蒽醌染料及中间体脱色优势菌的特性研究和基因定位

本文对分离到的两株蒽醌染料脱色优势菌的脱色能力及其基因定位进行了研究,结果表明,ＮＤ１,ＮＤ２均能有效脱除活性艳蓝ＫＮ－Ｒ及溴氨酸的色度;两株优势菌均含有质粒,其降解染料的能力是由质粒控制的;并考察了不同碳源、氧、温度、ｐＨ值等理化因素对菌株降解染料的影响。     

菌株NKS-3对溴氨酸脱色特性探讨

从受溴氨酸污染地筛选出菌株ＮＫＳ－ ３ ,它对溴氨酸有脱色作用。菌株生长随碳源浓度增加而旺盛,溴氨酸能刺激菌株生长。溴氨酸浓度即使达到１０００ ｍｇ／Ｌ 也能被菌株基本脱色。研究发现,盐度抑制菌生长,在含盐培养液中溴氨酸的脱色过程被抑制     

蒽醌染料中间体溴氨酸降解酶的特性

从污染地分离筛选出的菌株BX26对蒽醌染料中间体溴氨酸有显著的降解脱色作用,降解过程受降解酶的控制,试验结果表明,降解酶为溴氨酸诱导的胞外酶,该酶在温度高于50℃处理后失活,盐度对该酶失活有影响,盐度高于1%会显著降低该酶活力,酶对溴氨酸的催化脱色要有氧参加,氮气气氛中酶活受抑制。     

染料结构与其絮凝胶色效果关系的探讨

在对活性，酸性和碱性等１０种水溶性染料水样絮凝胶色和平衡渗析实验数据进行分析的基础上，初步探讨了染料结构与其絮凝脱色率之间的定性关系。ＰＡＮ－ＤＣＤ絮凝剂对１０种染料的最佳脱色ＰＨ范围〈５，尤其在ＰＨ〈４更佳。     

高锰酸钾对染料废水的脱色研究

研究了影响高锰酸钾对染料废水脱色的有关因素,结果表明,脱色反应的最佳ＰＨ值应小于１．５,高锰酸钾的浓度对脱色效果显著。     

氢氧化镁对水溶性阴离子染料废水脱色的研究

本文研究了氢氧化镁对水溶性阴离子染料模拟废水的脱色规律及机理。结果表明镁盐法具有优异的脱色效果。例如,染料浓度１００ｍｇ．ｌ＾－１,镁盐投加量１０００ｍｇ．ｌ＾－１用ＣａＯ调至ＰＨ１０．９－１１．５十种被研究的水溶性阴离子染料的脱色平均值在９９％以上。吸附机理属于离子吸附。     

纳米TiO2光催化降解水溶性染料溶液的研究

研究了纳米ＴｉＯ２光催化剂对活性黄Ｘ６Ｇ,活性红Ｘ３Ｂ,活性蓝ＸＢＲ,碱性绿,碱性紫５ＢＮ,碱性品红等６种染料溶液的光解脱色效果。结果表明,在ｐＨ２的酸性溶液中,对浓度为６０ｍｇ／Ｌ的６种染料溶液的脱色率均超过９３．３％;即使对浓度达２００ｍｇ／Ｌ的活性蓝溶液,其脱色率仍可达７８．８％。染料溶液的ｐＨ值对纳米ＴｉＯ２光催化脱色效果影响较大。     

絮凝剂PAN—DCD的结构和性质研究

以聚丙烯腈和双腈双胺为原料,合成了有机絮凝剂ＰＡＮ－ＤＣＤ。用ＩＲ、＾１ＨＮＭＲ和＾１３ＣＮＭＲ等方法对其结构进行了表征,探讨了ＰＡＮ－ＤＣＤ溶解度随ＰＨ值变化的规律,研究了ＰＡＮ－ＤＣＤ对活性染料的絮凝脱色和去除ＣＯＤｃｒ的性能。     

纳米TiO_2光催化降解水溶性染料溶液的研究

研究了纳米ＴｉＯ２光催化剂对活性黄Ｘ６Ｇ、活性红Ｘ３Ｂ、活性蓝ＸＢＲ、碱性绿、碱性紫５ＢＮ、碱性品红等６种染料溶液的光解脱色效果。结果表明，在ｐＨ２的酸性溶液中，对浓度为６０ｍｇ／Ｌ的６种染料溶液的脱色率均超过９３．３％；即使对浓度达２００ｍｇ／Ｌ的活性蓝溶液，其脱色率仍可达７８．８％。染料溶液的ｐＨ值对纳米ＴｉＯ２光催化脱色效果影响较大     

含溴氨酸体系中菌株NAX的生长及其吸附特性

从污染土壤筛选到的菌株NAX能在含溴氨酸的体系中生长,并能吸附溴氨酸。随碳源浓度的增加,菌体生长旺盛。体系中高浓度的溴氨酸和盐度抑制菌株生长。菌株对溴氨酸的吸附等温线数据用改型的Pearl生长模型拟合比用Freundlich方程好。这意味菌株吸附溴氨酸存在多层吸附机理。     

