红霉素生产废水中微生物群落结构分析

采用聚合酶链式反应-变性梯度凝胶电泳技术（PCR—DGGE）研究了序批式活性污泥法（SBR）处理红霉素生产废水过程中从厌氧处理阶段到好氧处理阶段的微生物群落结构变化,并对微生物群落的部分优势细菌进行了克隆测序和系统发育树分析。结果表明,微生物群落丰富度随SBR处理进程呈递增趋势;微生物群落的相似性在相邻的处理阶段间相对较高,相隔越远的处理阶段间则越低;6种优势菌的同源性均在95％以上,其中有4种细菌均为厌氧和好氧处理阶段的优势菌,有1种细菌仅为好氧处理阶段的优势菌。     

Differential fate of erythromycin and beta-lactam resistance genes from swine lagoon waste under different aquatic conditions

The attenuation and fate of erythromycin-resistance-methylase (erm) and extended-spectrum beta-lactamse (bla) genes were quantified over time in aquatic systems by adding 20-L swine waste to 11,300-L outdoor mesocosms that simulated receiving water conditions below intensive agricultural operations. The units were prepared with two different light-exposure scenarios and included artificial substrates to assess gene movement into biofilms. Of eleven genes tested, only erm(B), erm(F), bla_SHV and bla_TEM were found in sufficient quantity for monitoring. The genes disappeared rapidly from the water column and first-order water-column disappearance coefficients were calculated. However, detected gene levels became elevated in the biofilms within 2 days, but then disappeared over time. Differences were observed between sunlight and dark treatments and among individual genes, suggesting that ecological and gene-specific factors play roles in the fate of these genes after release into the environment. Ultimately, this information will aid in generating better predictive models for gene fate.     

污泥减量过程中臭氧氧化对硝化和反硝化影响的试验研究

采用AO工艺,考察了在污泥减量过程中臭氧(O3)氧化对生物系统硝化和反硝化能力的影响.结果表明,在每克SS中O3投量为0.05 g时,氧化后污泥中的CODcr由37.5 mg/L增至700mg/L,TN由4.86 mg/L增至36.6 mg/L,NH4 -N由0.353mg/L增至7.49 mg/L,NO3--N由2.19 mg/L增至5.15 mg/L.虽然氧化系统出水NH4 -N浓度略高于对照系统,但氧化系统NH4 -N的去除率大于98%,硝化能力基本没有受到O3氧化的影响.O3氧化污泥后增加的有机物作为附加的碳源循环至缺氧段,提高了反硝化的效果,当污泥氧化比例分别为10%、20%、30%时,进入缺氧段的CODCr/TN分别平均增至11.21、11.56、11.88,氧化系统的反硝化效果也随之分别提高5%、25%、37%.     

Sub-lethal effects of heavy metals on activated sludge microorganisms

The effects of heavy metals, at sub-lethal concentrations, on activated sludge microbial ecosystem were investigated. Adsorption capacity and rate of copper, chromium, lead and zinc on microbial flocs were much faster than that of organic matters. Metals affected not only the adsorption rate of organic matters but also the COD adsorption capacity of the activated sludge. Effects of heavy metals. on wastewater treatment performance of a sequencing batch reactor were also studied. Metal-laden wastewater at sub-lethal levels affected the performance to different extents, depending on the hydraulic retention time. Metal ions acted as a strong competitor against the organic compounds for active sites on the bioflocs instead of acting as a toxic microbial inhibitor, thus hampering organic adsorption and affecting the COD removal efficiency under shorter HRTs.     

