两种固定化方法对活性艳蓝KN-R的脱色比较研究

采用海藻酸钙和聚丙烯酰胺两种固定化材料对青霉菌进行固定化，分别考查了在不同温度、pH、转速、培养时间、染料浓度等条件下对活性艳蓝KN-R的脱色影响。实验结果表明，两种固定化青霉菌最适条件均为：培养温度30℃，pH=4．0，转速为150r／min；海藻酸钙固定化小球培养时间为48h，聚丙烯酰胺培养时间58h；染料浓度对脱色率有一定的影响。海藻酸钙固定化小球比聚丙烯酰胺固定化块状颗粒具有较好的脱色效果。两种固定化青霉菌经多次脱色后能重复使用。     

碱性品红染料废水处理研究

文章论述了以钢渣为吸附剂处理碱性品红染料废水,考察钢渣颗粒度大小、溶液PH值、温度、固液比等因素对吸附的影响,以及吸附等温曲线.结果表明:钢渣有较强的吸附能力,脱色率达97.87%,吸附量可达到42.4mg/g.     

椰壳活性炭对人工废水酸性大红G染料吸附影响因素的试验研究

采用自制椰壳活性炭对人工染料废水中酸性大红G进行吸附,并通过对比试验确定废水pH与温度对处理效果的影响。实验结果表明,在不同活性炭用量下,酸性条件对人工染料废水都具有更好的脱色效果,而温度从20℃~60℃范围内其吸附效果基本没有变化。     

磁性柿单宁吸附剂对污水中铅的吸附去除研究

利用反相悬浮法将柿单宁材料与壳聚糖基体材料复合并加入纳米Fe_3O_4粒子进行修饰赋予其磁性分离性能,研究了该吸附剂对水溶液中Pb(Ⅱ)的吸附性能,主要从溶液pH值、吸附热平衡和动力学角度出发。在温度为303 K,pH=4.5,Pb(Ⅱ)的初始浓度为200 mg/L时,磁性改性柿单宁吸附剂对水溶液中Pb(Ⅱ)的饱和吸附容量可达153 mg/g,其吸附平衡和吸附动力学能够很好地用Langmuir吸附方程和拟二级速率方程来拟合。研究工作表明,该吸附剂具有磁性易分离和金属离子高效吸附优良性能,在重金属污水治理方面具有很大的应用潜力。     

直接黄R染料废水的脱色研究

采用钛网作为阳极,钛网为阴极,对直接黄R模拟染料废水进行了实验研究,探讨了电解时间、电解质浓度、电流密度以及进水浓度对直接黄R脱色效率的影响。结果表明：增加电流密度,提高电解质浓度,延长反应时间有利于直接黄R色度的脱除,对于含有100mg/L的直接黄R溶液,电解质NaCl的质量浓度为25.0g/L,电流密度为2.5A/dm²,电解时间20min,溶液的脱色率达到69.86%。     

电催化氧化处理茜素红模拟染料废水试验研究

采用电催化氧化法,以RuO2-Ti板作为阳极,不锈钢板为阴极,研究了pH值、槽电压、电解质种类和浓度及最佳条件下对茜素红模拟染料废水处理效果.试验结果表明,槽电压为15V、初始pH为2.0、NaCl浓度为2.0g/L为实验的最佳条件.在此条件下电解15min后,茜素红模拟废水COD降解率可达到35.49%,脱色率可达到99.50%.研究表明,采用电催化氧化法可以显著提高能量效率和电流效率,降低处理成本.     

