Carbon dioxide fixation by Chlorella sp. USTB-01 with a fermentor-helical combined photobioreactor

A promising microalgal strain isolated from fresh water, which can grow both autotrophically on inorganic carbon under lighting and heterotrophically on organic carbon without lighting, was identified as Chlorella sp. USTB-01 with the phylogenetic analysis based on 18S ribosomal ribonucleic acid (rRNA) gene sequences. In the heterotrophic batch culture, more than 20.0 g·L⁻¹ of cell dry weight concentration (DWC) of Chlorella sp. USTB-01 was obtained at day 5, and which was used directly to seed the autotrophic culture. A novel fermentor-helical combined photobioreactor was established and used to cultivate Chlorella sp. USTB-01 for the fixation of carbon dioxide (CO₂). It showed that the autotrophic growth of Chlorella sp. USTB-01 in the combined photobioreactor was more effective than that in the fermentor alone and the maximum DWC of 2.5 g·L⁻¹ was obtained at day 6. The highest CO₂ fixation of 95% appeared on day 1 in the exponential growth phases of Chlorella sp. USTB-01 and 49.8% protein was found in the harvested microalgal cells.     

无机碳源对栅藻LX1生长及油脂积累特性的影响

以二级出水为培养基,比较了对照组和补充碳源（Na2CO3、NaHCO3和CO2）组栅藻LX1的生长和油脂积累特性.培养14d,4组试验中栅藻LX1的生长及油脂积累特性均无显著差别,藻细胞生物量、油脂及三酰甘油酯产量分别为0.70～0.77、0.27～0.34和0.029～0.033 g.L-1,单位藻细胞油脂含量约为3...     

不同营养源条件下螺旋鱼腥藻生长与产嗅特征研究

蓝藻次生代谢产物所导致的嗅味问题已成为饮用水的主要水质问题之一,然而不同种属蓝藻的产嗅特征往往差别明显.本研究将从洋河水库中分离得到的可高产土臭素（geosmin）的螺旋鱼腥藻（Anabaena sp.）进行扩大化培养,通过测定不同营养源条件下的生物量及土臭素等各项指标的变化,探讨了不同营养盐条件对该螺旋鱼腥藻生长及产...     

鲍希瓦氏菌吸附Au3+的影响因素及机理研究

吸附是生物回收贵金属的重要环节,本文考察了溶液p H、生物量、初始Au~(3+)浓度和温度对鲍希瓦氏菌吸附Au~(3+)的影响,研究了鲍希瓦氏菌吸附Au~(3+)的动力学和热力学特性,并初步探讨了吸附发生的可能机理.结果表明,p H明显影响鲍希瓦氏菌对Au~(3+)的吸附,最佳p H为2~3.在初始Au~(3+)浓度为115 mg·L~(-1)时,不同温度下90%的Au~(3+)可在10 min内被吸附,4 h后基本达到吸附平衡,且吸附容量随着温度的升高而增加.吸附符合Freundlich等温线模型(R2=0.954),最大吸附容量为148.7 mg·g~(-1).吸附动力学可用拟二级动力学方程描述(R2=0.999).热力学分析显示,鲍希瓦氏菌吸附Au~(3+)是自发的吸热过程.傅里叶红外和X射线光电子能谱分析表明,氨基、羧基和羟基是起主要作用的官能团,其中,质子化的氨基作用机理主要是静电吸附.     

