MnO2负载树脂的制备及对As（V）的去除效果

制备了大孔和DH302 2种MnO2的负载树脂。并用SEM、EDS手段表征了负载树脂，实验了负载MnO2后树脂对As（V）的去除效果。结果表明：负载树脂对As（V）的去除效果比原树脂有很大提高；吸附As（V）后的2种负载树脂，均能较好地解吸并可重新用于对As（V）的吸附实验。     

制浆废液降低普钙水分的应用研究

针对我国采用高临界流动水分的磷矿进行湿法生产普钙普遍存在产品水分达不到部颁标准的难题,直接采用制浆废液(利用其主要对环境有害成分之一--MNA作减水剂)进行降低普钙水分的研究和应用.实验结果表明,添加少量的减水剂MNA可显著降低国内朝阳、昆阳、浏阳和国外摩洛哥等单种磷矿以及昆阳-朝阳混矿的矿浆粘度和水分.采用国产昆阳-朝阳混矿进行工业生产试验结果表明,添加0.35%～0.4%干矿粉重量的减水剂MNA,不仅可使球磨添加水量从145 kg降至103 kg,矿浆含水量从30.5%降至27%,成品肥含水量从16.24%降至13.77%,而且可使有效磷从10.67%升至12.24%,转化率由86.57%提高到90.45%,矿浆细度由90.18%提高到93.12%.实验和工业生产试验表明,直接用造纸制浆废液降低普钙水分,既确保和改善了普钙的产品质量,又治理了环境污染,取得了较好的经济、环境和社会效益.     

氯化铜改性石墨相氮化碳吸附剂的脱汞性能

针对燃煤电厂汞污染物排放控制的问题, 以尿素为前驱体, 通过直接热聚合法制得绒毛状石墨相氮化碳(g-C₃N₄), 并用于低温条件下吸附脱除单质汞(Hg⁰)。利用透射电子显微镜(TEM)、X射线衍射(XRD)、氮气吸附-脱附、X射线光电子能谱(XPS)等手段对吸附剂进行表征。结果表明:未改性g-C₃N₄具有良好的低温脱汞活性, 在120 ℃时其脱汞效率可达84.7%;CuCl₂改性可以有效提高g-C₃N₄的脱汞性能, 其脱汞效率在40~200 ℃范围内均可达到97%以上; 温度对吸附剂脱汞效率的影响较小。XPS表征测试结果表明, 铜离子和共价态氯原子均参与了单质汞的吸附脱除反应, Hg⁰被Cu²⁺离子和共价态Cl原子氧化成了Hg²⁺离子, 再吸附于g-C₃N₄表面而脱除。CO₂、SO₂和水蒸气对吸附剂脱汞效率影响较小, 但水蒸气可提高汞吸附量。     

新生态MnO2吸附剂对酸性媒介染料废水脱色特性研究

本文主要报道了一种用于染料废水处理的新型材料即新生态MnO2 及其对三种酸性媒介染料染色废水的脱色作用及影响脱色效果的主要因素。研究结果表明 ,新生态MnO2 对酸性媒介染料的吸附能力很强 ,当染料浓度为2 0 0mg/L、pH <2时 ,其对酸性媒介黑T、酸性媒介绿G和酸性媒介黄GG的脱色率分别达 98.2 %、94.5 %和 96 .4%。染料吸附效果受体系pH值、MnO2 投加量、吸附时间及温度等因素的影响 ,其中pH值是最主要的影响因素。新生态MnO2 对酸性媒介黄GG的吸附作用符合Langmuir吸附等温式     

Presence of bacteria in aqueous solution influences virus adsorption on nanoparticles

Virus contamination in wastewater is usually accompanied by the existence of various bacteria. Nanoparticles (NPs) have been shown to efficiently remove virus. In this study, bacterial cells, supernatants, and cultures were harvested separately from three strains at the culture ages of 6 and 24 h, corresponding to the log and stationary phases, respectively. The aim is to investigate how their presence affects virus adsorption on the three Fe and Al oxide NPs (α-Fe₂O₃, γ-Fe₂O₃-B, and Al₂O₃) and how these effects change with bacterial growth phase. Bacteriophage phiX174 was used as a virus model. Results showed that bacterial cells, supernatants, and cultures harvested at 6 h generally reduced virus adsorption by an average of 0.75?±?0.84, 7.7?±?9.0, and 10.3?±?8.6 %, respectively, while those harvested at 24 h reduced virus adsorption by an average of 2.1?±?0.93, 21.5?±?6.6, and 24.6?±?6.9 %, respectively. Among the NPs, α-Fe₂O₃ showed more sensitivity to bacteria than the other two, probably because of its relatively higher value of point of zero charge. It was found that cell-induced and supernatant-induced reductions were combined to achieve added results, in which the supernatants contributed much more than the cells, implying that the bacterial exudates might be more crucial in the reduced virus adsorption than the bacterial cells. These results strongly demonstrated that the bacteria-induced reduction in virus adsorption became more significant with culture age. It is suggested that studies conducted in the absence of bacteria may not accurately evaluate the potential of virus removal efficiency of the NPs in bacteria-containing environments.     

