活性污泥对管式多孔α-Al_2O_3陶瓷膜支撑体性能影响的初步研究

以剩余活性污泥作为支撑体的成孔剂,采用滚压成型及熔膜芯法制备管状多孔α-Al2O3陶瓷膜支撑体,研究了粘结剂羧甲基纤维素(CMC)和活性污泥的加入量对氧化铝陶瓷膜支撑体品质的影响。结果表明,随着成孔剂和粘结剂的增多,支撑体孔隙率和渗透通量呈增大趋势,孔隙率最大可达43.07%,纯水通量在0.4~1.0 MPa压力下变化范围为12 786.67~37 617.84 L/(m2·h·MPa)。     

两种不同造孔剂对粉煤灰-黄土基支撑体性能的影响

以粉煤灰、黄土为混合骨料,甲基纤维素作粘结剂,采用挤压成型法和固态粒子烧结法制备陶瓷膜支撑体,探究淀粉和聚甲基丙烯酸甲酯两种造孔剂对支撑体的孔隙形成、抗折强度、酸碱腐蚀率、物相组成、显微结构及纯水通量等性能的影响。结果表明,聚甲基丙烯酸甲酯添加量为15%时,各项参数基本优于淀粉添加量为10%时支撑体的各项表征,并且其成品内部孔隙均一,分布较为均匀,孔径均在6μm左右,酸碱质量损失率分别为0.24%/0.19%,孔隙率为35%,抗折强度为30 MPa,支撑体纯水通量为9 523.28 L/(m²·h·MPa)。     

活性炭掺杂对多孔氧化铝陶瓷支撑体结构及性能的影响

以平均粒径为4μm的a-Al2O3为起始原料、活性炭为成孔剂,通过干压成型法制备片状多孔Al2O3支撑体。研究了活性炭含量对多孔氧化铝支撑体结构和性能的影响。结果表明：活性炭在高温烧成过程中的氧化可显著提高支撑体的孔隙率,进而提高其渗透性能。当活性炭添加量为17％（质量分数）、烧成温度为1450℃时,支撑体的孔隙率、平均孔径、三点抗弯强度和纯水渗透通量分别达到45．8％,2．1μm,44．6MPa和88m3／（m^2·h·MPa）。经过80℃、10％NaOH溶液腐蚀20d后,支撑体的三点抗弯强度仍可以维持在23．4MPa,表明支撑体具有较好的耐碱腐蚀性能。     

成孔剂的量对多孔氧化铝支撑体孔结构的影响

以氧化铝为骨料,淀粉及其它有机粘结剂为成孔剂制备出管状多孔氧化铝支撑体。系统地考察了成孔剂对多孔氧化铝支撑体孔结构的影响。研究表明:当支撑体中成孔剂的质量分数 <10%时,支撑体的孔隙率稳定在35%左右。当成孔剂的质量分数在 10% ~25%之间时,支撑体的孔隙率随成孔剂量的增大而显著增加。当成孔剂的质量分数>25%时,在保证支撑体完整性的前提下,支撑体的孔隙率随成孔剂量的增大变化不大,稳定在 45%左右。成孔剂质量分数的增加会使支撑体的平均孔径增大,孔径分布变宽,平均孔径与最可几孔径的差值增大。     

多孔氧化铝陶瓷膜支撑体的制备与表征

以粒径为0.5μm的超细氧化铝粉为原料,加入成孔剂和粘接剂,经干压成型及高温烧结制备出多孔氧化铝陶瓷膜支撑体。制备过程中,以纯水通量为实验指标进行正交试验,分别研究烧结温度、粘结剂含量、成型压力以及聚乙烯醇(PVA)浓度对膜性能的影响程度,并确定制备氧化铝支撑体的最佳工艺条件。使用扫描电镜(SEM)和聚乙二醇(PEG)截留实验对支撑体的微观结构和性能进行表征。实验结果表明:烧结温度和粘接剂含量对支撑体的纯水通量影响高度显著,成型压力和PVA浓度几乎无影响;加入1.75%(w)的粘接剂,80mg/mlPVA溶液2ml,采用9MPa的成型压力和1535℃的烧结温度制备的氧化铝超滤膜支撑体的纯水通量为60kg/(m2h),截留分子量(MWCO)为8 500。     