水体及沉积物氮磷水平对附植藻类的影响

为了探讨湖泊富营养化过程中沉积物及水体氮、磷浓度对附植藻类的影响,通过室内模拟实验,研究了水体及沉积物氮、磷升高对苦草(Vallisnerianatans(Lour.) Hara)上附植藻类生长、群落组成及其体内氮、磷含量的影响.结果表明,在实验条件下,随着水中氮、磷含量升高,附植藻类生物量及附植藻类氮、磷含量均呈极显著增加(p0.01).随着水体可获得的氮、磷浓度升高,附植藻类的相对丰度有所变化,舟形藻(Navicula)、小球藻(Chlorella)及微囊藻(Microcystis)相对丰度随着氮、磷水平的升高而下降,直链藻(Melosira)则相反,但舟形藻、直链藻、微囊藻、小环藻(Cyclotella)和小球藻均为群落的优势属种.沉积物氮、磷含量升高对附植藻类生物量、优势种丰度及群落氮、磷含量影响较小,均未达到显著水平(p0.05).在实验条件下,沉积物氮、磷含量对附植藻类影响不大,而水体氮、磷浓度升高显著地促进了附植藻类生长.研究结果也为解释富营养化湖泊沉水植物衰退及消亡提供了一定的科学依据.     

Biosorption and retention of orthophosphate onto Ca(OH)2-pretreated biomass of Phragmites sp.

The biosorption of phosphorus in the form of orthophosphate(Po) from wastewater using biomass as the sorbent is of potential importance because the Po-loaded biomass could be applied in the agricultural sector as fertilizer and soil conditioner. However, biomass generally displays a very low affinity for Posorption and therefore biomass surface modification is required. In the present study, the biomass(as model grinded leaves of Phragmites sp. were used)was pretreated with Ca(OH)2to enhance Pobiosorption capacity(qe). The results indicate that the alkaline pretreatment resulted in a modification of surface functional groups. It was concluded that the main sorption mechanisms were ligand exchange and electrostatic attraction. A series of experiments were conducted to investigate the performance of the pretreated biomass for Pouptake under various conditions. Isotherm and thermodynamic studies were also applied and analyzed. The biosorption process was best described by the pseudo-second order kinetic model and Langmuir isotherm, which gave a qmaxof 12.27 mg P/g at 25°C and p H 7. The Ca(OH)2treated Phragmites biomass applied in this study for Porecovery may present some potential advantages in terms of costs and environmental impact.     

Biosorption of copper ions from dilute aqueous solutions on base treated rubber (Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms

The effciency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions from aqueous solutions has been investigated. The e?ects of physicochemical parameters on biosorption capacities such as stirring speed, pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increased with increase in pH, stirring speed and copper concentration but decreased with increase in biosorbent dose and ionic strength...     

斜生栅藻对低浓度无机磷去除和生长情况的研究

研究分析了低磷浓度培养条件对斜生栅藻生长情况的影响,以及斜生栅藻对磷的去除效果.结果表明,斜生栅藻在初始细胞浓度为1×105个/mL时,可以在22h内将初始浓度0.02～0.10mg/L的磷全部去除.在初始磷浓度0.02～0.10mg/L范围内,随磷浓度的增加藻体的生长速度增加,且最大生物量也明显增大.研究发现磷浓度对斜生栅藻的形态有重要影响,在外源磷充足的条件下,斜生栅藻多为四聚体,但随着磷浓度的逐渐下降,藻细胞从四聚体,分离为二聚体,最后以单聚体为主要存在形式.     

黑藻吸附Cu2+机制研究

生物吸附法是一种经济有效的去除废水中有害重金属离子的方法.以黑藻(Hydrilla verticillata)干样为生物吸附材料,研究了黑藻对水体中Cu<'2+>等温吸附的基本特征,并通过测定吸附前后溶液离子浓度变化以及pH值、基团屏蔽对Cu<'2+>吸附的影响,结合红外光谱技术,从静电吸附作用、离子交换作用、基团作用...     

Immobilization study of biosorption of heavy metal ions onto activated sludge

Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10-100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pre-treated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃.Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.     

