水淬渣处理电厂生活污水的试验研究

通过石英砂和水淬渣单层滤料的对比试验,了解水淬渣的过滤性能.并采用水淬渣-石英砂双层滤料不加药直接过滤技术对电厂生活污水二级出水进行深度处理.试验结果表明:在去除浊度方面,水淬渣和石英砂的过滤性能相差不大;在去除COD方面,水淬渣的过滤性能优于石英砂.滤速为7.5 m/h时,水淬渣-石英砂滤料的平均出水浊度＜3 NTU、COD＜15 mg/L,满足回用标准,出水水质稳定.     

油田含聚污水过滤工艺因素及臭氧处理效果评价

油田含聚污水随着聚合物驱的应用而黏度增加,水相含油能力强,分离难度大,对处理方式的要求越来越严格。过滤法作为常用方法,其污水处理性能受工艺因素的影响,处理效果不稳定;同时,臭氧作为快速、高效的污水处理方式日益受到关注。本文研究了不同滤料厚度比例、进水流速、滤床压降及污水pH对污水浊度等过滤参数的影响,结果表明核桃壳、石英砂厚度比为9∶13时过滤效果最优,提高进水流速、增加滤床压降和降低污水碱性有利于过滤的进行。探究了臭氧对含油含聚污水的处理效果,结果表明臭氧可通过降解聚合物以显著降低含聚污水黏度,同时污水的浊度和含油量也会显著下降。测定了臭氧降黏的有效消耗量,结果表明5mg臭氧可把500mL的含聚污水黏度从2.6mPa·s降低到1mPa·s以下。最后提出了采用臭氧对过滤污水预处理及处理过滤装置中的板结滤料、提高过滤效率的建议。     

连续砂滤—超滤组合工艺的除污染效能与优化

构建了连续砂滤-超滤中试组合工艺,研究了其的除污染效能。结果表明,增加滤层厚度、降低滤速及延长洗砂周期均有助于提高连续砂滤的除污染效果。加氯反冲洗对超滤的除浊效果无影响,可以更有效地洗脱类腐殖质、类蛋白质以及微生物代谢产物等污染物,洗脱率比水力反冲洗的分别提高了57.9%、99.7%和107.3%,有效缓解了超滤的不可逆膜污染,超滤系统可以长期稳定运行,不需进行化学清洗。组合工艺的浊度去除效果极佳,出水浊度始终低于0.1 NTU;CODMn和UV254的去除率分别达34.2%和21.8%。连续砂滤有效控制了微污染原水的浊度和有机物含量,确保超滤系统可以稳定运行。研究成果可为微污染水源水的物化处理工艺提供技术支持。     

砂滤技术在水处理研究中的进展

对砂滤技术进行了简要的概述。从级配、滤料种类、特殊水质等方面对影响过滤的几个重要因素进行了论述。从除浊、除氨氮、除铁锰、除藻等方面详细的论述了砂滤技术的应用现状。对砂滤工艺中存在的问题,从滤料改性、微絮凝过滤、生物强化过滤等方面总结了强化过滤的措施和发展趋势。     

活性陶瓷滤料过滤器在高浊度含油水处理中的应用

针对高浊度含微量油原水,采用活性陶瓷滤料过滤器替代传统的多介质过滤器和活性炭过滤器作为化水制水预处理工艺。对活性陶瓷滤料的特性和过滤原理、活性陶瓷滤料过滤器系统组成进行了介绍,结合某钢厂化水站采用中水作为水源水制备锅炉补充水的工程实例,对活性陶瓷滤料过滤器的运行效果进行了分析。     

折叠滤芯气液过滤性能测试及优化

采用聚结型滤芯气液过滤性能实验装置,研究了油雾加载率和表观过滤速度对折叠滤芯过滤性能的影响及涂覆粘合剂对折叠滤芯过滤性能的优化作用。结果表明,涂覆粘合剂后,滤材抗张力强度明显增大,滤材孔径减小。随油雾加载率增大,滤芯过滤层液体运移通道数增加,通道压降升高。初始压降随表观过滤速度增加而升高。粘合剂主要凝固在渗透性低的区域,压降变化较小。表观过滤速度增加抑制了二次夹带,折叠滤芯过滤效率升高,而由于粘合剂脱落,涂覆粘合剂的滤芯过滤效率下降。表观过滤速度为0.10 m/s时,随油雾加载率增大,聚结在滤材表面的粘合剂抑制夹带,滤芯过滤效率升高。     

Performance and mechanism of a hydrophobic–oleophilic kapok filter for oil/water separation

