泡沫浮选法处理含氰废水

本文研究了在含氰废水中按化学计量比加入Fe~(2+)和Fe~(3+)离子以生成无毒的亚铁氰化铁絮状物沉淀,然后采用泡沫浮选进行分离的除氰方法。操作过程中拟加入一定量的阳离子表面活性剂,采用5~#烧结玻璃板作气体分布器,在pH值为4.0～6.5之间,能获得较高的分离效率。操作宜在阳光直射不到的阳暗处进行以避免亚铁氰化铁沉淀的光解反应发生。     

SiO2纳米颗粒对水相泡沫稳定性的影响

采用SiO_2纳米颗粒分别与阴离子表面活性剂十二烷基硫酸钠（SDS）、阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）、非离子表面活性剂十二烷基醇聚氧乙烯（3）醚（AEO-3）复配制备水相泡沫,研究了发泡体积、半衰期和微观结构的变化规律,以揭示SiO_2纳米颗粒对水相泡沫稳定性的影响机理。结果表明,在表面活性剂质量分数一定的条件下,随着纳米颗粒质量分数的增加,泡沫稳定性逐渐增强,当纳米颗粒质量分数为0.3%时,发泡体积达最大值,含气率分别为78.9%,78.4%和78.8%。与单组分质量分数分别为0.3%,0.3%和15%的SDS、CTAB、AEO-3体系相比,发泡体积未受影响,半衰期分别为9.0,8.2和360?min,提高了20%,28.1%和71.4%,泡沫的稳定性得到了不同程度的改善。     

胶团强化超滤与泡沫分离组合工艺深度处理含Cd2+废水

采用胶团强化超滤(MEUF)-泡沫分离(FF)组合工艺,对含镉重金属废水进行深度处理.探讨了两种技术联用对分离效果的影响.结果表明,表面活性剂SDS和金属Cd2 离子浓度对分离效果有很大的影响.MEUF-FF联用后,大大降低了表面活性剂SDS用量,节省了经济成本.相比于单一的MEUF,MEUF-FF联用后能降低出水中SDS浓度,显著提高Cd2 分离效率.经过组合工艺处理后,Cd2 出水的浓度小于0.1mg/L,满足国家污水综合排放标准(GB8978-1996).     

泡沫分离-Fenton氧化工艺处理表面活性剂废水

采用泡沫分离-Fenton氧化工艺进行处理某炼油公司含SDBS和Brij30废水,研究了气体流速、废水流速、塔内液体高度、pH和Fenton试剂用量对处理效果的影响。得到了优化后的工艺条件为:Fenton试剂用量0.05 mol/L,气体流速0.054~0.072 m3/h,分离塔内液体量为1.8~1.9 L,废水流速2.0~2.2 L/h,Fenton氧化处理pH=3~4。在此最佳工艺基础上进行了工业侧线实验,实验表明,采用泡沫分离-Fenton氧化工艺可将废水中SDBS和Brij30分别降至2 mg/L和5 mg/L以下。     

Fe^3＋掺杂纳米TiO2光催化剂的制备及其光催化性能研究

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,正丁醇为助表面活性剂,环己烷为油相,采用微乳液法制备出Fe3+掺杂纳米TiO2,用X-射线衍射(XRD)对纳米TiO2粒径、物相等方面进行了表征.通过光催化降解甲基橙溶液考察了TiO2的光催化性能.甲基橙降解实验结果表明,溶液的pH=2时降解率可达100%;掺杂Fe3+会影响TiO2光催化性能,n(Ti4+):n(Fe3+)=1:0.000 4的TiO2在前10 min降解率高达54.50%,60 min降解率可达93.33%,掺杂浓度增大到一定程度后,降解率反而下降,说明存在较佳掺杂浓度.另外,溶液初始浓度对TiO2光催化性能有一定的影响.     

纳米TiO2颗粒的表面改性研究进展

较全面概述了在纳米TiO2颗粒改性中表面活性剂的作用机理与应用。对应于不同目的采用不同的改性剂甚至进行改性剂的复配方法及工艺，即为了改善纳米二氧化钛颗粒表面的润湿性和分散性，采用有机物改性方法；为了提高经伙二氧化钛颗粒的耐久性和化学稳定性目的时，采用无机物包裹的方法等。文中重点介绍了多种主要的改性剂和改性工艺，对于其它纳米颗粒的改性也有参考意义。     

改性二氧化硅纳米粒子提升泡沫稳定性研究

利用3-氨基丙基三乙氧基硅烷(APTES)对SiO₂纳米粒子进行改性,得到改性SiO₂纳米粒子,通过FTIR和接触角分析对其进行了表征,并通过静态实验考察了十二烷基硫酸钠(SDS)溶液、SiO₂-SDS纳米流体、改性SiO₂-SDS纳米流体在有、无氯化镁存在下对CO₂泡沫的起泡性、发泡性和稳定性的影响。结果表明,经改性SiO₂纳米粒子表面改性的聚甲基丙烯酸甲酯(PMMA)表面在油-水体系中更亲油,在空气-水体系中更亲气;与SDS溶液(质量浓度0.236%,半衰期80 min)相比,SiO₂(质量浓度0.06%)-SDS纳米流体、改性SiO₂(质量浓度0.05%)-SDS纳米流体的泡沫半衰期均有所延长,分别延长至120 min、140 min;当SDS质量浓度从0.236%增至0.472%时,改性SiO₂-SDS纳米流体的泡沫半衰期从140 min延长至270 min;在氯化镁存在下,改性Si...     

