深层滤床反冲洗技术及其油田水处理领域应用进展

深层滤床过滤作为油田污水高效处理最重要的环节之一,滤床稳定运行的关键在于有效反冲洗。随着含油废水中聚合物浓度不断增大,聚合物吸附和滞留于滤床内,与滤料颗粒相互黏结,滤床反冲洗不彻底,导致滤床板结、过滤效率降低甚至作用失效。为了解决这一问题,本文介绍了重力作用下滤料反冲洗再生原理,回顾了单独水反冲洗技术、气水联合反冲洗技术及其加载场强化水力反冲洗技术,提出了一种颗粒滤床复合场反冲洗的新方法,将旋流场加载于滤床重力场的水力反冲洗过程,可以突破重力作用下滤料反冲洗再生效率低的技术瓶颈,丰富和发展了滤床水力反冲洗理论,为油田颗粒滤床反冲洗再生开辟新途径。     

上向流悬浮滤料滤池反冲洗的特性

通过中试试验和实际工程研究了上向流悬浮滤料滤池的反冲洗特性。中试结果表明,当滤速为8 m/h时,反冲洗周期宜为24 h,出水SS稳定且能达到一级A排放标准。通过中试滤池窗口观察,反冲洗时,滤料处于流化状态,且快速下落的水流对滤料扰动剧烈。显微照片显示反冲洗后滤料间空隙及表面均很清洁。水反冲洗能恢复滤池的过滤能力。工程结果表明,反冲洗时间为2、5、10 min时,滤池均能稳定运行,出水浊度稳定在1.32~1.51 NTU。从滤池反冲洗后恢复时间以及经济性两方面综合考虑,反冲洗时间2min为宜。     

核桃壳过滤器超声波辅助反冲洗实验研究

基于国内油田常用的核桃壳过滤器,对反冲洗进行了深入系统的实验研究。确定单独水反冲洗的反冲洗时间为10min、反冲洗强度为12m3·.h-1,但对于滤料的再生效果不够理想,且反冲洗强度较高、耗水量大;采用正交实验,确定超声波辅助反冲洗的超声波频率为30kHz、超声波功率为0.7kW、反冲洗时间为12min、反冲洗强度为8m3·h-1;并对两种方式的反冲洗效果进行了对比,发现超声波辅助反冲洗初始过滤压降下降极为明显,反冲洗效果优于单独水反冲洗,并能延长过滤周期、减少反冲洗次数、节约能耗及用水量,应用前景广阔。     

轴向动态反冲洗过滤器过滤含聚污水试验研究

研制一种新型的轴向动态反冲洗过滤器,并开展了过滤含聚污水现场试验,考察了油和悬浮物的去除效果、反冲洗强度、反冲洗历时及滤料反洗再生效能。试验结果表明:该技术过滤含聚污水效果良好,油和悬浮物去除率分别为96.0%和78.1%。反冲洗强度8.8 L/(s·m2)、反洗历时15 min时,过滤器内截留油排除率96.23%,核桃壳滤料油去除率为98.93%,反洗前后滤料表面油量变化明显。     

强化反冲洗在单水反冲滤池的实践应用

单水反冲滤池反冲洗方式单一、冲洗强度不足,导致滤池过滤效果下降,滤池出水水质波动,水厂供水安全难以保障。针对该问题,研究提出一种双阀滤池强化反冲洗方式,有效地解决了不具备升级改造条件的老旧中小水厂单水反冲滤池导致过滤效果下降问题。该改造方案主要通过曝气装置对滤池滤料进行人工曝气冲洗,实现滤池气-水结合反冲方式,恢复滤池过滤效果,实现滤池稳定高效运行。人工曝气处置后,滤池运行效果显著提升,出水浑浊度由0.24 NTU降低至0.16 NTU,滤池颗粒物去除率提高了12%;反冲洗周期由12 h延长至16 h,反冲水量年度节约了10.8万m³。该人工曝气方案投资少、无需对原有工艺进行升级改造,不会影响水厂正常运营生产,简单适用,可在存在相似问题的中小水厂推广使用。     

低压稳流核桃壳过滤器的开发及在油田废水处理中的应用

为了解决现有核桃壳过滤装置反冲洗憋压、跑料、滤料再生困难的问题,经过分析,根据反冲洗理论,对过滤器进行改造,开发出低压稳流核桃壳过滤器。通过现场测试,证明低压稳流核桃壳过滤器反冲洗压力可以由原来的0.15~0.40 MPa降低到0.03~0.06 MPa,且能够实现罐群水反冲洗,反冲洗效果好,滤料再生效果好。干净的滤料使进水压力由原来的0.15~0.30MPa降到0.10~0.20 MPa,改善了出水水质,含油质量浓度平均<10 mg/L。     