有序介孔碳与颗粒活性炭对Cr(Ⅵ)吸附能力的比较

采用介孔二氧化硅作为硬模板来制备有序介孔碳材料,探讨时间和pH值对OMC吸附Cr(Ⅵ)性能的影响,并且与颗粒活性炭(GAC)对Cr(Ⅵ)的吸附性能作比较。试验表明,随着振荡时间的延长,在2h左右Cr(Ⅵ)在OMC上的吸附就达到平衡,而在8h左右它在GAC上的吸附才达到平衡;当pH较小时,OMC与GAC对Cr(Ⅵ)的吸附率都达到98%以上,随着pH的增大,两者对Cr(Ⅵ)的吸附率随之减小,当pH>10时,OMC对(Ⅵ)的吸附率下降到40%左右并且达到平衡,而GAC对(Ⅵ)的吸附率则下降到10%;根据Langmuir吸附理论,当达到吸附平衡时OMC对Cr(Ⅵ)的最大吸附量为102.55mg/g,远远大于GAC的14.36mg/g。     

磁性纤维素微球对水相中的亚甲基蓝高效吸附研究

在低温下以氢氧化钠/尿素水溶液直接溶解纤维素,加入羧基化改的磁性纳米,通过直接滴落法制备磁性的纤维素微球吸附剂。为了研究此吸附剂在处理印染废水脱色中的效果,以亚甲基蓝为模型废水,考察了吸附剂用量、亚甲基蓝溶液pH值、初始浓度、吸附时间、温度等因素对吸附剂吸附亚甲基蓝的效果和规律。     

钙钛矿型复合材料LaFeO3的制备条件对光催化性能影响的研究

采用柠檬酸法合成钙钛矿复合材料LaFeO3,研究制备条件对其活性的影响,并测定该系列样品对不同水溶性染料溶液的光催化降解效率.采用XRD、SEM、光声光谱图等手段对样品进行了表征.结果表明,在柠檬酸加入量和焙烧温度一定时,反应体系的pH值在1-2、成胶温度为80℃时制备的LaFe03样品悬浮溶液中,亚甲基蓝溶液仅由光催化引起的脱色率迭48.17%.     

改性介孔分子筛去除水中微量环丙沙星的研究

针对水中微量环丙沙星抗生素,运用金属掺杂方法制备了能够高效去除水中微量环丙沙星污染的改性介孔分子筛吸附剂Al-SBA15,实现了低投加量下快速吸附(短吸附平衡时间),通过SEM、TEM、XRD、BET等手段详细分析材料理化性质,研究了材料对水中微量环丙沙星吸附效能、过程与机理。Al-SBA15比表面积为499. 04 cm~2/g,平均孔径为11. 09 nm,平均孔容为1. 25 cm~3/g,是一种含有大量均匀介孔孔道的介孔材料。在环丙沙星浓度为100μg/L时,最佳材料投加量为0. 02 g/L,60 min吸附后,环丙沙星去除率在90%以上,相比去除环丙沙星的的其他吸附剂,其所需的投加量更少,吸附平衡时间也更短(30 min左右即基本达到平衡)。动力学符合准二级动力学模型,等温线符合Langmuir模型,证明吸附过程是一种单层化学络合反应。吸附是自发的,吸热的。溶液p H值显著影响吸附剂对环丙沙星的吸附,最佳的p H为5. 0～7. 0。水中共存阴阳离子对吸附有一定影响。吸附机理为AlSBA15表面铝与环丙沙星形成较强络合作用,同时受到静电作用的影响。     

Characterization of the biosorption of fast black azo dye K salt by the bacterium Rhodopseudomonas palustris 51ATA strain

BackgroundRemoval of dyes from wastewater by microorganisms through adsorption, degradation, or accumulation has been investigated. Biological methods used for dye treatment are generally always effective and environmentally friendly. In this study, biosorption of the Fast Black K salt azo dye by the bacterium Rhodopseudomonas palustris 51ATA was studied spectrophotometrically, at various pH (2–10), temperatures (25°C, 35°C, and 45°C) and dye concentrations (25–400 mg L^-1).ResultsThe bacterial strain showed extremely good dye-removing potential at various dye concentrations. IR studies at different temperatures showed that the dye was adsorbed on the bacterial surface at lower temperatures. Characteristics of the adsorption process were investigated by Scatchard analysis at 25°C and 35°C. Scatchard analysis of the equilibrium binding data for the dye on this bacterium gave rise to linear plots, indicating that the Langmuir model could be applied. The regression coefficients obtained for the dye from the Freundlich and Langmuir models were significant and divergence from the Scatchard plot was observed.ConclusionThe adsorption behavior of the dye on this bacterium was expressed by the Langmuir, Freundlich, and Temkin isotherms. The adsorption data with respect to various temperatures provided an excellent fit to the Freundlich isotherm. However, when the Langmuir and Temkin isotherm models were applied to these data, a good fit was only obtained for the dye at lower temperatures, thus indicating that the biosorption ability of R. palustris 51ATA is dependent on temperature, pH, and dye concentration.How to cite: Öztürk A, Bayol E, Abdullah MI. Characterization of the biosorption of fast black azo dye K salt by the bacterium Rhodopseudomonas palustris 51ATA strain. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.05.002.     

