颗粒海藻酸镧对饮用水中氟的吸附去除

以氯化镧与海藻酸钠为原料,采用滴球法制备了粒径为1～1.5mm的海藻酸镧小球,经过水洗、干燥后得到镧负载量25%(质量分数)的海藻酸镧颗粒吸附剂,应用该吸附剂进行饮用水除氟研究.通过间歇吸附实验,分别进行了吸附速率、pH值影响、吸附等温线、共存离子影响等吸附性能评价,并对吸附前后吸附剂表面与溶液组成变化进行研究.结果表明,该颗粒的吸附速率很快,反应2h后出水氟浓度即逐渐趋于稳定,吸附速率曲线符合拟二级反应速率方程;吸附效果受pH影响显著,在pH=4附近吸附量最大;吸附等温线数据对Langmuir方程拟合较好,其最大吸附量高达197.2mg·g-1;在常见无机干扰离子中,磷酸根与碳酸根对吸附有较大负面影响.SEM照片显示吸附前、后颗粒表面形态差异明显;吸附前、后颗粒表面EDX成分分析及溶液中离子浓度测量结果显示,吸附过程中溶液中F-同时与颗粒表面Cl-及OH-发生离子交换作用.     

Phosphine functionalised multiwalled carbon nanotubes: A new adsorbent for the removal of nickel from aqueous solution

Synthesised triphenylphosphine-linked multiwalled carbon nanotubes (Tpp-MWCNTs) were used to study the adsorption of nickel in aqueous solutions and their adsorption capabilities were compared with purified MWCNTs. The adsorption capacity increased with an increase in pH for all adsorbents. The adsorption equilibrium was reached in 40 and 30 min for purified MWCNTs and Tpp-MWCNTs, respectively. Both Freundlich and Langmuir isotherms used to investigate the adsorption process fitted the experimental data well with the correlation coefficient R² close to 1 for all adsorbents. On the other hand, the experimental data fitted well with a pseudo second-order model. The speciation of nickel also influenced the adsorption on the purified and Tpp-MWCNTs. The adsorbents used in this study showed superior adsorption capacity when compared to other adsorbents reported in the literature.     

硅改性制备疏水性沸石分子筛蜂窝体

通过氢型沸石分子筛粉体与粘结剂、助剂和水混合成面团状后挤压成型,干燥焙烧,再通过四氯化硅疏水改性处理,制备了一种蜂窝状复合沸石分子筛吸附剂.通过低温N2吸附、XRD、吸苯等手段对所制备的分子筛蜂窝体进行表征和评价.结果表明所制备的复合沸石分子筛蜂窝体经过硅改性处理后,硅铝比由4提高至22,比表面和总孔容略降,P/P0=0.95时吸苯量比改性前稍高,达18.05%.相对湿度80%RH条件下（P/P0=0.95）苯的饱和吸附量还能达到15%,与改性前相比增加了1倍多,疏水性优良.     

染整废水深度处理纳滤工艺膜污染成因分析

为调查棉针织染整废水纳滤脱盐系统膜污染的类型和成因,使用电感耦合等离子发射光谱仪、扫描电子显微镜-EDX能谱仪、傅里叶变换红外光谱仪、热重分析仪、高倍光学显微镜和X射线荧光光谱仪,从膜进水水质、膜过程污染状况和膜清洗效果等三方面进行了联合互补检测和综合分析.结果表明,棉针织染整废水脱盐过程中纳滤膜的污染类型包括无机污染、有机污染和微生物污染;干燥(105℃)的污染物成分组成中结合水所占质量分数约8.2%,有机成分所占质量分数约41.0%,无机成分所占质量分数约50.8%;在无机污染物中铁盐污染较为突出,有机污染物所包含的主要官能团为—OH、—CH和—CC,微生物污染物中包含原生动物和后生动物;短期膜污染和长期膜污染分析结果表明有机污染和微生物污染的形成需要长时间的累积效应;纳滤膜清洗试验结果表明,有机污染和微生物污染是引起膜通量下降的主要原因,两者对膜通量影响的贡献率约53.3%.     

Bactericidal effects of adsorbent on Escherichia coli for use in disinfection of drinking water

A synergistic action of silver (Ag) and groundnut husk carbon was shown, which markedly enhanced inactivation of Escherichia coli. The purpose of this study was to assess the feasibility of using a silver-impregnated groundnut husk carbon adsorbent (AdSG) for drinking water disinfection and evaluate % disinfection of E. coli. The results showed that contact of bacterial cells with AdSG resulted in a transfer of Ag ion to the cell, as evidenced by bactericidal activity. It is also possible that Ag produced generation of reactive oxygen species in the cell that led to bactericidal activity of the adsorbent. Data indicated that AdSG was effective as a bactericidal agent and may prove to be economically beneficial in drinking water disinfection.     