铜对活性污泥微生物活性影响研究

通过人工投加铜离子对驯化污泥的破坏性实验,研究了各浓度铜离子对活性污泥氨氮、COD降解的影响及其TTC-脱氢酶活性、氧摄取速率(SOUR)、氨摄取速率(AUR)的影响。结果显示,0~5 mg/L的铜离子对处理系统有机物的去除率影响不大。铜离子浓度与活性污泥的TTC-脱氢酶活性、SOUR以及AUR之间呈现良好的相关性;低浓度的铜离子对TTC-脱氢酶活性和SOUR均有一定的促进作用,而对AUR则会产生一定的抑制作用。当铜离子浓度达到5 mg/L时,其对SOUR、TTC-脱氢酶活性以及AUR的抑制率均超过50%。在此情况下,采用TTC-脱氢酶活性、SOUR以及AUR等指标,能快速有效地表征铜离子对活性污泥微生物的毒害作用。     

Removal of tetrabromobisphenol A by conventional activated sludge, submerged membrane and membrane aerated biofilm reactors

The goal of this study was to compare removal efficiencies of tetrabromobisphenol A (TBBPA) using typical wastewater treatment technologies, and to identify the most significant mechanisms of removal. Two types of municipal wastewater reactors were studied: a full-scale conventional activated sludge (CAS) reactor with tertiary treatment; and three pilot-scale membrane bioreactors (MBRs) having different sludge retention times (SRTs). All four reactors were fed the same influent. A third reactor type, a membrane aerated biofilm reactor (MABR) was fed tap water, ammonia, and TBBPA. TBBPA in municipal influent ranged from 1 to 41 ng L⁻¹ (n = 10). The CAS effluent had an average TBBPA concentration of 0.7 ± 1.3 ng L⁻¹ (n = 3). Effluent concentrations from the MBRs were an average of 6 ± 6 ng L⁻¹ TBBPA (n = 26). Significant TBBPA removal was observed in the MABR throughout the 5 week of study (p ? 0.05). Removal of TBBPA from wastewater treatment was found to be due to a combination of adsorption and biological degradation. Based on experimental results, nitrification is likely a key process therein. No significant relationship between removal of TBBPA and SRT was identified (p ? 0.05).     

pH对活性污泥表面特性和形态结构的影响

采用4个平行的序批式反应器,研究了不同pH下活性污泥絮体表面特性和形态结构的变化.结果表明:酸性条件下(pH=4.0,5.5)污泥产生的胞外聚合物总量较多,其中多糖和蛋白质的含量远大于中性(pH=7.0)和偏碱性条件(pH=9.0).污泥表面Zeta电位随pH的升岛而降低;pH对污泥相对疏水性的影响规律并不明显,EPS组成比例较EPS总量本身更易影响污泥表面相对疏水性;此外,在酸性条件下,丝状菌大量生长,导致污泥絮体的平均粒径增大,并且呈现双峰粒径分布,絮体分形维数较低,结构松散;在中性条件下,无明显丝状菌牛长,絮体平均粒径减小,分形维数较高,结构致密;偏碱性条件下,虽然没有出现大量丝状菌,但絮体平均粒径较中性条件略有增大,分形维数相应减小.     

超声预处理对剩余污泥酶活性的影响

为了研究不同工况下超声波预处理对剩余污泥酶活性变化的影响,对剩余污泥进行不同输入能量、频率的超声预处理,测定了预处理后污泥蛋白酶和脱氢酶的变化规律。结果表明：1）超声预处理在低能量输入条件下对污泥蛋白酶和脱氢酶活性存在促进作用,而随着超声能量的进一步增加,酶活性逐渐降低直至出现抑制现象;2）超声频率对污泥酶活性影响较为显著,其中20 kHz超声频率对蛋白酶和脱氢酶活性的促进效果最高,其次分别为25和33 kHz;3）当输入能量高于8 000 kJ·（kg TS）-1后,25和33 kHz频率超声预处理对污泥蛋白酶和脱氢酶活性存在抑制效应,引起该现象的原因分析可能是高频超声空化现象及伴随的热化学效应引起的生物酶失活导致的。     

pH对SBR处理效果及活性污泥微生物群落结构的影响

采用序批式生物反应器（SBR）对pH值为5.0、6.0、7.0、8.0、9.0和10.0的原水进行处理,发现COD和TN去除率在pH=8.0时达到最大,NH4+-N去除率随pH升高而增大,在pH=10.0时可达91.0%,碱性条件下污水处理效果更佳;利用聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）技术分析不同pH值下的活性污泥总细菌群落结构,其结果显示,碱性条件下的优势菌为β-proteobacterium,承担脱氮功能的细菌中可培养的是Rhodanobacter sp.,pH=8.0时总细菌多样性指数最高。     

Effects of sludge properties on the thickening and dewatering of waste activated sludge.