Panus tigrinus as a potential biomass source for Reactive Blue decolorization: Isotherm and kinetic study

BackgroundTextile and dye industries pose a serious threat to the environment. Conventional methods used for dye treatment are generally not always effective and environmentally friendly. This drove attention of scores of researchers to investigate alternative methods for the biodegradation of dyes using fungal strains. In this work, white-rot fungus (Panus tigrinus) was used as a biosorbent for the decolorization of Reactive Blue 19. The process parameters that were varied were initial concentration (50–150 mg/L), contact time (30–90 min), and pH (2–6). In addition, to gain important data for the evaluation of a sorption process, the equilibrium and kinetics of the process were determined.ResultsWhite-rot fungus showed great potential in decolorizing Azo dyes. The strain showed the maximum decolorization of 83.18% at pH 2, a contact time of 90 min, and an initial concentration of 50 mg/L. The Langmuir isotherm described the uptake of the Reactive Blue 19 dye better than the Freundlich isotherm. Analysis of the kinetic data showed that the dye uptake process followed the pseudo second-order rate expression.ConclusionThe biosorption process provided vital information on the process parameters required to obtain the optimum level of dye removal. The isotherm study indicated the homogeneous distribution of active sites on the biomass surface, and the kinetic study suggested that chemisorption is the rate-limiting step that controlled the biosorption process. According to the obtained results, P. tigrinus biomass can be used effectively to decolorize textile dyes and tackle the pollution problems in the environment.     

红壤对稀土元素的吸附与解吸特性研究

对不同母质来源的红壤样品和粘粒矿物进行了稀土元素吸附、解吸和吸附动力学实验,并进行了三种吸附模式和六种吸附动力学模式的数学拟合⒚结果表明,测试样品对稀土元素的吸附过程可用 Ｌａｎｇｍ ｕｉｒ 吸附方程和 Ｌａｎｇｍ ｕｉｒ 吸附动力学方程来描述⒚     

有机改性沸石对水中多环芳烃的吸附性能研究

研究十六烷基三甲基溴化铵(CTMAB)有机改性沸石对水中2种典型多环芳烃(PAHs)菲、蒽的吸附性能。结果表明,Langmuir和Freundlich等温吸附方程均可以很好地描述有机改性沸石对菲、蒽的吸附行为;菲、蒽在有机改性沸石上的吸附主要受温度的影响,吸附随温度的上升而减少,说明吸附是放热行为。     

纤维素分解菌的分离、筛选及其环境适应性初步研究

以滤纸平板和羧甲基纤维素钠培养基为基础培养基,从采集的样品中筛选出具有分解纤维素能力的38株菌株。采用纤维素刚果红培养基进行粗选,得到10株透明圈较大的菌株。将这10株菌株进行液体发酵培养,测定其酶活力,得到4株分解纤维素能力较强的菌株。对这4株菌株进行碳源、温度、pH值的适应性研究。结果发现,真菌3和真菌6的适应性都比较好。     

A test strip for the estimation of urea in serum

We have developed a biostrip for determination of urea in serum. The test strip is based on enzymatic assay where urease has been immobilized on the chromatographic paper along with chromogen, phenol red. The chromogen is easily soluble in water and does not require other components for the color change. Serum urea reacts with urease and water to liberate ammonia and carbon dioxide. The liberated ammonia changes the pH of the reaction medium, which is monitored by the chromogen phenol red. A single step working reagent strip has been developed and the reaction is completed within 50 seconds at room temperature. With this test strip urea concentration is measured in serum as low as 0.15 g/L. The speed and convenience of determining urea in serum by this strip instantly makes it well suited for individuals, physicians and emergency centres.     

