活性黑5脱色产物对直接黄11生物脱色的促进作用研究

以沼泽红假单胞菌W1为研究对象,考察了活性黑5（reactive black 5,RB5）脱色产物对直接黄11（direct yellow 11,DY11）生物脱色的影响,并对其机制进行了分析.结果表明,RB5脱色产物能明显加快DY11生物脱色的速率.初始浓度为200 mg/L的DY11加入RB5脱色产物后脱色动力学常数k值可由17 mg/(L·h)增加到42.5 mg/(L·h),优化RB5脱色产物投量,k值可进一步提高到48.8　mg/(L·h).循环伏安分析结果表明,RB5脱色产物具有电化学活性,可媒介电子的转移,其可逆氧化峰（E₀）位于83　mV,可逆还原峰（E_r）位于－220　mV.FT-IR和HPLC-MS的分析结果表明,RB5脱色产物中具有电化学活性的物质为TAHNDS_DP-1.TAHNDS_DP-1具有醌式结构,能通过得失2［H］的方式在氧化态和还原态之间转化,可作为氧化还原介体加速菌株W1对DY11的还原.     

酵母Candida krusei对合成染料的脱色

通过筛选实验,从土壤中新分离到1株对活性艳红K-2BP具有明显脱色效果的酵母菌株Y-G-I,经鉴定为克鲁斯假丝酵母Candida krusei．该菌株对含活性艳红K-2BP起始浓度为200mg／L的培养基,最大脱色率为99％,达到最大脱色率的时间是12h．克鲁斯假丝酵母的最佳接种量应不低于5％（体积分数）,培养基最适pH在4～9之间,氮源（NH4）2S04浓度不低于0．1％,相对应的碳源葡萄糖浓度不低于0．5％．对脱色机理的研究表明,该菌株对活性艳红K-2BP的去除属于降解脱色．此外,该菌株对另外9种染料（50mg／L）的脱色率在62％～96％之间．其中,对偶氮染料弱酸艳红B、活性黑KN-B和活性红M-3BE的脱色率都达到了90％以上,对三苯甲烷染料（酸性媒介漂蓝B）的脱色率达到了93％．表明克鲁斯假丝酵母在染料废水的处理上可能具有较好地应用潜能．     

酵母Candida krusei对合成染料的脱色

通过筛选实验,从土壤中新分离到1株对活性艳红K-2BP具有明显脱色效果的酵母菌株Y-G-1,经鉴定为克鲁斯假丝酵母Candida krusei.该菌株对含活性艳红K-2BP起始浓度为200mg/L的培养基,最大脱色率为99%,达到最大脱色率的时间是12h.克鲁斯假丝酵母的最佳接种量应不低于5%(体积分数),培养基最适pH在4～9之间,氮源(NH₄)₂SO₄浓度不低于0.1%,相对应的碳源葡萄糖浓度不低于0.5%.对脱色机理的研究表明,该菌株对活性艳红K-2BP的去除属于降解脱色.此外,该菌株对另外9种染料(50mg/L)的脱色率在62%～96%之间.其中,对偶氮染料弱酸艳红B、活性黑KN-B和活性红M-3BE的脱色率都达到了90%以上,对三苯甲烷染料(酸性媒介漂蓝B)的脱色率达到了93%.表明克鲁斯假丝酵母在染料废水的处理上可能具有较好地应用潜能.     

液相高压放电降解RB5染料废水的试验研究

随着印染工艺不断更新,大量化学分子结构复杂的化工染料应用到印染行业,使得常规的水处理工艺难以降解印染废水中的染料。本文以活性黑（RB5）染料为研究对象,采用液相高压放电产生强氧化性自由基来降解染料废水,考察反应时间、初始浓度和气体流量对RB5降解的影响,研究结果表明：在外部功率相同的情况下,浓度高染料其降解率相对较低;通入氧气量增加,产生的活性自由基和活性物质数量也增加,RB5的降解率也增大,但气流量不宜过大;高压放电产生的各种活性物质容易破坏染料发色基团的分子链,使其脱色。     

FeS对CW-MFC系统降解活性艳红X-3B效果及过程的影响

在自行构建的人工湿地-微生物燃料电池(CW-MFC)系统中,以砾石填料为对照,研究了FeS对活性艳红X-3B脱色效果及降解过程的影响.结果表明,加在底层区域的FeS能够显著提高CW-MFC对活性艳红X-3B的脱色效果和系统产电性能.FeS的投加使得系统脱色率在进水活性艳红X-3B浓度200mg/L、葡萄糖浓度100mg/L条件下达到99.83%.在进水活性艳红X-3B浓度100mg/L、葡萄糖浓度200mg/L条件下,FeS组最大功率密度达到0.849W/m³.活性艳红X-3B在系统中的脱色主要发生在底层和阳极区域,由紫外-可见全波长扫描图谱和GC-MS扫描图谱可知FeS在该区域促进了偶氮双键的断裂,并有利于脱色产物苯胺、三嗪结构、萘环结构的进一步降解.     

