不同水溶肥配方对部分白菜品质及土壤性质的影响

本试验以白菜为试验材料,清水为对照探索了5种水溶肥配方对白菜品质及土壤性质的影响。结果表明,与对照相比,配方4处理的白菜Vc含量最多,配方1次之,分别较对照增加了210%、193%,硝酸盐含量除配方3和配方5外,其他处理均小于432 mg/kg,在安全范围内;5种水溶肥均能在一定程度上改善土壤p H值和电导率,配方1土壤碱解氮和有效磷含量最高,分别为327.8 mg/kg和118.23 mg/kg,参照菜园土壤有效养分丰缺状况的分级标准,土壤氮、磷含量过高,可能会对周边的水环境造成污染。     

Photodegradation of 2,4-D induced by NO2- in aqueous solutions：The role of NO2

To elucidate the effect of nitrite ion （NO2^-） on the photodegradation of organic pollutants, a 300 W mercury lamp and Pyrex tubes restricting the transmission of wavelengths below 290nm were used to simulate sunlight, and the photodegradation processes of 2,4-dichlorophenoxyacetic acid （2,4-D） with different concentrations of NO2^- in freshwater and seawater were studied. The effect of reactive oxygen species （ROS） on the photolysis of 2,4-D was also demonstrated using electron paramagnetic resonance （EPR）. The results indicated that the 2,4-D photolysis reaction followed the first-order kinetics in freshwater and seawater under different concentrations of NO2^-. Meanwhile, the photochemical reaction rate of 2,4-D increased with increasing concentration of NO2^-. When the concentration of NO2^- was lower than 23 mg/L, the photodegradation rate of 2,4-D in seawater was higher than that in freshwater. However, when the concentration of NO2^- was reached 230 mg/L, 2,4-D degradation slowed down in seawater. It was important to note that EPR spectra showed NO2 radical was generated in the NO5 solution under simulated sunlight irradiation, indicating that 2,4-D photodegradation could be induced by NO2. These results show the key role of NO2^- in photochemistry and are helpful for better understanding of the phototransformation of environmental contaminants in natural aquatic systems.     

希瓦氏菌介导纳米材料生物合成及其环境应用

纳米材料在环境领域的应用已经日益广泛,但是目前普遍使用的物理、化学的合成方法存在着费用高、环境危害大等问题,因此,通过生物方法合成纳米材料的新型绿色合成技术已经成为纳米材料研究领域的热点之一。金属还原菌希瓦氏菌(Shewanella)所具有的电子释放能力、硫代谢能力以及对毒性的高耐受力等特性,使其在纳米材料领域中具有重要的应用潜力,已成为该领域的研究热点,并受到广泛重视。文章对当前希瓦氏菌合成纳米材料最新进展及其在环境修复中的应用作简要的概述。     

A comparison on the phytoremediation ability of triazophos by different macrophytes

The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos(O,O-diethyl-O-(1-phenyl-1,2,4-triazol-3-base) sulfur phosphate, TAP), which is an organophosphorus pesticide widespread applied for agriculture in China and moderately toxic to higher animal and fish. The tolerance, uptake, transformation and removal of TAP by twelve species of macrophytes were examined in a hydroponic system and a comprehensive score(CS) of five parameters(relative growth rate(RGR), biomass, root/shoot ratio, removal capacity(RC), and bio-concentration factor(BCF)) by factor analysis was employed to screen the potential macrophyte species for TAP phytoremediation. The results showed that Thalia dealbata, Cyperus alternifolius, Canna indica and Acorus calamus had higher RGR values, indicating these four species having stronger growth capacity under TAP stress. The higher RC loading in Iris pseudacorus and Cyperus rotundus were 42.11 and 24.63 μg/(g fw·day), respectively. The highest values of BCF occurred in A. calamus(1.17), and TF occurred in Eichhornia crassipes(2.14). Biomass and root/shoot ratio of plant showed significant positive correlation with first-order kinetic constant of TAP removal in the hydroponic system, indicating that plant biomass and root system play important roles in remediation of TAP. Five plant species including C. alternifolius, A. calamus, T. dealbata, C. indica and Typha orientalis, which owned higher CS, would be potential species for TAP phytoremediation of contaminated water bodies.     

