黄孢原毛平革菌所产木素过氧化物酶系对染料降解的研究

白腐真菌黄孢原毛平革菌所产生的胞外过氧化物酶系由两类同功酶木素过氧化物酶和锰过氧化物酶组成，木素过氧化物酶对所研究的染料都有解作用，锰过氧化物酶只对部分染料起作用。加入H2O2，胞外酶液可以降解多种酶性染料如卡布龙红、酸性大兰、弱酸黄和弱酸大红，它们的脱色速率依次下降，以卡布龙红为例研究了各种条件因素对其降解脱色的影响，最佳H2O2浓度是100μmol/L，最佳PH为4．0，温度越高，脱色越快，但高于50℃酶将明显失活，木素过氧化物酶活性越高脱色速率越快，高浓度染料对其脱色有抑制作用，最佳条件下，50mg/L浓度卡布龙红第一分钟的脱色率达70％。随着稀释倍数的增加，酶液的降解速率呈抛物线加速下降，表明酶液中的某些组分如元素离子的浓度也是一个重要影响因素。     

白地霉处理玉米酒精醪液积累菌体蛋白的研究

以逐级驯化的白地霉为特定微生物,进行了玉米酒精醪液处理的同时积累菌体蛋白(SCP)的研究,并通过小试对其工艺条件进行了优化.结果表明,在接种量为15%(体积分数)、温度为25℃、起始pH为5、处理时间为4 d、硫酸铵(氮源)投加量为0.30 g/L的条件下,玉米酒精醪液COD去除率可达83.58%,同时回收白地霉SCP 62.03 g/L.该方法既可去除玉米酒精醪液中的有机污染物,又能回收一定量的SCP,可作为酒精废水资源化和一级生化处理的工艺.     

真菌和细菌协同作用对染料的吸附与脱色降解

比较了5种真菌对染料水中染料的吸附去除和与脱色降解细菌L-1菌株(Enterobacter sp.)和L-2菌株(Pseudomonas sp.)对吸附染料的脱色降解能力;以吸附去除率和完全脱色时间综合评价,对筛选出的吸附性强并与细菌共培养时染料分子脱色降解速度快的绿曲霉为染料吸附菌,进一步测定了温度和pH值对绿曲霉吸附和与细菌共培养脱色降解活性黄M-3RE(C.I.Re.Ye.145)的影响.结果表明,温度对绿曲霉的吸附能力影响不大,在16～36 ℃下吸附5 h对活性黄M-3RE的去除率在95.1%～97.9%之间,但染料的完全脱色降解时间受温度影响较大,32～36 ℃下染料分子脱色降解较快.pH值对绿曲霉和细菌吸附、脱色降解能力均有一定影响.利用绿曲霉和细菌对印染行业中染料含量较高的染浴废水进行处理,绿曲霉可通过吸附作用快速去除废水中的染料分子,废水经绿曲霉处理5 h,色度、COD去除率分别为85.8%和56.1%,BOD/COD值由处理前的0.238提高到处理后的0.652,吸附在菌丝上的染料分子在细菌的共同作用下脱色降解.     

开放体系下稻草-白腐菌对染料的吸附脱色与降解

在开放体系下,研究了稻草-白腐菌对孔雀绿和结晶紫的吸附脱色与降解.结果表明,稻草能有效地对孔雀绿和结晶紫进行吸附脱色,其中稻草用量、粒径和pH对稻草吸附染料有一定的影响,在合适条件下稻草对孔雀绿和结晶紫的最大吸附量分别可达到31.89、52.98mg/g;在吸附孔雀绿和结晶紫的稻草中接入白腐菌,发现开放体系下白腐菌能对两种染料进行降解,6d后,孔雀绿和结晶紫的脱色率分别达到93.67%和80.OO%;再生后的稻草基质对孔雀绿和结晶紫也有较好的吸附,最大再生率分别达到74.45%和43.34%.降解过程中白腐菌分泌酶的酶活力与染料及稻草基质降解没有直接的联系.     

