厌氧反应器技术的发展及ABR反应器的工艺特点

着重介绍了厌氧处理技术由第一代反应器到第三代反应器的发展过程，分析了新型第三代工艺－ABR反应器的性能特点。     

UASB反应器处理PTA废水的研究

采用UASB反应器，对两种不同方法驯化的污泥处理PTA废水进行了研究，结果表明，经对苯二甲(TA)酸驯化的厌氧污泥能够稳定地处理PTA废水，在水力停留时间29～32h、进水CODcr4600-7000mg／L、废水中对TA含量1800～2080mg／L条件下，CODcr的去除率稳定在80％以上，对TA去除率稳定在70％以上；而用PTA废水驯化的污泥在同样的条件下对CODcr，去除率在61％以下，对TA去除率在40％以下。经TA驯化的污泥，其物理、生物性状比PTA废水驯化的污泥有显著提高和改善。     

Thermophilic adaptation of a mesophilic anaerobic sludge for food waste treatment

As opposed to mesophilic, thermophilic anaerobic digestion of food waste can increase the biogas output of reactors. To facilitate the transition of anaerobic digesters, this paper investigated the impact of adapting mesophilic sludge to thermophilic conditions. A 5L bench scale reactor was seeded with mesophilic granular sludge obtained from an up-flow anaerobic sludge blanket digester. After 13 days of operation at 35 degrees C, the reactor temperature was instantaneously increased to 55 degrees C and operated at this temperature until day 21. The biomass was then fed food waste on days 21, 42 and 63, each time with an F/M (Food/Microorganism) ratio increasing from 0.12 to 4.43 gVS/gVSS. Sludge samples were collected on days 0, 21, 42 and 63 to conduct substrate activity tests, and reactor biogas production was monitored during the full experimental period. The sludge collected on day 21 demonstrated that the abrupt temperature change had no pasteurization effect, but rather lead to a biomass with a fermentative activity of 3.58 g Glucose/gVSS/d and a methanogenic activity of 0.47 and 0.26 g Substrate/gVSS/d, related respectively, to acetoclastic and hydrogenophilic microorganisms. At 55 degrees C, an ultimate gas production (Go) and a biodegradation potential (Bo) of 0.2-1.4 L(STP)/gVS(fed) and of 0.1-0.84 L(STP) CH(4)/gVS(fed) were obtained, respectively. For the treatment of food waste, a fully adapted inoculum was developed by eliminating the initial time-consuming acclimatization stage from mesophilic to thermophilic conditions. The feeding stage was initiated within 20 days, but to increase the population of thermophilic methanogenic microorganisms, a substrate supply program must be carefully observed.     

Effects of oxidizing environment on digestate humification and identification of substances governing the dissolved organic matter (DOM) transformation process

• Liquid digestate humification was investigated under different oxidizing environment. • Tryptophan-like substances dominated the transformation of the liquid digestate DOM. • The humification sequence of the liquid digestate DOM was identified. • UV₃₂₅ was first identified as a pre-humus intermediate during humification reaction. The formation of humic-like acids (HLAs) is an essential process for converting liquid digestate into organic soil amendments to enhance agricultural sustainability. The aim of this study was to investigate the impact of oxygen and/or MnO₂ on the production of HLAs. Herein, abiotic humification performance of the digestate dissolved organic matter (DOM) is investigated with fluxes of air and N₂ in the absence and presence of MnO₂. Our results demonstrated that the fate of digestate DOM greatly depends on the oxidizing environment, the MnO₂ enhanced nitrogen involved in the formation of HLAs. The synergistic effects of MnO₂ and oxygen effectively improved the production of HLAs, and the corresponding component evolution was analyzed using spectroscopic evidence. The two-dimensional correlation spectroscopy results demonstrated that the reaction sequence of digestate DOM followed the order of protein-like substances, substances with an absorbance at 325 nm, substances with UV absorbance at 254 nm and HLAs. Additionally, excitation emission matrix fluorescence combined with parallel factor analysis (EEM-PARAFAC) showed that tryptophan-like C3 was more prone to transformation than tyrosine-like C2 and was responsible for the humification process. The substance with an absorbance at 325 nm was a reaction intermediate in the transformation process of protein-like substances to HLAs. The above findings can be used to promote the production of liquid fertilizer associated with carbon sequestration as well as the sustainable development of biogas production.     