改性滤料对油田污水除油效果的影响研究

对核桃壳滤料表面进行活性改性,并将其用于含聚含油污水的处理。结果表明,当滤料填充高度为350 mm时,较未改性滤料,其除油率可提高25%~28%,反冲洗除油效果提高91%;当滤料填充高度提高到1 450 mm时,较未改性滤料,其除油率可提高34%。在过滤-反冲洗3个循环中,改性滤料较未改性滤料的反洗除油效果由44.8%提高到66.9%。改性滤料截留油污后容易被反冲洗除去而再生。相比于未改性滤料,过滤处理相同量的含油污水其寿命延长2倍以上。     

防止煤砂双层滤料滤池跑煤的反冲洗方式

本文根据对无烟煤，石英砂双层滤料气-水反冲洗的试验研究结果，提出了有效防止双层滤料跑料的气水反冲洗参数和操作程序。     

快滤池气水反冲洗技术的研究与设计

本文对快滤池滤料层中产生泥球，或使滤料层板结的原因进行了分析讨论，对气水反冲洗的机理进行了研究，进而提出了气水反冲洗技术应用于快滤池的必要性，并提出了可供设计选用的有关参数和注意事项。     

快滤池气水反冲洗技术的研究与设计

本文对快滤池滤料层中产生泥球，或使滤料层板结的原因进行了分析讨论，对气水反冲洗的机理进行了研究，进而提出了气水反冲洗技术应用于快滤池的必要性，并提出了可供设计选用的有关参数和注意事项。     

Toward an Optimization of the Backwashing Process in the Flexible Fiber Filter

Abstract

Backwashing process was used to recover the retention capacity of a deep bed filter. A field scale fiber filter was operated with an in‐line injection of a coagulant for the treatment of natural surface water (Nak‐dong River in Korea). A mass balance of SS could be made thus allowing a direct estimation of the effectiveness of the backwashing process. The purpose of this paper was to study the influence of two parameters of backwashing (air injection and number of backwashing stages) on its effectiveness. The backwashing efficiency was estimated through the initial pressure drop after the backwash, the effluent quality, the duration of the filtration time between two successive backwashes, and the detached mass of retained suspended solids. Conditions could be found for removing 99% of the retained SS. As a general conclusion, the effectiveness of backwashing mainly depended upon air injection. The duration of air injection and the number of sequences were the most important factors related to the efficiency of backwashing.     

Suspension concentration profiles during rapid gravity filter backwashing

Rapid gravity, granular media filters are widely used in the water and wastewater treatment industries. Regular backwashing to clean the filters is a vital part of their efficient operation. Experimental data on the development of suspension concentration profiles through laboratory scale filter beds during the backwash process were obtained. Previous attempts to obtain and record backwash profiles of this type have been unsuccessful due to the limited range of existing turbidimeters. The results have been used to validate a new model developed by the authors.     

纤维球过滤器在应用中出现问题的讨论

介绍了纤维球的特点及发展。概述了纤维球过滤器的在运行过程中暴露出的反冲洗问题、过滤速度的确定、滤床压紧量的确定、纤维球大小的选择、纤维球内部积泥、纤维球反洗强度等问题,并针对这些问题的改进措施进行了总结。     

场作用下的滤料反冲洗技术及发展

深床过滤技术是油田污水处理领域的重要环节,影响其运行关键在于滤床的有效反冲洗过程。通过对反冲洗理论和技术现状分析,提出反冲洗中场的概念,探讨反冲洗中场的作用形式,用场的视角来分析反冲洗技术。并基于不同功能场构建旋流场和重力场耦合的复合场反冲洗体系,提出的一种轴向动态复合场反冲洗理论,该理论丰富和发展滤料水力反冲洗方法,并为解决油田高含聚滤料反洗再生提供一种新途径。     

天然气过滤器反冲洗技术探讨

我国天然气中粉尘含量较高,经常影响生产设备的使用,急需研究高效反冲洗技术。研究适合天然气过滤的设备,具有非常大的经济效益。目前反冲洗技术在制药、纯净水生产等领域使用很广泛,使用效果非常好,但是国内外都还没有研究出适合天然气领域的反冲洗技术。根据其它行业反冲洗技术的经验,对天然气反冲洗过滤器的设计提出两点建议:在天然气领域反冲洗技术只适合立式过滤器,滤管要使用采用不锈钢密纹网过滤管和膜分离滤管。     

Variations in backwash efficiency during colloidal filtration of hollow-fiber microfiltration membranes

A series of filtration experiments was performed systematically to investigate physical and chemical factors affecting the efficiency of backwashing during microfiltration of colloidal suspensions. In this study, all experiments were conducted in dead-end filtration mode utilizing an outside-in, hollow-fiber module with a nominal pore size of 0.1 μm. Silica particles (mean diameter = 0.14 μm) were used as model colloids. Using a flux decline model based on the Happel's cell for the hydraulic resistance of the particle layer, the cake structure was determined from experimental fouling data and then correlated to backwash efficiency. Modeling of experimental data revealed no noticeable changes in cake layer structure when feed particle concentration and operating pressure increased. Specifically, the packing density of the cake layer (1-cake porosity) in the cake layer ranged from 0.66 to 0.67, which corresponds well to random packing density. However, the particle packing density increased drastically with ionic strength. The results of backwashing experiments demonstrated that the efficiency of backwashing decreased significantly with increasing solution ionic strength, while backwash efficiency did not vary when particle concentration and operating pressure increased. This finding suggests that backwash efficiency is closely related to the structure of the cake layer formed during particle filtration. More densely packed cake layers were formed under high ionic strength, and consequently less flux was recovered per given backwash volume during backwashing.     

