混合固定化酵母菌对苯并(α)芘污染土壤的修复

将3株酵母菌进行两两混合及3株混合后,采用物理法和化学法对其进行固定化包埋,用于多环芳烃苯并(α)芘污染土壤的修复.实验结果表明,酵母菌经过混合固定化包埋后,通过降解率及降解动力学分析可以得出,其降解效果明显好于游离菌,这是由于酵母菌经过包埋后,载体内部菌密度有效增加的结果.空白对照虽未接菌种,但污染物也有少量的下降,这是由于载体中含有一定量的活性炭,对污染物具有吸附作用,这种吸附作用随着时间的延长而趋于平缓.由实验结果还可以看出,物理法更适合对酵母菌进行混合固定化包埋,但并非混合酵母菌菌株越多,降解效果越好.菌株IM219-220-phy对苯并(α)芘的降解率最高达40.65%,半衰期为5.66 d.     

氨的超临界水氧化研究进展

在超临界水氧化过程中,氨作为含氮有机物氧化的中间产物,其氧化是有机物在超临界水中氧化降解速率的控制步骤.综述了氧化剂、温度、过氧量、停留时间和催化剂等因素对氨的超临界水氧化降解效果的影响,并总结了目前常用的两种反应动力学模型.与双氧水或氧相比,NO-3氧化荆具有更强的氧化能力;通过提高温度、过氧量和停留时间都可以促进氨的超临界水氧化降解.在氨的超临界水氧化中,当无催化剂作用时,氨的降解率很低;加入MnO2/CeO2等催化剂,可以显著提高氨的降解率.为加快超临界水氧化法处理含氮有机废水的应用进程,未来应侧重氨氧化机制的研究和催化剂的开发.     

清洁生产方案实施成效分析

清洁生产方案的质量及可实施性直接关系到企业清洁生产审核的成效。汇总江苏油田推行清洁生产审核单位实施的清洁生产方案380项,从方案的组成、分类、投资、经济效益等方面进行统计分析,阐明了多种无、低费方案,不仅资金投入的回报率高,而且投资风险少,有明显的效益。通过"节能、降耗、减污、增效"这一主导思想产生的各类清洁生产方案的实施,达到了较可观的经济、环境和社会效益。     

Impact of climate fluctuations on deposition of DDT and hexachlorocyclohexane in mountain glaciers: Evidence from ice core records

How do climate fluctuations affect DDT and hexachlorocyclohexane (HCH) distribution in the global scale? In this study, the interactions between climate variations and depositions of DDT and HCH in ice cores from Mt. Everest (the Tibetan Plateau), Mt. Muztagata (the eastern Pamirs) and the Rocky Mountains were investigated. All data regarding DDT/HCH deposition were obtained from the published results. Concentrations of DDT and HCH in an ice core from Mt. Everest were associated with the El Nino-Southern Oscillation. Concentrations of DDT in an ice core from Mt. Muztagata were significantly correlated with the Siberia High pattern. Concentrations of HCH in an ice core from Snow Dome of the Rocky Mountains responded to the North Atlantic Oscillation. These associations suggested that there are some linkages between climate variations and the global distribution of persistent organic pollutants.     

An efficient approach of aerosol thermodynamic equilibrium predictions by the HDMR method

In this paper, we develop a new and efficient approach for high dimensional atmospheric aerosol thermodynamic equilibrium predictions. The multi-phase and multi-component aerosol thermodynamic input–output systems are solved by the high dimensional model representation (HDMR) method combining with the moving multiple cut points. The developed approach improves the accuracy of numerical simulations for the general high dimensional input–output systems compared with the standard cut-HDMR method. It can simulate efficiently the atmospheric aerosol thermodynamic equilibrium problems in a large range of aerosol concentrations from 10^?10 to 10^?6 mol m^?3. Numerical experiments show that the approach has great computational efficiency and the CPU-time of the approach is much less than that of ISORROPIA. The method does excellent performance in predicting high dimensional aerosol thermodynamic components as well as particulate matters (PMs).     

Ensemble and bias-correction techniques for air quality model forecasts of surface O3 and PM2.5 during the TEXAQS-II experiment of 2006

Several air quality forecasting ensembles were created from seven models, running in real-time during the 2006 Texas Air Quality (TEXAQS-II) experiment. These multi-model ensembles incorporated a diverse set of meteorological models, chemical mechanisms, and emission inventories. Evaluation of individual model and ensemble forecasts of surface ozone and particulate matter (PM) was performed using data from 119 EPA AIRNow ozone sites and 38 PM sites during a 50-day period in August and September of 2006. From the original set of models, two new bias-corrected model data sets were built, either by applying a simple running mean average to the past 7 days of data or by a Kalman-Filter approach. From the original and two bias-corrected data sets, three ensembles were created by a simple averaging of the seven models. For further improvements three additional weighted model ensembles were created, where individual model weights were calculated using the singular value decomposition method. All six of the ensembles are compared to the individual models and to each other in terms of root mean square error, correlation, and contingency and probabilistic statistics. In most cases, each of the ensembles show improved skill compared to the best of the individual models. The over all best ensemble technique was found to be the combination of Kalman-Filtering and weighted averaging. PM_2.5 aerosol ensembles demonstrated significant improvement gains, mostly because the original model's skill was very low.     

模式生物大型溞在水生生态毒理实验教学中的应用

大型溞(Daphnia magna)因其个体小、繁殖快、易于培养及对污染物敏感等特点,而成为水生毒理学研究中广泛应用的模式物种.本文构建了一套以大型溞为受试动物的水生生态毒理学实验内容和方案,可用于本科生基础性、综合性实验教学.本方案以形态学观察、生理学和毒理学测试为主,也可扩展为包括分子毒理学在内的其他毒性终点的创新...     

环境污染损害评估方法初探——以某废油污染场地为例

以厦门市一废油污染场地为例,通过现场调查和监测主要污染物,从财产损失、应急处置费用、调查评估费用以及污染修复费用等方面对该污染场地所造成的环境污染损害进行了评估。该场地主要污染物为倾倒的废油和油底废物,部分污染土壤的石油类指标超标。经测算,污染面积为2 440 m2,造成的环境污染损失数额为162.25万元。     

Enhanced mixing state of black carbon with nitrate in single particles during haze periods in Zhengzhou, China

Black carbon（BC） plays an important role in air quality and climate change, which is closely associated with its mixing state and chemical compositions. In this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer（SPAMS） in March 2018 in Zhengzhou, China. The BC-containing particles accounted for 61.4% of total detected ambient single particles and were classified into f...     

正交实验选择嗜碱细菌降解木质素的最优综合培养条件

在复合碳源的碱性液体培养条件下(pH≈10.5),用正交实验法对影响嗜碱木质素降解细菌6号菌株降解木质素的7种单因素培养条件进行了优化.结果表明,第1碳源用量等单因素在不同程度上对6号菌株产生的木质素降解酶Laccase和MnP以及木质素降解率都有一定促进作用.正交实验表明,其中第1碳源用量和T-80用量是显著性的影响因素,7种单因素的最佳综合水平为:37℃静置培养10d、第1碳源(蔗糖)1g/L、氮源NH₄NO₃1.2g/L、培养基70ml/250ml锥形瓶、初始pH值10.6和第2碳源接种后第4d加入、添加0.3%的表面活性剂T-80.