铁自养反硝化污泥富集培养过程中化学与生物作用的变化规律

铁自养反硝化技术在低碳氮比废水处理中具有安全性高、成本低廉等优势,但目前对其反硝化过程机理,特别是其中生物与化学作用的关系仍缺乏清晰认识。为此,以铁自养反硝化系统为研究对象,结合反应动力学,分析不同阶段活性污泥自养反硝化过程中生物和化学作用变化规律,以期探究该过程的脱氮机制。结果表明,铁自养反硝化过程脱氮效率和速率分别可达(87.0±1.8)%和0.12 kg·(m³·d)⁻¹。铁自养条件下,未经驯化的活性污泥在反硝化过程中,Fe(Ⅱ)氧化由化学作用主导,$ {{\rm{NO}}_{\rm{2}}^{\rm{ - }}}$-N还原由生物作用主导,且生物过程由自养反硝化和以胞外聚合物为底物的异养反硝化共同作用;经驯化培养,Fe(II)氧化的生物作用增强,与${ {\rm{NO}}_{\rm{2}}^{\rm{ - }}}$-N还原均由生物作用主导。以上研究结果可为铁自养反硝化脱氮技术的发展提供参考。     

Urinary concentrations of phenols, oxidative stress biomarkers and thyroid cancer: Exploring associations and mediation effects

Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, and the underlying mechanisms are also poorly understood. We conducted a case-control study by age- and sex-matching 143 thyroid cancer and 224 controls to investigate the associations between phenol exposures and the risk of thyroid cancer, and further to explore the mediating role of oxidative stress. We found that elevated urinary triclosan (TCS), bisphenol A (BPA) and bisphenol S (BPS) levels were associated with increased risk of thyroid cancer (all P for trends < 0.05), and the adjusted odds ratios (ORs) comparing the extreme exposure groups were 3.52 (95% confidence interval (CI): 2.08, 5.95), 2.06 (95% CI: 1.06, 3.97) and 7.15 (95% CI: 3.12, 16.40), respectively. Positive associations were also observed between urinary TCS, BPA and BPS and three oxidative stress biomarkers measured by 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F_2α (8-isoPGF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), as well as between urinary 8-isoPGF_2α and HNE-MA and the risk of thyroid cancer. Mediation analysis showed that urinary 8-isoPGF_2α mediated 28.95%, 47.06% and 31.08% of the associations between TCS, BPA and BPS exposures and the risk of thyroid cancer, respectively (all P < 0.05). Our results suggest that exposure to TCS, BPA and BPS may be associated with increased risk of thyroid cancer and lipid peroxidation may be an intermediate mechanism. Further studies are warranted to confirm the findings.     

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water emulsions separation

• Underwater superoleophobic membrane was fabricated by deposition of catechol/chitosan. • The membrane had ultrahigh pure water flux and was stable under harsh pH conditions. • The membrane exhibited remarkable antifouling property in O/W emulsion separation. • The hydration layer on the membrane surface prevented oil droplets adhesion. Low-pressure membrane filtrations are considered as effective technologies for sustainable oil/water separation. However, conventional membranes usually suffer from severe pore clogging and surface fouling, and thus, novel membranes with superior wettability and antifouling features are urgently required. Herein, we report a facile green approach for the development of an underwater superoleophobic microfiltration membrane via one-step oxidant-induced ultrafast co-deposition of naturally available catechol/chitosan on a porous polyvinylidene fluoride (PVDF) substrate. Membrane morphology and surface chemistry were studied using a series of characterization techniques. The as-prepared membrane retained the original pore structure due to the ultrathin and uniform catechol/chitosan coating. It exhibited ultrahigh pure water permeability and robust chemical stability under harsh pH conditions. Moreover, the catechol/chitosan hydrophilic coating on the membrane surface acting as an energetic barrier for oil droplets could minimize oil adhesion on the surface, which endowed the membrane with remarkable antifouling property and reusability in a cyclic oil-in-water (O/W) emulsion separation. The modified membrane exhibited a competitive flux of ~428 L/(m²·h·bar) after three filtration cycles, which was 70% higher than that of the pristine PVDF membrane. These results suggest that the novel underwater superoleophobic membrane can potentially be used for sustainable O/W emulsions separation, and the proposed green facile modification approach can also be applied to other water-remediation materials considering its low cost and simplicity.     