Ni2+生物吸附动力学及吸附平衡研究

研究了金属离子Ni²⁺在酿酒酵母上的生物吸附特性,内容包括生物吸附动力学和吸附等温线.生物吸附动力学结果表明,当Ni²⁺初始浓度为65.6 mg/L时,Ni²⁺在酿酒酵母上的生物吸附可以分为2个阶段,第1阶段为物理吸附,在10　min内快速达到平衡.Ni²⁺在酵母上的吸附过程可以很好地用准二级动力学方程来描述 （R²=0.999）,动力学参数k₂为0.018 4 g/(mg·min),q_e为5.96 　mg/g.吸附等温线结果表明,Ni²⁺在酿酒酵母上的生物吸附可以用Langmuir和Freundlich方程来描述,最大吸附量q_max为6.32 　mg/g.酿酒酵母可用于处理低浓度的含Ni²⁺废水.     

重金属离子的生物吸附容量与离子性质之间的关系

利用金属离子毒性评价和预测领域中的QSAR方法,探讨了重金属离子性质对生物吸附容量的影响．选用啤酒工业废弃的酿酒酵母为生物吸附剂,进行了10种金属离子Ag^＋,Cs^＋,Zn^＋,Pb^2＋,Ni^2＋,Cu^2＋,CO^2＋,Sr^2＋,Cd^2＋,Cr^3＋的生物吸附实验．选用22种参数来表征金属离子的物理化学性质,建立了金属的离子特性与生物吸附容量之间的关系．利用Langmuir方程计算得到酵母吸附金属离子的理论最大吸附量qmax,由大到小排序为Pb^2＋〉Ag^＋〉Cr^3＋〉Cu^2＋〉Zn^2＋〉Cd^2＋〉Co^2＋〉Sr^2＋〉Ni^2＋〉Cs^＋．离子性质与吸附量之间的线性拟合分析结果表明,共价指数Xm^2r与qmax具有良好的线性关系,共价指数越高,离子吸附量越大,金属离子与吸附剂表面官能团共价结合所占比重越大,键结合越牢固．对金属离子进行分类（按价态或离子的软硬性质）可以改善拟合效果．极化力Z^2／r、水解常数｜lgKOH｜、电离势,尸等多种物化性质与不含软离子的离子之间的理论最大吸附量也表现出良好的线性关系．     

耐高浓度沼液产油小球藻的分离鉴定与特征分析

本研究从长期在空气中放置的沼液中分离得到1株可以耐受高浓度沼液的藻株,经形态和分子生物学方法鉴定为小球藻属的一种,命名为Chlorella sp.BWY-1.本研究所用的沼液来自于以固液分离后的猪场废水为发酵原料的沼气工程.与普通小球藻Chlorella regularis(FACHB-729)的对比研究表明,Chlorella sp.BWY-1在BG11和不同浓度的沼液中都有相对较强的生长速率、生物量积累能力和氮磷等污染物去除能力.Chlorella sp.BWY-1在BG11中有最高的生长速率和生物量生产力(324.40 mg·L-1,以dw计),但是其含油量和油脂生产力随着沼液浓度的增加而增加.在未稀释的沼液中Chlorella sp.BWY-1的含油量可达44.43%,油脂生产力达108.70 mg·L-1.分析结果表明该藻株在养殖废水处理和生物能源方面具有一定的应用潜力,可以结合固液分离、厌氧发酵等其他技术用于养殖场废水的处理和生物柴油的制取.     

毛霉菌回收金纳米颗粒的影响因素及吸附行为

生物吸附在贵金属的回收中具有较高的应用潜力.本研究以毛霉菌(Mucor varians)菌株(CGMCC 3.02549)为菌种资源,探究了毛霉菌吸附Au~(3+)的影响因素,包括初始Au~(3+)浓度、温度和pH值,研究了毛霉菌吸附Au~(3+)的动力学和热力学特性.结果表明,随着初始Au~(3+)浓度升高,毛霉菌的吸附率降低,吸附容量增高;吸附率随着温度的升高而增加;pH对毛霉菌吸附Au~(3+)的效果影响明显,pH为3时吸附效果最佳.毛霉菌对Au~(3+)的等温吸附过程更符合Langmuir方程(R2=0.985),最大吸附量为325.418 mg·g~(-1).拟二级动力学方程更适合描述Au~(3+)在毛霉菌上的吸附动力学(R2=0.910~0.922).通过热力学分析得出,毛霉菌吸附Au~(3+)是自发的吸热过程.傅里叶红外光谱、X射线光电子能谱、X射线衍射和透射电镜分析表明,回收产物为金纳米颗粒,羰基和羟基是起主要作用的官能团.     

