诺氟沙星对胡敏酸吸附铜的影响

根据OECD Guideline 106批平衡试验,研究了诺氟沙星对胡敏酸吸附铜的动力学、吸附等温线以及热力学的影响。结果表明,铜单独存在以及铜与诺氟沙星共存时,伪二级动力学方程均能较好地描述铜在胡敏酸上的吸附动力学曲线,相关系数都超过了0.99,而诺氟沙星的存在降低了铜的吸附速率。在pH 3.0~5.5范围内,铜在胡敏酸上的吸附均符合Langmuir方程,诺氟沙星的存在抑制了胡敏酸对铜的吸附,一个原因是铜与诺氟沙星形成带正电的络合物,胡敏酸对该络合物的亲和力比铜低,另一个原因是带正电的诺氟沙星阳离子与铜在胡敏酸上产生了竞争吸附,导致铜在胡敏酸上的吸附量降低。pH从3.0升高至5.5时,铜单独存在以及铜与诺氟沙星共存时,铜在胡敏酸上的吸附量均随pH的升高而增加,表明铜离子及带正电的铜与诺氟沙星的络合物是通过阳离子交换作用和静电作用力吸附到胡敏酸上。热力学实验结果表明,诺氟沙星存在时铜在胡敏酸上的吸附是一个吸附热及混乱度增加的过程。     

阳离子对Bt蛋白在矿物表面吸附动力学的影响

为了探讨金属阳离子对Bt蛋白在矿物表面吸附动力学的影响,选取蒙脱石、高岭石、凹凸棒石和碳酸钙四种不同类型的矿物,在Na~+、K~+、Mg~(2+)、Ca~(2+)添加浓度均为1 mmol·L-1的条件下,采用静态吸附法研究Bt蛋白的吸附动力学特征,并采用一级动力学、二级动力学、内扩散和Elovich四种模型对动力学数据进行拟合,依据相关系数和拟合吸附量对模型优劣进行评价。结果表明,Na~+、K~+、Mg~(2+)、Ca~(2+)均对Bt蛋白的吸附有促进作用,其作用强弱依次为Ca~(2+)Mg~(2+)K~+Na~+。模型分析结果表明:二级动力学模型R20.995 1,由拟合模型计算得出的平衡吸附量与实测值吻合,因此适合描述Bt蛋白的吸附动力学特征;Elovich模型R2在0.914 1~0.982 9之间,也能够较好描述矿物对Bt蛋白的吸附特性;一级动力学模型R2在0.710 8~0.987 6之间,相关系数分布范围过宽,且由模型计算得出的平衡吸附量与实测值差异较大,故不适合用于动力学特征描述;内扩散模型相关系数低(R20.619 4),不建议在Bt蛋白吸附动力学中使用。     

组合型生态浮床系统脱氮效果的周年变化

构建集挺水植物、沉水植物和微生物于一体的组合型生态浮床系统,并对其技术工艺周年运行效果进行探究。分析了组合型生态浮床对水中氨氮(NH_4~+-N)与总氮(TN)的去除动力学,不同介质对水体净化的贡献率及削减模型。实验结果表明,组合型生态浮床脱氮效果明显,其中浮床上层贡献率15.6%±1.2%,中层37.6%±2.2%,下层23.8%±1.8%,说明浮床系统中层介质对氨氮与总氮的降解能力占主导地位。实验组NH_4~+-N最高去除率为93.0%±3.4%,TN最高去除率达94.2%±0.9%,而上中下层兼具有的池5去除效果最显著(P0.10)。由各实验组消解NH_4~+-N和TN的去除动力学曲线得出其削减模型及不同程度的衰减指数曲线。初步探索了组合型生态浮床脱氮效果的周年变化,为其进一步推广应用提供了技术支撑。     

Release performance and sustained-release efficacy of emamectin benzoate-loaded polylactic acid microspheres