Effects of cotton straw amendment on soil fertility and microbial communities

Maintaining soil fertility, while controlling pollution from excessive chemical fertilizer application is important for keeping soil productivity of sustainable agriculture. Variety of straws have been used and proven to be good soil amendments for increasing soil organic matter (OM) and a range of additional soil nutrients. However, little is known about the utilization of cotton straw for soil amendment. To better understand the mechanism behind cotton straw soil amendments, investigations were performed upon cucumber seedlings, where changes to soil nutrients and microbial communities were investigated. The results revealed that the cotton straw application promoted the cucumber seedling growth by significantly increasing the soil OM, available nitrogen, available phosphorus, and available potassium. The concentration of cotton straw was positively correlated to both the number of the culturable microorganisms and also the total microbial biomass within soil. Furthermore, assessment of cotton straw application using Biolog metabolic profiling and phospholipid fatty acid analysis revealed that such application increased the microbial community metabolic activity, and markedly changed the structure of microbial community. 16S rRNA gene clone library construction and phylogenetic analysis of soil bacteria revealed γ- Proteobacteria sequences dominated the cotton straw amendment soil, comprising 27.8% of the total number of analyzed sequences, while they were less represented in control soil (13.4%). On the contrary, the Sphingobacteria (7.8%) and Verrucomicrobia (2.4%) in the cotton straw amendment soil decreased after application when compared to the control soil 15.2% and 15.2%.     

丁二酰亚胺基修饰的吸附树脂对苯胺的吸附热力学性能

有效去除废水中苯胺及其衍生物是重要的环境问题. 由氯甲基聚苯乙烯树脂与丁二酰亚胺反应,合成大孔交联聚(对乙烯基苄基丁二酰亚胺)树脂(简称丁二酰亚胺树脂),测定了丁二酰亚胺树脂对正庚烷溶液中苯胺的吸附性能. 结果表明:丁二酰亚胺树脂对正庚烷溶液中苯胺的吸附量大于原料树脂. 吸附等温线符合Freundlich等温吸附方程,相关系数大于0.99. 利用热力学函数计算了等量吸附焓变、吸附自由能变和吸附熵变. 树脂对正庚烷中苯胺的等量吸附焓变在20～30 kJ/mol,推测吸附过程为氢键吸附;同时,通过比较树脂对正庚烷溶液中苯胺和N,N-二甲基苯胺的吸附性能的差别,进一步论证了丁二酰亚胺树脂对正庚烷中苯胺的吸附是基于氢键作用的机理.      

负载型钛凝胶的制备及其吸附去除三价砷的性能

针对钛凝胶（titanium xerogel,TAX）对三价砷[As （Ⅲ）]的吸附容量高（254 mg ·g^-1）但速率慢的问题,通过浸渍法,将TAX负载到活性炭、海绵及树脂材料制备负载型吸附剂,并评价其除砷性能.除海绵外,活性炭和树脂均能成功负载TAX,其中活性炭基材料的钛负载量在1.4%左右,树脂基材料在5%左右.树脂和活性炭的负载均提高了TAX的除砷速率,且树脂基材料提高的程度更明显.对于初始质量浓度为1.0 mg ·L^-1的As （Ⅲ）溶液,树脂基材料（TAX@D201）的吸附速率为0.85 mg ·（g ·min）^-1,是未负载TAX吸附速率[0.04 mg ·（g ·min）^-1]的21倍.在处理实际含砷地下水的柱实验中,TAX@树脂的有效床体积（BV）达560 BV,是相同金属负载量载铁树脂材料的2.8倍（199 BV）.本文结果表明将TAX负载于大孔树脂是一条有效的策略,为TAX应用于含砷地下水的净化提供了新思路.     

钛硅分子筛催化双氧水氧化水中间甲酚

探索催化双氧水氧化去除间甲酚对开发炼油厂碱渣废水处理新技术意义重大。采用钛硅分子筛催化双氧水氧化水中间甲酚,考察了反应时间、反应温度、双氧水加入量、催化剂加入量和初始溶液pH对间甲酚去除率的影响。实验结果表明：钛硅分子筛对双氧水氧化间甲酚具有显著的催化作用;在反应时间为90 min、反应温度为80 ℃、n（H₂O₂）∶n（间甲酚）为4、催化剂加入量为1.5 g/L、初始溶液pH为1.0~11.0的条件下,间甲酚去除率约为94%,间甲酚溶液的BOD₅/COD从氧化前的0.26提高到氧化后的0.38,可生化性显著提高。     

爬山虎茎粉对水体中氨氮的吸附特性

为从植物材料中筛选适宜的氨氮吸附材料,通过批实验研究了爬山虎茎在不同初始pH值、振荡时间、初始浓度和温度下对水溶液中氨氮的吸附情况,进而分析了吸附等温线、动力学和热力学特性.结果表明,爬山虎茎已经达到或超过矿物吸附氨氮的水平.氨氮吸附最适pH值为5~9.吸附过程基本在第18h达到平衡,控速步骤主要是膜扩散和粒内扩散.等温吸附符合Langmuir模型,最大吸附量在15,25,35°C下分别为3.18,4.69,5.19mg/g.热力学参数ΔG°、ΔH°和ΔS°表明,爬山虎茎对氨氮的吸附属于自发的吸热反应,且属于物理吸附.因此,爬山虎茎可以作为开发氨氮吸附剂的原材料.