臭氧-上向流生物活性炭工艺运行参数的优化

以典型含氮消毒副产物(N-DBPs)--二氯乙腈(DCAN)和二氯乙酰胺(DCAM)前体物的去除为目标,综合考虑浑浊度、CODMn、溶解性有机碳(DOC)、溶解性有机氮(DON)等指标的去除效果。通过调整臭氧投加量、上升流速、反冲洗周期、反冲洗时间4个因素,研究臭氧-上向流生物活性炭(O3-UBAC)工艺对典型N-DBPs的去除效果,确定O3-UBAC工艺的最佳运行参数:在春季和秋季时,最佳臭氧投加量为1.2 mg/L,最佳上升流速为9 m/h,最佳反冲洗周期为11 d;在夏季藻类暴发时,最佳臭氧投加量为1.6 mg/L,最佳上升流速为10 m/h,最佳反冲洗周期为9 d;在初冬蟹塘排水时,最佳臭氧投加量为1.5mg/L,最佳上升流速为8 m/h,最佳反冲洗周期同夏季,为9 d。春夏秋冬四季O3-UBAC工艺的最佳水反冲洗时间为30 min。     

氧化铁改性石英砂过滤性能及反冲洗效果研究

对自制涂铁砂进行过滤和反冲洗试验,研究不同滤层(每层为12 cm)的截污性能,并与原始石英砂和活性炭-涂铁砂组合滤料的性能进行对比研究,探讨涂铁砂对浊度和有机物的过滤效果及其再生能力。结果表明,(1)涂铁砂存在一个使用成熟期,约3个工作周期。成熟期后,其对浊度和有机物的去除率最高,为96.5%、75.4%。(2)涂铁砂对浊度的有效截污滤层集中在前2层,总去除率为88.73%。(3)经相同强度气水反冲洗后,涂铁砂滤层厚增加幅度最大(为5 cm),过滤周期为石英砂的1.5倍。(4)改进后的气水反冲洗强度为:气冲4 min,q气=12L.m-.2s-1;气水同时冲5 min,q气=12 L.m-.2s-1,qNaOH=10 L.m-2.s-1,NaOH=0.1 mol.L-1;清水漂洗3 min,q水=10 L.m-2.s-1。(5)反冲洗后,活性炭-涂铁砂组合滤料中涂铁砂表面的块状及针状形态学特征不变,对有机物的去除效果保持不变,为74.1%。     

Filtering surface water with a polyurethane-based hollow fiber membrane: effects of operating pressure on membrane fouling

Membrane fouling seriously restricts applications of membrane technology. A novel strategy was ap-plied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane. A polyurethane-based hollow fiber membrane was used to treat surface water for evaluating the effect of operating pressure on membrane fouling. Some bench-scale tests in dead-end mode were carried out. In the experi-ments without backwashing, as operating pressure increased, severe membrane fouling occurred on membrane sur-face, while the permeate quality was improved obviously, which is considered to be due to shrinkage deformation. The total resistance, irreversible resistance and reversible resistance under different backwash pressures were de-termined in filtration/backwashing test. With the increase of backwash pressure, the total resistance decreased, and more importantly, the irreversible resistance also decreased, which implies that small particles deposited inside membrane pores and cake layers on membrane surface are effectively removed. Similar results could be obtained in mass balance tests. The results of the present study indicate that the application of pressure responsibility membrane in surface water treatment may be an effective strategy for reducing membrane fouling.     

过滤技术在油浆分离中的应用

在催化裂化、加氢裂化等催化反应过程中,产品油浆中催化剂细粉不仅会导致下游设备的腐蚀和堵塞,也限制和降低了其直接作为产品、副产品的应用领域和经济价值。而对于低温费托合成反应而言,将费托合成蜡从气液固三相的浆态床反应器内分离出来,是整个费托合成工艺的的技术难点和关键之一。由此看出,油浆分离和净化技术的选择关系到以上催化反应的稳定运行和产品质量。本文回顾了目前国内外油浆过滤技术的研究及工业应用现状,总结了以美国MOTT公司为代表的金属烧结粉末和Pall公司为代表的金属烧结丝网两种主流滤芯的机械加工特性和过滤精度等特点,从操作条件、分离效率、反冲洗方式等方面进行比较,分析了各种油浆过滤技术的工艺特点,以及过滤工艺与参数对过滤效果和过滤技术选择的影响,可以为传统石油化工油浆过滤以及费托合成浆态床过滤分离技术在滤芯和过滤工艺选择等方面提供参考。