漆酶/HBT介质系统对靛蓝染料及废水脱色的初步研究

以云芝(Trametes versicolor)1126发酵所得漆酶粗酶液与1-羟基苯并三唑(HBT)组成的漆酶/HBT介质系统对靛蓝染料进行脱色实验,分别考察了温度、转速、pH和HBT与漆酶的加入量等条件对靛蓝染料脱色的影响.最终确定的优化脱色条件为:温度60℃,转速200r/min, pH4.5, 100mL靛蓝染料"溶液"中粗酶液和HBT溶液分别加入2mL.以上述脱色条件对靛蓝印染废水进行脱色实验,反应80min,脱色率可达90.1%.     

活性艳蓝KN-R在ACF电极上成对电解脱色的影响因素

分别以活性炭纤维(ACF)为阳极和阴极，在无隔膜电解槽中研究了利用成对电解降解蒽醌染料活性艳蓝KN-R脱色过程的影响因素。考察了染料初始浓度、支持电解质Na₂SO₄、pH及温度诸条件对脱色性能的作用。结果表明：适当增加染料初始浓度和支持电解质浓度，酸性和中性条件以及适中的温度均对成对电解脱色性能有利。当染料初始浓度为251 mg/L，在合适的处理条件下，脱色率达到95%，脱除单位质量染料电耗仅为1.22 kWh/kg染料。     

灵芝漆酶对直接蓝86的催化脱色性能

利用灵芝菌Ganoderma lucidum U-281漆酶对直接蓝86进行酶促氧化脱色,并对其降解机理进行了探讨。结果表明,染料-漆酶共反应体系在20～50℃及pH小于5.0范围内,直接蓝86均可脱色50%以上;漆酶对直接蓝86具有宽泛的浓度适应性,对300 mg/L的该染料仍具有耐受性。最优脱色工艺参数为温度40℃、pH 5.0、染料初始浓度200 mg/L、漆酶用量1 U/mL。在优化条件下,直接蓝863 h的脱色率达到54.54%,48 h脱色率达到91.54%。紫外-可见吸收光谱分析表明,漆酶的酶促氧化导致染料的分子结构产生了变化,是造成直接蓝86脱色的主要发生机制。     

活性黑KN-B染料模拟废水电化学脱色

为进一步明确活性染料在可溶性阳极电化学体系中的脱色机理，以铝为牺牲阳极，不锈钢为阴极，在恒电流操作模式下，针对活性黑KN-B模拟废水，考察了电流密度、初始pH值、电解质种类及浓度、温度、染料浓度因素对染料脱色过程的影响。结果表明：(1)电流密度、电解液初始pH值、氯化钠电解质浓度、温度、染料浓度对染料溶液脱色效率影响显著，在一定实验条件下，染料溶液脱色率可达到88%；(2) 在不同pH的范围内，活性黑KN-B表现的脱色机理不同，pH 4～9为混凝与阴极还原脱色共同作用；pH＜4和＞9则表现为阴极还原脱色为主； (3) 氯化钠的加入在增强染料脱色的同时，也有助于芳环类物质的后续混凝去除。     

漆酶对活性黑KN-B和直接大红染料的脱色性能

利用白腐真菌漆酶对活性黑KN-B和直接大红2种偶氮染料进行脱色实验。考察反应时间、加酶量、pH值、染料浓度、温度对脱色率的影响，研究了ABTS介体以及金属离子存在下的脱色效果，并分析了漆酶脱色的动力学性能以及其对偶氮染料的降解规律。结果表明，活性黑KN-B和直接大红脱色适宜条件为：反应时间为30 min，加酶量8 U/mL，pH=7，染料浓度分别为50 mg/L和80 mg/L，温度40~45℃。ABTS介体对酶促偶氮染料脱色没有明显促进作用。Fe²⁺对漆酶脱色有较强的抑制作用；Cu²⁺对漆酶催化活性黑KN-B促进作用较大，对直接大红影响较小。漆酶对2种染料的脱色反应符合米氏方程，其催化活性黑KN-B和直接大红染料的K_m值分别为114.81 mg/L，317.5 mg/L，v_max值分别为6.57 mg/（L·min）和26.0 mg/（L·min）。     

