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751.
通过间歇实验研究了油脂对餐厨废弃物单相厌氧定向产酸(VFA)的影响.考察了油脂含量为0.0,5.0,15.0及25.0g/L条件下发酵液中有机酸浓度及组成的变化情况.结果表明,油脂对发酵液中VFA浓度影响显著,随油脂含量提高最大VFA浓度呈下降趋势,当油脂含量达到25.0g/L时,最大VFA浓度仅为23.22g/L,为未添加油脂条件下的55.3%,其次油脂可延后开始产酸的时间,油脂含量为5.0g/L时,达到最高VFA浓度50%所需的反应时间分别为49.4h相对未添加油脂组滞后27.1h.此外油脂会影响发酵液中VFA各组分比例,提高丙酸含量促使发酵类型由丁酸型发酵向丙酸型发酵转变,当油脂含量为5.0g/L时丙酸所占比例分别为32.2%,而未添加油脂组的丙酸含量仅占8.7%.  相似文献   
752.
    
A combination system of biotrickling filter (BTF) and biofilter (BF), adopting surfactant-modified clinoptilolite and surfactant- modified wood chip as the media respectively, was applied to treat H2S and NH3 simultaneously. The identification and sole carbon sources utilization patterns of isolates in the combination system were studied by Biolog system. The isolates were identified as Bacillus sphaericus, Geobacillus themoglucosidasius (55℃) and Micrococcus luteus (ATCC 9341) in BTF, and Aspergillus sydowii (Bainier & Sartory) Thom& Church in BE Among 95 substrate classes supplied by Biolog system, the carboxylic acids and methyl esters had the highest utilization extent for the four species, followed by the amino acids and peptides. The descending sequence of carbon sources utilization capability of isolates was A. sydowii (52.6%), M. luteus (39.5%), B. sphaericus (21.6%), and G. thermoglucosidasius (17.7%).  相似文献   
753.
    
Capillary electrophoresis coupled to mass spectrometry(CE–MS) was used for the analysis of naphthenic acid fraction compounds(NAFCs) of oil sands process-affected water(OSPW). A standard mixture of amine-derivatized naphthenic acids is injected directly onto the CE column and analyzed by CE–MS in less than 15 min. Time of flight MS analysis(TOFMS), optimized for high molecular weight ions, showed NAFCs between 250 and 800 m/z. With a quadrupole mass analyzer, only low-molecular weight NAFCs(between 100 and 450 m/z) are visible under our experimental conditions. Derivatization of NAFCs consisted of two-step amidation reactions mediated by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide(EDC), or mediated by a mixture of EDC and N-hydroxysuccinimide, in dimethyl sulfoxide, dichloromethane or ethyl acetate. The optimum background electrolyte composition was determined to be 30%(V/V) methanol in water and 2%(V/V) formic acid. NAFCs extracted from OSPW in the Athabasca oil sands region were used to demonstrate the feasibility of CE–MS for the analysis of NAFCs in environmental samples, showing that the labeled naphthenic acids are in the mass range of 350 to 1500 m/z.  相似文献   
754.
以餐厨垃圾和剩余污泥为研究对象,考察不同物料配比(餐厨垃圾投加比例为0%,25%,50%,75%和100%)对16 d的厌氧共发酵产挥发性脂肪酸(volatile fatty acids,VFAs)的影响.结果表明:餐厨垃圾的加入有助于有机质的溶解,平衡体系C/N,弥补营养物质,从而提升厌氧发酵系统的性能.当餐厨垃圾投加比例为50%时,厌氧共发酵产VFAs 达到最高为(282.8±2.9)mg COD/g VSS.在厌氧发酵过程中,产酸微生物(Prevotella_7,Lactobacillus,Veillonella)丰度逐渐升高,水解酶和产酸酶的相对活性在发酵初期被抑制,在中后期被促进,而产甲烷酶在整个过程均被抑制,从而促进了 VFAs的产量.该成果为餐厨垃圾和剩余污泥厌氧共发酵产酸资源化利用提供了一定的理论基础.  相似文献   
755.
本文综述了碳链延长技术在处理有机废料及碳资源回收领域的优势,梳理了其发展历程为后续研究提供方向指导,阐释了其生化代谢途径中物质转变、能量传递和信号传输等机理,验证了其延长为丁酸、己酸等产物的热力和动力学可行性,总结归纳了其已优化的关键反应参数和已运行的工程试验案例等方面内容.本文为揭示细胞碳链延长机制和应用碳链延长技术...  相似文献   
756.
         下载免费PDF全文
Lipid metabolism play an essential role in occurrence and development of asthma, and it can be disturbed by phthalate esters(PAEs) and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease, the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure, but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the disease. We have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled w...  相似文献   
757.
腐殖酸铝盐絮凝体的动态特性   总被引:2,自引:0,他引:2       下载免费PDF全文
通过显微摄影分析研究了腐殖酸铝盐絮凝体成长的动态过程以及在混凝过程中絮凝体构造(分形维数)的变化规律.结果表明,在腐殖酸混凝过程中,随搅拌历时延长,絮凝体粒径不断成长变大,最终达到平衡状态.随着絮凝体的成长,其构造呈现由密实逐渐向疏松过渡的过程,空隙率变大,二维分形维数由初期的1.8左右下降到1.4左右.絮凝体分形维数Df和粒径df之间具有Df=Adf-  相似文献   
758.
    