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.     

Modelling anaerobic biofilm reactors--a review

Anaerobic treatment has become a technically as well as economically feasible option for treatment of liquid effluents after the development of reactors such as the upflow anaerobic sludge blanket (UASB) reactor, expanded granular sludge bed (EGSB) reactor, anaerobic biofilter and anaerobic fluidized bed reactor (AFBR). Considerable effort has gone into developing mathematical models for these reactors in order to optimize their design, design the process control systems used in their operation and enhance their operational efficiency. This article presents a critical review of the different mathematical models available for these reactors. The unified anaerobic digestion model (ADM1) and its application to anaerobic biofilm reactors are also outlined.     

Anaerobic biodegradation of PAHs in mangrove sediment with amendment of NaHCO3

Mangrove sediment is unique in chemical and biological properties. Many of them suffer polycyclic aromatic hydrocarbon(PAH) contamination. However, the study on PAH biological remediation for mangrove sediment is deficient. Enriched PAH-degrading microbial consortium and electron acceptor amendment are considered as two effective measures. Compared to other electron acceptors, the study on CO2, which is used by methanogens, is still seldom. This study investigated the effect of Na HCO3 amendment on the anaerobic biodegradation of four mixed PAHs, namely fluorene(Fl), phenanthrene(Phe),fluoranthene(Flua) and pyrene(Pyr), with or without enriched PAH-degrading microbial consortium in mangrove sediment slurry. The trends of various parameters, including PAH concentrations, microbial population size, electron-transport system activities, electron acceptor and anaerobic gas production were monitored. The results revealed that the inoculation of enriched PAH-degrading consortium had a significant effect with half lives shortened by 7–13 days for 3-ring PAHs and 11–24 days for 4-ring PAHs. While Na HCO3 amendment did not have a significant effect on the biodegradation of PAHs and other parameters, except that CO2 gas in the headspace of experimental flasks was increased.One of the possible reasons is that mangrove sediment contains high concentrations of other electron acceptors which are easier to be utilized by anaerobic bacteria, the other one is that the anaerobes in mangrove sediment can produce enough CO2 gas even without adding Na HCO3.     

IC反应器技术的发展

扼要介绍IC反应器的基本结构和原理,并从工艺思想的角度对该反应器进行了分析,即IC反应器是现有废水处理工艺成果与内循环技术相结合的产物.最后总结了IC反应器的应用特点.     

消化液回流比与有机负荷率对餐厨垃圾厌氧消化的影响

在试验的基础上研究了消化液回流比与有机负荷率(OLR)对餐厨垃圾厌氧消化的影响.试验通过改变OLR、消化液回流比等参数来控制其运行.研究发现,当回流比从零提高到180%时,OLR分别为9.933、14.900 g/(L·d)的厌氧消化系统COD去除率分别从79.45%、80.13%上升到81.98%、83.33%;当OLR为19.866 g/(L·d)时,提高回流比会造成COD去除率的下降.系统在较低负荷运行时,回流比的提高使系统的产气率有明显的增加.研究认为,180%的回流比仅适用于低OLR(9.933、14.900 g/(L·d)),当系统处于高OLR(19.866 g/(L·d))时,高回流比会造成挥发性脂肪酸(VFA)和钠离子的积累,进而影响消化系统的性能.     

厌氧消化治理造纸黑液

造纸黑液是最严重的水污染物之一,目前国内还没有一种能彻底治理黑液的方法,球溪河糖厂经过多年探索,试验,工业化治理运行,认为厌氧消化是治理中小型,亚铵法纸厂制浆黑液适宜方法。