A natural vegetable fiber, kapok, was evaluated for its feasibility as filter material for separating immiscible liquids such as oil/water mixtures. Two types of oils, namely diesel and hydraulic, were investigated. Various simulated oily waters were prepared by mixing tap water with one of these oils to produce binary oil/water mixtures of varying oil percentages, such as 5%, 10% and 15% by weight. The effect of filter packing density on the dynamics of oil/water separation during the filtration process and the filtrate quality were investigated. Due to the hydrophobic–oleophilic surface characteristic of the kapok fiber, water could be filtered through the filter while oils were retained, causing separation of oil from water. The filtration efficiency for removal of diesel and hydraulic oil from their respective oily waters reached 100% and more than 99.4%, respectively, which showed an excellent performance of kapok in removing oils from oily waters. The hydraulic conductivity of the kapok filter was found to decrease with the advance of the oil front. The filtration rate of both types of oily waters decreased with increasing filter packing densities and influent oil contents. The kapok filter performed equally well in terms of total filtrate collected before breakthrough for the two different oils, albeit the filtrate rate could be viscosity dependent. A packing density of 0.07 g/cm³ was the optimum one for diesel and hydraulic oil removal. At breakthrough, the oil/water/air three-phase partition within the filter bed is a function of influent oil concentration, oil type, and packing density of the filter.     

Comparison of Efficiency between Poly‐aluminium Chloride and Aluminium Sulphate Coagulants during Full‐scale Experiments in a Drinking Water Treatment Plant

Abstract

The efficiency of poly‐aluminium chloride (PACl) and of aluminium sulphate (alum), two commonly applied coagulant agents, was studied comparatively in this work, during full‐scale experiments in a drinking water treatment plant. The removal of suspended solids (turbidity) and the residual aluminium concentrations were carefully monitored and they were used for the evaluation of effectiveness for each coagulant, as well as for the determination of optimal operative conditions. Two alternative treatment processes were examined:

• (a) the conventional coagulation‐flocculation‐sedimentation process, followed by gravity filtration through sand filter beds, and

• (b) the direct filtration process, i.e., coagulation‐flocculation and sand filtration, but without the intermediate sedimentation step.

PACl proved to be a more efficient coagulant than alum, as lower dosages of PACl, about 1.35 mg Al/L in this case, resulted to the production of treated water with low turbidity and residual aluminium content. In addition, the direct filtration process through dual sand‐anthracite filter beds was found to be equally sufficient, as the conventional one, i.e., when applying the sedimentation step; in this case, 0.70 mg Al/L of PACl resulted in low turbidity water (around 0.1 NTU) and residual aluminium content (lower than 150 µg/L). In addition, the operation time of filters was extended to more than 24 hours.     

Pilot filtration study to reduce fouling on Marbella seawater RO plant

The seawater RO plant at Marbella had operated intermittently, and at low flowrates, since its construction 10 years ago. This was because the plant had been designed to operate at times of water shortage, to provide water when the conventional supplies were not available.

During the early part of the 21st century, the mode of the plant changed, and it was expected to operate at design capacity for most of the time. This brought two facts to light — that during high abstraction rates the intake water quality deteriorated significantly, and that the filtration system that had been installed was not capable of adequately filtering the feed water to make it suitable for feeding to a reverse osmosis plant.

The plant was originally built using DuPont B10 permeators. Due to the unavailabilty of these permeators, the plant is currently being converted, stream by stream, to spiral wound membranes supplied by Hydranautics.

At design flowrates, the DuPont system fouled rapidly, and required cleaning every two weeks. The spiral trains fouled more slowly, but still required cleaning at a higher frequency than would be considered normal for this type of plant.

A pilot filtration plant was installed on site to attempt to find the following;

• An optimum coagulant for the water.

• An approximate dose rate for that coagulant.

• The effect of different media on the quality of filtered water.

• The length of run between backwashes using different media.

• The quality of water that can be achieved using this coagulant and media.

By installing pressure tapping points along the length of the filter, the area of differential pressure could be measured. This was used to ensure depth filtration was taking place, and the foulants were being removed through the length of the bed rather than surface filtration.

The trials lasted a total of three months and achieved all of the targets set. The SDI typically achieved by the main plant was approximately 5. The pilot filter showed that the SDI could be reduced to below 2 by modifying the filters and applying a coagulant. Filter runs achieved by the pilot filters were in excess of 48 h.

Following the trials, the plant commenced replacing the media in the filtration system, and is expected to install a coagulant dosing system once this was complete.

This paper describes the pilot plant built, the selection of the media, and the coagulants used, and presents the operating data produced from the trials.     