壮观链霉菌红色素稳定性和抑菌活性的初步研究

经过溶剂萃取壮观链霉菌发酵菌体、浓缩萃取液获得色素浸膏,再经过柱层层析、薄层层析从1L的发酵菌体中获得1.06g的红色素纯物质。研究了壮观链霉菌红色素的热稳定性、氧化还原稳定性和pH稳定性;并针对柠檬酸、苯甲酸钠、抗坏血酸和蔗糖等常用的食品添加剂对红色素稳定性的影响进行了探讨,及初步研究了其抗菌生理活性,结果表明:除pH(>7.0)对壮观链霉菌红色素有明显的影响外,高温、食品添加剂等对其稳定性无不良的影响。红色素表现出较好的抗菌(革兰氏阳性菌和啤酒酵母)生理活性。     

普伐他汀钠胶囊溶出度测定方法探讨

目的：采用高效液相色谱法测定普伐他汀钠胶囊的溶出度。方法：按照《中国药典》2005年版Ⅱ部溶出度测定法中的第二法,以水900ml为溶剂,转数为50r min-1,30min时采样。采样后以高效液相色谱法测定。色谱柱：DiamonsilTM C18（200min×4．60 mm,5μm）,流动相：磷酸盐缓冲液甲醇（40：60）pH3．5±0．05,流速：1．0ml＊min-1,检测波长：238 nm,以外标法测定普伐他汀钠胶囊的溶出度。结果：线性范围为3．0—12．0 μm-1（r=0．9999）。平均回收率为99．86％,（RSD=1．7％,n--6）,溶出度符合规定。结论：该方法简便、易行。结果准确。     

海洋表层沉积物中的无机氮在扰动情况下的行为特征

本文模拟了海洋表层沉积物再悬浮对海水中NH+4-N、NＯ-3-N浓度的贡献。通过实验，观察到海水中NH+4-N的浓度与沉积物和海水的混合比例成负相关性。在不同震荡速率的试验中，60rpm震荡速率下的NH+4-N浓度逐渐降低到三种速率中的最低,120rpm震荡速率下的NH+4-N浓度升至最高。所选海区的沉积物在再悬浮过程中细粒径沉积物对上层水体NH+4-N的贡献最大，其次是中粒径沉积物、粗粒径沉积物。海水中NＯ-3-N的浓度与混合比例和震荡速率均成负相关性。粗、细粒径沉积物在试验过程中对水体的贡献具有很强的一致性，中粒径沉积物对水体的贡献要大于粗、细粒径沉积物的贡献。再悬浮过程中沉积物对海水中NＯ-3-N、NH+4-N的贡献主要来源于KCl浸取态氮和HAc-NaAc浸取态氮。     

SBR亚硝化处理化肥厂氨氮废水影响因素分析

利用SBR亚硝化处理化肥厂实际废水,研究其短程生物脱氮过程中pH、溶解氧、进水氨氮负荷和温度等因素影响,并确定亚硝化处理的最佳操作条件。结果表明,pH过低会抑制亚硝酸盐的生成,过高则不利于反硝化菌反硝化过程TN的去除;当pH值控制在8.0左右时,亚硝化率保持较高水平,同时出水TN浓度控制较好。当DO浓度为0.2~0.3 mg/L时,亚硝化反应继续进行,但NH4+-N亚硝化反应速率较慢;当DO浓度为1.5~2.8 mg/l时,无法实现系统中亚硝化的运行,硝化作用成为主要反应。高氨氮负荷进水有利于亚硝酸盐的积累,但对出水氨氮去除效果不佳。较高的温度有利于亚硝化反应进行。当t=35℃,初始pH控制在7.8~8.2,DO控制在0.5~0.6mg/L,进水浓度NH4+-N为100mg/L时,SBR亚硝化操作过程为最佳,此时亚硝化率基本稳定在90%以上。