DBD降解CF2ClBr过程中自由基与电子能量

利用介质阻挡放电方法对环境污染物ＣＦ₂ＣｌＢｒ进行了等离子体降解的研究．在前人对该体系的降解产物分析及活性粒子推测的基础上,采用动态反应装置得到了等离子体的发射光谱,进一步确证了等离子体系中出现的ＣＦ₂、ＣＦＣｌ、Ｆ、Ｃｌ、Ｂｒ等主要自由基,并从中推出了等离子态气体可能发生的自由基反应．同时通过发射光谱的分析,近似得到该体系的平均电子能量约为２．４２ｅＶ     

单级SBR生物膜中全程自养脱氮的研究

研究了具有全程自养脱氮作用的生物膜中无机碳源浓度、pH值、溶解氧(DO)对全程自养脱氮的影响.结果表明,当NaHCO3浓度从1.75g/L上升到2.50g/L时,反应体系中的pH值从7.6～8.0上升到8.8左右,氨氮转化率和总无机氮去除率分别急剧下降到53%和48.8%.在进水氨氮负荷为60g/(m³·d)时,最佳DO应控制在0.5～0.7mg/L,此时氨氮转化率达到90%以上.     

Persistent free radicals in humin under redox conditions and their impact in transforming polycyclic aromatic hydrocarbons

• Regulation of redox conditions promotes the generation of free radicals on HM. • HM-PFRs can be fractionated into active and inactive types depending on stability. • The newly produced PFRs readily release electrons to oxygen and generate ROS. • PFR-induced ROS mediate the transformation of organic contaminants adsorbed on HM. The role of humic substance-associated persistent free radicals (PFRs) in the fate of organic contaminants under various redox conditions remains unknown. This study examined the characterization of original metal-free peat humin (HM), and HM treated with varying concentrations of H₂O₂ and L-ascorbic acid (VC) (assigned as H₂O₂-HM and VC-HM). The concentration of PFRs in HM increased with the addition of VC/H₂O₂ at concentrations less than 0.08 M. The evolution of PFRs in HM under different environmental conditions (e.g., oxic/anoxic and humidity) was investigated. Two types of PFRs were detected in HM: a relatively stable radical existed in the original sample, and the other type, which was generated by redox treatments, was relatively unstable. The spin densities of VC/H₂O₂-HM readily returned to the original value under relatively high humidity and oxic conditions. During this process, the HM-associated “unstable” free radicals released an electron to O₂, inducing the formation of reactive oxygen species (ROS, i.e., ^•OH and ^•O₂⁻). The generated ROS promoted the degradation of polycyclic aromatic hydrocarbons based on the radical quenching measurements. The transformation rates followed the order naphthalene>phenanthrene>anthracene>benzo[a]pyrene. Our results provide valuable insight into the HM-induced transformation of organic contaminants under natural conditions.     

两种有机酸存在下铜对中华圆田螺肝脏的氧化应激效应

为探讨不同水平EDTA和柠檬酸(CA)作用下沉积物中铜对底栖无脊椎动物生态毒理学效应,以中华圆田螺为受试生物,研究了肝脏中活性氧(ROS)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)以及过氧化氢酶(CAT)活性的变化规律。研究结果表明:有机酸存在下,铜污染底泥可诱导中华圆田螺肝脏产生ROS。电子顺磁共振(EPR)技术得出的3组双重峰分裂谱线为典型的α-苯基-N-叔丁基甲亚胺-N-氧化物(PBN)捕获羟自由基(·OH)形成PBN/·OH的EPR波谱。有机酸存在下,低剂量铜(≤100 mg·kg-1)对MDA产量影响不显著。较高剂量铜暴露下,EDTA的存在抑制MDA产生,CA的添加则均使MDA含量增加。EDTA存在下铜可显著抑制中华圆田螺肝脏中SOD和CAT活性。相对而言,CA的加入可减缓高剂量铜暴露下中华圆田螺肝脏SOD与CAT酶活性的剧烈变化。     

Preparation and application of a phosphorous free and non-nitrogen scale inhibitor in industrial cooling water systems

A novel environmentally friendly type of calcium carbonate, zinc (II) and iron (III) scale inhibitor Acrylic acid- allylpolyethoxy carboxylate copolymer (AA-APEL) was synthesized. The anti-scale property of the AA-APEL toward CaCO₃, zinc (II) and iron (III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate, zinc (II) and iron (III) inhibition increase with increasing the dosage of AA-APEL. The effect on formation of CaCO₃ was investigated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and fourier transform infrared spectrometer, respectively. The results showed that the AA-APEL copolymer not only influenced calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO₃ in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the AA-APEL copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems.     