Aerosol filtration performance of nanofibrous mats produced via electrically assisted industrial-scale solution blowing

Highly efficient polyamide 6 (PA6)-based nanofibrous air filter media was developed for particulate matter (PM) removal in the ambient atmosphere. The PA6 nanofibrous mats exhibited 85% PM0.3 capture performance at a cost of 164 Pa pressure drop when the multiple-nozzle solution blowing system was set to 8 m/h fabric winding speed. However, an increase in the winding speed at a constant feeding rate lowered the filtration efficiency to 62% due to the less amount of nanofibrous mats collected on the substrate. The application of electrical field at the same parameters allowed us to produce a filter media having FFP3-level filtration performance, which means 99% PM0.3 capture performance. This was attributed to a fine fiber diameter (116 nm), higher solidity value (0.149), and lower average pore size (2.28 μm). These results show that the electrically assisted solution blowing provides a feasible route for the production of high-quality nanofibrous filter media.     

Effect of coagluant dosage and grain size on the performance of direct filtration

The performance of flocculation in direct depth-filtration was assessed in relation to the shear rate and the floc size in the filter pore. Quantitative measurements of the pressure drop of bed, as well as the turbidity and the floc size in the filtrate, and estimation of the shear rate in the filter during filtration were made to investigate the effects of chemical doses and grain sizes on the performance of direct filtration. Furthermore, a method was suggested to determine the porosity in the deposited layer. In this study, the product was estimated to be two to three times that in the initially clean bed after a 6 h operation of the filter using 50–100 ppm of alum. It was also found that the porosity of the deposited layer is very high up to a range of 0.93–0.99. The porosity decreased with the filtering time and filtration rate, and increased with the alum dosage. However, it was only slightly affected by the grain size used in the study.     

上向流过滤实验研究

通过实验确定了对应于不同滤料粒径的上向流过滤的极限滤速，该结果与理论公式计算值在滤料粒径小于1．10mm范畴吻合；以过滤性能指数FPI(ME)及过滤水头损失增加率为判断依据，同等条件下，上向流过滤优于下向流过滤；对L／d10分别为1140、710、691、400、230滤层进行上向流过滤比较：在实验条件下，L／d10＝1140滤层抵抗进水浊度变化冲击的能力最强，单位面积产水量最大。按传统滤池8—10m／h滤速，上向流过滤采用L／d10≥400的滤层，出水浊度小于INTU；最后简述了上、下向流过滤在滤料选择上的区别。     

Efficiency of wood cellulose filtration

木浆纤维素作为助滤剂应用广泛,其过滤性能亟待研究。不同的过滤条件对木浆纤维素滤饼层的过滤性能会有很大影响。本文通过单因素法考察了过滤压力对滤饼层截留精度和平均滤速的影响,并通过正交实验法考察了木浆悬浮液黏度、木浆浓度、木浆添加量、悬浮液含水对滤饼层截留精度和平均滤速的影响。实验表明木浆纤维素属于中等可压缩性物料,其过滤性能随过滤条件变化呈规律性变化。通过对实验结果的分析,确定了优化方案。研究结果为木浆纤维素过滤的小型工业试验提供参考。     

Assessment of recycled glass and expanded clay in a dual media configuration for drinking water treatment

The aim of this study was to investigate the overall performance of different types of recycled glass media with the optimized coagulation conditions for drinking water treatment. Tests were performed using a laboratory-based filtration unit, with dual filter media configurations and synthetic raw water. The glass media showed comparable performance for both filtration and backwashing and avoided the breakthrough of particles in the effluent. Moreover, the promising performance of the glass media was a slow head loss development which should grant longer filtration runs, less backwashing requirement and thus possible clean water and energy savings. Finally, the optimized combination of filtration media and coagulation operations can lead to the best filtration performance.     

Novel pre-treatment method for seawater reverse osmosis: Fibre media filtration

A high rate fibre filter was used as a pre-treatment to seawater reverse osmosis (SWRO) to reduce membrane fouling. Seawater was drawn from Chowder Bay where the Sydney Institute of Marine Science, Australia is located. A lab-scale fibre filter with a height of 1000 mm and a diameter of 30 mm was used in conjunction with in-line coagulation. The effect of operating the fibre filter with different packing densities (105, 115 kg/m³) and filtration velocities (40, 60 m/h) was investigated in terms of silt density index (SDI₁₀), modified fouling index (MFI), pressure drop (ΔP), turbidity and molecular weight distribution (MWD). The use of in-line coagulation improved the performance of fibre filter as measured by the MFI and SDI. Regardless of filtration velocity and packing density the MFI and SDI₁₀ values remained low as did the turbidity until the end of the filtration run. The MWD analysis showed the removal efficiencies of organic materials like biopolymers, fulvic acids, low MW acids for even experiments with the highest filtration velocity (60 m/h) and lowest packing density (105 kg/m³). This pre-treatment has a small foot print as it has the capacity of operating at a very high filtration velocity.     

