纳米Ag粒子原位杂化PVDF超滤膜的抗污染性能

以AgNO3为前驱体,聚偏氟乙烯(PVDF)为聚合物基体,聚乙烯吡咯烷酮(PVP)为分散剂和成孔剂,N,N-二甲基甲酰胺(DMF)为还原剂和溶剂,利用相转化法制备了纳米Ag粒子原位杂化PVDF超滤膜.采用扫描电镜、透射电镜、原子力显微镜及接触角测定仪对杂化膜的结构和性能进行了表征.结果表明:原位形成的纳米Ag粒子均匀地分散在聚合物基体中,纳米Ag粒子的添加改善了PVDF膜的亲水性能.以腐殖酸和牛血清蛋白作为污染物的代表,考察了Ag/PVDF膜的抗有机污染性能.以大肠杆菌、耐甲氧西林金黄色葡萄球菌及活性污泥作为微生物的代表,考察了杂化膜的抗生物污染性能.结果证实了与纯PVDF膜相比,Ag/PVDF膜通量衰减较慢,可有效抑制微生物的生长,表面受活性污泥污染程度小,具有显著的抗有机污染和抗生物污染性能.     

污泥中汞的存在形态及其在干化过程中的动态变化

在测定市政污泥、印染污泥和造纸污泥中汞含量及其存在形态分布特征的基础上,通过模拟实验,系统研究了不同类型污泥中汞存在形态在干化过程中的动态变化,同时分析了污泥中汞含量和各存在形态发生变化的原因.结果表明,市政污泥的汞含量依次大于印染污泥和造纸污泥;污泥中无酸溶态汞和可还原态汞,只存在可氧化态汞和残渣态汞;被试污泥在25~100℃干化时,含水率降低不会导致汞的析出;在100~200℃干化时,污泥中汞含量随温度的升高呈现出缓慢降低的趋势;当干化温度200~300℃时,随污泥中有机质和硫化物的分解,可氧化态汞消失;当干化温度达到400℃时,污泥中汞不复存在.     

污泥处理处置技术的现状与探讨

污泥的处理处置是一项关系民生的社会化工程,由于前些年对污泥处理的忽视,导致污泥引起的环境问题愈来愈严重。对现阶段污泥常用处理处置的各种工艺与方法进行梳理和总结,同时对各种工艺及处理措施技术的优劣进行了探讨。     

Biogenic C-doped titania templated by cyanobacteria for visible-light photocatalytic degradation of Rhodamine B

Cyanobacteria, which occurred in eutrophic water harvest solar light to carry out photosynthesis with high efficiency. In this work, cyanobacteria （Microcystis sp.） were used as biotemplate to synthesize titania structure. The synthesized titania sample had similar morphology to that of the original template in spite of the fragile unicellular structures and extremely high water content of cyanobacterial cells. Incorporation of biogenic C, as well as the morphology inherited from biotemplate improved visible- light absorbance of the titania structure. The sample exhibited higher visible-light photocatalytic activity than commercial titania photocatalyst Degussa P25 for Rhodamine B （RhB） degradation. Compared with those C-doped titania photocatalysts prepared by other methods, cyanobacteria templated titania photocatalyst offer some potential for competitive advantages. The reported strategy opened up a new use for the cyanobacteria. It could also be used for titania in applications such as treatment of polluted water, dye-sensitized solar cells, or other regions.     

Effect of ozone on the performance of a hybrid ceramic membrane-biological activated carbon process

Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm （UV254, a parameter indicating organic matter with aromatic structure） were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively.     

F&EI评价法在汽车加油站安全评价中的应用

运用"道化学公司火灾、爆炸危险指数评价方法"对加油站的埋地汽油储罐和埋地柴油储罐进行安全评价,并提出相关的注意事项.     

四川如何协调推进两化互动与环境保护

两化互动是指在科学发展观的指导下,以新型工业化为主导推进新型城镇化,四川两化互动推动和促进区域发展的同时也引发了大量的环境问题,今后,遵循科学发展观、强化生态规划、加强生态基础和法治建设才能协调推进两化互动与环境保护。     

小学英语游戏教学策略研究

《论语》中说:"知之者不如好之者,好之者不如乐之者。"这句话说明了学习兴趣的培养是至关重要的。在当下的小学英语教学中,学生的学习意识还不够,教师的教授方式存在着很大的问题,这就要求教师必须找出一个比较相适应于现行教育的方式,让学生很好地学习。其实,教学质量的好坏主要是因素来自教学方式,一个没有创新的教育模式,教学质量不可能高的。教学模式应该根据不同的学生、不同的年龄阶段进行不同的教育。在小学英语教学过程中,教师应该以培养学生的学习兴趣为主,游戏式教学方式就是一个可以很好地培养学生学习兴趣的教学方式。     

课程数学 生活数学

《3~6岁儿童学习与指南》的颁布,对幼儿园数学有了更新的认识,其中课程数学、生活数学的理念将幼儿园数学进行了融合。由于数学教育本身所蕴含独特的科学性和操作性,促使进一步思考如何在主题课程、日常生活中有效实施数学教育,使其体现出主题课程的整体性、日常生活的趣味性,真正发挥数学教学最有价值的意义。     

综合利用不同类型污泥处置方法探究

本文对于不同来源的污泥分类,分析污泥的不同处置方法,同时探讨对于多类型工业污泥,如何综合利用不同污水处理设施、有效利用污泥特性以及副产能源处理的综合处置方法。