两相厌氧工艺在制糖废水处理中的应用

由于两相厌氧工艺具有产酸相与产甲烷相分离的特性,因此在处理具有高有机负荷、高悬浮物浓度（SS）的制糖废水方面具有独特的优势。针对制糖废水的特征、传统的治理技术进行了论述,并对两相厌氧工艺在处理制糖废水方面所存在的独特优势进行了分析。     

介绍一种废水处理新工艺：两相厌氧消化原理及其应用

厌氧法处理工业有机废水,既能除去有机污染物,又能获得沼气作为能源,我国从80年代初开始,对应用厌氧法处理制浆废水进行了大量的研究,并取得了令人振奋的进展,轻工业部环保所为芜湖纸板厂处理废水的设计已通过评审。 为了进一步提高厌氧处理的效率,国外开发了一系列的新型厌氧消化装置和工艺,两相消化工艺便是其中     

糖蜜废水在两相厌氧消化工艺中的应用

针对糖蜜废水排放量大、有机负荷高、悬浮物浓度高和成分复杂等特点,结合两相厌氧消化工艺具有产酸相与产甲烷相分离的特性,在处理高浓度有机废水和能源回收利用上有独特优势进行讨论。并例举了糖蜜废水在两相厌氧消化工艺中的应用实例和特性研究,指出了两相厌氧消化工艺存在的问题和未来的发展趋势。     

城市有机废物厌氧消化技术研究进展

我国目前在有机垃圾厌氧消化工程应用方面的研究很少,厌氧消化的研究主要集中在水处理方面,对固体废物的处理处置还较少,在厌氧发酵工艺中存在自动化程度低,技术装备差的问题,厌氧消化工艺还有很多工作有待进一步研究,本文主要对厌氧消化技术处理有机废物的微生物学机理、影响因素以及消化工艺的研究进展进行了综述,对促进厌氧消化技术的研究具有重要意义。     

NADH酶对电化学厌氧消化产甲烷代谢的影响

为了探究NADH酶对电化学厌氧消化产甲烷代谢的影响,文章以猪粪发酵后的厌氧活性污泥作为接种物,以葡萄糖为底物,用日产气量、气体含量、挥发性酸作为分析指标,研究NADH酶活性变化对EAD体系产甲烷代谢的影响。结果表明,NADH酶在EAD产甲烷途径中起到电子传递的作用,涉及产氢、甲酸发酵、丙酸发酵、丁酸发酵以及乙醇发酵等途径,从而影响EAD体系产甲烷量。     

两相厌氧耦合生物脱硫组合工艺处理糖蜜乙醇废水的性能

采用两相厌氧耦合生物脱硫组合工艺处理糖蜜乙醇废水,在启动和运行过程对各处理单元的效能进行了测定分析。结果表明,当进水COD和SO_4~(2-)负荷提升至18~21 kg/(m~3·d)和0.8~1.1 kg/(m~3·d)时,组合工艺的COD和SO42-去除率可分别达到95%~96%和86%~90%,出水中COD、SO_4~(2-)和硫化物含量分别为6 000~6 500、800~850、750~800 mg/L。从各处理单元的运行效能来看,一级厌氧和二级厌氧对COD去除的贡献率分别为86%和11%,同时两者对硫酸盐去除的贡献率分别为90%和7%;而生物脱硫贡献率较小,均在3%左右。由此可见,一级厌氧的处理效能要显著高于二级厌氧。此外生物脱硫单元在高负荷运行条件下的硫化物去除率较低(30%左右),增加曝气量虽然一定程度上可以增加溶氧以及缓解单质硫在陶粒表面的吸附,但同时也可能会影响生物膜的形成和硫细菌的固定,从而造成微生物大量流失。因此如何保证氧气、底物与硫细菌之间的高效传质将是今后需要进一步解决的关键问题之一。     

