真菌降解光-氧氧化内蒙古胜利褐煤产物分析

为掌握黄孢原毛平革菌降解光-氧氧化内蒙古胜利褐煤固体残渣的成分、结构和热稳定性的变化规律,以及降解液的主要物质构成,为降解工艺的改进以及降解产物的分离和利用提供参考,对降解所得的固体和液体产物进行了检测分析.结果表明:光-氧氧化煤被黄孢原毛平革菌作用后,煤残渣的水分、灰分和挥发分的质量分数均增加,固定碳的质量分数降低,...     

微生物降解低阶煤的光氧化预处理工艺条件优化

利用旋转床光化学反应器光氧化预处理低阶煤(内蒙古胜利褐煤),再采用黄孢原毛平革菌降解光氧化煤,以降解煤液的A_(450)值为考核指标,采用正交实验优化光氧化预处理工艺条件。结果表明:煤样粒度、紫外灯功率和氧化时间对褐煤光氧化效果的影响极显著,马达转速对褐煤光氧化效果的影响较显著;最佳工艺条件为:煤样20 g、氧气流量200 mL·min~(-1)、通氧时间40 min、煤样粒度(-0.15+0.075) mm、紫外灯功率150 W、马达转速120 r·min~(-1)、氧化时间42 h。     

煤的微生物降解率与降解液吸光度的关系拟合

为了准确且便捷地得出煤样粒度较细时微生物对煤的降解率,分别采用绿孢链霉菌、恶臭假单胞菌和黄孢原毛平革菌对光氧化内蒙胜利褐煤进行微生物降解,测得了降解率(η)和降解液在450 nm处吸光度A_(450)(Y)的相关数据,进行线性拟合得到拟合方程,并采用光氧化云南昭通褐煤、光氧化山西浑源褐煤和光氧化内蒙元宝山褐煤对拟合方程进行了验证实验。结果表明,绿孢链霉菌、恶臭假单胞菌和黄孢原毛平革菌对光氧化内蒙胜利褐煤的η与降解液Y值之间的拟合方程分别为η=0.02466+0.07453Y,R~2=0.98392;η=0.02919+0.06412Y,R~2=0.99075;η=0.02336+0.08945Y,R~2=0.97836。3个拟合方程分别对3种不同光氧化褐煤的降解率预测值与实测值相比,相对误差较小,具有一定的普适性。     

黄孢原毛平革菌降解光氧化褐煤的过程特性

研究了黄孢原毛平革菌降解光氧化内蒙胜利褐煤的过程特性,分析了降解过程的微量热曲线,并比较了降解液、纯培养液及培养基溶煤液的pH值、表面张力及450 nm处吸光度A_(450)值随培养时间的变化情况。结果表明,黄孢原毛平革菌降解光氧化内蒙胜利褐煤的微量热曲线可分为迟缓期、指数生长期、稳定期和衰亡期,与菌株的生长曲线相吻合,降解过程释放的总热量为186.73 kJ·g~(-1),降解时间为15.1 d,指数生长期生长速率常数k为4.040 8×10~(-4) min~(-1);黄孢原毛平革菌在生长代谢过程中产生了碱性物质和表面活性剂,与纯培养液相比,降解液的pH值降低、表面张力增强;黄孢原毛平革菌纯培养液和培养基溶煤液的A_(450)值均很小,充分证实黄孢原毛平革菌的作用使得光氧化内蒙胜利褐煤发生了降解。     

黄孢原毛平革菌的降解机制及其应用

黄孢原毛平革菌产生的胞外酶由木素过氧化酶、锰过氧化酶和己二醛氧化酶等组成，对染料废水有降解功能．并具有传统处理方法所无法比拟的优点。本文对黄孢原毛平革菌的降解机制和在工业上的应用做一简要综述。有16篇参考文献。     

光氧化预处理对神府煤生物转化的影响

用黄孢原毛平革菌(PC菌)对光氧化预处理神府煤进行了生物转化研究。采用元素分析、腐殖酸含量测定、红外分析,以及对降解后残液的紫外分析等分析方法研究了神府煤生物转化残煤的组成和结构,对比了氧气及氧气与氨气混合气体对紫外光氧化预处理的神府煤生物转化性能的影响。结果表明,紫外氧化预处理可以促进神府煤的生物转化。与单纯氧气氛相比,氨气存在下,光氧化预处理可更有效地促进神府煤的生物转化。     

好氧微生物抑制煤自燃机理研究现状及展望

综述了微生物对煤脱硫、降解方面的研究现状，利用好氧微生物处理煤可降低煤中硫含量(黄铁矿)、破坏煤中羟基、羰基、羧基等活性基团以及消耗O₂、产生CO₂气体等特性，提出用生物技术来延缓煤氧化进程、阻断煤氧化路径从而抑制煤自燃的设想。基于利用微生物对煤表面环境状态以及微观结构改变的特性，从煤氧化反应本身为切入点防控煤自燃。针对好氧微生物改性驯化对煤中硫含量、活性基团的影响，对现阶段常用的煤炭脱硫、降解类微生物(如嗜酸氧化亚铁硫杆菌、黄孢原毛平革菌等)进行分析，总结了可用于抑制煤自燃的微生物生长特性及其差异性，最终提出可用多种功能微生物分步协同作用来抑制煤自燃的思路，对煤自燃新型绿色阻化剂的开发进行了展望。     

