季铵盐壳聚糖膜对水体中十二烷基苯磺酸钠吸附的研究

以壳聚糖为原料,制备季铵盐壳聚糖膜(QCSM)吸附剂,研究吸附剂对十二烷基苯磺酸钠(SDBS)的吸附性能,考察了溶液pH值、吸附时间、浓度和温度的影响。结果表明,吸附适宜条件的为:pH 4.0,吸附时间120 min,吸附过程可以很好地用准二级动力学方程描述,吸附等温线用Langmuir方程的拟合效果优于Freundlich和Tempkin方程。在热力学研究表中,ΔG0<0,ΔH0>0,ΔS0>0,表明此吸附过程是自发、吸热和熵增加的过程。     

A novel method to synthesize polyaluminum chloride with a membrane reactor

Al13 or Alb is usually regarded as the most efficient species of polyaluminum chloride(PAC), the performance flocculant for water treatment. This paper was intended to report a new method to synthesize PAC with high content Alb, by using the membrane reactor. NaOH solutions were managed to permeate slowly through the micropores of ultrafiltration membrane into AlCl3 solutions under the suitable transmembrane pressure(TMP). Meanwhile NaOH drops size was limited to nano-scale, resulting in dramatical reduction of the characteristic diffusion time and great increment of contact interface between the strong base and AI ions in solution to favor the formation of Al(OH)4^-, the precursor of AI,3, so few precipitates and much Alb are produced. When the initial concentration of AlCl3/NaOH is 0.40/2.0 (mol/L), MWCO = 10000, TMP = 0.0085 MPa, T= 305 K and B(molar ratio of OH^-/Al^3 ) = 2.25, the quantity of Alb attains about 80%. The results of ^27Al-NMR determination showed that the Al13 content is equal to Alb content. And our PAC product has shown better flocculation effects than the commercial product.     

Methanation and chemolitrophic nitrogen removal by an anaerobic membrane bioreactor coupled partial nitrification and Anammox

● Efficient carbon methanation and nitrogen removal was achieved in AnMBR-PN/A system. ● AOB outcompeted NOB in PN section by limiting aeration and shortening SRT. ● The moderate residual organic matter of PN section triggered PD in anammox unit. ● AnAOB located at the bottom of UASB played an important role in nitrogen removal. An AnMBR-PN/A system was developed for mainstream sewage treatment. To verify the efficient methanation and subsequent chemolitrophic nitrogen removal, a long-term experiment and analysis of microbial activity were carried out. AnMBR performance was less affected by the change of hydraulic retention time (HRT), which could provide a stable influent for subsequent PN/A units. The COD removal efficiency of AnMBR was > 93% during the experiment, 85.5% of COD could be recovered in form of CH₄. With the HRT of PN/A being shortened from 10 to 6 h, nitrogen removal efficiency (NRE) of PN/A increased from 60.5% to 80.4%, but decreased to 68.8% when the HRT_PN/A further decreased to 4 h. Microbial analysis revealed that the highest specific ammonia oxidation activity (SAOA) and the ratio of SAOA to specific nitrate oxidation activity (SNOA) provide stable NO₂⁻-N/NH₄⁺-N for anammox, and anammox bacteria (mainly identified as Candidatus Brocadia) enriched at the bottom of Anammox-UASB might play an important role in nitrogen removal. In addition, the decrease of COD in Anammox-UASB indicated partial denitrification occurred, which jointly promoted nitrogen removal with anammox.     

无矩阵迭代法在膜结构风振耦合分析中的应用

提出在采用浸入物体法(IOM)对膜结构和空气流体建模时,可以采用带有预定条件的无矩阵Newton-Krylov迭代算法求解浸入物体法,并引入了预定条件矩阵。将提出的无矩阵迭代方法应用于一双坡型膜结构的风振耦合分析中,得出了结构的风压和风速分布,并对带有预定条件和不带预定条件的无矩阵迭代算法进行了对比。结果表明,将带有预定条件的无矩阵迭代算法应用于膜结构风振的耦合分析中,可以得到准确结果,并使计算效率大大提高。     

膜分离技术治理糠醛废水

糠醛生产废水中含1—2.5％的乙酸,若废水外排,会造成大量损失且污染环境.通过30—80对膜组装的400×800mm电渗析器中试操作,回收了浓度为20％的乙酸,再经萃取、精馏工艺得到工业一级乙酸.治理后的废水含酸量为0.02—0.05％,可安全排放及回用.中试技术指标优于小试,重现良好.     

