Efficient abatement of an iodinated X-ray contrast media iohexol by Co(II) or Cu(II) activated sulfite autoxidation process

Efficient abatement of an iodinated X-ray contrast media iohexol by an emerging sulfite autoxidation advanced oxidation process is demonstrated, which is based on transition metal ion–catalyzed autoxidation of sulfite to form active oxidizing species. The efficacy of the combination of sulfite and transition metal ions (Ag(I), Mn(II), Co(II), Fe(II), Cu(II), Fe(III), or Ce(III)) was tested for iohexol abatement. Co(II) and Cu(II) are proven to show more pronounced catalytic activity than other metals at pH 8.0. According to the quenching studies, sulfate radical (SO₄^??) is identified to be the primary species for oxidation of iohexol. Increasing dosages of metal ion or sulfite and higher pH values are favorable for iohexol abatement. Inhibition of iohexol abatement is observed in the absence of dissolved oxygen, which is vital for the production of SO₅^?? and subsequent formation of SO₄^??. Overall, activation of sulfite to produce reactive radicals with extremely low Co(II) or Cu(II) concentrations (in the range of μg L^?1) in circumneutral conditions is confirmed, which offers a potential SO₄^??-based advanced oxidation process in treatment of aquatic organic contaminants.

     

生物炭和碳纳米管固定化漆酶去除水体雌二醇

漆酶是一类具有高效的催化氧化能力的含铜多酚的氧化酶,而固定化漆酶技术在有机废水处理领域受到了越来越多的关注。通过比较吸附法和包埋法利用木炭(WB)、竹炭(BB)和碳纳米管(CNT)固定游离漆酶去除水体雌二醇(E2)。在25 °C 、pH=5条件下,固定化漆酶经120 h 贮存仍保留80%的活性。经过5次循环研究,固载的漆酶仍保留了27%~58%的剩余活性。结合扫描电子显微镜和傅里叶变换红外光谱,证实了漆酶成功地负载在碳基材料上。仅在 8 h内,50 mg·L⁻¹ E2通过吸附法制备的WB、BB、CNT固定化漆酶去除了42.92%、47.66%、43.92%,而包埋法制备的WB、BB、CNT固定化漆酶分别去除84.08%、87.20%、87.86%。结果表明,包埋法固定化漆酶对E2的去除效率更优,这是由于包埋固载在生物炭和CNT的漆酶更为稳定。此外,K⁺和Mn²⁺离子可能通过干扰漆酶的电子传递过程影响漆酶的活性,从而抑制E2的去除。本研究旨在为固定化漆酶在有机废水处理的实际应用提供指导。     

应用TOXI模型进行重金属在河流中迁移转化规律的研究

ＴＯＸＩ模型是美国环保局的ＷＡＳＰ（水质分析模拟程序）中的一部分。由于该模型考虑了污染物质在河流中溶解态，颗粒态和底泥态的分布关系，对于模拟重金属在河流中的浓度变化效果较好。为保证计算结果的可靠性，首先应对重金属浓度的衰减变化特性进行研究，本文重点讨论的是重金属在河流中迁移转化的过程，并如何将这一过程用数学公式来进行模拟。     

宁波-舟山海域入海污染物环境容量研究

在宁波-舟山海域数值模拟潮流场的基础上,建立了该海域各污染源的响应系数场,计算了主要污染源COD、无机氮和活性磷酸盐的分担率场,及各污染源和控制单元的环境容量.研究结果将为该海域入海污染物总量控制提供科学依据.     

城市生活污水处理后回用作热电厂循环冷却水的可行性研究

选用适合热电厂特点的水处理剂,利用静态试验,动态模拟试验手段,对城市生活污水回用于热电厂循环冷却水系统中的复配药剂的阻垢缓蚀性能进行了研究.通过试验表明,污水回用是可行的,为城市生活污水回用于热电厂循环冷却水系统工程提供了可靠的参数.     

天然气引射调峰系统的噪声形成及其治理研究

采用天然气引射调峰技术,能使上海某储配站10台天然气高压球罐的储气调峰能率提高68%,大大有助于解决天然气用气高峰时的供需平衡问题,并能节约初投资人民币1亿元.但使用超音速引射器后,当球罐压力下降到某一值时会产生高频噪声,影响管束区操作环境.本文分析了噪声产生的原因,提出了合理的噪声治理方案,并进行了方案的实施.实践证明:噪声治理效果良好,降低了管束区噪声污染,达到了国家"工业企业噪声卫生标准".     

前处理-水解-生物接触氧化工艺处理染料废水

介绍了前处理-水解-生物接触氧化工艺处理染料废水的工程实例.当进水COD≤8000 mg/L时,出水可达到国家〈污水综合排放标准〉（GB8978-1996）二级标准.     

The effects of elevated CO2 on clonal growth and nutrient content of submerge plant Vallisneria spinulosa

An approximately four months long glasshouse experiment was conducted to examine the effects of elevated carbon dioxide (CO(2)) concentration (1,000 +/- 50 micromol mol(-1)) in the atmosphere on biomass accumulation and allocation pattern, clonal growth and nitrogen (N), phosphorus (P) accumulation by the submerged plant Vallisneria spinulosa Yan. Elevated CO(2) significantly increased V. spinulosa total fresh biomass ( approximately 130%) after 120 days, due to more biomass accumulation in all morphological organs than in those at ambient CO(2) (390 +/- 20 micromol mol(-1)). About 75% of the additional total biomass at elevated CO(2) was accounted for by leaf and rhizome (above ground) biomass and only 25% of it belonged to root and turion (below ground). However, the turions biomass exhibited a greater increase rate than that of organ above ground, which caused reduction in the above/below ground biomass ratio. The clonal growth of V. spinulosa responded positively to elevated CO(2). The number of primary ramets increased up to 1.4-folds at elevated CO(2) and induced a dense growth pattern. For nutrients absorption, concentration of N in leaf and in turion was significantly (p 相似文献   

Removal of cyanobacterial blooms in Taihu Lake using local soils. I. Equilibrium and kinetic screening on the flocculation of Microcystis aeruginosa using commercially available clays and minerals

Algal removal abilities of 26 clays/minerals were classified into three categories according to the 8-h equilibrium removal efficiency (Q8h) and removal rate at a clay loading of 0.7 g/L. Type I clays (sepiolite, talc, ferric oxide, and kaolinite) had a Q8h > 90%, a t50 (time needed to remove 50% of the algae) < 15 min, and a t80 < 2.5 h. Type II clays (6 clays) had a Q8h 50-90%, a t50 < 2.5 h, and a t80 > 2.5 h. Type III clays (14 clays) with Q8h < 50%, t50 > 8 h and t80 > 14 h had no practical value in removal of algal blooms. When the clay loading was reduced to 0.2 g/L, Q8h for all the 25 materials decreased to below 60%, except for sepiolite whose Q8h remained about 97%. The high efficiency for sepiolite to flocculate M. aeruginosa cells in freshwaters was due to the mechanism of netting and bridging effect.