仿生矿化法制备壳聚糖/纳米CdS复合粒子对猩红B光催化降解研究

用仿生矿化法制备了壳聚糖/纳米CdS复合粒子，并用于可见光光催化降解猩红B染料模拟废水，系统地研究了染料初始浓度、pH值、催化剂投加量、光照情况和催化剂重复使用等因素对猩红B的光解脱色效率的影响。结果表明，当pH=3.0，催化剂投加量为0.7 g/L的条件下，对初始溶液为20 mg/L的猩红B模拟废水，60 min之内脱色率超过96%。酸性媒介比碱性媒介更有利于猩红B染料光解脱色。实验范围内Br^-、NO^-₃和Cl^-等无机阴离子，均对降解脱色有促进作用，其中NO₃^-对脱色作用促进最显著。处理前后的UV-Vis谱图分析表明猩红B在壳聚糖/纳米CdS复合粒子可见光光解处理过程中脱色是因为染料发生氧化光降作用。催化剂重复利用5次后，处理60 min对猩红B的脱色率仍可达到80.7%。     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

Effects of Mn(II) and Fe(II) on microbial removal of arsenic (III)

Goal, scope, and background  Arsenic contamination in groundwater creates severe health problems in the world. There are many physiochemical and biological methods available for remediation of arsenic from groundwater. Among them, microbial remediation could be taken as one of the least expensive methods, though it takes longer treatment time. The main objective of this research was to study the improvement on remediation by addition of some essential ion salts such as Mn and Fe. Materials and methods   Staphylococcus aureus, Bacillus subtilis, Klebsiella oxytoca, and Escherichia coli were taken as model microbes from Dhulikhel, 30 km east from Kathmandu, Nepal. Results and discussion  Microbes used in this study showed different abilities in their removal of As(III) with and without addition of Mn and Fe salts. The trend of remediation increased with time. S. aureus was found to be the best among the microbes used. It showed almost 100% removal after 48-h culture, both with and without Fe and Mn salts. Rate of removal of As increased with addition of Fe and Mn for all microbes. Removal efficiency was found to increase by about 32% on average after addition of salts in 24-h cultures of S. aureus.     

Bioindicators for toxicity assesment of effluents from a wastewater treatment plant

The discharge of effluents and toxic compounds into aquatic systems represents a growing environmental problem involving an impact on water ecology and potential effect on human health. Most municipal wastewaters are complex mixtures; their complexity led as to carry out a hazard assessment using chemical analyses and biological tests.This study investigates biochemical alteratiobns in two sentinel organisms, the Anodonta cygnea mussel and the Xenopus laevis frog exposed for different lengths of time to various concentrartion of wastewater of the S. Antonino Ticino treatment plant. The results point out the long-life of toxic compounds.     

利用发光菌和大型蚤对北方某城市再生水急性毒性的调查

利用发光菌和大型蚤作为受试生物测定了北方某城市5个再生水原水(城市污水厂二级出水)和2个再生水处理系统的各工艺出水的急性毒性.结果表明,各再生水原水对大型蚤和发光菌具有不同程度的毒性效应,其中工业废水占较大比例的K和B厂再生水原水的大型蚤48 h总抑制率分别高达90%和100%,发光菌发光抑制率分别达到74.2%和46...     

污泥堆肥施用于草坪草栽培:Zn和Cu的分布特征简

为了探索污泥堆肥中重金属在土壤-植物系统中的积累与转移特性，通过温室盆栽实验，分析了污泥堆肥对草坪草高羊茅、黑麦草和白三叶生物量积累的情况，研究了污泥堆肥中Zn和Cu在植物和土壤中的分布特征。结果表明，污泥堆肥施用可以有效促进3种草坪草的积累生物量，在0~6 kg/m²的污泥堆肥施用量范围内，草坪草的生物量积累随着施用量的增加而提高。土壤中Zn和Cu的含量随污泥堆肥施加量的增加而增大，85%以上的Zn和Cu残留在土壤中。污泥堆肥中的Zn和Cu均可以被植物吸收，随着污泥堆肥施用量的增加，草坪草对Zn和Cu的吸收量增大，但当污泥堆肥施用量超过一定阈值时，草坪草吸收Zn和Cu不再增加，甚至减少；对于不同的草坪草，这一阈值有所不同。植物对Zn和Cu的吸收量只占土壤中Zn和Cu减少量的5%左右。根据生物富集系数（BCF）的计算结果推测，污泥堆肥的施用对土壤环境的影响大于对植物体内累积Zn和Cu的影响。     

