Reprint of: Concentrations, distribution, and bioaccumulation of synthetic musks in the Haihe River of China

Seven typical synthetic musks (SMs) in the samples from the surface water, sediment and fish of the Haihe River were measured. The SM concentrations in the sediment and surface water of the Haihe River were significantly lower than those in the Dagu Drainage River and Chentaizi Drainage River (p < 0.05). Along the flow direction, the SM concentrations in surface water and sediment tended to increase from the upstream to the downstream of Dagu Drainage River. The Bioaccumulation factors (BAFs) of galaxolide (HHCB) and tonalide (AHTN) were calculated at high levels in the muscles of crucian carp, common carp, and silver carp. Most of the biota-sediment accumulation factors (BSAFs) for HHCB and AHTN were higher than 1.7, suggesting magnification possibly exist in the musk bioaccumulations of the three fishes in the Haihe River. No significant differences in HHCB/AHTN ratios were observed among the water, fish, and sediment samples (p > 0.05). However, the HHCB/AHTN values in the Haihe River were much lower than those in the Dagu Drainage River and Chentaizi Drainage River (p < 0.05). Compared with several typical persistent organic pollutants (POPs), the musk concentrations were higher or comparable in the Haihe River.     

The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe

A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha⁻¹ yr⁻¹) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extractable nitrate and ammonium concentrations did not show any relationship with nitrogen deposition. The above-ground tissue nitrogen contents of three plant species were examined: Agrostis capillaris (grass), Galium saxatile (forb) and Rhytidiadelphus squarrosus (bryophyte). The tissue nitrogen content of neither vascular plant species showed any relationship with nitrogen deposition, but there was a weak positive relationship between R. squarrosus nitrogen content and nitrogen deposition. None of the species showed strong relationships between above-ground tissue N:P or C:N and nitrogen deposition, indicating that they are not good indicators of deposition rate.     

淀粉-g-丙烯酸/凹凸棒土复合物制备及其吸附废水中NH_4~＋-N性能

采用反相乳液聚合法以凹凸棒土为原料,合成了新型NH4＋-N吸附剂淀粉-g-丙烯酸/凹凸棒土,并进行了氨氮吸附对比实验。结果表明：凹凸棒土氨氮单位吸附量为4.243 mg/g;淀粉-g-丙烯酸/凹凸棒土氨氮单位吸附量为5.301 mg/g,吸附能力比未改性的凹凸棒土提高了25%。淀粉-g-丙烯酸/凹凸棒土的氨氮吸附过程比凹凸棒土更符合Freundlich等温吸附模型。随着pH、温度的升高,凹凸棒土和淀粉-g-丙烯酸/凹凸棒土对NH4＋-N吸附量逐渐增大。     

凹凸棒土的氨氮吸附性能研究

在以氨氮去除率为指标,在振荡时间60 min,振荡温度25℃,振荡速度140r/min的条件下发现凹凸棒土的最佳投加量2.5 g;添加凹凸棒土可以加强SBR生物系统去除氨氮的能力;拟合凹凸棒土吸附氨氮的等温线方程符合Freundlich吸附模型.     

人工湿地基质的筛选及其对猪场废水厌氧消化液中氨氮吸附性能研究

采用静态吸附实验,对比了岷江砂、沱江砂、青衣江砂、沸石、活性炭对猪场废水厌氧消化液中氨氮的吸附去除效率,基于氨氮去除能力、购买成本与运费的比较,筛选出性价比较高的基质--岷江砂作为四川地区人工湿地的基质处理猪场废水厌氧消化液.吸附实验表明,砂对氨氮的去除率随振荡时间和投加量的增加而增加.通过吸附等温曲线Langmuir...     

固定化微生物法去除模拟渗滤液中氨氮的研究

采用固定化微生物曝气生物滤池（I-BAF）技术成功处理了模拟垃圾渗滤液,探讨了pH和溶解氧（DO）对系统脱氮性能的影响。结果表明,固定化微生物曝气生物滤池反应系统启动迅速,运行稳定,可以有效去除模拟垃圾渗滤液中的有机物和氨氮,其去除率分别达到97.1%和99.9%。在pH为7.5～8.5之间,DO 4.0 mg/L左右的条件下对模拟垃圾渗滤液中氮的去除最为有利,同步硝化反硝化效率以及总氮去除率均达到最高,分别为96.2%和94.3%。这主要是由于I-BAF系统中大孔载体提供了厌氧-兼氧-好氧的微环境,使硝化和反硝化反应在同一个反应器内发生,共同作用实现模拟垃圾渗滤液中总氮的去除。     

PVA降解混合菌系生长和产酶的营养条件分析

研究碳源、氮源以及不同金属离子对PVA降解混合菌系生长和产酶的影响。结果表明,混合菌系生长过程中无机氮源优于有机氮源;补充碳源可促进混合菌系的生长,但酶活比不添加时稍有降低。金属离子对酶活影响的正交实验表明Mg2＋浓度影响最大,其次是Fe2＋和K＋浓度,Ca2＋、Mn2＋、Zn2＋和Cu2＋浓度影响较小;最佳浓度分别为Mg2＋0.05 g/L、Fe2＋0.04 g/L、K＋2 g/L和Ca2＋0.05 g/L。     

搁置过夜的青菜汤中的亚硝酸盐氮

通过对搁置过夜的青菜汤中亚硝酸盐氮的测定,来说明搁置过夜的青菜汤不能再吃,以利于人体健康。     

提高炼油废水处理场的氨氮去除率

对炼油废水处理场现有工艺进行流程优化,将MBR装置调整在接触氧化池之后运行.优化流程后氨氮平均去除率可从近于0提高至71.70％;COD平均去除率可从50.00％提高至72.00％.通过对工艺流程的对比,分析了现有工艺氨氮质量浓度难以降低的原因,指出废水中存在的某些污染物对硝化细菌起到抑制作用,减少了反应器中硝化细菌的...     

水质凯氏氮标准样品的研究

提出了水质凯氏氮标准样品的研究方法。在研究过程中，完成了样品的配制、均匀性、稳定性等工作。经过多家实验室协作定值，确定了样品的标准值及不确定度，并提供使用。