Evaluation of Bacillus sp. MZS10 for decolorizing Azure B dye and its decolorization mechanism

To evaluate decolorization and detoxification of Azure B dye by a newly isolated Bacillus sp. MZS10 strain, the cultivation medium and decolorization mechanism of the isolate were investigated. The decolorization was discovered to be dependent on cell density of the isolate and reached 93.55%(0.04 g/L) after 14 hr of cultivation in a 5 L stirred-tank fermenter at 2.0 g/L yeast extract and 6.0 g/L soluble starch and a small amount of mineral salts. The decolorization metabolites were identified with ultra performance liquid chromatography-tandem mass spectroscopy(UPLC-MS). A mechanism for decolorization of Azure B was proposed as follows: the C=N in Azure B was initially reduced to –NH by nicotinamide adenine dinucleotide phosphate(NADPH)-dependent quinone dehydrogenase, and then the –NH further combined with –OH derived from glucose to form a stable and colorless compound through a dehydration reaction. The phytotoxicity was evaluated for both Azure B and its related derivatives produced by Bacillus sp. MZS10 decolorization, indicating that the decolorization metabolites were less toxic than original dye. The decolorization efficiency and mechanism shown by Bacillus sp. MZS10 provided insight on its potential application for the bioremediation of the dye Azure B.     

营养盐添加对水华蓝藻——卵孢金孢藻生长和竞争影响的原位实验

为探究在水体营养盐浓度持续增加的条件下,卵孢金孢藻(Chrysosporum ovalisporum)的生长趋势和其它藻类的生长响应,在上海滴水湖畔采用39个大桶(100 L)进行不同浓度N、P添加的原位中型模拟实验.结果表明,高浓度营养盐添加可促进卵孢金孢藻和绿藻生物量的增加,加P组二者生物量的增加趋势高于加N组,但差异并不显著(P0.05),加NP组二者生物量的增加趋势显著高于加N组和加P组(P0.001).在加N组和加NP组,卵孢金孢藻相对丰度随营养盐添加量的增加呈显著的下降趋势(P0.05),而在加P组其相对丰度随着P浓度的增加略有上升,但不显著(P0.05).实验结束时,所有处理组中卵孢金孢藻的生物量不占优势,而小粒径藻类[色球藻属(Chroococcus spp.)、空星藻属(Coelastrum spp.)、小球藻属(Chlorella spp.)、四角藻属(Tetraedron spp.)、栅藻属(Scenedesmus spp.)]的生物量随营养盐浓度升高的增加趋势显著高于卵孢金孢藻(P0.05),小型绿藻占据绝对优势,表明在高温和相对静止的条件下,随着水体中营养盐浓度的持续增加,小粒径藻类易替代卵孢金孢藻而占据竞争优势;这与小粒径藻类在高营养条件下代谢速率较高有关,也与绿藻喜静止、高光强的生物学特性有关.小型绿藻占据优势可能成为小型超富营养水体中浮游植物群落在高温季节的演替方向之一.     