大豆中磷脂的提取技术研究

用酶解法(羧酸水解酶)使大豆油中不溶于水的非水合磷脂转化为能溶于水的溶血性磷脂,使油脂中的磷含量小于或等于10×10-6,使用膜去除杂质后再离心分离。实验结果表明,使用膜技术和离心法联用的新工艺较为经济实惠,操作简单,附加值较高。     

Recent trends in treatment technologies of emerging contaminants

In the recent years a group of contaminants, known collectively as emerging contaminants (ECs), have attracted considerable attention due to their widespread in the environment, and lack of knowledge on their impacts on ecosystem and human health. This review gives an overview on the sources, impacts, and conventional treatment technologies of ECs and an in-depth review of the literature on the state-of-the-art treatment technologies and their performance in the removal of ECs from water sources and drinking water. A careful statistical analysis of the number of publications on the different treatment technologies of ECs was performed to identify the hot spots in this research area. Conventional treatment technologies are not able to remove ECs sufficiently. The discharge of raw or partially treated wastewater is the main source of ECs in the environment. The research in recent years is focusing on using advanced treatment process (AOPs), followed by adsorption and membrane technologies. From a technical point of view, AOPs surpass other treatment technologies as they can completely eradicate ECs without the generation of side products. Developing efficient, green, and cost-effective materials to be used as adsorbents, photocatalysts, membranes, or membrane fillers, is one of the main research trends nowadays. Combined AOPs based on exploiting solar light, ultrasound and electrochemistry are gaining growing interest and show high potential for the treatment of ECs.     

Tailor-made FAU zeolite composite membrane for wastewater treatment

In this work, a novel multipurpose Faujasite (FAU) zeolite composite membrane was fabricated by in-situ hydrothermal method to separate different solute molecules such as vanillic acid, phenol, and brilliant green from the aqueous solution. The coal fly ash based ceramic substrate was synthesized and used as substrate for preparing the zeolite composite membrane. The X-ray diffraction (XRD) pattern confirmed the crystalline nature of membranes and the presence of Quartz and hematite in the composite membrane. The presence of Si-O and Al-O in zeolite coated composite membrane was confirmed by Fourier Transform infrared spectroscopy (FTIR) analysis. Scanning electron microscope (SEM) analysis showed the porous structure and 8.34 μm thickness of zeolite coating on membrane. The isoelectric point of composite membrane was observed at pH 2.07 through zeta potential analysis. Brunauer-Emmett-Teller (BET) surface area, average pore volume and pore diameter of zeolite composite membrane were estimated as 6.406 m²/gm, 0.0070 cm³/gm, and 4.371 nm, respectively. The hydraulic pore radius and porosity of composite membranes were 27.7 nm and 20.1%. The maximum separation efficiency of FAU zeolite composite membrane towards vanillic acid, phenol and brilliant green was estimated as 78.67%, 89.13%, and 94.28%, respectively, for 200 mg/L feed concentration at 276 kPa applied pressure. The results obtained in this study reveals that the multipurpose FAU zeolite composite membrane fabricated in this study can be effectively used for separation of various solutes molecules present in the wastewater.     

基于氧猝灭的有机改性溶胶-凝胶微生物传感器测定BOD的研究

通过有机改性溶胶凝胶PVA包埋方法固定微生物菌株，以氧光化学传感器作为二次传感，制备了响应良好的光化学BOD微生物传感器．在此基础上，考察了微生物传感膜的活化浓度、温度、pH、无机盐及部分金属离子对传感器响应的影响．并对传感器的重现性、储存稳定性和线性范围进行了考察，实验结果表明BOD含量在0—100mg/L浓度范围内与传感器的荧光值成线性关系，传感膜的响应活性保持较好，具有较长的使用寿命和良好的稳定性．     

采用浸没式超滤膜技术处理东江水的中试研究

以混凝沉淀为预处理,通过中试试验,对浸没式超滤膜处理东江水的最佳运行方式进行了研究.考察了气洗周期为24h时,膜通量及浓缩液水质的变化规律.结果表明,过滤48h后,膜通量变化趋于平缓,气洗逐渐失去作用;除曝气后4h,浓缩液主要水质指标含量均接近或低于膜装置进水.对3种不同运行方式进行比较,认为水洗周期48h和气洗周期24h相结合的运行方式最为适宜,连续运行30d,单位水洗周期内的平均膜通量由39.8L/(m2·h)降至30.3L/(m2·h).