造纸漂白废水有机氯化物的厌氧抑制作用研究

介绍了传统漂白工艺过程中产生的有机氯化物的主要种类，分析了漂白废水的厌氧抑制毒性来源，比较了不同的预处理化学工艺降低废水毒性的效果，提出了微生物絮凝剂和高级氧化方法在降低废水毒性的应用前景，最后从可持续发展的角度提出造纸工业应该大力提倡清洁生产漂白工艺，彻底消除造纸行业有机氯化物污染。     

厌氧膜生物反应器处理高浓度有机废水的中试研究

对厌氧膜生物反应器(AnMBR)处理高浓度有机废水的运行效能进行了中试研究。在不排泥工况下(SRT无限长),AnMBR的COD去除负荷和沼气生产强度可分别稳定在4.4~4.8 kg/(m~3·d)和2.2 m~3/(m3~·d)左右;而在排泥条件下(SRT=50 d)两者可分别稳定在5.2~6.0 kg/(m~3·d)和2.9 m~3/(m~3·d)左右。在整个220 d的运行过程中,AnMBR的COD总去除率都可维持在90%以上,且沼气中甲烷体积分数基本保持在58%左右。发酵系统中pH较为稳定,保持在7.6~7.8之间;VFA含量始终维持在较低水平。此外,虽然运行过程中有较高浓度的氨氮积累,但是并没有对厌氧消化性能造成显著影响,展现了AnMBR对内源性抑制因素的良好耐受力。排泥和不排泥条件下的运行参数对比表明,AnMBR运行过程中SRT的优化非常关键,不同SRT会导致发酵体系发生一系列的变化,很大程度上决定了AnMBR的处理效能。中试结果表明,AnMBR可以实现高效厌氧消化系统的快速启动,而且良好的抗冲击负荷能力能够保证消化体系长期高效稳定运行。     

造纸废水中三氯苯酚对厌氧颗粒污泥毒性的影响研究

进行了造纸废水中不同浓度2,4,6-三氯苯酚(2,4,6-TCP)的产甲烷毒性及产甲烷活性恢复实验,结果发现,2,4,6-TCP浓度与对产甲烷菌的抑制作用正相关,与产甲烷活性恢复程度负相关,表明2,4,6-TCP是一类杀菌性有机物。研究了不同浓度2,4,6-TCP对经驯化的厌氧颗粒污泥特性的影响,结果表明,浓度为20 mg/L和30 mg/L的2,4,6-TCP能促进污泥颗粒化,加速大颗粒的形成;同时使颗粒污泥的活性提高,因营养供应不足形成空腔导致沉降速度降低;2,4,6-TCP在高浓度(20 mg/L和30 mg/L)的条件下,以还原脱氯代谢为主,增加了生物质的量;并且为还原脱氯微生物和厌氧微生物协同代谢提供了充足的营养物质,厌氧微生物表现出较强的生物活性,辅酶浓度升高。在2,4,6-TCP浓度较高时(20 mg/L和30 mg/L),菌体分解,渗透至胞外,胞外聚合物总量增加。     

Unravelling the influence of sulfate loading on enhancing anaerobic co-digestion of corn stover and bio-kerosene production wastewater

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4-氨基偶氮苯在乙腈-盐双水相系统中的萃取

为解决纺织品中的4-氨基偶氮苯萃取试时间长,乙醚挥发以及污染环境和结果不准确等问题,以乙腈-无机盐-水双水相系统,建立一种环保高效的4-氨基偶氮苯前处理方法。经由无机盐分相能力差异,分析乙腈与几种常见盐构成双水相系统中各成分之间配比、有机相加入量、水相中氢氧化钠的质量分数对有机相的萃取率和4-氨基偶氮苯回收率的影响,筛选4-氨基偶氮苯萃取的最优系统。结果表明：乙腈/碳酸钾系统为4-氨基偶氮苯萃取的最佳系统;当2%氢氧化钠溶液10 mL,乙腈体积为4 mL,无水碳酸钾质量为4.0 g时,效果最优,线性范围为0 ~20 mg/kg ,相关系数为0.9999,检出限为0.036 mg/kg;4-氨基偶氮苯的回收率在89.71%~101.6%之间,其相对标准偏差为1.40%~3.86%;乙腈萃取率在96.25%~101.00之间,其相对标准偏差为0.63%~1.27%。     