DLL-1菌对甲基对硫磷农药的降解作用及其降解机理

研究了假单胞菌 (DLL - 1)在水溶液介质中降解甲基对硫磷的性能与影响因素及其降解机理。结果表明 ,当菌体浓度为 10 5个·ml-1时 ,即发生快速的降解作用 ,3h时 ,降解率达 88.5 %。在pH为 5 .0、7.0和 9.0条件下 ,DLL - 1菌均产生对甲基对硫磷农药的高效降解作用。采用气相色谱 -质谱联用技术与离子色谱法 ,测定了DLL - 1菌 -甲基对硫磷作用过程产生的中间产物和最终产物 ,表明对硝基苯酚为主要中间产物 ,且DLL - 1菌能将其进一步降解为NO2 -和NO3 -。     

Study on removing selenate from groundwater by autohydrogenotrophic microorganisms

Performance of autohydrogenotrophic bacteria for bio-reduction of selenate (Se(VI)) under anaerobic conditions was investigated with batch experiments. Results showed Se(VI) was bio-reduced to selenite (Se(IV)) as an intermediate product, and then to elemental selenium (Se⁰). Reduction kinetics could be described by the pseudo-first-order model. In particular, the influences of pH value and temperature on Se(VI) reduction by autohydrogentrophic organisms were examined. The high degradation rate was achieved at pH 7.0 to 8.0; and the best reduction temperature was between 25°C and 35°C. This study is of help for treating groundwater with selenium contamination by autohydrogenotrophic bacteria as well as its reactor development.     

钢铁工业遗留场地土壤重金属洗脱剂筛选研究

土壤重金属污染限制了工业遗留场地再利用,通过振荡试验考察了HCl、HNO3和EDTA对工业遗留场地土壤中超标重金属Pb、Zn、Cd和As的洗脱效果。结果表明：土壤Pb、Zn、Cd、As的脱除效果均随洗脱剂浓度增加而增加;HCl、HNO3和EDTA等3种洗脱剂浓度分别为0.5、0.5和0.1 mol.L-1时,土壤Pb、Cd质量分数可降低至场地安全再利用的控制标准以内（分别为140 mg.kg-1、1mg.kg-1）;洗脱剂浓度分别增至2、2和0.2 mol.L-1时,土壤Pb、Cd质量分数继续降低,Zn、As质量分数有大幅降低但没有达到其相应的场地安全控制标准（分别为200、20 mg.kg-1）;与EDTA相比,HCl在低浓度时的重金属脱除效果较差,但HCl浓度增加对重金属脱除率的提高效果更为明显;洗脱液pH值（7.88~0.15）与重金属脱除率均呈显著负相关且与As的负相关系数最小,说明洗脱液pH值变化对As去除的影响相对较小;与HCl和HNO3相比,EDTA洗脱液pH值与Pb脱除率之间的负相关系数较大,与Zn、Cd、As脱除率之间的负相关系数较较小,说明EDTA洗脱液pH值变化更易对Pb的去除产生影响。     

假单胞茵胞内酶粗提液对藻毒素MCLR的降解

对比研究了假单胞菌M-6及其细胞内外提取液对微囊藻毒素-LR(MCLR)的降解效率.结果表明,细胞外提取液对藻毒素没有降解作用,胞内酶粗提液能在24h内降解MCLR,日均MCLR降解率是纯菌株M-6的4.7倍.进而研究了酶蛋白浓度、底物MCLR浓度、pH值及环境温度对胞内酶粗提液降解藻毒素效率的影响.当MCLR浓度为15.0mg·l~(-1)时,MCLR适宜的酶促降解反应条件为:酶蛋白浓度280mg·l~(-1),温度为30℃,反应pH值为7.0.MCLR液相色谱结构变化图表明,至少有3种酶参与了胞内酶粗提液降解MCLR的分子过程.     

Gastrointestinal pH and development of the acid digestion in larvae and early juveniles of<Emphasis Type="Italic"> Sparus aurata</Emphasis> (Pisces: Teleostei)

Changes in digestive pH and protease activity have been determined throughout the transition from larvae to the juvenile stage in Sparus aurata in rearing conditions (from 0.04 to 100 g wet weight). Measurements of pH have been taken in the stomach and different segments along the length of the intestine using a pH microelectrode. In starved fish, the gastric pH ranged between 6.0 and 8.0 approximately, except in juveniles of intermediate size (between 1.0 and 7.0 g wet weight), which exhibited a wider pH range of 2.0–8.0. Fed fish with digestive content showed, in general, lower pH values in the stomach. A progressive decrease was observed from a pH range of 5.5–8.0 in the youngest animals (0.04 g) to a pH range of 2.0–6.2 when juveniles were approaching 1.0 g wet weight. Above this weight, the gastric pH remained constant (between 2.0 and 6.0 approximately). The pH values in the intestine ranged between 6.7 and 8.4. They were similar in the different segments and weight classes examined, and there were no significant differences between fed and starved animals. Specific acid protease activity (units per milligram soluble protein) in fed animals increased from small (0.04–1.0 g) to intermediate juveniles (1.0 and 7.0 g), but then remained similar in larger juveniles. On the contrary, specific alkaline protease activity in fed animals decreased from small to intermediate juveniles, and then remained at a similar level in larger juveniles. The results reflect a progressive transition during several months from alkaline digestion in larvae with undeveloped stomachs to the acid digestion in juveniles with fully developed stomachs. Full gastric capacity is developed in seabream juveniles of 1 g wet weight, which represents approximately 100 days post-hatching in cultured populations. Nevertheless, in the following 2.5 months, during which the intestine reaches the appropriate length, juveniles still show a transitional period in the regulatory mechanism of digestion, probably linked to the adaptation to a different feeding habit.Communicated by S.A. Poulet, RoscoffThis revised version was published in December 2003 with corrections to the legend of Fig. 3.     