High-performance liquid chromatography(HPLC) was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behavior. The effects of particle size and release medium p H on the release rate were also investigated. The indoor toxicity of emamectin benzoate-loaded polylactic acid microspheres on the diamondback moth larva(Plutella xylostella) was studied to explore drug sustained-release performance. In acidic and neutral media, the drug release behavior of the microspheres was in accord with the first-order kinetics equation. Increasing the spray dosage of emamectin benzoate-loaded polylactic acid microspheres initially resulted in an equivalent insecticidal efficacy with the conventional emamectin benzoate microemulsion. However, the drug persistence period was four-fold longer than that observed using the conventional formulation. The developed emamectin benzoate-loaded polylactic acid microspheres showed dramatic sustained-release performance. A treatment threshold of greater than 35 mg m L–1 was established for an efficient accumulated release concentration of emamectin benzoate-loaded microspheres.     

两种复合菌剂对油菜秸秆降解和小麦生长的影响

以油菜华油杂62的秸秆为供试作物秸秆,复合菌剂A[黑曲霉（Aspergillus niger）+产紫篮状菌（Talaromyces purpureogenus）]、复合菌剂E[欧洲链霉菌（Eurotiomycetes sp. genotype 631 JMUR-2016）+扩展青霉（Penicillium expansum）]为供试复合菌剂,在盆栽模拟秸秆还田试验中测定复合菌剂对秸秆降解率、土壤及小麦生长的影响,为提高油菜秸秆直接还田的秸秆利用率、实现绿肥作物还田的高效利用提供理论依据和实践参考。结果表明：两种复合菌剂的施用均能够提高油菜秸秆降解率,对小麦生长指标均有不同程度的提升效果,且有降低土壤pH值、增加土壤电导率的作用。     

不同碳源条件下金黄色蝶形担孢酵母发酵合成多糖的动力学及结构差异

为探究碳源对金黄色蝶形担孢酵母(Papiliotrema aurea)DF-12合成胞外多糖(EPS)的动力学及结构和功能的影响,本试验利用Logistic、Luedeking-Piret、Herbert-pirt模型拟合不同碳源条件下金黄色蝶形担孢酵母DF-12的动力学变化,并通过高效凝胶渗透色谱、红外光谱、扫描电子显微镜和气相色谱初步分析了不同碳源所得EPS的结构差异。结果表明,以葡萄糖为碳源时最大比生长速率为0.15 h^-1,高于其他碳源,而以蔗糖为碳源时多糖比生产速率较高,达11.95 h^-1。同时不同EPS均具有较好的抗氧化活性。以葡萄糖和蔗糖为碳源所得不同EPS组分表面形貌存在差异,但其分子量、官能团和化学键无较大差异。此外,不同碳源(葡萄和蔗糖)所得EPS均由岩藻糖、鼠李糖、甘露糖、葡萄糖等单糖组成,但其摩尔比存在一定的差异。本研究结果为酵母菌EPS的进一步开发和利用提供了理论依据。     

豆磺隆残留污染水田的生物降解技术研究

利用田间人工模拟豆磺隆残留土壤的方法进行大田试验,对研究生物肥降解水田残留豆磺隆的剂量,及对土壤和植株中豆磺隆的降解率。进行系统研究。结果表明：各处理叶龄各处理差异不大,但是残留量1.2μg/kg的处理比残留量0~0.4μg/kg的处理略低;单株分蘖豆磺隆残留量1.2μg/kg的处理比残留量0~0.4μg/kg的处理单株分蘖低1倍左右;生物肥对水稻生长发育和干物质积累有一定影响,当生物肥用量2.0kg/亩30.0kg/hm2时,干物质积累最快,根量最多;豆磺隆残留量1.2μg/kg的处理生育成熟期拖后10d左右,不施生物肥的处理比施生物肥处理成熟期晚2－~3d;豆磺隆残留量相同时,生物肥用量2.0kg/亩30.0kg/hm2的处理产量最高;随着豆黄隆残留量的增加,水稻产量降低。当豆磺隆残留量0～达到0.4μg/kg时,减产不超过20%;豆磺隆残留量1.2μg/kg时,水稻减产一半左右。总之：生物肥对水田豆磺隆有一定的降解作用,生物肥用量以30.0kg/hm2最佳     