生物膜贴壁培养小球藻净化猪粪沼液废水的效果

微藻处理猪粪沼液废水是一项污水资源化生物技术.本文以小球藻为研究对象,通过贴壁培养方式,对稀释不同倍数的猪粪沼液废水进行净化处理同时提取藻细胞油脂,旨在探究小球藻贴壁培养处理猪粪沼液废水的效果,分析小球藻耐受猪粪沼液废水的氨氮浓度.将猪粪沼液废水分别稀释1倍(原水)、2倍、5倍、10倍制成培养基.测定贴壁培养小球藻对各处理组猪粪沼液废水中COD、氨氮、总氮、总磷的去除效率及对重金属铜、锌、铁的富集效果,同时探究小球藻的油脂合成情况.结果表明,当猪粪沼液废水稀释5倍时,贴壁小球藻对COD、氨氮、总氮、总磷的净化效果最佳,其去除效率分别为:86.8%、94.1%、85.2%、84.3%;油脂含量高达32.7%;对重金属铜、锌、铁的去除效率分别为:72.9%、70.0%、73.0%;培养一个周期结束时生物产率达到4.21 g·(m~2·d)~(-1).该研究将微藻与难处理的猪粪沼液废水深度净化进行了有效的结合,为实现藻类生物燃料工艺生产及降低废水处理成本提供理论基础.     

营养盐比例对硅藻水华优势种小环藻生长和生理的影响

近年来,一些淡水水体如河流、水库等暴发了以小环藻为优势种的硅藻水华,对水生态系统健康产生了不利影响.为探究不同营养盐水平下营养盐结构对小环藻生长的影响作用,研究了不同N/P（N与P质量浓度之比,下同）、Si/P、Si/N下小环藻培养物的藻细胞密度、叶绿素a浓度以及叶绿素荧光参数的变化.结果表明:在试验所设定的营养盐浓度范围内,随着N/P、Si/N的升高,小环藻的藻细胞密度和叶绿素a浓度显著增加,在N/P为30、Si/N为5.0的环境中有较好的生长潜力.小环藻在磷浓度低于0.10 mg/L的水体中,生长潜能与Si/P呈正相关,最适Si/P为100;在磷浓度为0.30 mg/L条件下,最适Si/P为50.综合对比分析,水体Si/P对小环藻生长的影响最为显著.在保持水体营养盐比例不变的条件下,营养盐浓度的变化对小环藻生长亦有明显的影响.当水体氮浓度高于6.0 mg/L、磷浓度高于0.10 mg/L时,硅是小环藻的主要限制元素,其最适浓度为15 mg/L.此外,在初始磷浓度为0.03 mg/L,氮浓度低于0.6 mg/L、硅浓度低于1.5 mg/L时,小环藻生长较为缓慢,光合活性低,因此,若实际水体营养盐浓度低于此水平,将能有效控制硅藻水华的暴发.研究显示,小环藻生长最适N/P为30、Si/N为5.0;最适Si/P与初始磷浓度有关,在磷浓度低于0.10 mg/L时,最适Si/P为100;磷浓度为0.30 mg/L时,最适Si/P为50.总体而言,小环藻生长受Si/P的影响最为明显.      

Removal of Crystal Violet from aqueous solution using powdered mycelial biomass of Ceriporia lacerata P2

A simple and efficient biosorbent prepared from powdered mycelial biomass of Ceriporia lacerata was used to removal Crystal Violet, poorly degraded as recalcitrant molecule by microorganism.     

Biosorption of Cd2+ and Cu2+ on immobilized Saccharomyces cerevisiae

The biosorption of Cd²⁺ and Cu²⁺ onto the immobilized Saccharomyces cerevisiae (S. cerevisiae) was investigated in this study. Adsorption kinetics, isotherms and the effect of pH were studied. The results indicated that the biosorption of Cd²⁺ and Cu²⁺ on the immobilized S. cerevisiae was fast at initial stage and then became slow. The maximum biosorption of heavy metal ions on immobilized S. cerevisiae were observed at pH 4 for Cd²⁺ and Cu²⁺. by the pseudo-second-order model described the sorption kinetic data well according to the high correlation coefficient (R ²) obtained. The biosorption isotherm was fitted well by the Langmuir model, indicating possible mono-layer biosorption of Cd²⁺ and Cu²⁺ on the immobilized S. cerevisiae. Moreover, the immobilized S. cerevisiae after the sorption of Cd²⁺ and Cu²⁺ could be regenerated and reused.