Zr-MOFs loaded on polyurethane foam by polydopamine for enhanced dye adsorption

Zirconium-based metal-organic frameworks (Zr-MOFs) have attracted widespread attention due to their high specific surface area, high porosity, abundant metal active sites and excellent hydrothermal stability. However, Zr-MOFs materials are mostly powdery in nature and thus difficult to separate from aqueous media, which limits their application in wastewater treatment. In this study, PDA/Zr-MOFs/PU foam was constructed by growing Zr-MOFs nanoparticles on a dopamine-modified polyurethane foam substrate by in-situ hydrothermal synthesis as an adsorbent for removing dyes from wastewater. The results demonstrated that the polydopamine coating improves the dispersion of the Zr-MOFs nanoparticles on the substrate and enhances the interaction between the Zr-MOFs nanoparticles and the PU foam substrate. As a result, compared with Zr-MOFs/PU foam, the prepared PDA/Zr-MOFs/PU foam exhibits higher adsorption capacity for crystal violet (CV) (63.38 mg/g) and rhodamine B (RB) (67.73 mg/g), with maximum adsorption efficiencies of CV and RB of 98.4% (pH=11) and 93.5% (pH=7), respectively, at a concentration of 10 mg/L. The PDA/Zr-MOFs/PU foam can simultaneously remove CV and RB from the mixed solution. Moreover, the PDA/Zr-MOFs/PU foam still exhibits high stability and reusability after five cycles.     

多菌灵降解菌NY97-1的鉴定及降解条件

分离筛选出一株能高效降解多菌灵的芽孢杆菌菌株NY97-1,经生理生化和序列同源性分析,将该菌株鉴定为短小芽孢杆菌Bacillus pumilus.该细菌降解多菌灵的最适pH值为6.0～10.0,最适温度为35.0～40.0℃.该菌在多菌灵浓度为10、30、50、100、300 mg·L-1的无机盐培养基中,30℃振荡培养24 h后,其对多菌灵的降解率分别为42.44％、48.97％、77.19％、78.66％和90.07％.添加少量有机氮源如酵母浸出粉、胰蛋白胨、酵母膏可促进菌株NY97-1对多菌灵的降解作用,添加少量无机氮源尿素会抑制菌株NY97-1对多菌灵的降解作用.     

WS2对Fe2+/过氧化钙类芬顿体系降解双酚A的助催化作用

Fe²⁺/过氧化钙类芬顿体系(Fe²⁺/CaO₂)在实际应用中易受到铁离子循环缓慢的限制.因此,本研究利用商业WS₂作为Fe²⁺/CaO₂体系的助催化剂以促进Fe³⁺/Fe²⁺快速循环,进而高效降解双酚A(BPA).在最佳条件下,WS₂/Fe²⁺/CaO₂体系在15 min内对BPA(10 mg·L^-1)的降解率为99.7%.同时,该体系展示出良好的应用前景,可适用于多种水体,亦可高效降解多种难降解有机污染物.自由基淬灭实验和EPR分析表明,羟基自由基(·OH)、单线态氧(¹O₂)和超氧自由基(·O₂^-)是BPA降解的主要活性氧物种,其中·OH贡献最大.WS₂表面暴露的W⁴⁺还原性位点,促进了Fe...     

微生物絮凝剂的研究及应用前景

对微生物絮凝剂的研究及应用进展进行综述,包括产生絮凝剂的微生物种类,微生物絮凝剂的提取纯化,微生物絮凝剂的絮凝机理,影响因素,研究动向以及微生物絮凝剂的应用。     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in different tissues of the cormorants (Phalacrocorax carbo) from Dongting Lake, China