Fe3O4/Ag磁性纳米颗粒去除水中的铅离子

采用水相共沉淀法制备小尺寸磁性Fe₃O₄纳米颗粒,以没食子酸作为还原剂和表面修饰剂,还原Ag[(NH₃)₂]⁺制备出Fe₃O₄/Ag磁性纳米颗粒。研究该磁性纳米颗粒对水溶液中铅离子的吸附行为,研究结果表明,pH为7.0,吸附温度30℃时可得到最好的处理效果,铅的去除率可达99.7%以上,Fe₃O₄/Ag颗粒吸附行为符合二级动力学模型(R² > 0.99)。该磁性纳米颗粒经过多次再生处理后,仍具有很好的吸附效果,表明Fe₃O₄/Ag在水处理方面拥有良好的应用前景。     

Photodegradation of the antimicrobial triclocarban in aqueous systems under ultraviolet radiation

This work aimed to investigate the effectiveness of ultraviolet (UV) radiation on the degradation of the antimicrobial triclocarban (TCC). We investigated the effects of several operational parameters, including solution pH, initial TCC concentration, photocatalyst TiO₂ loading, presence of natural organic matter, and most common anions in surface waters (e.g., bicarbonate, nitrate, and sulfate). The results showed that UV radiation was very effective for TCC photodegradation and that the photolysis followed pseudo-first-order kinetics. The TCC photolysis rate was pH dependent and favored at high pH. A higher TCC photolysis rate was observed by direct photolysis than TiO₂ photocatalysis. The presence of the inorganic ions bicarbonate, nitrate, and sulfate hindered TCC photolysis. Negative effects on TCC photolysis were also observed by the addition of humic acid due to competitive UV absorbance. The main degradation products of TCC were tentatively identified by gas chromatograph with mass spectrometer, and a possible degradation pathway of TCC was also proposed.     

Degradation of bisphenol A in aqueous solution by persulfate activated with ferrous ion

Degradation of bisphenol A (BPA) in aqueous solution was studied with high-efficiency sulfate radical (SO₄ ^?·), which was generated by the activation of persulfate (S₂O₈ ^2?) with ferrous ion (Fe²⁺). S₂O₈ ^2? was activated by Fe²⁺ to produce SO₄ ^?·, and iron powder (Fe⁰) was used as a slow-releasing source of dissolved Fe²⁺. The major oxidation products of BPA were determined by liquid chromatography-mass spectrometer. The mineralization efficiency of BPA was monitored by total organic carbon (TOC) analyzer. BPA removal efficiency was improved by the increase of initial S₂O₈ ^2? or Fe²⁺ concentrations and then decreased with excess Fe²⁺ concentration. The adding mode of Fe²⁺ had significant impact on BPA degradation and mineralization. BPA removal rates increased from 49 to 97 % with sequential addition of Fe²⁺, while complete degradation was observed with continuous diffusion of Fe²⁺, and the latter achieved higher TOC removal rate. When Fe⁰ was employed as a slow-releasing source of dissolved Fe²⁺, 100 % of BPA degradation efficiency was achieved, and the highest removal rate of TOC (85 %) was obtained within 2 h. In the Fe⁰–S₂O₈ ^2? system, Fe⁰ as the activator of S₂O₈ ^2? could offer sustainable oxidation for BPA, and higher TOC removal rate was achieved. It was proved that Fe⁰–S₂O₈ ^2? system has perspective for future works.     

活性炭吸附室内空气中挥发性有机化合物

活性炭吸附室内空气中挥发性有机化合物的１０％穿透时间与气相浓度及挥发性有机化合物的种类有关,通过对苯、甲苯和丙酮的实验研究,得出了由高浓度估算室内低浓度时炭床１０％穿透时间的经验公式ｔｂ,１＝ｔｂ,ｈ（Ｃ０,１／Ｃ０,ｈ）＾ａ,其中ａ值是与炭床性能及挥发性有机化合物种类有关的参数,可通过实验确定。