;峰D荧光强度表现为微弱增加趋势;峰E荧光强度为先减少后增加趋势.荧光光谱指数FI、HIX、BIX表明,废水具有明显生物源特征.建立高激发波长色氨酸、低激发波长色氨酸特征峰荧光强度与色氨酸荧光强度之和与氨氮浓度在反应周期内的相关性,其相关系数分别为0.8136、0.9390、0.9153,说明可通过三维荧光光谱技术快速监测食品废水厌氧生物处理过程中的氨氮浓度.     

外源葡萄糖对麦秸厌氧发酵产沼气的影响

为进一步阐释混合厌氧发酵的内在机制,在中温(35±1)℃条件下,以麦秸为原料,以葡萄糖为外源易分解有机碳,采用批式发酵方式,进行了葡萄糖不同添加量和不同添加方式对秸秆厌氧发酵产沼气影响试验。结果表明,在试验初始添加葡萄糖可提高日产气量,但葡萄糖添加量太少对提高秸秆总固体(TS)产气量无促进作用,当葡萄糖添加量为秸秆TS质量的6%时获得最大秸秆TS产气量,为303.13 m L·g-1,继续增加葡萄糖添加量,秸秆TS产气量反而降低;在秸秆厌氧发酵日产气量下降阶段一次性或者分次添加葡萄糖对促进秸秆厌氧发酵产沼气均无效果,仅在试验初始一次性添加秸秆TS质量6%的葡萄糖时对秸秆厌氧发酵产沼气有促进作用,秸秆TS产气量较对照提高9.24%;添加葡萄糖对秸秆厌氧发酵过程产气中甲烷含量无明显影响,但提高累积产气中甲烷平均含量,且在日产气量下降后添加葡萄糖的效果更好,但这种促进效果与对照间差异并不显著。综合以上结果,在试验初始一次性添加秸秆TS质量6%的葡萄糖可以获得最佳的产气效果。     

Organic matter balances in anaerobic digestors

Organic carbon and COD balances in a system of 12 anaerobic units operating at organic loading levels 0.4–0.8 kg COD/m³.d and hydraulic detention times 8–20 d resulted in a mean CH₄ production of 341 ml/g COD converted and a mean CH₄ + CO₂ production 1815 ml/g OC converted. The gas retained in the liquid anaerobic effluent was mainly carbon dioxide (94–98%).     

沸石生物基材料促进污泥消化工艺研究

将活化沸石在厌氧状态下进行生物膜挂膜,制成沸石生物基材料并将其运用于城市剩余污泥消化中,研究沸石生物材料促进污泥厌氧消化的效果。结果表明:沸石生物基材料对污泥总固体量和挥发性固体都有较好的去除效果,去除率分别在50.4%～62.8%和56.8%～81.4%,其中粒径为200目的风干沸石生物基材料对污泥总固体减重率高达62.8%;对污泥上清液中氨氮和COD的去除效果明显且稳定,沸石生物基材料在风干状态下对污泥消化的促进效果更佳。     

ASBR反应器厌氧氨氧化脱氮II:反应动力学

研究了ASBR厌氧氨氧化(ANAMMOX)反应器稳定条件下周期内的基质动力学特性以及过程抑制动力学特性,并得到适合描述上述特性的动力学模型.其中,稳态下周期内基质去除模型是首次被调查研究,研究发现,修正的Logistic模型和修正的Boltzmann模型相比Grau二级基质去除模型和修正的Gompertz模型而言,更适合描述稳态下周期内基质去除特性,并且通过模型得到了周期内任意t时刻下的出水总氮和总氮去除率预测公式.运用Haldane模型和Aiba模型建立了出水FA浓度与总氮去除负荷(TN RR)以及出水NO2--N浓度与总氮去除负荷(TN RR)之间的关系,结果表明:Haldane模型更适合用来描述基质抑制动力学特性,模型预测得到的出水FA和出水NO2--N抑制浓度分别为72.36mg/L和140.60mg/L.上述动力学模型的应用和动力学参数的获得可能会有助于ASBR反应器的优化设计和过程控制.     