Removal of perchlorate from aqueous solution by cross-linked Fe(Ⅲ)-chitosan complex

Cross-linked Fe（III）-chitosan composite （Fe-CB） was used as the adsorbent for removing perchlorate from the aqueous solution. The adsorption experiments were carried out by varying contact time, initial concentrations, temperatures, pH, and the presence of co-existing anions. The morphology of the adsorbent was discussed using FT-IR and SEM with X-EDS analysis. The pH ranging from 3.0-10.2 exhibited very little effect on the adsorption capability. The perchlorate uptake onto Fe-CB obeyed Langmuir isotherm model. The adsorption process was rapid and the kinetics data obeyed the pseudo second-order model well. The eluent of 2.5% （W/V） NaC1 could regenerate the exhausted adsorbent efficiently. The adsorption mechanism was also discussed.     

Distribution and spectral characteristics of chromophoric dissolved organic matter in a coastal bay in northern China

The absorption spectra of chromophoric dissolved organic matter(CDOM),along with general physical,chemical and biological variables,were determined in the Bohai Bay,China,in the springs of 2011 and 2012. The absorption coefficient of CDOM at 350 nm(a350) in surface water ranged from 1.00 to 1.83 m-1(mean: 1.35 m-1) in May 2011 and from 0.78 to 1.92 m-1(mean:1.19 m-1) in April 2012. Little surface-bottom difference was observed due to strong vertical mixing. The a350 was weakly anti-correlated to salinity but positively correlated to chlorophyll a(Chl-a) concentration. A shoulder over 260–290 nm,suggestive of biogenic molecules,superimposed the overall pattern of exponentially decreasing CDOM absorption with wavelength. The wavelength distribution of the absorption spectral slope manifested a pronounced peak at ca. 300 nm characteristic of algal-derived CDOM. All a250/a365 ratios exceeded 6,corresponding to CDOM molecular weights(Mw) of less than 1 kDa. Spectroscopically,CDOM in the Bohai Bay differed substantively from that in the Haihe River,the bay's dominant source of land runoff; photobleaching of the riverine CDOM enlarged the difference.Results point to marine biological production being the principal source of CDOM in the Bohai Bay during the sampling seasons. Relatively low runoff,fast dilution,and selective photodegradation are postulated to be among the overarching elements responsible for the lack of terrigenous CDOM signature in the bay water.     

延迟焦化焦粉夹带的原因及应对措施

详述了焦炭塔发生焦粉夹带的危害、原因及预防措施,描述了分馏系统焦粉的处理措施。     

南京市钢铁行业烧结机二噁英排放调查研究

以南京市三家钢铁企业烧结机为例,对排放废气中的二噁英进行监测,分析各组分的含量,进一步研究排放废气中二噁英的种类组成及含量分布特征,依据现行的标准二噁英排放浓度达标,但是南京的排放水平远高于国外排放水平。分析成因,结果表明烧结过程中的二噁英主要是在料层中生成的,主要以多氯二苯并呋喃存在,为减少烧结过程二噁英的生成,可以从改变工艺、控制原材料和增加处理设施等方面进行控制,尽可能减少气态氯化氢的形成,防止再合成物和其它前驱化合物的产生。     

东京湾水环境治理对深圳的启示

分析东京湾社会经济、水环境状况和治理历程,其水环境变化经历了先污染后治理的历程.近几十年东京湾环境管理内容纳入行政管理范围,环境对策、措施随着主要环境问题的变化也经历了诸多变化,促进东京湾水环境逐步改善和恢复.结合东京湾环境管理历程和深圳湾区水环境主要问题,分析深圳湾区水环境治理存在的差距及经验借鉴,可从制度建设、体制机制、投融资渠道和公众参与等方面进行完善,为深圳湾区水环境治理和改善提供参考.     

饮用水在线监测及预警研究

饮用水是人类生存的基本需求之一,其安全是影响人民生命健康和社会经济可持续发展的重要因素.在取水、制水、输配水和贮水各个环节对饮用水水质的卫生指标进行实时动态监测及预警,可有效预防因为自然灾害、人为事故、犯罪引起的用水安全事故的发生.文章概述了水质在线监测系统在从水源到用户的全流程的应用,并对饮用水在线监测与预警各种关键技术的应用予以简单的介绍.