Tissue distribution provides important information regarding the pharmacokinetic behavior of pollutants and is invaluable when analyzing the risk posed to avian species by the exposure to such kind of pollutants. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in muscle, liver, spleen, kidney, stomach, gall bladder, skin, heart, pancreas, intestine and lung tissue extracts of cormorants collected from Dongting Lake, China. Tissue distribution results showed preferential accumulation of PCDD/Fs in both liver and skin. The total concentration of PCDD/Fs ranged from 421 to 5696 pg/g lipid weight. Octachlorinated dibenzo-p-dioxin (OCDD) was the predominant congener in all tissues and contributed between 31% and 82% to all 17 PCDD/Fs in different tissues. The liver/muscle ratios progressively increased with the degree of chlorination of PCDDs, except for OCDD. The relative toxic potential of PCDDs and PCDFs in tissues were calculated using the World Health Organization (WHO) Toxic Equivalency Factors (TEFs) for birds. The concentrations of WHO-toxic equivalent in different tissues ranged between 14.8 and 2021 pg/g lipid weight. These results indicated PCDD/Fs may have been bio-accumulated in cormorant via food-web. Furthermore, when compared with studies reported in the literatures, the PCDD/Fs levels in the cormorant collected from Dongting Lake were still relatively high.     

浅议城市发展规划中环境与经济的协调

针对当前城市的经济规划和环境规划是相互独立的两个规划，环境规划在城市发展规划中未能反映出春应有的地位，以可持续发展理论为基础，描述了城市发展规划中应引入的新观念，并较为系统地介绍了可持续发展模式的城市经济与环境相互协调发展的规划体系。     

绿色城市评价指标体系的构建与权重

在全球城市化的高速进程中，城市经济的增长与资源环境的矛盾日渐加剧，城市的"绿色"转型势在必行.对城市绿色发展程度进行评估，是建设绿色城市的重要内容.绿色城市评价指标体系能够反映绿色城市发展潜力及存在问题，而如何选择评价指标及指标权重的设置是开展绿色城市评价的首要科学问题.本文首先基于绿色城市发展理念与指标构建原则，从绿色生产、绿色生活、环境质量3个维度构建了10个二级指标、29个三级指标，并按照属性将基础指标分为正向、负向、特定向指标3类.然后，基于主体功能区与城市发展阶段，分别对不同类型城市设立权重系数，通过整合综合权重系数，实现了对不同类型城市的差异化评价，提升了评价结果的公正性.本研究建立的绿色城市评价指标体系充分结合了联合国可持续发展目标，可为绿色城市评价提供科学依据.     

苯酚、苯在水／阴离子有机膨润土界面的环境行为研究

研究了苯酚在水／阴离子有机膨润土界面的吸附行为，初步探讨了阴离子有机膨润土对苯酚、苯的吸附性能、机理及影响因素。结果表明，阴离子表面活性剂改性后，膨润土中有机碳含量增加了10～38倍，对苯酚、苯的吸附能力大大提高。水中苯酚、苯在水／阴离子有机膨润土界面的吸附行为主要分配作用所致，其吸附等温线呈线性。     

应用DAT-IAT工艺污水处理厂的运行效果分析

天津经济技术开发区污水处理厂采用先进的DATIAT工艺,针对该污水处理厂冬季和夏季的实际运行效果分别进行研究、比较,并就DAT池和IAT池对有机物的去除效果进行分析。研究发现,污水处理厂实际运行中,对BOD5的去除效果十分彻底,对CODCr的去除效果一般,但都能够保证出水达标。DATIAT工艺系统的抗冲击负荷能力较强污水处理厂DAT池过高的BOD5去除率对后续的脱氮除磷效果会产生不利的影响。     

Immobilization of an enzyme from a Fusarium fungus WZ-I for chlorpyrifos degradation

The free enzyme extracted from WZ-I,which was identified as Fusarium LK.ex Fx,could effectively degrade chlorpyrifos,an organophosphate insecticide.The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated.The properties of the immobilized enzyme were compared with those of the free enzyme.The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4°C for 4-12 hr.The immobilized enzyme showed the maximal activity at pH 8.0,45°C.The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme.The immobilized enzyme,therefore,had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme.With varying pH and temperatures,the immobilized enzyme was more active than the free enzyme in the degradation reaction.In addition,the immobilized enzyme exhibited only a slight loss in its initial activity,even after three repeated uses.The results showed that the immobilized enzyme was more resistant to different environmental conditions,suggesting that it was viable for future practical use.