The thickening and dewatering of waste activated sludge, from a pilot-scale submerged membrane bioreactor and two bench-scale, complete-mix activated sludge reactors (high-shear and low-shear aeration) treating the same municipal primary effluent, were investigated. Solids settling and compaction were measured using the diluted sludge volume index (DSVI) analysis and a batch centrifugation analysis, respectively. Elevated levels of filamentous microorganisms resulted in higher DSVI values and lower centrifuged pellet concentration. Elevated levels of nocardioform bacteria resulted in lower solids float concentrations, and higher colloidal material reduced solids recovery in batch flotation experiments. Sludge filterability, measured as time-to-filter, was shown to be a function of extracelluar polymeric substances and colloidal material, where higher levels of either reduced sludge filterability. Additional research is necessary to confirm these results using full- or demonstration-scale thickening and dewatering units.     

用污泥生物指数评价活性污泥的运转效能

污泥生物指数(SBI)由对活性污泥混合液中微型动物群落结构的分析得出,用于评价活性污泥的运转效能。SBI为0~10的生物指数,分为4个质量等级,为一客观的指数。此方法的优点在于通过对微型动物的日常检验,就能对活性污泥的运行状况给出一量化且客观的评价。     

用污泥生物指数评价活性污泥的运转效能

污泥生物指数（SBI）由对活性污泥混合液中微型动物群落结构的分析得出,用于评价活性污泥的运转效能.SBI为0～10的生物指数,分为4个质量等级,为一客观的指数.此方法的优点在于通过对微型动物的日常检验,就能对活性污泥的运行状况给出一量化且客观的评价.     

超声处理对活性污泥系统污泥减量效果的研究

在活性污泥系统采用超声波处理剩余污泥以考察污泥减量效果及其对系统处理效果的影响.结果表明：在声能密度0.25～0.50 W/mL范围内,经过1～30 min的超声波处理,系统表观产率显著下降,剩余污泥的产量可以减少20%～50%左右.同时发现,污泥的沉降性能指标SVI有所下降,而污泥的稳定性有所提高,活性污泥系统的出水水质略有不同程度的下降.     

超声处理对活性污泥系统污泥减量效果的研究

在活性污泥系统采用超声波处理剩余污泥以考察污泥减量效果及其对系统处理效果的影响.结果表明:在声能密度0.25～0.50 W/mL范围内,经过1～30 min的超声波处理,系统表观产率显著下降,剩余污泥的产量可以减少20%～50%左右.同时发现,污泥的沉降性能指标SVI有所下降,而污泥的稳定性有所提高,活性污泥系统的出水水质略有不同程度的下降.     

金霉素在活性污泥上的吸附行为

通过批次实验考察了活性污泥对金霉素（chlortetracycline,CTC）的吸附特性,研究了包括吸附平衡时间、污泥浓度（MLSS）、温度以及pH值对吸附的影响。结果表明,CTC在活性污泥上的吸附是一个快速的过程,5 min可达到平衡吸附量的90%以上,6 h达到吸附平衡;CTC的总去除率随着MLSS浓度的增加而增大,而污泥单位吸附量却随之减少,当CTC初始浓度为500 μg/L,MLSS浓度从1 000 mg/L增至8 000 mg/L时,吸附平衡时CTC的总去除率从30.97%上升至60.42%,而污泥单位吸附量则从151 326.70 μg/kg下降至37 530.98 μg/kg;在10、20、30℃条件下,吸附较好地符合Freundlich等温吸附模型和线性分配吸附模型,K_d值依次为190.93、162.32和121.08 L/kg;热力学数据表明,CTC在污泥上的吸附为放热过程,低温有利于吸附的进行;当pH值介于3~11之间时,CTC在污泥上的吸附量随着pH值的增加而减少。     

