单甲脒等农药的土壤薄层层析行为

用土壤薄层层析法研究单甲脒，单甲脒盐酸盐、灭幼脲和涕灭威等农药在不同土壤中的迁移行为，分别获得了这几种化合物的Ｒｆ值，它们分别为０．１４、０．１７，０．０８，０．７６，研究表明，单脒，单甲脒盐酸盐和灭幼脲不会污染地下水，而涕灭威则会对地下水污染构成严重的威胁。     

湘南水田施含SO_4~(2-)和Cl~-肥料对作物生长和养分吸收的效应

1990年4—11月,在湖南祁阳中国农科院红壤实验站布置田间试验,比较含SO_4~(2-)和Cl~ -类肥料对作物生长的效应。结果表明,SO_4~(2-)促进早稻和晚稻营养生长,但水稻收获时的稻谷产量以Cl~-肥料处理区较高。两种阴离子对水稻养分吸收无显著差异,但SO_4~(2-)对早稻体内的磷素转化不利,可能是稻谷产量较低的原因之一。     

好氧颗粒污泥处理高浓度氨氮废水的研究

在不同接种源污泥颗粒化过程中污泥理化性状对比研究的基础上,采用成熟好氧颗粒污泥处理高浓度氨氮废水,对其脱氮行为以及不同C/N条件下好氧颗粒污泥微生物的比耗氧速率、好氧颗粒污泥对氨氮的比降解速率随时间的变化等进行了研究.实验结果表明,在进水氨氮质量浓度较高(480 mg/L)、温度30℃左右的条件下,稳定运行15 d,氨氮的去除率维持在85%左右;进水氨氮的浓度越高,随着微生物对环境的逐渐适应,硝化菌的活性也逐步增加;随着进水氨氮浓度的提高,好氧颗粒污泥对氨氮的比降解速率也逐渐上升.     

The Danish eulerian hemispheric model — a three-dimensional air pollution model used for the arctic

A three-dimensional Eulerian hemispheric air pollution model, the Danish Eulerian Hemispheric Model (DEHM), is in development at the National Environmental Research Institute (NERI). The model has been used to study long-range transport of air pollution in the Northern Hemisphere. The present version of the model includes long-range transport of sulphur dioxide (SO₂) and particulate sulphate (SC₄²⁻. The chemistry in the model is described by a simple linear oxidation of SO₂ to SO₄²⁻, and the wet deposition of SO₂ and SO₄⁻ is estimated based on the amount of precipitation, which is calculated from the contents of liquid cloud water (see Christensen, Air Pollution Modelling and its Applicatioons, Vol. X, pp. 119–127, Vol. XI, pp. 249–256, Plenum press, New York; 1995, Ph.D. thesis, National Environmental Research Institute, Denmark). The model has been used to study the air pollution in the Arctic. Results from yr simulation with an analysis of the results is presented: the model results are verified by comparisons, to measurements not only from the Arctic region but also from Europe and Canada. Some examples of episodes in the Arctic including analysis of the meteorological conditions during the episodes are presented. Finally, the model has been used to estimate the contribution from the different source regions on the northern hemisphere to the Arctic sulphur pollution.     

溶液中阴离子对UV/H2O2降解十二烷基苯磺酸钠的影响及其机理

研究了UV/H2O2工艺对十二烷基苯磺酸钠(LAS)的去除效果、溶液中阴离子对LAS降解的影响及机理.结果表明:UV/H2O2工艺可以有效地去除水中的LAS;在H2O2投加量为8 mg/L,14 W低压汞灯照射下,LAS在蒸馏水和自来水中的反应速率常数分别为0.018 0 、0.012 2 min-1;NO-3、Cl-、SO2-4和HCO-3对LAS光降解有抑制作用,当该4种离子摩尔浓度均分别为5、10、15 mmol/L时,对LAS光降解的抑制程度为HCO-3》NO-3》Cl-》SO2-4,且随着离子摩尔浓度的增大,抑制作用增强;LAS在自来水中的反应速率常数低于在蒸馏水中的反应速率常数是由于水中多种离子影响的结果.     

Development of GC capillary column for isomer-specific separation of toxic isomer of PCDDs and PCDFs in environmental samples

Analysis of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) has been performed using gas chromatography mass spectrometry (GC-MS). Analysis of the most toxic isomers, in particular, 2,3,7,8-substituted PCDD/PCDF in the presence of other isomers requires a special isomer specific capillary column or high performance liquid chromatography (HPLC) fractionation prior to GC-MS analysis. Commercially available long (>50 m) polar columns can separate 2,3,7,8-TCDD from other tetra isomers. However, those columns are not satisfactory for the analyses of total PCDD/PCDF in the environmental samples. Gas chromatography -high resolution mass spectrometry (GC-HRMS) and GC-MS/MS techniques are not helpful in the analysis of 2,3,7,8-TCDD unless it is separated from the other tetra isomers. The analysis of 2,3,7,8-TCDD and total PCDD and PCDF in a single GC-MS run can ease the laborious techniques presently used. In this study we have developed a new stationary phase for the GC capillary column. The capillary column developed using this new stationary phase showed unsurpassed selectivity for the separation of 2,3,7,8-TCDD from other tetra isomers. There are several advantages of the newly developed GC capillary column.     

