传统酸面团全麦粉馒头的工艺优化研究

全麦粉馒头是以全麦粉为原料制作的产品,因其含有丰富的膳食纤维、矿物质、维生素等营养成分而备受消费者喜爱。为了提高全麦粉馒头的营养品质,以传统酸面团为发酵剂,结合冷藏中种发酵法制作酸面团全麦粉馒头。通过单因素试验,研究酸种的添加量、中种面团中全麦粉的添加比例、全麦粉中种面团的冷藏发酵时间对馒头品质的影响。进一步通过Box-Behnken设计进行响应面优化试验,以全麦粉馒头的感官评分为响应值确定出最佳工艺参数:酸种的添加量为40%、中种面团中全麦粉的添加比例为70%、全麦粉中种面团的冷藏发酵时间为27 h。在此工艺条件下制作酸面团全麦粉馒头,感官评分为86.22,与预测值86.50无显著性差异。与酵母全麦粉馒头相比,酸面团全麦粉馒头具有更大的比容,更细腻、更均匀的组织结构,更松软的口感,并具有传统老面馒头特有的发酵风味。     

等离子体改性海绵铁活化过硫酸盐处理含酚废水

采用低温等离子体技术对海绵铁表面进行改性，并将其用于活化过硫酸盐（PS）处理含酚废水。通过氮气等温吸附（BET）、X射线衍射（XRD）和扫描电子显微镜（SEM）等手段对改性前后的海绵铁进行表征分析。以苯酚为目标污染物，通过静态实验考察催化剂投加量、催化剂/PS摩尔比、pH和苯酚初始浓度对等离子体改性海绵铁活化PS处理含酚废水的影响。结果表明，改性后的海绵铁比表面积、孔容及孔径均有增大，活化PS能力显著提高；在最佳反应条件（等离子改性海绵铁的投加量为0.4g/L，催化剂/PS摩尔比为1∶15，溶液pH为2，苯酚的初始浓度为250mg/L）下，苯酚的去除率可达95%；反应过程符合二级反应动力学，主要是硫酸根自由基和羟基自由基起氧化作用。等离子体技术改性海绵铁活化过硫酸钠可有效去除水中苯酚，为实际含酚废水的处理提供一些思路。     

基于低影响开发理念的雨水控制设计计算

文中介绍了某电影文化综合体项目采用的集中雨水控制利用技术:透水性地面铺装、屋顶绿化、下凹式绿地、微生态雨水处理回用一体机。通过合理划分汇水面积,结合项目实际情况,计算给出了在限定年径流总量控制率的条件下,合理采用多种手段联合,使项目符合《绿色建筑评价标准》(GB/T 50378—2014)中的场地生态设计要求,实现了海绵城市的控制目标,也为类似工程提供了参考思路。     

海绵城市建设PPP项目委托代理契约分析

针对海绵城市PPP(Public-Private Partnership)项目建设、运营管理问题,为了降低由于项目参与的各方掌握信息、地位的不对称而产生的道德风险、维护各参与方的合法权益,基于一定的前提假设,构建海绵城市建设PPP项目契约模型,利用优化理论分别从代理企业和政府方两个主体的效用对模型的各个参数相关关系进行了分析,并利用数值模拟讨论了监控机制各参数对政府方监控意愿的影响。最后,结合常德市海绵城市PPP项目建设的案例,分别分析在当前考核机制下项目在建设、运营期可能存在的问题,并提出了相应的对策以解决这些问题。结果表明:代理企业的监控和激励措施具有互补性,海绵工程项目风险来源广泛,企业为规避风险会偏好零风险的固定收益,设定监控机制能激励企业更加努力的工作。     

海绵负载纳米Al2O3复合吸附剂去除水中硒研究

研究制备了海绵负载纳米Al2O3微球的复合吸附剂(NAS),并用于对Se(Ⅳ)和Se(Ⅵ)的吸附。结果表明,合成的纳米Al2O3微球(NAO)的平均尺寸为200~400 nm,在海绵上负载NAO会使其分散性更好。当NAO负载量分别为80 mg/g和60 mg/g时,NAS对Se(Ⅳ)和Se(Ⅵ)的吸附性能为佳,分别需要60、120 min达到平衡,适应pH为2~5;两者均符合准2级动力学模型;NAS对Se(Ⅳ)、Se(Ⅵ)的最大吸附容量分别为137.2、143.9 mg/g,能很好地与Freundlich模型拟合,说明NAS表面不均匀,且属于多层吸附。经过2次的循环,对Se(Ⅳ)和Se(Ⅵ)的去除率有所降低,但均仍保持在一定的水平,说明NAS可再生循环利用。NAS作为一种新型吸附剂去除水中Se具有较好的应用前景。     