不同泥龄对活性污泥絮凝特性的影响

为了揭示不同污泥龄活性污泥的絮凝特性及作用机制,采用序批式反应器,考察污泥龄（solid retention time,SRT）对絮体EPS（extra-micro colony polymeric substances,EMPS）和菌胶团EPS（extra-cellular polymeric substances,ECPS）2种EPS组分的影响,通过扩展的DLVO理论和EPS组分解析不同污泥龄的絮凝性能。研究结果表明,随着SRT的增大,活性污泥的相互作用能曲线存在明显的势垒和势垒值逐渐减少,EMPS和ECPS含量逐渐减少,且相对于ECPS的变化,EMPS含量随泥龄的变化更加明显,其中蛋白质与腐殖质含量逐渐降低,污泥絮凝性能变好。这表明,较高的污泥相互作用能势垒和EMPS组分含量是污泥絮凝性能低的内在机制,且EMPS中蛋白质和腐殖质含量的变化是不同污泥龄污泥絮凝性能差异的主要原因。     

Reduction of toxicity of antimicrobial compounds by degradation processes using activated sludge,gamma radiation,and UV

The occurrence and persistence of pharmacologically active compounds in the environment has been an increasingly important issue. The objectives of this study were to investigate the decomposition of aqueous antimicrobial compounds using activated sludge, γ-irradiation, and UV treatment, and to evaluate the toxicity towards green algae, Pseudokirchneriella subcapitata, before and after treatment. Tetracycline (TCN), lincomycin (LMC) and sulfamethazine (SMZ) were used as target compounds. Gamma (γ)-irradiation showed the highest removal efficiency for all target compounds, while UV and activated sludge treatment showed compound-dependent removal efficiencies. TCN and SMZ were well degraded by all three treatment methods. However, LMC showed extremely low removal efficiency for UV and activated sludge treatments. Overall, the algal toxicity after degradation processes was significantly decreased, and was closely correlated to removal efficiency. However, in the case of γ-irradiated TCN, UV and activated sludge treated LMC as well as sludge treated SMZ, the observed toxicity was higher than expected, which indicates the substantial generation of byproducts or transformed compounds of a greater toxicity in the treated sample. Consequently, γ-radiation treatment could be an effective method for removal of recalcitrant compounds such as antibiotics.     

剩余污泥制备活性炭及其应用研究

以城市污水处理厂二沉池排出的剩余污泥为原料,采用不同活化方法制备活性炭,同时对比活化效果,研究了制备工艺条件对污泥活性炭吸附性能及产率的影响。结合比表面积、孔径分布和扫描电镜表征分析,对制备的污泥活性炭的性能进行评价,并探讨了污泥活性炭作为水处理吸附剂的去除效果。结果表明,以ZnCl2为活化剂制备的活性炭性能较好,其最佳制备条件为：活化温度550℃,活化时间45 min,ZnCl2浓度40％,固液比1∶2。制得的污泥活性炭的碘吸附值为496 mg/g,产率为51.8％,比表面积为301.4 m2/g,孔体积为0.37 mL/g,微孔体积为0.08 mL/g,平均孔径为5.78 nm。将该产品用于处理城市污水,投加量为0.8％,吸附平衡时间约为60 min时,对COD的去除率为81％,吸附容量为42.53 mg/g。     

4-硝基酚的污泥减量化作用及对污泥性质的影响

为了有效减少活性污泥法中剩余污泥的产生,采用解偶联剂4-硝基酚对活性污泥工艺中的剩余污泥进行减量化研究。研究了4-硝基酚对污泥的增长速率、基质去除率以及污泥性质的影响。结果表明:4-硝基酚对污泥的减量化作用明显,在对微生物解偶联的过程中并不影响微生物对基质的利用能力;对出水中的氨氮影响甚小,总氮、总磷浓度有轻微的升高。4-硝基酚能够刺激污泥中微生物的活性,比耗氧速率增加,促进能量解偶联,从而降低污泥产率。4-硝基酚使污泥中微生物的群落结构发生了轻微的变化,但对污泥的松散程度和絮凝沉降性能影响甚小。