泡沫分离回收水中低浓度磷酸三丁酯

以吐温系列表面活性剂采用泡沫法回收水中的微量磷酸三丁酯．实验结果表明,在本实验条件下,泡沫法可以回收水中的磷酸三丁酯,磷酸三丁酯的提浓率与残留率与起始磷酸三丁酯浓度、起始表面活性剂浓度和表面活性剂种类有关。     

含纳米颗粒的泡沫体系及其在水力压裂中的研究进展

阐述了纳米颗粒与表面活性剂之间通过协同作用减缓液膜排液、气泡并聚与破裂、泡沫粗化的衰变过程;简述了不同表面活性剂与纳米颗粒在稳定泡沫机理上的异同;综述了纳米颗粒浓度和亲疏水性对不同表面活性剂泡沫流体性能的影响;分析发现纳米颗粒的加入使泡沫压裂液体系性能得到改善。提出对纳米颗粒稳泡机理、表面活性、改性修饰、稳定性的研究是今后的重要探索方向,最后对纳米颗粒未来在泡沫压裂液中的应用进行了展望。     

Removal of cadmium from wastewater by enhanced ultrafiltration using surfactants

In order to recover cadmium ion from wastewater, a process based on enhanced ultrafiltration was finalised. The originality of the solution here proposed lies on the coupled use of ceramic membranes and of a surfactant added to the water to be treated. This paper deals with the study of the influence of experimental conditions upon permeation flux and selectivity of the separation. The process is efficient and flexible since a single stage treatment allows to reduce the concentration of cadmium in the effluent by a factor of about 750; this high performance in selectivity is on a par with high fluxes of permeate (roughly 170 L.h.^?1.m^?2 at 25°C and 3 × 10⁵ Pa).     

An investigation of the recovery of cryolite from alumina-electrolyte froth by flotation

In the industrial production of aluminium by the electrolysis of alumina, electrolyte froth, which is a mixture of carbon and cryolite is obtained at a rate of 50 kg of froth per ton of aluminium produced. Cryolite can be recovered from this mixture by flotation. In this study, the effects of the following parameters on flotation were experimentally investigated: particle size, type, combination, dosage and ratio of reagents, and conditioning time. It is found that it is possible to decrease the carbon content of cryolite below 1% by suitably choosing the operating parameters. Electrolyte froth must be ground to —100 mesh size for the liberation of carbon particles captured in the cryolite matrix. Any combination of two of the reagents, kerosene, fuel oil, creosote and terebenthene yield good results if used together with pine oil. Pine oil is found to be a more effective frother compared to Pril, a commercial detergent. Satisfactory separations are obtained when a kerosene-fuel oil mixture (50:50, v/v) is used as the collector with a dosage of 3.7 kg per ton of feed together with pine oil, the frother, with a dosage of 0.095 kg per ton of feed.     

Removal of sulfur from Assam coal by bacterial conditioning and froth flotation

Reduction of sulfur by bacterial leaching from a high sulfur‐bearing coal sample from Assam was attempted. Flotation of the sample with light diesel oil could not depress the pyrite and also the Thiobacillus ferrooxidans was found to be ineffective in leaching the sulfur from the flotation concentrate. Conditioning of the same coal sample with Thiobacillus ferrooxidans was found to assist in selectively depressing the pyrite, thereby reducing nearly 60% of the pyritic sulfur present in the sample. © 1999 Society of Chemical Industry     

Degradation of wastewater from carbon capture plants using metal-impregnated TiO2 photocatalyst

Amine-based carbon capture (ABCC) is an advanced and cost-effective technology used to reduce the effects of climate change by capturing ${\mathrm{CO}}_2$ emitted from different sources. Although it has been demonstrated commercially, amine degradation poses a significant threat to humans and aquatic life. Amine degradation produces a wide variety of complex products such as nitrosamines and some organic acids. Some of these products are carcinogenic and mutagenic in nature and have demonstrated acute toxicity for laboratory animals. In order to mitigate the adverse impact of these compounds on human health and aquatic life, heterogeneous photocatalysis, an advanced oxidation process which can degrade a wide variety of chemical species with potent reactive hydroxyl radicals, was considered for the degradation of these compounds. The photocatalytic degradation of N-nitrosodiethylamine (NDEA), acetic acid, and formic acid were tested using TiO₂ and metal-impregnated TiO₂ catalysts such as Fe, Co, Ni, and Cu. Various techniques, such as thermogravimetric analysis (TGA), UV–Vis, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and X-ray fluorescence (XRF) were used to characterize these catalysts. The operational parameters for the photocatalytic degradation process were chosen as solution pH, catalyst dose, and metal impregnation percentage (imp%), and they were optimized using response surface methodology (RSM). pH was found as an important factor, and its impact on the photocatalytic degradation efficiency was more significant than the other operational parameters. The average degradation efficiency of the compounds reached 93.1% for Fe-TiO₂, 92.08% for Co-TiO₂, 89.09% for Ni-TiO₂, 88.81% for Cu-TiO₂, and 86.3% for TiO₂ at the optimum conditions.     