Review on the Adsorption Mechanism and Kinetics ofAdsorption Biodegradation Process

Due to that the traditional theory cannot explain the special adsorption mechanism concerning the removal of organic waste with high efficiency in non-generated situation. The research on adsorption mechanism and kinetics in recent years was reviewed in this paper for further research on this problem.     

Kinetics of the hydroxymethylation of phenol I: Rate equation and method of analysis

Seven reactions take place consecutively and competitively during the hydroxymethylation of phenol in aqueous alkaline media. This hydroxymethylation is the first step in the formation of phenolic resins and has long been studied. However, the rate equation, which can describe the seven reactions in those reaction systems where the alkali/phenol molar ratios are <1.0, has not yet been obtained. The authors present a rate equation (in a differential form) for a computer simulation. This equation involves the concentration of hydroxide ion, [OH^–], which changes with the change in the composition of the reaction system and cannot be expressed as a function of reaction time. However, the value of [OH^–] can be obtained by numerical calculation. In the computer simulation the reactions occur for an infinitesimal unit of time, and the changes in the concentrations of formaldehyde, phenols, and hydroxide ion are calculated. The next step of the reaction takes place according to the reaction conditions that result from the previous step. In this manner the reactions progress step by step in a computer. Using this method we can describe the reaction time course, (i.e., the changes in the concentrations of phenol, formaldehyde, and five species of hydroxymethylphenols with the reaction time).Part of this paper was presented at the 47th Annual Meeting of the Japan Wood Research Society, Kochi, April 1997     

链状亚历山大藻暴露下紫贻贝体内麻痹性贝毒蓄积转化规律

本研究将紫贻贝(Mytilus galloprovincialis)暴露于一株麻痹性贝类毒素(paralytic shellfish toxins, PSTs)优势产毒藻——链状亚历山大藻(Alexandrium catenella, GY-H25株),模拟现场赤潮藻密度,探究了紫贻贝内脏团和可食组织中蓄积代谢及生物转化过程,并通过蓄积代谢动力学,重点比较了不同细胞密度GY-H25对紫贻贝体内毒素蓄积代谢和转化情况的影响。结果显示,GY-H25生长及产毒稳定,PSTs组分主要为N-磺酰胺甲酰基类毒素(C1和C2),单细胞最高产毒能力为2.96 pg STXeq/cell。暴露实验中,紫贻贝对PSTs有较强的蓄积作用,2种暴露浓度下PSTs含量变化趋势一致,实验结束时,2种暴露组紫贻贝内脏团中PSTs均超过欧盟国际限量标准(800 μg STXeq/kg),但可食组织则均低于限量标准;比较发现,高浓度组紫贻贝内脏团最高蓄积浓度达到6 815.36 μg STXeq/kg,且高浓度组暴露期间平均蓄积速率为17.89%,显著高于低浓度组13.06%的蓄积速率。另外,紫贻贝对PSTs表现出较强的生物转化能力,在对C1、C2和GTX5三者的转化研究中发现,快速代谢时期和平稳期C2→GTX5的转化为GTX5生成的主要途径,同时期C1的相关转化中C1→GTX5途径超过C2→C1,致使C1整体占比减少。综合评估紫贻贝中PSTs转化产物和毒性当量因子(toxic equivalency factor, TEF),发现紫贻贝对PSTs代谢转化进一步促使高毒性GTX5的生成和占比提升,总体终端毒性升高,这也可能是秦皇岛紫贻贝中PSTs风险严峻的主要原因之一。因此,本研究有助于科学评估紫贻贝中PSTs风险,为建立区域性风险监测技术提供科学基础。