黄孢原毛平革菌降解偶氮染料的氮源调控及机理研究

利用黄孢原毛平革菌(Phanerochaete chrysosporium,PC菌),研究在氮源调控下,偶氮苯染料的降解过程,以及脱色率、TN、TOC和COD浓度等出水水质特性变化情况,初步分析了这些指标变化的内在关系;并由色谱检测结果简单分析了偶氮苯染料降解机理。结果表明:黄孢原毛平革菌对偶氮苯染料具有很好的脱色降解效果;在偶氮苯的降解中发生了偶氮键的断裂,生成了苯胺中间降解产物。     

应用黄孢原毛平革菌处理工业废水的研究进展

黄孢原毛平革菌能有效降解各种有机污染物，因此可用来净化工业废水。其降解主要依赖于它产生的胞外木素降解酶系，此酶系主要由木素过氧化物酶、锰过氧化物酶组成，本文介绍了黄孢原毛平革菌的降解机制和它在处理工业废水主要是造纸废水和印染废水方面的研究进展并对其应用前景进行了探讨。     

固定化白腐真菌对复合污染废水的处理

实验将黄孢原毛平革菌接种至含不同浓度(0,100,200,300,500μg/L)诺氟沙星和镉离子的固体培养基中,考察黄孢原毛平革菌对诺氟沙星和镉离子复合污染的耐受性.结果表明,诺氟沙星和镉离子对黄孢原毛平革菌有一定抑制作用,黄孢原毛平革菌对高浓度敏感性较强;以海藻酸钠、沸石粉等为载体固定化黄孢原毛平革菌,研究了固定化...     

几种低阶煤的过氧化氢氧化解聚性能研究

在40℃利用5％H2 O2水溶液分别对神府次烟煤（ SF）、准东次烟煤（ ZD）、胜利褐煤（ SL）和先锋褐煤（ XF）四种低阶煤进行了氧解,计算其氧解转化率和CO2生成率,结合元素分析、红外光谱以及酸性官能团测定结果比较了四种低阶煤的氧解性能以及其结构特征对氧化解聚性能的影响。结果表明,煤的氧化解聚与变质程度密切相关,变质程度越高,氧化反应性降低。另外煤的氧含量越高,特别是羧基以及酚羟基含量较高时,氧化解聚程度增大。     

多噬香鞘氨醇单胞菌降解陕西神府褐煤的工艺条件及产物研究

利用多噬香鞘氨醇单胞菌对陕西神府褐煤进行降解实验,通过单因素和正交实验确定了多噬香鞘氨醇单胞菌降解陕西神府褐煤的最佳工艺条件.煤样预处理采用10 mol/L硝酸氧化,煤样粒度为0.074 mm～0.125 mm,菌液量为8 mL/50 mL(培养基),降解时间为14 d,培养温度为35℃,培养方式为摇床培养,此时最大降...     

Combustion and Pollutant Emission Characteristics of Lignite Dried by Low Temperature Air

Lignite is a kind of coal that has high moisture content and needs to be dried before being utilized. In this article, a Chinese lignite was dried in air at 120–180°C and the changes in its physical and chemical structures after drying were investigated. The results showed that the pore volume and specific surface area of the lignite decreased after drying. Some of the methylene and methyl groups were oxidized by the oxygen in the drying air, resulting in an increase in oxygen functional groups. The combustion characteristics of the dried coals and parent coal (dry basis) were studied via thermogravimetric analysis. The total volatile yields of the dried coals increased compared to the parent coal. The burnout temperatures of the dried coals were higher than the parent coal, whereas the ignition temperatures stayed almost unchanged. An entrained flow system was set up to study the release of nitrogenous gas products during rapid pyrolysis and combustion. The HCN yields of the dried coals during pyrolysis were higher than that of the parent coal, and a similar trend was found for the NO yield during combustion. The mechanism changes of combustion and pollutant emission characteristics were discussed according to the results of the physical and chemical structure analyses.     