烧结温度对氧化铝陶瓷膜支撑体性能的影响

实验以α-Al_2O_3为骨料,TiO_2-MnO_2-MgO为复相烧结助剂,采用挤压成型法和固态粒子烧结法制备Al_2O_3陶瓷膜支撑体,并探究烧结温度对陶瓷膜支撑体性能的影响。通过压汞法、自制纯水通量测定装置、三点弯曲法、质量损失法、X-射线衍射(XRD)、扫描电镜(SEM)等方法对α-Al_2O_3陶瓷支撑体的孔隙率、纯水通量、抗折强度、酸碱腐蚀率、晶相变化以及表面形貌等微观结构进行分析表征。研究结果表明:TiO_2-MnO_2-MgO能显著降低α-Al_2O_3陶瓷支撑体的烧结温度,烧结温度低于800℃,无法提供足够的激活能,支撑体没有新相生成;超过1 300℃时,支撑体纯水通量随着烧结温度升高而急剧下降。当烧结温度为1 300℃时,制得的支撑体性能良好,孔隙率达到了44.84%、抗折强度为80.21 MPa、纯水通量为8 979.37 L/(m~2·h·MPa)、酸/碱腐蚀质量损失率为0.87%/1.09%。     

烧结制度对铝矾土/黄土基支撑体性能影响

试验以铝矾土和黄土为骨料,白云石为成孔剂,采用滚压成型法和固态粒子烧结法制备低成本无机陶瓷膜支撑体,并探究烧结制度对支撑体性能的影响。通过X-射线衍射(XRD)、扫描电镜(SEM)、压汞法、三点弯曲法、质量损失法、自制纯水渗透率测定装置等方法对支撑体的晶相变化、微观形貌、孔隙率、抗折强度、酸碱腐蚀率、纯水渗透率进行分析表征。结果表明:支撑体晶相组成主要为刚玉(Al_2O_3)、石英(SiO_2)、莫来石(3Al_2O_3·2SiO_2)和钙长石(CaO·Al_2O_3·6SiO_2);烧结温度为1 140℃,保温9 h制备出的支撑体综合性能最优,此时的支撑体纯水渗透率为4.02 m~3/(m~2·h·MPa),抗折强度为30.24 MPa,孔隙率为28.59%,耐酸、碱腐蚀率分别为97.73%和99%。     

SiO2基多孔陶瓷膜支撑体的制备

以海泡石矿物为原料,通过干压成型制备了氧化硅( SiO2)基多孔陶瓷膜支撑体,研究了烧成温度对制备试样的物相组成、微观结构、平均孔径、孔隙率、纯水渗透通量和抗弯强度的影响.结果表明,经1100 ～ 1200℃保温2h烧成制备的SiO2基多孔陶瓷支撑体试样主要由石英主晶相和少量滑石晶相组成,具有良好的结构与性能,可用于SiO2复合陶瓷膜的制备.1200℃烧成制备的试样孔隙率和平均孔径分别为31.4％和1.72 μm,其水通量和抗弯强度分别可达到20.30 m3·m-2·h-1·bar-1和61.0 MPa.     

烧结温度对黄土陶瓷膜支撑体性能的影响

实验以洛川黄土为骨料,十二烷基苯磺酸钠(SDBS)为烧结助剂.利用滚压成型法、固态离子烧结法来制备黄土陶瓷膜支撑体,并对制备的支撑体的性能影响因素进行了探究.通过压汞法、三点弯曲法、X-射线衍射(XRD)、扫描电镜(SEM)以及自制装置对支撑体试样进行测试.分别研究孔径分布、孔隙率、抗折强度、晶相变化、表面形貌、酸碱腐蚀率以及纯水通量等对黄土陶瓷膜支撑体性能的影响.研究结果表明:十二烷基苯磺酸钠能显著降低黄土陶瓷膜烧结时候的温度.当烧结温度小于1000℃时,支撑体中没有新物质生成;当烧结温度大于1090℃时,纯水通量随烧结温度的升高呈现出下降趋势;当烧结温度恰好达到1070℃,此时制得的支撑体性能良好,中值孔径为6975.9 nm、抗折强度37.83 MPa、孔隙率20.65％、纯水通量1943.70 L/(m2·h·MPa)、酸/碱腐蚀率0.340％/0.195％.     

低成本大孔陶瓷膜支撑体的制备与表征(英文)

以高岭土和白云石为主要原料,通过反应烧结法制备低成本大孔陶瓷膜支撑体,对制备的支撑体进行了结构和性能表征.结果表明:在高岭土中引入质量分数为20%的白云石,可显著抑制高岭土的高温烧结;加入白云石后制备的支撑体在1 150~1 300℃保温1h后,主晶相为莫来石、堇青石和钙长石,平均孔径和抗弯强度随烧成温度升高而增大,而水通量和孔隙率降低;加入20%白云石并在1 250℃保温1 h制各的大孔支撑体的孔隙率和平均孔径分别为44.6%和4.7μm,抗弯强度和纯净水通量分别达到47.6MPa和10.76m3/(m2·h·bar).     