氧化亚铁硫杆菌浸铜作用研究

为研究氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.f)对铜浸出的作用,从某煤堆积水中分离得到A.f菌,利用该菌对铜进行浸出实验,设置3个处理,3个处理的浸出液分别为9 K培养基(简称S),成熟菌液(简称MS)和过滤除菌液(简称FS)。结果表明,3个处理中铜都得到了浸出,浸出铜浓度按S、FS和MS依次递增分别为4 433、5 377和6 296 mg/L;浸出初期,MS中的铜,浸出速度最快,过滤除菌液中次之,而培养基中的速度比较稳定,比前两者均慢,24 h后三者浸铜速度趋近一致;三者中pH、Eh变化相似,pH均先升高至3.4左右保持相对稳定,Eh均先迅速下降至280 mV后保持稳定。由实验可知,氧化亚铁硫杆菌主要在浸出初期促进了铜的浸出,且菌液中溶解氧氧化Fe2+以及酸性条件下氧化Cu0对铜的浸出作用不容忽视。     

Marine macroalgal community structure, metal content and reproductive function near an acid mine drainage outflow

Marine macroalgal communities were examined near the outflow of acid mine drainage (AMD) from the Britannia Mine, British Columbia, Canada. No marine algae were present within 100 m of the mouth of Britannia Creek, which carries the AMD into the marine environment. At greater distances (300-700 m) from this Creek, mean summer cover of filamentous green algae, mostly Enteromorpha intestinalis, was >60%, which was significantly higher than at nearby reference stations. At still greater distances (600-1000 m) from Britannia Creek, Fucus gardneri dominated algal communities that were similar to those at reference stations. No consistent differences were detected in mean plant length, mean per cent cover or mean oocyte production between F. gardneri near Britannia Creek and those at reference stations. Cu body burden in F. gardneri near Britannia Creek was five to 17 times higher than in reference plants.     

不同水温下鲴鱼对铜绿微囊藻的控制作用及对水质的影响

在室内受控模拟条件下开展实验,研究了在19、23、27、31、35℃5个水温梯度下鲴鱼对铜绿微囊藻和水质的影响。研究结果表明,在不同水温下,鲴鱼对铜绿微囊藻具有较强的控制作用,实验结束时铜绿微囊藻密度减少至初始密度的18%~30%,摄食率和消化率分别为6.83×104~8.32×104cells/(g·d)、93%~98%;叶绿素a的去除率为68%~88%;实验组TP、TN去除率分别为22%~25%、20%~38%,对照组的分别为80%~94%、28%~40%。对照组NH+4-N浓度变化很小(0.071~0.073 mg/L),而实验组氨氮浓度显著增大(2.222~3.645 mg/L),分别为初始值的31、34、42、51和46倍。     

不同质量浓度黄菖蒲和狭叶香蒲对铜绿微囊藻的化感作用简

分别采用黄菖蒲（Iris pseudacorus L.）、狭叶香蒲（Typha angustifolia L.）和铜绿微囊藻（Microcystis aeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明，黄菖蒲在质量浓度大于10 g/L时对初始密度为1.0×10⁷ ind/mL的铜绿微囊藻具有较好的抑制作用，表现为黄菖蒲质量浓度为10、20和40 g/L时，第15天对铜绿微囊藻的抑制率分别为30.1%、51.8%和84.0%；狭叶香蒲在质量浓度大于20 g/L时对铜绿微囊藻有明显的抑制作用，表现为狭叶香蒲质量浓度为20 g/L和40 g/L时，第15天对铜绿微囊藻的抑制率分别为34.2%和77.7%，实验过程中，铜绿微囊藻叶绿素a含量逐渐减少，而藻密度、SOD活性及MDA含量先增加后逐渐降低，表明经过一段时间持续地化感胁迫，黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫，导致细胞结构严重损伤和叶绿素大量分解，从而强烈抑制铜绿微囊藻的生长。