嗜麦芽寡养单胞菌降解羽毛5 L发酵罐工业小试过程研究

为了将微生物处理羽毛工艺产业化,在摇瓶发酵条件优化的基础上进行5 L发酵罐工业小试研究,确定了放大发酵条件并根据发酵条件记录对发酵过程进行分析,推测代谢过程中的物质及能量变化及产物形成的动力学模型。在通气气压为0.08 MPa,空气流量为2.5 L/min及恒温40℃的条件下,产物得率比摇瓶发酵提高了2～3倍,发酵周期缩短了1 d。为羽毛废弃物的利用提供了可靠的依据。     

应用生命周期模型评价餐厨垃圾处理技术

运用生命周期模型对餐厨垃圾常用处理技术——厌氧发酵、好氧堆肥、饲料化技术、生化处理机进行评价和筛选。结果表明,厌氧发酵、好氧堆肥、饲料化技术、小型生化处理机的环境影响潜力分别为1.35×10-3、4.42×10-3、3.78×10-2和1.18×10-2,单位处理成本为2.1、5.65、0.37和1.4元/（人.a）,综合评估得出厌氧发酵和饲料化是当前具有优势的餐厨垃圾处理技术。     

城市生活垃圾中纤维素含量测定方法优化

对传统硫酸法进行改进,建立适用于城市生活垃圾纤维素含量的测定方法。以脂肪抽提时间、硫酸浓度、水解反应温度、水解反应时间、稀释硫酸浓度、回流时间为考察因素进行6因素5水平正交实验。结果表明,测定纤维素含量的最佳条件为：脂肪抽提时间4h、硫酸浓度70％、水解反应温度30℃、水解反应时间5h、稀释硫酸浓度5％、回流时间3h。优化后纤维素测定条件RSD均小于1．69％,平均回收率98．76％,表明该方法的精度高,可靠行强。     

Polybrominated diphenyl ethers in sediments of the Daliao River Estuary, China: levels, distribution and their influencing factors

The concentrations, compositional profiles, possible sources of polybrominated diphenyl ethers (PBDEs) in sediments of the Daliao River Estuary as well as the factors influencing the distribution of PBDEs were investigated. The total concentrations of PBDEs ranged from 0.13 to 1.98 ng g⁻¹ d.w. BDE209 was the dominating congener in all sediment samples, indicating the pollution of PBDEs in the Daliao River Estuary mainly came from the use of deca-BDE commercial mixtures. The intrusion of sea waters promoted the deposition of the colloid-associated PBDEs in the estuary. There were significantly negative correlations between PBDE concentration in sediment with pH value and salinity in the bottom water. The higher river flow in the flood season (summer) obviously accelerated the transport of PBDEs, and thereby increased the risk of PBDE contamination to the deep ocean. Moreover, a positive correlation between TOC and PBDE distributions was observed, suggesting that TOC regulated the distributions of PBDEs in sediments of Daliao River Estuary.     

Qualitative analysis of volatile organic compounds on biochar

Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs can directly inhibit/stimulate microbial and plant processes. Over 70 biochars encompassing a variety of parent feedstocks and manufacturing processes were evaluated and were observed to possess diverse sorbed VOC composition. There were over 140 individual chemical compounds thermally desorbed from some biochars, with hydrothermal carbonization (HTC) and fast pyrolysis biochars typically possessing the greatest number of sorbed volatiles. In contrast, gasification, thermal or chemical processed biochars, soil kiln mound, and open pit biochars possessed low to non-detectable levels of VOCs. Slow pyrolysis biochars were highly variable in terms of their sorbed VOC content. There were no clear feedstock dependencies to the sorbed VOC composition, suggesting a stronger linkage with biochar production conditions coupled to post-production handling and processing. Lower pyrolytic temperatures (?350 °C) produced biochars with sorbed VOCs consisting of short carbon chain aldehydes, furans and ketones; elevated temperature biochars (>350 °C) typically were dominated by sorbed aromatic compounds and longer carbon chain hydrocarbons. The presence of oxygen during pyrolysis also reduced sorbed VOCs. These compositional results suggest that sorbed VOCs are highly variable and that their chemical dissimilarity could play a role in the wide variety of plant and soil microbial responses to biochar soil amendment noted in the literature. This variability in VOC composition may argue for VOC characterization before land application to predict possible agroecosystem effects.     

高氯离子味精尾母液废水厌氧处理研究

味精尾母液废水COD浓度极高同时含有大最氯离子.采用UASB反应器对味精尾母液废水进行处理,其中接种污泥来自啤酒厂UASB反应器.实验表明:当氯离子浓度在4 500 mg/L以下时,对厌氧微生物没有明礁的抑制作用;5 000 mg/L的氯离子浓度可以看作一个抑制限值,但经过驯化后,仍可获得较好的COD去除效果;当氯离子浓度达到8 000mg/L左右时,COD平均去除率在80%以上.     

