应用浮动生物滤清器除藻研究

根据浮游植物（藻类）与浮游动物（轮虫类）之间的生态食物链关系，Ｅｌｔｏｎａｉａｎ金字塔风言风语服动生物滤清器”（ＦＢＥ）、在该设备化虫（类）创造了一个生长、系列和栖息的地方，并让它澡类，应用该设备在不同地点进行了实际观测试验，其除藻效率达到８４％～９３％。     

Effect of alginate on the aggregation kinetics of copper oxide nanoparticles (CuO NPs): bridging interaction and hetero-aggregation induced by Ca<Superscript>2+</Superscript>

The stability of CuO nanoparticles (NPs) is expected to play a key role in the environmental risk assessment of nanotoxicity in aquatic systems. In this study, the effect of alginate (model polysaccharides) on the stability of CuO NPs in various environmentally relevant ionic strength conditions was investigated by using time-resolved dynamic light scattering. Significant aggregation of CuO NPs was observed in the presence of both monovalent and divalent cations. The critical coagulation concentrations (CCC) were 54.5 and 2.9 mM for NaNO₃ and Ca(NO₃)₂, respectively. The presence of alginate slowed nano-CuO aggregation rates over the entire NaNO₃ concentration range due to the combined electrostatic and steric effect. High concentrations of Ca²⁺ (>6 mM) resulted in stronger adsorption of alginate onto CuO NPs; however, enhanced aggregation of CuO NPs occurred simultaneously under the same conditions. Spectroscopic analysis revealed that the bridging interaction of alginate with Ca²⁺ might be an important mechanism for the enhanced aggregation. Furthermore, significant coagulation of the alginate molecules was observed in solutions of high Ca²⁺ concentrations, indicating a hetero-aggregation mechanism between the alginate-covered CuO NPs and the unabsorbed alginate. These results suggested a different aggregation mechanism of NPs might co-exist in aqueous systems enriched with natural organic matter, which should be taken into consideration in future studies.

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Graphical abstract Hetero-aggregation mechanism of CuO nanoparticles and alginate under high concentration of Ca²⁺

     

Salicylic acid involved in the regulation of nutrient elements uptake and oxidative stress in Vallisneria natans (Lour.) Hara under Pb stress

In this study, the alterations in nutrient elements content, reactive oxygen species level and antioxidant response were studied in leaves of Vallisneria natans (Lour.) Hara exposed to salicylic acid (SA, 10 or 100 μM), or Pb (50 μM) or their combinations for 4 d. No significant alterations in Mn and Ca content were observed but content of Cu, Zn, Fe and P decreased in plants exposed to SA alone. SA application inhibited the uptake of Pb and partially reversed Pb-induced the alterations in Mn, Ca and Fe content in leaves of V. natans exposed to 50 μM Pb. The decreased chlorophyll (a + b) and increased malondialdehyde and O²⁻ and H₂O₂ content were detected in plants exposed to 100 μM SA, 50 μM Pb, 10 μM SA + 50 μM Pb or 100 μM SA + 50 μM Pb. Application SA partially inhibited Pb-induced the increase of malondialdehyde, O²⁻ and H₂O₂ content. 100 μM SA decreased the activity of NADH oxidase and the content of non-protein thiols, carotenoids and ascorbic acid and increased the content of dehydroascorbate in plants treated with or without Pb. SA alone decreased the ascorbate peroxidase activity and increased the catalase and peroxidase activity, while SA application increased catalase activity but had no significant effect on ascorbate peroxidase and peroxidase activity in V. natans exposed to Pb. The results indicate that SA involves in the regulation of Pb uptake, nutrient balance and oxidative stress.     

应用概率物种敏感度分布法研究太湖重金属水生生物水质基准

目前广泛使用的水质基准推导方法—物种敏感度分布法存在曲线拟合模型不确定、曲线拟合效果不佳、种内差异欠考虑、基准值不准确等诸多问题,概率物种敏感度分布法可有效解决上述问题。应用概率物种敏感度分布法构建了太湖水体中5种重金属Ag、Pb、Cd、Hg和Zn的概率物种敏感度分布曲线,在此基础上得到了保护水生生物的急性水质基准分别为1.079μg·L~(-1)、637.973μg·L~(-1)、19.465μg·L~(-1)、8.729μg·L~(-1)和105.506μg·L~(-1),慢性水质基准分别为0.108μg·L~(-1)、63.797μg·L~(-1)、1.947μg·L~(-1)、2.340μg·L~(-1)和52.753μg·L~(-1);不同类群间生物对重金属的敏感度存在差异,不同重金属对同一类群生物的毒性也存在差异;通过与国内外已有的重金属水质基准值比较,发现水质基准具有明显的区域性,目前基于国外水质基准或我国整体水域特点来制定的太湖水质标准,往往造成对太湖水生生物欠保护或过保护的状况。     