高效苯酚降解菌Bacillus sp.L5-1的分离及其降解特性

从污水处理厂活性污泥中分离筛选出一株高效苯酚降解菌L5-1,经菌落形态观察和16S rDNA基因测序,结果表明菌株L5-1为蜡样芽胞杆菌（Bacillus cereus）,美国国家生物信息中心（NCBI）的注册号为MN784421.将苯酚设置为唯一碳源,对其生长和苯酚降解特性展开研究.结果表明：菌株L5-1在10%接种量、温度30~35℃、pH值7~8的条件下,均能高效降解培养基中苯酚（培养基体积为100mL,初始苯酚浓度为500mg/L,14h时降解率>93%）.而在最优降解条件下（10%接种量,培养温度为35℃,pH值7.0,NaCl浓度为1%）,初始苯酚浓度为500mg/L,菌株在14h内的苯酚降解率可达97.1%;而当初始苯酚浓度为1000mg/L,菌株也可在46h内达到97.71%的降解率.运用Haldance方程动力学模拟菌株在不同浓度苯酚下的生长过程,其最大比生长速率为0.355h^-1,半饱合常数104.27mg/L,抑制常数为322.83mg/L,R²=0.997.菌株L5-1为目前已报道的Bacillus菌属中降解苯酚能力较强的菌株,为实际处理含酚废水中提供理论参考.     

黄曲霉A5p1对偶氮染料的降解特性和降解途径

以黄曲霉菌株A5p1为生物材料,研究其脱色染料的广谱性,并选择偶氮染料直接蓝71（DB71）为模型底物,探讨脱色特性及降解产物.该菌株对15种染料的脱色测试结果表明,染料浓度为100mg/L时脱色效率为61.7%~100%.该菌对偶氮染料DB71具有生物吸附和生物降解的双重作用,在pH值7.0,温度30℃,染料浓度300mg/L,蔗糖为碳源时对DB71 脱色率为100%.酶分析显示葡萄糖氧化酶和锰过氧化物酶参与染料的降解.FTIR、GC-MS和LC-MS分析确定代谢终产物为萘胺、叠氮萘、2-羟基-6-草酰-苯甲酸和1-萘酚.     

菌株Sphingomonas sp. FL降解溴氨酸的特性研究

分离了1株溴氨酸降解菌,其可以溴氨酸为唯一碳源进行降解并使其脱色,通过16S rRNA基因序列比较和生理生化特性分析,将其归为鞘氨醇单胞菌属.溴氨酸降解和菌株生长的最适条件为：温度30℃,pH 7.0,摇床转速100 r/min ,(NH₄)₂SO₄作为氮源,在此条件下,溴氨酸（100 mg/L）在14 h内的脱色率可达99%.低浓度NaCl（<2%）对脱色有促进作用,而高浓度NaCl（≥2%）对脱色产生抑制.以Haldane底物抑制模型表征溴氨酸初始浓度对脱色的影响,确定当初始浓度为1 393.5 mg/L 时可取得最佳比降解速率1.4 h^-1.菌株不能将溴氨酸完全矿化,至反应终点52.4%的有机碳得到去除.利用GC-MS和HPLC-MS分析代谢产物显示,溴氨酸降解的中间产物是邻苯二甲酸,终产物可能为2-氨基-3-羟基-5-溴苯磺酸或2-氨基-4-羟基-5-溴苯磺酸,邻苯二甲酸可经3,4-二羟基苯甲酸途径进一步降解而被菌体利用.     

蒽降解菌烟曲霉A10的分离及降解性能研究

从污染环境中筛选出1株蒽降解菌A10,经鉴定为烟曲霉（Aspergillus fumigatus）,其对蒽的降解率随时间的延长逐渐升高,在12～84 h,蒽降解率增长速率较快;此后降解率的增加趋于平缓,最终（168 h）能够达到83%左右.当无机盐培养液中蒽初始浓度为10 mg/L,A10投菌量为50 g/L（以湿重计）,菌龄为36 h时, 5 d内蒽降解率为79.37%.蒽浓度对菌发挥降解作用有较大影响,浓度为5 mg/L时,降解率最高,达92.17%.培养液初始pH为5.0～7.5时,降解率维持在60%左右;温度为30℃、氧气量为4.30 mg/L时蒽降解效果较好.一定量的营养盐的添加能在一定程度上促进蒽的降解.共代谢底物乳糖的添加,能使蒽的降解率提高37.15%.对蒽降解过程的初步研究表明,菌株A10对蒽的降解是一个胞外吸附/胞内降解的动态变化过程.红外光谱分析显示,在微生物作用下,蒽的结构发生改变,生成了含有1～2个苯环的芳香酸、芳香酮、芳香醛和饱和碳氢化合物等一系列降解产物.     

东方伊萨酵母YP-1对染料活性艳红K-2BP的脱色

利用含染料的选择性培养基从土壤中分离出一株对活性艳红K-2BP有明显脱色效果的酵母菌株YP-1,经鉴定为东方伊萨酵母Issatchenkia orientalis.结果表明,该酵母菌对￡400mg/L的活性艳红K-2BP有较好的脱色效果.对于活性艳红K-2BP起始浓度为100mg/L的培养基,该菌株可在12h达到99%以上的最大脱色率,其最佳接种量为10%(体积分数),最适pH值在3~9之间,氮源(NH4)2SO4的浓度30.02%,碳源葡萄糖的浓度30.2%.脱色机理研究结果表明,该酵母对活性艳红K-2BP的去除是先吸附后生物降解.此外,该菌株对初始浓度为200mg/L的偶氮染料活性黑KN-B的脱色率也可达99.5%.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.