Influence of dextrin content and sintering temperature on the properties of coal fly ash-based tubular ceramic membrane for flue gas moisture recovery

In this paper, in order to reduce the preparation cost of high-performance ceramic membrane, coal fly ash-based tubular ceramic membrane for flue gas moisture recovery was prepared, and its properties were optimized from two aspects: pore-forming agent (dextrin) content and sintering temperature. The results show that the ceramic membrane with dextrin content of 3 wt.% and sintering temperature of 1150 ℃ has the best performance. Through characterization, the ceramic membrane exhibits an open porosity of 42.0 %, mechanical strength of 26.6 MPa, average pore size of 0.49 μm, pure water flux of 5616 L/(m² barh). And, it has excellent corrosion resistance in acid and alkali. In addition, the flue gas moisture recovery performance of coal fly ash-based tubular ceramic membrane was studied experimentally. The highest water recovery ratio and the highest recovered water flux is 87.7 % and 6.01 kg/(m² h, respectively.     

Preparation and characterization of new tubular kaolino-illitic ceramic membrane used for dairy wastewater treatment

Low cost asymmetric tubular ceramic membrane was developed from kaolino-illitic clay collected from the region of Medenin (Tunisia). The obtained membrane was designed to be used for ultrafiltration. The effect of pore forming agent on the plasticity, porosity, pore size distribution, mechanical strength, and permeability was evaluated. The support was performed by extrusion using the raw clay and olive pomace (OP) as pore forming agent. The effect of the use of OP was noticeable; it improved the plasticity of the paste. Also it helped to ameliorate both permeability and porosity of the obtained supports. Top layer was prepared using acid activated clay suspension. The obtained membrane had gas permeability of about 13 cm³.s⁻¹.cm⁻².bar⁻¹ at a pressure of 1.5 bar and water flux of 1700 L.h⁻¹.m⁻² at a pressure of 1 bar. The final membrane was successfully used to eliminate the fat present in a solution containing 10% of milk. Regeneration of the used membrane was carried out by calcination at 550°C. The performances of the used membrane were recovered by 97% after regeneration.     

Short-term fouling propensity and flux behavior in an osmotic membrane bioreactor for wastewater treatment

The short-term fouling behavior of forward osmosis (FO) membrane in an osmotic membrane bioreactor (OMBR) was investigated, using NaCl or MgCl₂ as the draw solutions. The effect of membrane orientation, mixed liquor suspended solids (MLSS) concentration and draw solution (DS) osmotic pressure on water flux and membrane fouling behaviors was examined, along with the effects of simulated elevated salinity on sludge properties and on membrane fouling. Water flux and membrane fouling were not significantly affected by both MLSS concentration (4.91–12.60 g/L) and osmotic pressure (3.0–15.0 MPa), but were severely affected by elevated salinity, due to changes in activated sludge properties, in particular the increase in extracellular polymeric substances (EPS) and sludge hydrophobicity. MgCl₂ as the DS showed more significant influence on activated sludge properties and membrane fouling than NaCl but gave rise to lower salt accumulation. Analyses of the membrane foulants showed that small sludge floc/particles and EPS (in particular, proteins) were enriched in the fouling layer. UPLC–MS/MS analyses of the proteins showed that hydrophobic proteins were the main cause of membrane fouling.     

炼油净化水结垢原因分析及膜法深度处理

对炼油厂净化水回用过程结垢原因进行分析,针对结垢成因采用陶瓷膜对净化水做深度处理,而经膜处理后净化水pH在6.9左右,净化水呈中性,试图使得炼油净化水达到工艺水回用目的.着重考察了膜孔径、操作压差、膜面流速、料液温度等对膜通量的影响.结果表明,孔径为50nm的氧化锆陶瓷膜处理炼油净化水其渗透通量高达800L·m~2·h~(-1),渗透液中COD小于200mg·L~(-1);体系的操作压差可控制在0.25MPa,较大的膜面流速大和料液温度有利于渗透通量的提高;膜污染的清洗采用在线反冲和离线化学清洗的方法,料液渗透通量可恢复到新膜的95%.     