实施清洁生产 创建绿色企业——开展清洁生产工作的几点体会

文章阐述了辽河油田公司开展清洁生产工作的基本情况,结合管理现状,分析总结了开展清洁生产工作的管理经验,阐述了通过科技进步所取得的清洁生产成绩,归纳整理出可借鉴的清洁生产审核经验,为清洁生产审核工作提供了有益的建议。     

正压生物防护服研究进展

正压生物防护服是针对高危生物污染环境作业人员防护而研制的一类个体防护装备。本文从防护服材料、正压形成与保持、微环境、人体工效学等方面出发,综述了正压生物防护服关键技术研究的成果与不足。提出以功能通用化、监控自动化、使用信息化、研制规范化为特点的正压防护服是未来发展的趋势。     

Sustainable design for automotive products: Dismantling and recycling of end-of-life vehicles

The growth in automotive production has increased the number of end-of-life vehicles (ELVs) annually. The traditional approach ELV processing involves dismantling, shredding, and landfill disposal. The “3R” (i.e., reduce, reuse, and recycle) principle has been increasingly employed in processing ELVs, particularly ELV parts, to promote sustainable development. The first step in processing ELVs is dismantling. However, certain parts of the vehicle are difficult to disassemble and use in practice. The extended producer responsibility policy requires carmakers to contribute in the processing of scrap cars either for their own developmental needs or for social responsibility. The design for dismantling approach can be an effective solution to the existing difficulties in dismantling ELVs. This approach can also provide guidelines in the design of automotive products. This paper illustrates the difficulty of handling polymers in dashboards. The physical properties of polymers prevent easy separation and recycling by using mechanical methods. Thus, dealers have to rely on chemical methods such as pyrolysis. Therefore, car designers should use a single material to benefit dealers. The use of materials for effective end-of-life processing without sacrificing the original performance requirements of the vehicle should be explored.     

监控系统在智能变电站的应用

为了适应传统变电站向智能变电站的转变,需要用智能监控系统来满足变电站智能化的需求。针对银川110 kV开元变电站“三层两网”网络架构及智能监控系统的应用,结合调试实践,对智能变电站监控系统在现场应用中存在的问题和解决的办法作了研究和讨论。结果表明:智能监控技术更利于实现信息的综合利用,可以获得更高的可靠性和冗余性。     

论二十一世纪环境文明

人类社会进入21世纪，工业文明带来严重的环境污染已成为全球性问题。人们在建设物质文明和精神文明的同时，呼唤有一个优美的生存环境。可持续发展战略已忧为社会经济发展的主旋律。环境文明成为人们生活新的追求和社会经济发展新的目标。环保产业的充分发展，环境污染得到有效控制，社会各行各业和所有产品都达到环保标准，生态协调平衡，这就铸成21世纪环境文明。     

Hydrological Responses to Climate and Land‐Use Changes along the North American East Coast: A 110‐Year Historical Reconstruction

The North American east coast (NAEC) region experienced significant climate and land‐use changes in the past century. To explore how these changes have affected land water cycling, the Dynamic Land Ecosystem Model (DLEM 2.0) was used to investigate the spatial and temporal variability of runoff and river discharge during 1901‐2010 in the study area. Annual runoff over the NAEC was 420 ± 61 mm/yr (average ± standard deviation). Runoff increased in parts of the northern NAEC but decreased in some areas of the southern NAEC. Annual freshwater discharge from the study area was 378 ± 61 km³/yr (average ± standard deviation). Factorial simulation experiments suggested that climate change and variability explained 97.5% of the interannual variability of runoff and also resulted in the opposite changes in runoff in northern and southern regions of the NAEC. Land‐use change reduced runoff by 5‐22 mm/yr from 1931 to 2010, but the impacts were divergent over the Piedmont region and Coastal Plain areas of the southern NAEC. Land‐use change impacts were more significant at local and watershed spatial scales rather than at regional scales. Different responses of runoff to changing climate and land‐use should be noted in future water resource management. Hydrological impacts of afforestation and deforestation as well as urbanization should also be noted by land‐use policy makers.     

土壤水分管理对甲烷和氧化亚氮排放的影响

为控制农田温室气体排放的途径提供依据,通过实验室培养的方法测定了不同水分管理条件下CH4和N2O的排放,干旱处理（60％-70％WFP）和长期淹水土样在施肥后的Eh变化。最终得出：稻田CH4和N2O排放之间存在着互为消长的关系（R2=0．609）,CH4和N2O的排放是水肥共同作用的结果,水分管理通过Eh来影响气体排放,有机质是造成前后期排放浓度差异的主要原因。