盐度和pH对崇明东滩沉积物中NH+4释放的影响研究

采集长江口下游的崇明东滩沉积物样，通过实验模拟研究盐度和pH对沉积物中NH4^ 释放的影响。结果表明，潮滩沉积物中NH4^ 的释放受盐度和pH的共同控制。NH4^ 随着盐度的变化呈明显的“M”型双峰曲线，释放量最小出现在盐度为0‰。释放峰值出现在盐度为5‰、20‰。NH4^ 随着pH的释放规律因盐度环境和沉积物类型的不同而显著不同。NH4^ 的释放量与沉积物类型有关，沙性物质含量高的低潮滩沉积物中NH4^ 的释放量明显低于沙性物质少的中潮滩。     

城市化进程中长江经济带长江干流水化学演变特征及影响因素

快速的城市化过程对城市周边水体水化学组成特征产生了诸多影响.为揭示长江经济带城市群发展对长江水化学特征的影响,于2020年10—11月沿长江干流,采集了四川宜宾至上海145个河流水样,并对比了历史水化学数据.同时,运用数理统计、离子比值法等方法探究了长江经济带平水期水化学特征.结果表明：长江河水的主要水化学类型为HCO₃·SO₄-Ca型,主要受流域内分布的碳酸盐岩等岩石风化作用控制;河水中阳离子以Ca²⁺为主,阴离子以HCO₃^-为主,Cl^-浓度沿径流方向升高,Ca²⁺和Mg²⁺浓度沿径流方向先升高后降低,SO₄^2-浓度沿径流方向逐渐上升,HCO₃^-浓度沿径流方向降低;城市化进程中,由于人类活动和工业活动加剧,除HCO₃^-外,Ca²⁺、Mg²⁺     

基于集成分析的环渤海地区河流硝酸盐污染解析

近几十年全球人口剧增,粮食生产及燃料消耗都增加了地表水中的氮负荷,而地表水是连接大陆氮库和海洋氮库的重要通道,地表水中的硝酸盐的增加将直接导致河口及沿海硝酸盐浓度的增加,因此研究近海河流的氮污染情况、确定影响因素将会为近海营养物质的控制及水环境管理提供重要信息.以环渤海地区的入海河流为主要研究对象,通过收集公开数据建立环渤海地表水硝酸盐数据库集成分析,研究入海河流的水体硝酸盐的时空污染特征及其与各影响因素之间的关系.结果表明,环渤海区域地表水中硝酸盐浓度的变化范围在0.0~76.4 mg·L~(-1),与溶解氧、总氮、总磷和电导率有显著的相关关系(p=0.01).在空间变化方面,黄河下游及浑太河上游流域硝酸盐污染较为严重.在除去来自城市污废水排放的人工河道带来的硝酸盐浓度异常值后,丰水期(平均浓度4.55 mg·L~(-1))与平水期(平均浓度5.39 mg·L~(-1))的硝酸盐浓度的平均水平较枯水期(平均浓度4.03 mg·L~(-1))更高,且浓度的变化范围(丰水期:0.00~34.90 mg·L~(-1);平水期:0.00~31.00 mg·L~(-1))亦大于枯水期(0.00~25.64 mg·L~(-1)).影响因素方面,硝酸盐浓度与降水量有显著相关性(r=0.122,p=0.01).土地利用相关性研究表明耕地与建设用地是硝酸盐的主要来源,林地和草地对硝酸盐污染有改善作用.硝酸盐的入海通量约为33.4×10~4t·a-1.     

抗高温环保钻井液体系研究

文章选择清洁环保的钻井液处理剂进行抗高温钻井液体系实验研究与评价,对包被增粘剂、降失水剂等进行优选,对抗高温环保钻井液配方进行评价,研究出无毒、无害,抗温能力强、流变性好,失水较低的钻井液体系,现场应用满足高温深井的钻井生产要求。     

典型挥发性有机化合物在气体采样罐中的存储稳定性

选取了6种有代表性的挥发性有机化合物（VOCs）,异丙醇、二氯甲烷、乙酸乙烯酯、正己烷、苯和四氯化碳,实测了这些VOCs在气体采样罐（SUMMA罐）中的存储稳定性。结果表明：苯、正己烷和二氯甲烷在采样罐中均较稳定,其含量在84 d的存储期内基本无变化;乙酸乙烯酯在6个VOCs中最不稳定,在普通和惰性采样罐中含量均明显下降;异丙醇和四氯化碳的稳定性与采样罐的类型有关,在普通采样罐内含量下降明显,而在惰性采样罐内则相对稳定。实际监测工作中,为提高VOCs分析的准确性,如目标分析物有含氧类（醇,酮,酯等）或含卤素类VOCs,则采样后需尽快分析,同时尽量选择惰性采样罐为采样容器。