Waste environmental sources of metakaolin and corn cob ash for preparation and characterisation of green ceramic hollow fibre membrane (h-MCa) for oil-water separation

This study describes the preparation of green ceramic hollow fibre membranes derived from metakaolin (MK) and corn cob ash waste (CCA) as membrane support for water filtration and oil-water separation using phase inversion and sintering techniques. Pristine MK membrane is closely associated with its brittleness property and possesses low strength. In this study, a proportion of MK was substituted with corn cob ash (CCA), an agricultural waste by-product as pore forming agent material and sintering aid in preparing MK–corn cob ash hollow fibre membrane (h-MCa) for enhanced permeation and strength properties. MK:CCA ratio loadings at 35 wt % of powder were adjusted for fibres A-100:0, B-75:25, C-50:50, D-25:75, and E−0:100. The SEM image supported by EDSA revealed the high agglomeration of CCA–SiO₂ particles coated with KCl, as the XRD analysis displayed mainly the crystal phases of KCl. The high content of CCA–KCl revealed its significant effect as body shaping and body forming in preform controlling the h-MCa suspension matrix structure. The viscosity of the suspension correlated with the dissolution of KCl in NMP suspension and MK–CCA fraction ratio to effectively function as a green enhancer and porogen towards the particle arrangement in the ceramic membrane matrix. The feasibility study showed that fibre B exhibited higher permeability (1359.93 L/m²h), oil/water removal efficiency (74.73%), and CCA maintained superior mechanical strength (41.61 MPa) at a significant low sintering temperature of 1200 °C, as the CCA possessed a great fluxing agent in the sintered membrane. Therefore, this study proved that green MK–CCA was effective, sustainable, and ecologically environmentally friendly for ceramic membrane support applications.     

次毫米过滤组件分区高含量污泥试验研究

采用次毫米过滤(SMF)组件实现高含量污泥(MLSS)分区(A区和B区),为膜生物反应器(B区)的稳定高效运行提供适宜的污泥质量浓度(5.0～10.0 g.L-1)。研究了回流体积比≥2.0条件下SMF组件(孔径0.47 mm)分离高含量污泥的运行特征及分区效果,对比分析了两区微生物实测与理论含量的差异,并考察了SMF组件耦合A区对营养物的去除效果。结果表明,在分离高含量污泥时,目标B区的污泥的质量浓度为2.0～10.0 g.L-1,对膜生物反应器是适用的;对应A区的污泥的质量浓度在15.5～33.5 g.L-1。SMF组件滤出液MLSS的质量浓度在1.4～4.2g.L-1,平均通量可达192 L.m-.2h-1。此外,SMF组件耦合A区对COD的去除率在82%以上。     

高通量陶瓷膜研制及其除藻性能的初步研究

针对富营养化水中藻细胞的去除,研制了通量大、强度符合使用要求的无机陶瓷膜。所研制的陶瓷膜具有通量大、过滤精度高、易反冲再生等优点。过滤压差为0.08MPa时,清水通量为15.79m^3/（m^2·h）,对水中微型颗粒物的分离精度为0.06μm,且可反冲再生。对富营养化湖水深度处理实验表明,该陶瓷膜可有效去除“混凝-沉淀-砂滤”工艺出水中残存的藻细胞;对水中CODMn、TP也有一定的去除效果。研究结果为富营养化源水中藻细胞的去除提供了新的技术途径。     

Experiment and calculation of filtration processes in an external-loop airlift ceramic membrane bioreactor

Air sparging is recognized as an effective way to increase permeate flux in membrane filtration processes. The application of air sparging with an external-loop airlift ceramic membrane bioreactor was studied at different gas flow rates, biomass concentrations and suction pressures. A 180% increase in permeate flux was obtained while filtering a 2 g/L activated sludge wastewater suspension with the airlift cross-flow operation for U_g=0.21 m/s. The mechanism of flux enhancement in the case of slug flow in tubular membrane was discussed. The region near the gas slug was divided into three different zones: falling film zone, wake zone and remaining liquid slug zone. Air sparging significantly lowered cake thickness and consequently cake resistances for the wake region and the falling film region. A novel model combining hydrodynamic of gas-liquid two-phase flow and cake resistance was developed to simulate the process. The model was validated with experimental data with an error of 8.3%.     

陶瓷膜处理高硬度深井水的研究

采用碱处理剂并结合外压管式陶瓷微滤膜对四川彭山地区深井水(水中钙镁以CaCO3计为625～1000ppm)进行处理,比较了经预处理后的膜管与未预处理的膜管其膜通量衰减的差异,并采用超声波对污染后的陶瓷膜进行了清洗。结果表明加入碱处理剂能有效降低深井水的硬度,经预处理后的膜管通量衰减较慢,适宜的操作压力和温度能得到较高的通量。