Fish from the Great Lakes contain polychlorinated biphenyls(PCBs)which have been shown to disrupt endocrine function and mimic thyroid hormones,but they also contain beneficial omega-3 fatty acids that may offer protection against endocrine cancers.The purpose of this study was to examine the effects of Lake Ontario fish consumption and the estimated consumption of PCBs and omega-3 fatty acids on the risk of thyroid cancer in a group of sport fishermen.Anglers from the New York State Angler Cohort Study were followed for cancer incidence from 1991–2008.Twenty-seven cases of incident thyroid cancer and 108 controls were included in the analyses.Total estimated fish consumption,estimated omega-3 fatty acid consumption,and estimated PCB consumption from Lake Ontario fish were examined for an association with the incidence of thyroid cancer,while matching on sex,and controlling for age and smoking status.Results from logistic regression indicate no significant associations between fish consumption,short-term estimated omega-3 fatty acids,or estimated PCB consumption from Great Lakes fish and the development of thyroid cancer,but it was suggested that long-term omega-3 fatty acid from Great Lakes fish may be protective of the development of thyroid cancer.In conclusion,fish consumption,with the possible concomitant PCBs,from the Great Lakes does not appear to increase the risk of thyroid cancer in New York anglers.Further research is needed in order to separate the individual health effects of PCBs from omega-3 fatty acids contained within the fish.  相似文献   
759.
利用废弃蛋白质制备氨基酸螯合微肥的研究进展   总被引:4,自引:0,他引:4  
复合氨基酸螯合微肥是一种高效、无公害环境友好的绿色肥料,开发前景广阔,综述了废弃蛋白质水解制备复合氨基酸螯合微肥的研究现状,展望了氨基酸螯合微肥研究领域的发展。  相似文献   
760.
黄河水中氨基酸对铅(Ⅱ)与悬浮粒子相互作用的影响   总被引:7,自引:0,他引:7  
研究了五种氨基酸对黄河水中铅 ( )与悬浮粒子相互作用的离子交换率 E( % )— p H关系曲线的影响 ,结果表明 :( 1)水体中五种氨基酸浓度分别为 2μmol· L- 1 时提高 E( % )的顺序是 :组氨酸 >脯氨酸 >丙氨酸 >天门冬氨酸 >赖氨酸 ;( 2 )与未加有机物相比“S型曲线”左移 0 .4~ 1.3个 p H单位 ,Δ p H左移值顺序为 :组氨酸 >天门冬氨酸 >丙氨酸 >赖氨酸 >脯氨酸 ;( 3 )随着脯氨酸、丙氨酸、天门冬氨酸和胱氨酸浓度增加 ,离子交换率提高。  相似文献   
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