非金属矿物负载纳米二氧化钛研究进展

二氧化钛在解决环境污染问题方面有着广阔的应用前景。将二氧化钛负载固定于非金属矿物载体之上,能够更好地提高二氧化钛的催化和应用性能。简单介绍了二氧化钛的催化机理,综述了非金属矿物材料负载二氧化钛的研究进展,并就未来的发展趋势进行了展望。     

聚合物强化超滤过程处理含Hg~(2+)废水

研究聚丙烯酸钠(PAASS)与Hg2+络合反应动力学,当PAASS大量过剩及pH值恒为5时,络合反应达到平衡时间为25 m in,反应行为可用拟一级速率方程描述。测定PAASS对Hg2+络合能力,pH=5时每mg PAASS络合容量为1.0 mg。考察pH值、盐浓度和竞争络合剂对Hg2+截留系数的影响,可得:pH=5及负载比LR=1时适宜截留Hg2+;当C l-和SO42-浓度增大时,Hg2+截留系数逐渐降低;酒石酸钠和三乙醇胺不干扰PAASS与Hg2+的络合。进一步研究超滤浓缩行为,结果表明:当pH=5,PAASS及Hg2+初始质量浓度均为100 mg/L时,原料液浓缩15倍,膜通量仅衰减15.0%,浓缩液及渗透液汞质量浓度分别为1499.6,0.03 mg/L。     

强化泡沫排液下浮选富集和回收工程纳米颗粒

鉴于水体中工程纳米颗粒（ENP）的环境毒性与潜在价值,高效富集/回收ENP是其资源化处理的重要课题。为了突破浮选ENP中富集程度低且后续分离难度大的技术瓶颈,本文基于强化泡沫排液建立了富集/回收ENP的浮选法。以TiO₂纳米颗粒（TNP）为研究对象、十六烷基三甲基溴化铵（CTAB）为捕收剂和起泡剂,构筑了正八边形中空棱台（RHP）构件强化泡沫排液,分别从持液率、气泡直径和富集比等方面探讨了RHP强化排液的效果,分析了其机理。实验结果表明,在RHP构件安装于泡沫相中部、pH9.0、CTAB浓度100mg/L和气速250mL/min的条件下,TNP的富集比和回收率分别达到48.3±2.4和98.2%±4.9%;与不添加RHP相比,浮选过程中持液率降低了72.1%,TNP富集比升高了68.9%。综上,本文开发的浮选法为有效治理ENP水污染提供了重要的理论指导和技术支持。     

多通道TiO_2超滤膜的制备及其在印染废水中的应用

以多通道α-Al2O3陶瓷微滤膜为支撑体,采用溶胶凝胶法制备完整TiO2超滤膜。通过扫描电镜(SEM)表征膜的形貌,采用错流过滤方式考察膜的纯水通量、截留相对分子质量及分离性能。结果表明:制备的多通道TiO2超滤膜,其膜层表面完整,无裂缝、针孔等缺陷且厚度均匀,纯水通量为1.08×10-3L/(m2.h.Pa),截留相对分子质量为9 000。对直接黑OB染料及退浆废水中聚乙烯醇(PVA)的截留率均达到99%以上,截留效果显著。     

基于胶束强化超滤的金属离子去除技术研究进展

胶束强化超滤技术(MEUF)作为一种新兴的含金属废水处理技术,有着较好的应用前景.通过总结前人的研究结果,综合讨论了影响金属离子截留效果的各个因素,为优化MEUF提出了一些建议.并就当前采用胶束强化超滤法处理金属离子技术的最新发展与表面活性剂的循环再利用作了简要的介绍.     

Effect of frothers on removal of unburned carbon from coal-fired power plant fly ash by froth flotation

The effect of single frothers and their blends on bubble size, froth stability, and unburned carbon (UC) flotation performance was studied. Methyl isobutyl carbinol that produces smaller bubbles is efficient in floating ultrafine particles and producing concentrate. DF-250 that gives higher froth stability is effective for recovering coarse particles and improving recovery. The presence of DF-250 in the blend increases bubble size and significantly enhances froth stability, and hence the optimal flotation performance is achieved with 75% DF-250. It indicates that the frother giving high froth stability is better in UC flotation due to the little effect of UC on froth stability.