福建茶园土壤Zn含量及其影响因素

通过对62份福建茶园土壤样品的测定,应用通径分析等统计方法研究了土壤Zn含量及其有效性等的影响因素。结果表明：福建茶园土壤全Zn质量分数平均值为28.85 mg.kg-1,中值58.80 mg.kg-1,变异系数45.16%;有效Zn质量分数为0.11~15.04 mg.kg-1,平均值为2.95 mg.kg-1,中值1.47 mg.kg-1,变异系数123.14%;Zn活化率0.26%~24.53%,平均值为5.02%,中值2.72%,变异系数114.87%。相关分析表明全Zn与pH呈极显著正相关,有效Zn与有机质、全氮呈极显著正相关;Zn活化率与pH呈极显著负相关,与有机质、全N呈极显著正相关。通径分析表明pH对全Zn的直接效应最明显;全N对有效Zn和Zn活化率的直接效应最明显,pH和全P对有效Zn和Zn活化率也有较大的负效应。     

二氧化氯对水中病毒、藻类和浮游动物的失活效果

本文研究了二氧化氯对水中一些主要病毒、藻类和浮游动物的失活效果,以及在不同消毒剂投量、接触时间和pH值等条件下,二氧化氯(ClO_2)对水体中一些微生物的杀灭和失活效果.与液氯对比的结果表明:ClO_2对藻类失活效果优于或相当于液氯;ClO_2对病毒和浮游动物的失活效果显著优于液氯;ClO_2可在一广泛的pH值范围内杀灭微生物.此外,还从理论上初步探讨了ClO_2对病毒的失活机理.研究结果表明,ClO_2是一种优良的液氯替代消毒剂,这对开展ClO_2的研究及其应用有重要意义.     

Effective degradation of tetracycline by mesoporous Bi<Subscript>2</Subscript>WO<Subscript>6</Subscript> under visible light irradiation

Bi₂WO₆ was synthesized with a hydrothermal method at different pHs and used for the degradation of tetracycline (TC) in water. The mesoporous Bi₂WO₆ prepared at pH 1 (BWO-1) displayed the highest adsorption and degradation capacity to TC due to its large surface area and more efficient capacity to separate photogenerated electrons and holes. 97% of TC at 20 mg·L^?1 was removed by BWO-1 at 0.5 g·L^?1 after 120 min irradiation under simulated solar light. Only 31% of the total organic carbon (TOC) was removed after 360 min irradiation although the TC removal reached 100%, suggesting that TC was mainly transformed to intermediate products rather than completely mineralized. The intermediates were identified by high-performance liquid chromatography-time of flight-mass spectrometry (HPLC-TOF-MS) and possible photodegradation pathways were proposed.     

Sorption and desorption of pymetrozine on six Chinese soils

Pymetrozine is a selective insecticide with a unique chemical structure and mode to control hemipteran and homopteran. While pymetrozine has brought great benefits to crop production by killing insects, its residues in soil may have a detrimental effect on environment. Therefore, it is of great importance to investigate its behaviors in soil. In this study, the sorption and desorption of pymetrozine on six Chinese soils were investigated using a batch equilibrium approach to understand its mobile behavior in the soils. Both sorption and desorption isotherms of pymetrozine were in good agreement with the Freundlich model. The sorption coefficient K_F varied between 3.37 and 58.32 mL∙g⁻¹ and the sorption isotherms were nonlinear, with 1/n ranging from 0.57 to 0.91. A regression equation was proposed to predict the sorption of pymetrozine on six different soil samples: log K_F = 4.3708 − 4.5709 × log (pH in 0.01mol·L⁻¹ CaCl₂) + 0.4700 × log OC% + 0.0057 × sand (%) + 0.0022 × CEC(clay), with R² = 0.9982. The organic carbon content of soil positively affected the sorption of pymetrozine, but soil pH had a negative effect on the sorption. Additionally, effects of CaCl₂ concentration, soil to solution ratio and pesticide form were investigated. The sorption was promoted with an increase in soil to solution ratio and a decrease in CaCl₂ concentration. The possible variation of the five formulated products of pymetrozine was also investigated.