Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.     

多功能富氧净水器在养殖领域的研究与应用

多功能富氧净水器的研究,采用聚丙烯微孔滤膜、复合活性炭纤维、酸性洗涤纤维及复合炭粒作为过滤吸附材料,并采用三碘树脂杀菌剂和载银活性炭复合杀菌剂进行灭菌,应用"综合过滤渗透法"的机理,将净化、矿化、灭菌、增氧等有机结合并进行反复的研究和试验,有效去除了水中微生物、污染物,降低化学需氧量和水的硬度,达到净化水质,增加水中溶解氧等预期效果,成功的应用在水产养殖等领域。     

膜生物反应器中膜组件性能的对比研究

膜生物反应器中不同膜组件对废水的处理效果不同。论文主要对膜生物反应器中分别产自日本和德国的聚乙烯中空纤维膜膜组件处理生活污水的情况进行了考察,在给定的水力停留时间、污泥浓度、pH值等参数的条件下,对其膜组件性能进行了对比研究。通过对生活污水的降解试验发现,在相同的条件下,两种膜组件在浊度的去除方面均达到100%,并且系统处理出水COD均<50mg/L,去除率可分别达到86%和85%,但对氨氮去除两者均未达到60%,另外两种膜组件的膜通量的衰减相差较大,日本膜组件的衰减较缓慢而德国膜组件的衰减很快。     

金属纤维织物的屏波原理及其研究现状

以电磁辐射的危害及防护为切入点,介绍了金属纤维及其织物的屏蔽机理,阐述了其制备工艺、屏蔽效能的检测技术和主要影响因素,并对金属纤维屏蔽织物的进一步发展进行了展望。     

内压式中空纤维超滤膜污染模型研究

以流体力学和过滤理论为基础,建立了一个描述内压式中空纤维超滤膜污染的数学模型。该模型将膜的性质、原水的性质、清洗条件等多种因素对超滤过程的影响,用一个参数——膜堵塞系数表示。实验以造纸黒液稀释水为原水,对模型参数进行了拟合、验证,模拟计算结果与实验实测数据比较吻合,说明该模型能较好的模拟内压式中空纤维超滤膜过滤过程。     

复掺轻骨料纤维喷射混凝土力学及导热性能试验研究*

为有效隔绝高地温公路隧道、深部高温巷道施工过程中的围岩散热,利用正交试验方法,以不同复合陶粒、陶砂掺量、聚丙烯纤维为影响因素,设计出1种隔热效应的轻骨料纤维喷射混凝土（Lightweight Aggregate Fiber Shotcrete,LAFS）,进行含水率、抗压、劈裂抗拉及导热性能试验,并借助X射线衍射、扫描电镜对LAFS进行机理分析。结果表明:3种因素对LAFS力学及导热性能的影响程度均为陶粒掺量>陶砂掺量>聚丙烯纤维掺量,本试验条件下,复合双掺陶粒、陶砂分别取代石子、砂子的最佳体积率为12%,6%,聚丙烯纤维的最佳掺量范围为0.2%~0.3%。建立的LAFS各性能预测模型可为工程应用LAFS确定其配比时提供试验依据。     

活性炭纤维-固相微萃取技术快速检测烤肉中多环芳烃

文章采用新型活性炭纤维(ACF)做为固相微萃取(SPME)的萃取纤维与气相色谱-质谱(GC/MS)联用,建立了一种快速检测烤肉中持久性污染物多环芳烃(PAHs)的方法.烤肉由于其独特的风味深受人们喜爱.但是,在烤肉中含有致癌的PAHs,影响着人们的身体健康.烤肉中PAHs最佳提取条件为:2g匀浆样品,丙酮+甲醇(1∶0...     

无机添加剂对PVDF/PMMA/TPU中空纤维共混膜结构与性能的影响

采用相转化法制备纳米氧化物PVDF/PMMA/TPU共混中空纤维膜。测定共混膜的纯水接触角和黏度、并经扫描电子显微镜、共混膜的超滤实验和拉伸实验分别对不同添加剂膜的亲水性能、微观结构、超滤性能和机械性能进行了分析。结果表明,纳米氧化物的加入使膜的性能有明显的改善,其中无氧化物、添加SiO2、TiO2、Al2O3的PVDF/PMMA/TPU复合膜对牛血清白蛋白的截留率分别为28.7%、65.8%7、1.4%和79.6%,同时添加无机氧化物的膜水通量也较未添加无机氧化物的膜有所提高;而且无机氧化物的加入还能改善膜的亲水性能和机械性能。     

Polyphenylene sulfide based anion exchange fiber: Synthesis, characterization and adsorption of Cr(VI)

A fibrous strong base anion exchanger (QAPPS) was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber (PPS), and its physical-chemical structure and adsorption behavior for Cr(VI) were characterized by FT-IR, Energy Dispersive Spectrometry, TG-DTG, elemental analysis and batch adsorptive technique, respectively. The novel fibrous adsorbent could effectively adsorb Cr(VI) over the pH range 1-12, the maximum adsorption capacity was 166.39 mg/g at pH 3.5, and the adsorption behavior could be described well by Langmuir isotherm equation model. The adsorption kinetics was studied using pseudo first-order and pseudo second-order models, and the t_1/2 and equilibrium adsorption time were 5 and 20 min respectively when initial Cr(VI) concentration was 100 mg/L. The saturated fibers could be regenerated rapidly by a mixed solution of 0.5 mol/L NaOH and 0.5 mol/L NaCl, and the adsorption capacity was well maintained after six adsorption-desorption cycles.     

微电解-电/Fenton-曝气池工艺预处理高浓度亚麻废水

高浓度亚麻废水不宜直接进行生化处理。试验采用"Fe-C柱微电解-电/Fenton-曝气池"工艺对其进行预处理,即先采用Fe/C微电解,然后基于Fe2+的生成几乎同步引入电/Fenton反应,之后再调节流出液pH至碱性并鼓入空气以除去部分NH3-N。相应优化工艺条件为:Fe/C柱微电解时mFe/mC为2:1,废水停留时间为1.5 h;电/Fenton时双氧水(30%)滴加速度为0.025 mL/min;调节水样pH10并在空气流速为1.5 L/min的条件下空气吹脱1.5 h。采用该工艺预处理高浓度亚麻废水后,出水几乎为无色;固体悬浮物的去除率可达94.2%,NH3-N去除率可达71.4%,COD去除率可达51.8%,BOD5去除率可达28.3%,为后续生化深度处理创造了有利条件;BOD5/COD值由原来的0.12上升至0.19,废水的可生化性得到较明显的改善。电/Fenton反应的处理效果好于普通的Fenton反应,其原因可能是由于电/Fenton既有"原位"的均相/非均相Fenton反应发生,又有在微电解电场协助下的"电催化Fenton"反应发生。