厌氧水解－好氧两段SBR处理焦化废水的研究

焦化废水含有毒物质多,生物降解性能差,对环境危害大。实验采用厌氧水解（酸化）－好氧（高效复合菌＋活性污泥）工艺处理焦化废水,进水COD、BOD5浓度分别为：698．13mg／l、232．0mg／l,经12h厌氧水解、18h好氧曝气后出水COD、BOD,浓度分别为136．93mg／1、39．3mg／l,NH3一N的去除率为68．37％。出水COD、BOD,满足《污水综合排放标准》（GB8978－96）中的排放要求。     

不完全厌氧—好氧同反应器工艺处理印染废水的研究

不完全厌氧—好氧同反应器工艺是通过时段切换在同一反应器内实现印染废水处理的过程。结果表明,反应器体积为30L,水力停留时间为12h,总COD_(Cr)去除率达85％,总BOD_5达94.3％,总色度为87.5％,处理出水COD_(Cr)为140mg/L,BOD_5为8mg/L,色度为50倍,达到了国家二级排放标准。实验表明,经厌氧时间段后,BOD_5/COD_(Cr)由0.15提高至0.37,色度由400倍降至50倍,为好氧时间段的COD_(Cr)去除和总的处理效果提供了保证。     

厌氧氨氧化工艺在UASB反应器中的启动运行研究

利用UASB反应器进行了厌氧氨氧化工艺的启动运行研究。以自配高氮低碳废水为进水,普通厌氧污泥为接种污泥,在温度35℃,pH7.5～8.0的条件下连续运行220d,成功实现了厌氧氨氧化工艺的启动,氨氮容积负荷为0.43kg/(m~3·d)时,氨氮的去除率最高达88.3％,扫描电镜的观察结果表明,厌氧氨氧化污泥中的细菌以形状不规则的短杆菌为主。     

芳香类污染物的厌氧生物降解研究

综述了国内外芳香类污染物厌氧降解的研究进展,详细阐述了含氮芳香类、氯代芳香类和酚类污染物厌氧降解的微生物类群与机理.提出了芳香类污染物生物降解今后发展方向的重点是共基质条件下生物降解性研究、厌氧-好氧条件下的生物降解性研究、高效工程菌和固定化细胞技术应用研究、构建基因工程菌和遗传学研究等技术领域.     

Insights on the solubilization products after combined alkaline and ultrasonic pre-treatment of sewage sludge

This work provides insights on the solubilization products after a simultaneous combination of alkaline and ultrasonic (ALK + ULS) pre-treatment of sewage sludge. Soluble chemical oxygen demand (SCOD) increased from 1200 to 11,000 mg/L after such treatment. Organics with molecular weight around 5.6 kDa were solubilized because of the synergistic effect of ultrasound and alkali. Organics with molecular weight larger than 300 kDa increased from 7.8% to 60%, 16% and 42.3% after ULS, ALK and ALK + ULS treatment, respectively. Excitation emission matrix fluorescence spectroscopy analysis identified soluble microbial product-like and humic acid-like matters as the main solubilization products. Sludge anaerobic biodegradability was significantly enhanced with the simultaneous application of ALK + ULS pre-treatment. ALK + ULS pre-treatment resulted in 37.8% biodegradability increase compared to the untreated sludge. This value was higher compared to the biodegradability increase induced by individual ALK pre-treatment (5.7%) or individual ULS pre-treatment (20.7%) under the same conditions applied.     

高温厌氧消化处理城市有机垃圾的正交试验研究

针对城市垃圾高温厌氧消化处理中反应复杂、影响因素多的特点,采用正交试验,利用自行设计的厌氧发酵罐,以产气量为观察值,分析含固率(TS)、消化温度和碳氮比(C/N比)对厌氧消化过程的影响,并分析比较了高产气区与低产气区的挥发性脂肪酸(VFA)以及比产气速率的变化情况.在相同条件下,高温可以提高系统的最大比产气速率,并且还可以有效抑制VFA的积累,提高总产气量.结果表明,温度对厌氧消化过程影响最大,TS次之,C/N比影响最小.     