典型油制气废水处理工艺改造过程分析

典型油制气废水是一类毒性强、CODCr、NH3 N浓度高、难生物降解的有机废水。如何有效处理重油制气废水 ,一直是油制气行业的环保难题。在分析中 ,研究了常规厌氧 好氧活性污泥法工艺处理油制气废水的缺陷 ,介绍了采用人工选育微生物在缺氧 活性污泥法系统中处理油制气废水的新工艺。实践证明 ,新工艺可以取得较好的处理效果 ,废水排放达到国家二级排放标准。     

Ferrioxalate-mediated photodegradation and mineralization of 4-Chlorophenol

INTENTION, GOAL, SCOPE, BACKGROUND: Advanced oxidation processes are powerful methods which are capable of transforming refractory, nonbiodegradable and/or toxic organic compounds into harmless end products such as carbon dioxide and water. However, one commen problem of all advanced oxidation processes is the high demand of electrical energy for ultraviolet lamps, which causes high operational costs. Minimization of the required irradiation time, and therefore the energy consumption, by optimization of other reaction conditions such as catalyst-oxidant type and concentration, pH, temperature, pollutant/oxidant ratio etc., therefore continues to gain importance. OBJECTIVE: The main objective of this study was the minimization of the required irradiation time through optimization of the use of a newly patented catalyst, ferrioxalate, and also to compare the performance of this catalyst with the performance of other AOPs. METHODS: Oxidation of 4-chlorophenol by photo-Fenton process using potassium ferrioxalate as a mediator was studied in a lab scale photoreactor. The influence of parameters such as hydrogen peroxide and ferrioxalate concentrations, initial pH, power-output, oxalate/iron ratio and different iron sources was evaluated. An upflow photoreactor equipped with a 1000 Watt high-pressure mercury vapour lamp and operating in a recirculation mode was used during photodegradation experiments. The extent of the reduction of 4-chlorophenol, Total Organic Carbon and Chemical Oxygen Demand was used to evaluate the photodegradation reaction. RESULTS AND DISCUSSION: The optimum pH range observed was found to be 2.7-3. The efficiency of 4-chlorophenol oxidation increased with increasing concentrations of hydrogen peroxide and ferrioxalate, reaching a plateau after the addition of 10 and 0.072 mM of those reagents, respectively. Using an Oxalate/iron ratio of 12 was 18% less efficient than using a ratio of 3:1. The efficiency increased with increasing radiation power. However, this increase was not linear. The UV/ferrioxalate/H2O2 process, by which complete mineralization of 100 mg l(-1) 4-chlorophenol was achieved in 20 min of total reaction time, was the most efficient process among the alternatives applied. CONCLUSIONS: The use of ferrioxalate as the catalyst was found to be more efficient than the use of Fe(II) and Fe(III) iron species. It was possible to completely mineralize 4-chlorophenol. RECOMMENDATION AND OUTLOOK: The results of this study demonstrate that the ferrioxalate-mediated degradation of 4-chlorophenol requires less irradiation times than other advanced oxidation processes. There are mainly 19 phenol isomers and other toxic and nonbiodegradable organic compounds. We recommend that similar studies should be performed on many such compounds in order to attain a clear understanding of the performance of this catalyst. Because of its light sensitivity, this catalyst should be used immediately after its preparation. The use of low pressure mercury vapour lamps in this process should also be considered, since low power outputs may be enough for the process.     

A/A/O微曝氧化沟处理城市污水的工程设计

以某日处理量为80 000 m3城市污水处理厂为例,介绍了A/A/O微曝氧化沟工艺的设计思路及参数选择,能够满足设计要求,且可信度高,有实用参考价值.     

六氯苯的O3及UV/O3高级氧化降解试验研究

采用O₃、UV/O₃高级氧化法对水中六氯苯（HCB）的降解效果及机理进行了研究，并对结果进行了比较，结果表明，UV本身对HCB的去除率贡献不大，HCB可被O₃、UV/O₃快速降解，即UV＜O₃＜UV/O₃；O₃、UV/O₃作用时，提高体系的初始pH值不利于HCB的降解，在pH＝3，HCB=0.2 mg/L，反应40 min时，HCB的去除可达50%左右，酸性条件下有利于降解反应的进行；无论是O₃单独作用还是UV/O₃联合作用，HCB的降解基本上满足准一级反应动力学规律，如果体系的pH值基本保持恒定，这种规律就更为明显。根据离子色谱(IC)、GC对六氯苯降解中间产物进行了测定，探讨了O₃、UV/O₃降解六氯苯的途径和机理。