柠檬酸盐对秸秆厌氧降解体系产沼气的影响

将马氏甲烷八叠球菌、地农芽胞杆菌、施氏假单胞菌、谢氏丙酸杆菌接种于秸秆厌氧发酵体系中,考察添加柠檬酸盐对沼气产量、纤维素降解率和木质素降解率的影响.研究发现:添加3g/L柠檬酸盐(添加组)促进了体系的产气效率,沼气产量比对照提高了1倍,其总固体(TS)、挥发性固体(VS)含量分别比对照降低11.2％和5.1％.对照挥发性脂肪酸(VFA)浓度在84h达最大值,达到7.07g/L,仅为添加组的80％,其平均积累速率51.6mg/(L·h),比添加组69.2mg/(L·h)降低25.4％,说明添加柠檬酸盐提高了厌氧发酵体系TS、VS的利用率,促进了厌氧体系乙酸和丙酸、丁酸等VFA的合成.同时发现:秸秆厌氧发酵体系的纤维素降解率普遍高于木质素降解率7.5％左右,说明多菌耦合厌氧发酵产沼气体系的降解纤维素能力高于降解木质素的能力.     

Enhanced treatment efficiency of an anaerobic sequencing batch reactor (ASBR) for cassava stillage with high solids content

Cassava stillage is a high strength organic wastewater with high suspended solids (SS) content. The efficiency of cassava stillage treatment using an anaerobic sequencing batch reactor (ASBR) was significantly enhanced by discharging settled sludge to maintain a lower sludge concentration (about 30 g/L) in the reactor. Three hydraulic retention times (HRTs), namely 10 d, 7.5 d, 5 d, were evaluated at this condition. The study demonstrated that at an HRT of 5 d and an organic loading rate (OLR) of 11.3 kg COD/(m³ d), the total chemical oxygen demand (TCOD) and soluble COD (SCOD) removal efficiency can still be maintained at above 80%. The settleability of digested cassava stillage was improved significantly, and thus only a small amount of settled sludge needed to be discharged to maintain the sludge concentration in the reactor. Furthermore, the performance of ASBR operated at low and high sludge concentration (about 79.5 g/L without sludge discharged) was evaluated at an HRT of 5 d. The TCOD removal efficiency and SS in the effluent were 61% and 21.9 g/L respectively at high sludge concentration, while the values were 85.1% and 2.4 g/L at low sludge concentration. Therefore, low sludge concentration is recommended for ASBR treating cassava stillage at an HRT 5 d due to lower TCOD and SS in the effluent, which could facilitate post-treatment.     

E．harbinense YUAN-3厌氧发酵影响因素的初步研究

产乙醇杆菌YUAN-3是一种具有良好自凝集特性的高效产氢菌株,已经引起了国内外研究者们的广泛关注。为了提高其发酵性能,有利推进利用该菌株发酵产氢的产业化进程,通过发酵罐静态试验的手段,从接种时间、接种浓度、培养基初始pH值等方面优化了YUAN-3厌氧发酵的条件。结果表明,在种子活化3天后进行接种发酵的效果良好;在5L的发酵罐中,YUAN-3的最优接种浓度是6％;而且,当培养基的初始pH值为6．40时,该厌氧发酵体系的氢气产量最高。因此得出结论,接种时间、接种浓度、培养基初始pH值等对于YUAN-3发酵的氢气产量都具有重要影响。     