Evaluation of Reference Evapotranspiration Methods in Arid,Semiarid, and Humid Regions

It is often necessary to find a simpler method in different climatic regions to calculate reference crop evapotranspiration (ET_o) since the application of the FAO‐56 Penman‐Monteith method is often restricted due to the unavailability of a comprehensive weather dataset. Seven ET_o methods, namely the standard FAO‐56 Penman‐Monteith, the FAO‐24 Radiation, FAO‐24 Blaney Criddle, 1985 Hargreaves, Priestley‐Taylor, 1957 Makkink, and 1961 Turc, were applied to calculate monthly averages of daily ET_o, total annual ET_o, and daily ET_o in an arid region at Aksu, China, in a semiarid region at Tongchuan, China, and in a humid region at Starkville, Mississippi, United States. Comparisons were made between the FAO‐56 method and the other six simple alternative methods, using the index of agreement D, modeling efficiency (EF), and root mean square error (RMSE). For the monthly averages of daily ET_o, the values of D, EF, and RMSE ranged from 0.82 to 0.98, 0.55 to 0.98, and 0.23 to 1.00 mm/day, respectively. For the total annual ET_o, the values of D, EF, and RMSE ranged from 0.21 to 0.91, ?43.08 to 0.82, and 24.80 to 234.08 mm/year, respectively. For the daily ET_o, the values of D, EF, and RMSE ranged from 0.58 to 0.97, 0.57 to 0.97, and 0.30 to 1.06 mm/day, respectively. The results showed that the Priestly‐Taylor and 1985 Hargreaves methods worked best in the arid and semiarid regions, while the 1957 Makkink worked best in the humid region.     

添加NaOH对水生植物固体厌氧发酵产甲烷的作用

为了提高木质纤维素生物质的甲烷产率,固体厌氧发酵以及预处理技术得到了广泛应用。本研究以水生植物菹草为例,探讨了厌氧固体发酵同步碱处理提高甲烷产率的可行性。采用2种来源的微生物(厌氧污泥和牛粪),初始生物质浓度为20%TS(total solid,总固体重量),考察不同的NaOH添加量(基于反应体系总TS 0%、2.0%、3.5%和5.0%)对菹草厌氧发酵产气和固体水解效率的影响。结果表明,与对照实验组相比,初始NaOH加入量为3.5%时,接种污泥和牛粪的实验组中甲烷总产量分别为787.1 mL和1 165.4 mL,与对照实验组相比(619.1 mL和834.8 mL),分别提高了27.1%和39.6%,而且接种牛粪的实验组中单位挥发性固体(VS)产甲烷率最高,为186.5 mL/g。对发酵后的木质纤维素残渣组分进行分析,结果表明,NaOH有助于促进菹草中纤维素及半纤维素的分解,以及木质素结构的破坏,从而提高了菹草厌氧发酵产气产甲烷效率。     

厌氧硫酸盐还原-氨氧化的研究

采用厌氧序批式反应器,在无机营养条件下培养历时354 d,成功实现了SO2-4和NH+4的同步生物去除。结果表明,提高进水的TN负荷有利于促进硫酸盐还原-氨氧化的发生,当进水TN负荷提高到120 mg/(L·d)时,对TN的平均去除速率和硫酸盐硫的平均去除速率达到了最大,分别为64.43 mg/(L·d)和44.82 mg/(L·d);在同步生物脱氮除硫前期生成了大量的NO-3-N,平均浓度为53.88 mg/L,远大于由Anammox反应生成的量,推测部分NO-3是直接由NH+4和SO2-4发生氧化还原反应生成。该体系中存在单质硫的自养反硝化,可以解释反应后期硫酸盐重生成的现象。     

Performance analysis of bioethanol (Water Hyacinth) on diesel engine

The increasing consumption and excessive extraction of conventional fuels is the matter of serious concern. Nowadays, world is looking for alternative sources of fuel which can partially replace conventional fuel dependence. The current investigation intends to provide evaluation of bio-ethanol preparation from Water Hyacinth (WH) and its influence on diesel engine performance under various operating conditions. This study explores the extraction of glucose from WH (Eichhornia crassipes) pretreated with sulfuric acid (H₂SO₄) for production of bio-ethanol. For the production of bio-ethanol different concentrations of H₂SO₄ acid hydrolysate (1%, 2%, 4%, 6%, 8%, and 10%) were prepared which was then followed by fermentation with cellulose fermenting yeasts. From results, it was observed that 4% H₂SO₄ acid hydrolysis produces higher concentrations of ethanol than other concentrations. Bio-ethanol extracted from WH was blended with diesel in different proportions (5%, 10%, 15%, 20%, and 25%) v/v and performance and emissions were experimentally investigated on single cylinder diesel engine under various load conditions. Experimental results show that 5 BED [5% bio-ethanol (WH + 95%diesel v/v) and 10BED (10% bio-ethanol (WH + 90%diesel v/v)] produces higher brake power, brake thermal efficiency and brake mean effective pressure with improved exhaust emission profiles than any other blend.