阿卡波糖生产废水的光催化降解工艺研究

在实验室用溶胶-凝胶法合成一种复合光催化剂,以难生化降解的阿卡波糖废水作为降解对象,研究经光催化降解后的废水,对后续生化装置的影响。     

Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation

Biodegradation of lower chlorinated benzenes (tri-, di- and monochlorobenzene) was assessed at a coastal aquifer contaminated with multiple chlorinated aromatic hydrocarbons. Field-derived microcosms, established with groundwater from the source zone and amended with a mixture of lower chlorinated benzenes, evidenced biodegradation of monochlorobenzene (MCB) and 1,4-dichlorobenzene (1,4-DCB) in aerobic microcosms, whereas the addition of lactate in anaerobic microcosms did not enhance anaerobic reductive dechlorination. Aerobic microcosms established with groundwater from the plume consumed several doses of MCB and concomitantly degraded the three isomers of dichlorobenzene with no observable inhibitory effect. In the light of these results, we assessed the applicability of compound stable isotope analysis to monitor a potential aerobic remediation treatment of MCB and 1,4-DCB in this site. The carbon isotopic fractionation factors (ε) obtained from field-derived microcosms were -0.7‰ ± 0.1 ‰ and -1.0‰ ± 0.2 ‰ for MCB and 1,4-DCB, respectively. For 1,4-DCB, the carbon isotope fractionation during aerobic biodegradation was reported for the first time. The weak carbon isotope fractionation values for the aerobic pathway would only allow tracing of in situ degradation in aquifer parts with high extent of biodegradation. However, based on the carbon isotope effects measured in this and previous studies, relatively high carbon isotope shifts (i.e., ∆δ¹³C > 4.0 ‰) of MCB or 1,4-DCB in contaminated groundwater would suggest that their biodegradation is controlled by anaerobic reductive dechlorination.     

Mechanisms of allicin exposure for the sludge fermentation enhancement: Focusing on the fermentation processes and microbial metabolic traits

As a frequently used product with antimicrobial activity, consumed allicin might be discharged and concentrated in waste-activated sludge (WAS). However, the influence of allicin (as an exogenous pollutant) on WAS fermentation has not been clearly revealed. This study aimed to disclose the impacts of allicin on volatile fatty acid (VFA) generation during WAS fermentation. The results showed that the appropriate presence of allicin (10 mg/g TSS) significantly enhanced the VFA yield (1894 versus 575 mg COD/L in the control) with increased acetate proportion (24.3%). Further exploration found that allicin promoted WAS solubilization, hydrolysis and acidification simultaneously. Metagenomic analysis revealed that the key genes involved in extracellular hydrolysis metabolism (i.e., CAZymes), membrane transport (i.e., gtsA and ytfT), substrate metabolism (i.e., yhdR and pfkC) and fatty acid synthesis (i.e., accA and accD) were all highly expressed. Allicin also induced the bacteria to produce more signalling molecules and regulate cellular functions, thereby enhancing the microbial adaptive and regulatory capacity to the unfavourable environment. Moreover, the variations in fermentative microbes and their contributions to the upregulation of functional genes (i.e., ytfR, gltL, INV, iolD and pflD) for VFA generation were disclosed. Overall, the simultaneous stimulation of functional microbial abundances and metabolic activities contributed to VFA production in allicin-conditioned reactors.     

Citrus essential oils and their influence on the anaerobic digestion process: An overview

Citrus waste accounts for more than half of the whole fruit when processed for juice extraction. Among valorisation possibilities, anaerobic digestion for methane generation appears to be the most technically feasible and environmentally friendly alternative. However, citrus essential oils can inhibit this biological process. In this paper, the characteristics of citrus essential oils, as well as the mechanisms of their antimicrobial effects and potential adaptation mechanisms are reviewed. Previous studies of anaerobic digestion of citrus waste under different conditions are presented; however, some controversy exists regarding the limiting dosage of limonene for a stable process (24–192 mg of citrus essential oil per liter of digester and day). Successful strategies to avoid process inhibition by citrus essential oils are based either on recovery or removal of the limonene, by extraction or fungal pre-treatment respectively.