富氧条件下煤粉气流的着火性能变化

利用一维火焰炉对不同富氧条件下的煤粉气流着火燃烧特性进行了研究,得到了富氧条件下煤粉气流的着火性能变化规律。研究结果表明:随着助燃气体氧浓度的提高,各煤样的着火温度均大幅下降,其中低挥发分煤种在着火方面对富氧条件的改善更为敏感,即富氧条件的改善可减弱煤种间着火性能方面的差异性;随着氧浓度的提高,煤粉气流的着火方式明显从均相着火向非均相着火转变,其中燃用褐煤时发生着火方式转变所对应的氧浓度为50%~60%,燃用烟煤时约为40%,燃用贫煤和无烟煤时都约为30%;对于烟煤和褐煤,随着氧浓度的提高,对应的最佳煤粉浓度值先增大后减小,而对于贫煤和无烟煤,由于其在整个实验氧浓度范围内基本上都以"非均相着火"为主,因此随着氧浓度的提高,对应的最佳煤粉浓度的值基本上呈缓慢下降的趋势。     

Changes associated with natural in situ weathering of a coking coal from southeastern British Columbia

A suite of naturally oxidized coals from a single coal seam from southeastern British Columbia was examined by means of pyrolysis gas chromatography together with ultimate and petrographic analysis. With increasing degree of oxidation (FSI decreasing from 7.5 to 0) a consistent decrease in fixed carbon and hydrogen and an increase in oxygen and moisture were found. Comparing the mildly oxidized coal (FSI 7.5 to 3) with the unweathered coal, there is very little detectable change in pyrolysis gas composition or chemistry. At more advanced stages of oxidation (FSI 3 to 0) the pyrolysis gas is markedly depleted in CO, CH₄, C₂H₄ and C₂H₆ and correspondingly enriched in CO₂. The carbon and hydrogen contents decrease and the oxygen content increases significantly. In the mildly oxidized coal, oxidation rinds develop on vitrinite particles, whereas in the more oxidized coal, microfissures and a darkish cast are evident.     

Reactivity of hydrolysed coals in liquefaction

A hvA bituminous, a subbituminous and a lignite coal have been hydrolysed by 20–30% aqueous caustic solution at 100–300 °C and total pressure from ambient to 8.3 MPa (1200 psi). Reactivity of these pretreated coals toward liquefaction has been examined. The conversion to benzene-soluble material (BS) and oil increases, and the preasphaltene and char residue decreases after pretreatment. Improvement in the conversion to the BS fraction is only marginal for the pretreated bituminous coal, but substantial for the low-rank coals. For the subbituminous coal, the liquefaction reactivity (conversion to BS) increases with the severity of hydrolysis pretreatment. Analyses of chemical compositions, ¹H n.m.r. nuclei distributions and hydroxyl concentrations of the acid-insoluble hydrolysis coal extracts indicate that both O and S are enriched in the extracts with half of the oxygen atoms being in hydroxyl forms. The hydroxyl concentrations of the extracts (acid-insoluble) are ≈2 to 3 times higher than their parent coals. Coal activation by this alkali pretreatment is explained by the hydrolytic attacks on ether C–O linkages, and the removal of some constituents rich in oxygen functional groups which are responsible for poor liquefaction behaviour.     

多粘类芽孢杆菌对褐煤的降解转化试验研究

通过正交试验分析多粘类芽孢杆菌降解褐煤时,煤样粒度、煤浆浓度、菌液用量及降解时间4因素对褐煤微生物降解率的影响;结果表明,煤样粒度对褐煤微生物降解率的影响最大。     

Model for coal oxidation kinetics. 2. An effectiveness factor interpretation

Rate expressions are developed to describe the oxidation of coal in a fixed-bed reactor under conditions of significant diffusional effects. The model defines individual effectiveness factors for carbonic gas formation, oxygen deposition, and water production, to modify a chemical model derived previously. Experiments carried out on seven coals ranging in rank from lignite to bituminous to anthracite. All the coals exhibited particle size effects and the results fit the model in most cases to within ±10% both in the rate of overall oxidation and with respect to the individual reaction rates for several products. Activation energies and effectiveness factors were obtained for each coal and for each reaction. The effluent gas $\text{CO}{}_2\text{CO}$ ratio was found to be virtually constant for all five bituminous coals, being independent of reaction temperature, coal particle size, and oxygen partial pressure.     

Enhancement in hydrophobicity of low rank coal by surfactants — A critical overview

The flotation of fine (− 0.5 mm) low rank or oxidized coal is difficult to achieve with the common coal flotation collectors like kerosene, fuel oil or diesel oil (oily collector). The presence of small amounts of oxygen is enough to cause oxidation. The oxidation of coals starts with the physical adsorption of oxygen on the surface to form an oxycomplex followed by chemical adsorption of oxygen to form polar phenolic-OH, carbonyls, phenols and peroxide type oxygenated moieties by the rupture of cyclic rings. The addition of promoter, surfactant or oxygenated functional groups to the collector molecule markedly enhances the flotation of lower rank and oxidized coals due to the hydrogen bonding with the polar part of the coal surface and the reagent. The performance of these reagents is compared with that of oily collectors, namely kerosene, dodecane, nonylbenzene and polar part of the surfactant having an oxygen atom. The mode of addition of non-ionic surfactant with oily collector also has a major role in the flotation response. The addition of non-ionic surfactant after the oily collector has shown a positive effect on yield and grade.