不同污染区巨菌草生物炭内源污染物分布及其生物毒性

由于生物质原料来源广泛,缺乏生物炭内源污染物及其用量限制标准,极有可能将含有高内源污染物的生物炭用于环境修复,产生潜在的环境风险.采用清洁区、中度和重度污染区的巨菌草为原料制备生物炭,考察其内源铜（Cu）和镉（Cd）全量及其酸溶态含量和持久性自由基（PFRs）分布,并研究生物炭浸出液对小麦根伸长抑制率和抗氧化酶活性的影响.结果表明,重度污染区九牛生物炭Cu和中度污染区水泉生物炭中Cd含量分别是清洁区红壤生物炭Cu和Cd的3.73倍和4.43倍,九牛生物炭中酸溶态Cu含量分别是水泉和红壤生物炭的3.32倍和2.84倍,水泉和九牛生物炭中酸溶态Cd含量分别是红壤生物炭的7.95倍和5.11倍.3种生物炭中均含有相邻氧原子以碳为中心的PFRs,表现为：红壤>九牛>水泉.3种生物炭浸出液对小麦根伸长均表现为抑制作用,但均不同程度地提高了小麦幼苗超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,其中九牛生物炭浸出液对小麦根伸长抑制率最高,达到27.7%.本研究表明,生物炭中内源重金属及PFRs等污染物的共同作用对小麦幼苗产生了显著的生物毒性,后期的研究需关注生物炭内源污染物的潜在环境风险,避免产生二次污染等环境问题.     

Free ‐ living animals as indicators of environmental pollution by chlorinated hydrocarbons

As some species of game and free‐living animals promptly respond to ecosystem damage by a reaction that is easy to interpret, they are important ecological indicators in assessing the total contamination of the environment. Consumers of the highest order like predators, predatory and fish‐eating birds are among the most important bioindicators of environmental contamination by chlorinated hydrocarbons and PCB.

Data on chlorinated hydrocarbons and PCB levels were collected throughout 1988–1992 and obtained from 16 species of free‐living animals from 9 protected areas of Slovakia. Muscle tissue, liver, kidney and egg samples were examined for HCB, HCH isomers, DDT and its analogues, and PCB.

Levels of organic chlorinated contaminants reveal a decreasing tendency and thus cease to be a toxicologically important risk factor in game, with the exception of predatory birds, as significant values have been recorded in their eggs and reproductive organs.     

十字花科植物中的芥子碱对果蝇的抗衰老作用

芥子碱对Ｏ－２和ＯＨ的清除效率达５０％时的质量浓度（ρ）分别为５ｍｇＬ－１和３３０ｍｇＬ－１,４０ｍｇＬ－１的芥子碱对Ｏ－２的清除效率即可达８９．７％,证明芥子碱是一Ｏ－２与ＯＨ的清除剂．分别以ρ为１０ｍｇＬ－１和５０ｍｇＬ－１芥子碱的培养基饲喂果蝇,对果蝇的最高寿命、平均寿命及半数寿命均有一定的延长作用,其中１０ｍｇＬ－１的芥子碱组可明显延长雄性果蝇的最高寿命（１１．９０％）、平均寿命（１１．２４％）及半数寿命（１７．２１％）,两种浓度的芥子碱溶液对果蝇的平均寿命的延长作用的差异显著．芥子碱对果蝇的延寿作用有一定的性别差异,对雄蝇的效果好于雌蝇     

不同调控策略对CANON工艺快速适应氨氮浓度提升的影响

针对进水氨氮浓度变化会影响CANON颗粒污泥功能微生物间的协同导致系统不稳定的问题,通过接种常温下贮存2个月的自养颗粒污泥,并采用3种调控策略（维持HRT不变,快速提升氨氮浓度(R1);维持HRT不变,逐级提升氨氮浓度(R2);逐级提升进水氨氮浓度同时调整HRT,以125 mg·L⁻¹为进水氨氮增幅(R3)）,分别考察各种调控策略对系统适应275 mg·L⁻¹和400 mg·L^-1氨氮浓度的效能影响,探讨调控策略与污泥性能的关系及游离氨(FA)、溶解氧(DO)的影响。结果表明,污泥性能提升期,负荷变化最为平稳的策略R3率先适应进水氨氮浓度的提升,仅44 d内总氮去除负荷可达到3.5 kg·(m³·d)⁻¹;污泥性能成熟期,快速提升负荷的策略R1可缩短适应时间至25 d,总氮去除率稳定在80%以上,去除负荷达到5.3 kg·(m³·d)⁻¹。FA会影响功能微生物活性,策略R1在污泥性能提升期,FA浓度高达16.6~26.7 mg·L⁻¹,一定程度上抑制了好氧氨氧化菌(AOB)和厌氧氨氧化菌(AMX)的活性,导致系统适应期延长。在污泥适应高氨氮负荷过程中,比氨氧化速率(S_AOR)和比总氮去除速率(S_NRR)逐渐提高,污泥浓度和颗粒粒径逐渐增大。f值(Δ$ {\rm{NO}}_3^{-}$-N/ΔTN)可作为DO调节的重要依据,DO与氨氮去除负荷呈良好的正相关性。