改性石英砂强化火电厂中水回用微污染物处理效果研究

通过对石英砂滤料的改性研究改变原滤料表面物理化学性质,提高滤料吸附能力和截污能力,强化对中水中有机物的去除效率。分别试验了对石英砂进行铝盐和铁盐方法的改性,过对比了静态吸附试验和动态过滤试验改性石英砂和未改性石英砂对微污染水中有机物和浊度的去除效果。结果表明,改性砂对COD和浊度的吸附效果较之未改性前均有明显提高,COD去除率由5%提高到20%～30%,浊度的去除率由37%提高到55%～65%,动态试验与静态试验结果一致,去除率也均有提高;不同金属氧化物的改性砂性能不同。     

景观用水处理及中水再生回用示范工程

采用适合其分散处置特点的流化床和臭氧气浮装置对高档社区的景观水以及建筑中水进行再生处理。首先针对流化床工艺,用Fe3O4作为回流絮凝助凝剂,以增强悬浮层的稳定形成。其次,增设微孔曝气系统。一方面对流化床回流的Fe3O4进行水力再生;另一方面提高水中的溶解氧,降低臭味,提高系统的好氧微生物处理能力。最后,改变工艺流程,使景观水进水杂排水池,通过流化床处理。运行结果表明,出水水质完全符合GB/T18920-2002和GB/T18921-2002中的娱乐性景观环境用水、道路清扫、城市绿化和车辆冲洗的用水水质标准。     

旋转圆筒型过滤器精密平衡过滤O/W乳浊液特性研究

以油分（煤油）浓度较低的（ｋｅｒｏｓｅｎｅ）Ｏ／Ｗ（ｗａｔｅｒ）乳浊液为对象,通过旋转圆筒型过滤器进行精密过滤,对影响平衡过滤的油分滤饼层的压缩性,以及过滤速度与诸操作因子间的关系进行了探讨。结果表明高速旋转的圆筒型过滤膜对附着在过滤膜表面的滤饼产生很大的扫流力,具有不断扫流过滤膜表面上生成的滤饼的特性,因此对难过滤性Ｏ／Ｗ乳浊液进行高速精密过滤具有广泛的实用价值。     

Filter life comparison of different levels of nanofiber coated cleanable-surface filter for gas turbine

High-efficiency air filtration is a basic requirement for the most cost-effective operation of high-efficiency gas turbines. The filtration system protects the gas turbine from damaging debris. In gas turbine/dust collector applications, higher efficiency filtration could be achieved with nanofibers, which provide higher equipment protection than traditional media. With a nanofiber performance filter layer, the dust accumulates on the surface of the filtration media rather than within the media and could be cleaned off easily with a back pulse resulting in long filter life and a low-operating pressure drop. In this study five type of gas tribune nanofiber coated corrugated cellulose/synthetic filter media were developed. Nanofiber coating was adjusted for five filtration efficiency level, 50 ≤ E < 60, 60 ≤ E < 70, 70 ≤ E < 85, 85 ≤ E < 95 and 95 ≤ E, pore size and filter-life of the developed media were evaluated. One of the developed nanofiber coated media was also compared with two other commercial nanofiber coated gas tribune filter media, a glass fiber type filter media and a commercial fine fiber gas tribune filter media. It was seen that, with decreasing penetration levels due to nanofiber coating level, initial 30 cycle durations of filter life evaluation could reach about 229.9 to 250.7 min. Highest final cycle duration of 188.7 min belonged to cellulose/synthetic blend corrugated filter media with penetration of 13.66%. Nanofiber based surface filter media was cleaned up better than fine fiber media and final 30 cycle sequences were significantly higher. Surface of the nanofiber coated media was smoother when compared to fine fiber media and during the initial and final cycle test dust could not penetrate inside and could not hang to this smooth surface. So, with back pulse cleaning cake releasing have performed easily. It was also seen that, for higher filter life nanofiber coating should be uniform and robust to back pulse cleaning.     

新型钛混凝剂的制备及应用评估

随着钛工业的快速发展,钛混凝剂受到广泛关注。通过溶胶-凝胶法改性制备得到的钛凝胶混凝剂具有稳定性高、絮体生成速率快等特点,有望替代铁铝盐应用到水处理中。结合钛混凝剂的发展历程和研究现状,重点分析了钛凝胶混凝剂的应用潜力。钛凝胶混凝剂可应用于低温低浊水、含藻水和印染废水的处理以及膜前预处理,解决铁铝混凝剂应用中存在的问题。此外,通过复配使用以及污泥资源化,有望降低钛混凝剂的应用成本。