硝酸盐对畜粪秸秆体系厌氧发酵产沼气的影响

秸秆畜粪体系厌氧发酵过程发生了基质酸化,其pH值在5.2～5.5之间,虽然接种兼性氨化菌(粪产碱菌/苏云金芽胞杆菌)后体系的pH值提高了2.9％～13.6％,但仍在6.0以下.同时添加硝酸钾(2g/L)和氨化菌(接种体积比例为1∶2)厌氧发酵168h的产气量、pH值和挥发性脂肪酸(VFA)浓度分别为350mL、7.12g/L和2.54g/L,比对照组(只添加氨化菌)提高了62.8％、22.8％和降低了13.0％.表明硝酸钾对秸秆畜粪厌氧发酵体系pH影响极为显著,当培养环境中硝酸盐的可获得性不足时,氨化菌并不能被诱导并表现出硝酸盐呼吸的功能,因而其单独使用的缓冲pH效果并不明显.硝酸钾的加入改变了厌氧条件发酵的碳代谢途径,体系VFA的降低显著缓冲了体系的pH值,提高了体系pH值和厌氧菌系的代谢活性,促进了有机物向沼气转化的效率.同时也说明秸秆畜粪厌氧体系产沼气的限制性因子不是体系VFA的生成效率,而是VFA积累到临界浓度以上所造成的过低pH值.本研究为解决秸秆畜粪体系厌氧条件下因“基质酸化”而使沼气产量降低的矛盾提供了一种易行策略.     

A laboratory-scale test of anaerobic digestion and methane production after phosphorus recovery from waste activated sludge

In enhanced biological phosphorus removal (EBPR) processes, activated sludge microorganisms accumulate large quantities of polyphosphate (polyP) intracellularly. We previously discovered that nearly all of polyP could be released from waste activated sludge simply by heating it at 70 degrees C for about 1 h. We also demonstrated that this simple method was applicable to phosphorus (P) recovery from waste activated sludge in a pilot plant-scale EBPR process. In the present study, we evaluated the effect of this sludge processing (heat treatment followed by calcium phosphate precipitation) on anaerobic digestion in laboratory-scale experiments. The results suggested that the sludge processing for P recovery could improve digestive efficiency and methane productivity at both mesophilic (37 degrees C) and thermophilic (53 degrees C) temperatures. In addition, heat-treated waste sludge released far less P into the digested sludge liquor than did untreated waste sludge. It is likely that the P recovery step prior to anaerobic digestion has a potential advantage for controlling struvite (magnesium ammonium phosphate) deposit problems in sludge handling processes.     

有机溶剂对回收涤纶碱减量废渣中对苯二甲酸的影响

为了有效回收涤纶碱减量废渣中的对苯二甲酸（TPA）,用N,N-二甲基甲酰胺（DMF）作为溶剂,蒸馏水为析出剂,并以活性炭为除杂脱色剂,通过溶析结晶的方法从碱减量废渣中回收TPA。采用红外光谱、紫外分光光度计和酸值滴定分析了回收产物的基团、纯度和酸值等。结果表明,废渣与DMF和活性炭与废渣合理质量比分别为1:12与0.6:1。回收的TPA产品纯度接近于标准试剂（纯度≥99.0%）,酸值达到了标准试剂酸值的96.43%,回收率达到86.54%。研究表明：采用DMF溶剂能够有效回收碱减量废渣中的TPA。     

Effect of conventional and organic production systems on the yield and quality of field tomato cultivars grown in Tunisia

BACKGROUND: The agricultural production system and cultivation practices are critical factors in determining yield and food nutritional quality. Controversy remains regarding whether or not organic foods have a nutritional advantage when compared with their conventionally produced counterparts. In this study the effect of conventional and organic production systems on yield, physicochemical and nutritional properties of four field tomato cultivars (Perfectpeel, Rio Grande, Hypeel 108 and Firenze) was determined. In the organic system, different fertiliser combination treatments were used. RESULTS: When production system data were combined, marketable yield was not affected by cultivar. When averaged across cultivars, organic yield was about 63% of conventional yield. The production system affected fruit soluble solids, pH, titratable acidity and firmness only in some cultivars. However, no effect was found on lycopene and total phenolics in all cultivars. In the organic system, fertiliser combination treatments affected tomato yield of Rio Grande and fruit quality of Firenze and Hypeel 108. A general trend of higher quality data was obtained by using mixed compost C2 combined with its extract and codahumus 20. CONCLUSION: The production system affects tomato yield and some fruit quality attributes. The effect on fruit quality varies among cultivars, thus highlighting the need to use a range of varieties in this kind of study. Copyright © 2009 Society of Chemical Industry