污泥厌氧消化和后续处理中沙门氏菌杀灭及VBNC发生

应用最大或然数(MPN)培养法和反转录定量PCR(RT-qPCR)技术研究了4种污泥厌氧消化方式以及后续处理过程中沙门氏菌杀灭及有活性但不可培养(VBNC)状态的发生情况.中温厌氧消化(MAD)和高温预处理后中温消化(65℃+MAD)的沙门氏菌分别减少了2.8和5.6个数量级;高温厌氧消化(TAD)和高温-中温两相厌氧消化(TPAD)的沙门氏菌含量均低于检测限.沙门氏菌的杀灭速率常数排序为65℃+MAD>TAD>TPAD> MAD.结果显示高温对病原菌的灭活效果显著增加,高温短时预处理使得杀灭速率明显加快.TAD和TPAD的污泥VBNC沙门氏菌数量高于MAD和65℃+MAD 2个数量级,表明长时间的高温厌氧消化易导致沙门氏菌进入VBNC状态.消化污泥经过离心脱水后会出现沙门氏菌数量增加的现象,MAD、65℃+MAD、TAD和TPAD的消化污泥中沙门氏菌分别增加了1.1、2.4、3.7和2.5个数量级.但其中VBNC状态的沙门氏菌数量明显降低了1~3个数量级,表明消化后污泥中部分VBNC沙门氏菌在离心脱水过程中复活并生长,使得MPN检测得到的可培养沙门氏菌数量增加,初步解释了消化污泥经离心脱水后的病原菌再生长现象.消化污泥中沙门氏菌数量在室温放置过程中会进一步下降.     

Biological treatment of the dye Reactive Blue 19 by cattails and anaerobic bacterial consortia

This study demonstrates the bioremediation potential of anaerobic sludge and cattail (Typha angustifolia) for the treatment of the dye Reactive Blue 19 (RB19). The anaerobic sludge and cattails used in this study were not previously exposed to dyes or other xenobiotics. Different anaerobic sludge concentrations (30%, 50%, and 70%) were used along fixed dye concentrations at pH 8.0 and 25 °C. Subsequently, 50% sludge was selected to treat RB19 at various concentrations. The discoloration of non-hydrolyzed dye was between 70% and 85% using 50% biomass. For the hydrolyzed form of RB19, the range of decoloration was 70%–90%. Dye treatment efficiencies between 50% and 75% were observed for the two forms of the dye when treated with T. angustifolia. Overall, the anaerobic biomass at pH 8.0 showed better potential than cattails to treat RB19. The observation that non-enriched anaerobic sludge can decolorize RB19 is important because it opens up the prospects of developing anaerobic treatment systems, which can easily decolorize dyes in industrial wastewaters and also possesses potential advantages over systems using defined bacterial cultures.     

Anaerobic decolorization of an azo dye by a mixed culture

Wool dyeing wastewater contains xenobiotic compounds that can be removed by biotechnological processes. Studies on various dyes showed that anaerobic processes are suitable to alter azo dyes as a first step of the biodegradation process. These compounds are reduced by anaerobic consortia to aromatic amines and its ultimate degradation can be achieved by a further aerobic treatment.

Studies on degradation rate of an wool acid dye were performed in batch systems inoculated with anaerobic biomass. A commercial diazo dye, Acid Red 73, was added to the synthetic medium in which glucose was used as sole carbon source.

Results indicated that the Acid Red 73 was partially degraded by a mixed culture of anaerobic bacteria and a decolorization of 90% was obtained. Kinetics studies on removal of the colour showed that the decolorization rate was several times faster than the degradation rate of glucose for a range of dye concentrations between 60 mg/L and 400 mg/L. A first order kinetic model was used for dye concentrations up to 200 mg/L. For higher concentrations a model similar to the Michaelis‐Menten equation was better fitted to the experimental data.     

Performance of an ANAMMOX reactor treating wastewater generated by antibiotic and starch production processes

A pilot-scale anaerobic ammonia oxidation (ANAMMOX) reactor was used to treat mixed wastewater resulting from a chlortetracycline and starch production process. The results, collected over the course of 272 days, show that the ratio of influent ammonium to nitrite, pH, and temperature can all affect the efficiency of nitrogen removal. The ratio of influent ammonium to nitrite was maintained at about 1:1 at a concentration below 200 mg·L^-1 for both influent ammonium and nitrite. The total nitrogen (TN) loading rate was 0.15–0.30 kgN·m^-3·d^-1, pH remained at 7.8–8.5, and temperature was recorded at 33±1°C. The rate of removal of ammonia, nitrite, and TN were over 90%, 90%, and 80%, and the effluent ammonium, nitrite and TN concentrations were below 50, 30, and 100 mg·L^-1.     

添加剂对污泥厌氧消化性能的影响

在间歇培养条件下,研究了还原型辅酶Ⅱ（NADPH）、乙酰辅酶A（Acetyl Co A）和对氨基苯甲酸（PABA）3种添加剂对污泥厌氧消化性能的影响.结果表明,3种微生物活性促进剂均能促进污泥厌氧消化产气.其中,NADPH的促进效果最为显著,消化第35 d,产甲烷量比对照组高15.90%.在污泥含固率为3%、未调初始pH（pH=6.7）和温度35℃的厌氧消化条件下,NADPH的最佳添加量为50 mg.L-1,消化第36 d,污泥累积产甲烷量127.13 mL.g-1VSS.在含固率3%、初始pH=8.5、温度55℃和NADPH添加量为50 mg.L-1的工艺条件下,污泥厌氧产气效果最佳,消化第30 d时累积产甲烷量达158.02 mL.g-1VSS.