Self-assembly of ultralight and compressible inorganic sponges with hierarchical porosity by electrospinning

The construction of three dimensional macroporous architectures holds exciting implications for applications such as catalysis, sensing, tissue engineering and thermal insulation. Here, we report a general self-assembly process for inorganic sponges with hierarchical porosity of intrafibre micro-/meso-/macropores and interfibre macropores. The as-fabricated SiO₂-TiO₂ sponge possesses a high porosity of >99.86%, ultralow bulk density of 2.9 mg cm⁻³ and enhanced compressibility (recovery from 50% compression). The self-assembly mechanism of the SiO₂-TiO₂ sponge has been investigated in detail. The results confirmed that the hydrolysis and polycondensation of mixed inorganic alkoxides could affect the solidification process and the charge transpote during electrospinning, and plays an essential role on the hierarchical porosity and the self-assembly of the sponge macro-structure. The concerted effects of the solidification and electrostatic repulsion between fibres are responsible for the self-assembly process of the electrospun PVP-SiO₂-TiO₂ sponge. When used as a thermal insulation material, the SiO₂-TiO₂ sponge shows good fireproof performances. The current contribution may guide more construction of functional inorganic macroporous architectures for advance applications in future.     

Graphite powder coated polyurethane sponge hollow tube as a high-efficiency and cost-effective oil-removal materials for continuous oil collection from water surface

In this study, the cost-effective graphite powder (GPd)-coated polyurethane (PGPd-PU) sponge hollow tube (PGPd-PUHT) was prepared for high-efficient continuous oil removal, the hydrophobicity-superoleophilicity PGPd-PU sponge was fabricated through a simple dip-coating method, which dipping PU sponge into GPd dispersion and drying, then coating polydimethylsiloxane (PDMS) on sponge skeleton, as-prepared sponge could selectively absorb a variety of oils up to 34 times of its own weight for dimethyl sulfoxide (DMSO). The PGPd-PUHT was prepared via wrapping PGPd-PU sponge on porous tubular support. The obtained PGPd-PUHT could continuously collect various types of oils from water surface with flux as high as 1.52 kL/m²h, and excellent separation efficiency (up to 97.7%) for toluene, as well as remarkable reusability. Moreover, a continuous floating oil collection device based on PGPd-PUHT was designed which showed excellent floating oil collection ability. In addition, our strategy possesses the advantages of low cost, simple preparation, highly efficient, and easily scale-up, showing a great potential for dealing with practical oil spill remediation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48921.     

生物海绵铁载体最佳使用参数研究

通过生物海绵铁复合载体与SBBR结合处理城市生活污水,研究了影响铁离子释放的主要影响因素pH、 DO以及复合载体结合方式对处理效果的影响,最终确定出最佳的设计使用参数。结果表明,复合载体以B方式结合时脱氮除磷效果最佳;进水pH在中性或偏碱性条件下,脱氮除磷效果最佳,氨氮去除率为90%, TP去除率为86%; DO为2~4 mg/L时, COD去除率提高,达到76%, TN、 TP去除率均在85%以上。研究为载体的实际化应用打下了基础,也为同类研究提供了参考。     

Application of electrooxidation process for treating concentrated wastewater from distillery industry with a voluminous electrode

Experiments in a laboratory scale were carried out to reduce color and chemical oxygen demand (COD) in distillery wastewater by using electrooxidation processes. A cylindrical electrochemical reactor constructed in an axial configuration with 0.2m diameter and 0.35 m height was employed in this study. Two materials including graphite particles and titanium sponge were used as the voluminous anodes. A cathode made from Ti/RuO(2) was placed 0.04-0.05 m above the upper level of anode particles. Effect of parameters including initial pH of wastewater (1-5), time of dilution, current intensity (1-10A), type of additive (H(2)O(2) and NaCl), and additive concentration were investigated. The results indicated that the anode made from titanium sponge showed a higher potential to treat wastewater than the another one. The treatment in acidic condition (pH=1) provided the maximum oxidation of organic pollutants in wastewater. The presence of additives can promote the reduction of COD and color in wastewater approximately 89.62% and 92.24%, respectively. The maximum current efficiency was reached at the first 30 min and decreased slightly as electrolysis time proceeded due to the formation of passivation on the electrode surface. The energy consumption was obtained in the range of 2.82-4.83 kWh/kgCOD or 24.08-28.07 kWh/m(3) wastewater depending upon the concentration of additive. The kinetics of COD reduction was the pseudo first-order reaction with a fast rate constant of 6.78 min(-1).