纳米KDF去除水中余氯的实验研究

对纳米KDF去除水中余氯的影响因素进行了一系列的实验研究,分析了不同初始余氯浓度、滤速、柱高及停留时间对去除率的影响情况。实验结果表明,随着滤速和初始余氯含量的降低以及滤柱高度的提高,纳米KDF对余氯的去除率有明显的提高。     

微污染水中镍离子初始浓度对其在不同生物慢滤柱中去除的影响

采用生物慢滤技术研究镍离子初始浓度对不同滤料(活性炭、沸石和石英砂)的生物慢滤去除微污染水中镍离子的影响。结果表明,不论微污染水中的初始镍离子浓度(0.04,0.08,0.12,0.16 mg/L)为多少,在不同滤料(活性炭、沸石和石英砂)的生物慢滤中均呈现出镍离子去除率先下降后上升。系统稳定后,活性炭滤柱的去除率先保持90%后下降至87%左右;沸石滤柱的去除率先从85%上升至87%后下降至83%;石英砂滤柱的去除率先从70%上升至84%后降至79%。刚开始镍离子对除镍微生物有毒害作用,导致其去除率降低,随后因为除镍微生物活性的恢复,去除率又开始升高;适当提高镍离子初始浓度有助于提高去除率,但镍离子初始浓度过高会对除镍微生物造成不可恢复的损害,导致去除率显著降低,微污染水中镍离子的初始浓度分别为0.08,0.12 mg/L时去除水平最高;活性炭滤柱的去除率最高,其次是沸石滤柱和石英砂滤柱。     

水化硅酸钙与沸石滤柱去除水中低浓度氮磷

模拟洱海的入湖河流——罗时江低浓度氮磷营养盐条件,采用水化硅酸钙与天然沸石作为吸附介质进行滤柱试验。试验设计4个滤柱并列运行,分别装填单一水化硅酸钙滤料、单一沸石滤料、水化硅酸钙与沸石双层滤料(1∶3)和水化硅酸钙与沸石双层滤料(1∶1),对比不同滤柱在不同滤速条件下的效果。单一水化硅酸钙填充滤柱对磷酸盐的去除效果最高,平均可保持在90.75%左右,但对氨氮去除不稳定;单一的沸石填充滤柱对磷酸盐吸附能力较弱,平均在77.30%,且受滤速影响较大。在水化硅酸钙与天然沸石配比为1∶1,滤速为0.696 m/d时,对低浓度营养盐的水质起到稳定良好的去除效率,出水浓度均可达到国家地表Ⅲ类水标准。     

生物填料-砂滤强化去除饮用水中氨氮中试

结合水厂水处理常规工艺进行中试,研究在普通砂滤池上方悬挂生物填料强化去除饮用水中的NH3-N。结果表明,滤料、填料、悬挂密度以及不同滤层等均对NH3-N的去除效果有影响,旧石英砂滤柱(即采用水厂现有滤池滤料)较新石英砂滤柱(即新购石英砂滤料)具有更强的NH3-N去除能力,且去除效果更稳定;上层滤床(50 cm)对砂滤床过滤去除NH3-N贡献最高;悬挂弹性填料较组合填料可更好地提高生物填料-砂滤单元对NH3-N去除效果;增大生物填料悬挂密度可提高生物量,在进水NH3-N含量较高时具有良好的去除率;且反冲洗对NH3-N去除效果也有较大影响。     

凹凸棒复合滤料生物过滤去除Ni~(2+)性能研究

采用凹凸棒复合滤料部分替代石英砂滤料,利用凹凸棒复合滤料良好的吸附和生物挂膜性能对普通滤池进行生物强化。探讨了温度,水力负荷,初始浓度对生物过滤去除水中Ni2+的吸附效果的影响。实验结果表明,温度在17.5～20℃时,吸附率可达87.14%以上,最高可达到93.17%;降低滤速可提高滤料对Ni2+去除率,最佳水力负荷为4m/h;Ni2+初始浓度在2～4mg/L时滤料的吸附效果显著。     

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。     

新型纤维丝滤料处理城市景观水的效能研究

采用石英砂和新型纤维丝滤料对比研究微絮凝过滤工艺处理城市景观河水的净化效能.研究表明,石英砂滤床在投药量10mg·L-1,滤速10m·h-1时,过滤周期为12h左右;在投药量10mg·L-1,滤速15 m·h-1时,过滤周期仅为4h.而新型纤维丝滤料则具有更为优越的过滤性能,在投药量10mg·L-1,滤速30m·h-1时,新型纤维丝过滤柱的过滤周期达到了12h.在滤速为30m·h-1时,投药量在20mg·L-1以上时,过滤周期可以达到20h以上.10min的气水联合反冲洗能够将过滤后的新型纤维丝清洗干净.新型纤维丝滤料的产水率高,一个过滤周期内反冲洗水量:过滤水量约为1:100.     

外循环连续砂滤器试验研究

连续砂滤技术是一种应用于水处理行业的新型过滤技术，能够在过滤口寺同时对滤料进行清洗，不需停车对滤料进行清洗，保证过滤装置自寺连续稳定运行。以炼化污水回用为背景，建立了一套由提升泵、砂滤器、洗砂器及水循环系统等部件构成的外循环连续砂滤装置，研究了砂循环速率、滤速等参数对其性能的影响。     

改性氧化铁沸石用于生物慢滤柱去除窖水中氨氮的实验研究

对比分析改性氧化铁沸石和普通沸石用于生物慢滤柱中的挂膜情况和对氨氮的去除效果,研究滤层厚度、滤速、水温、进水氨氮和CODMn负荷对氨氮去除率的影响。结果表明,沸石经改性后改善了表面性能,装填改性沸石的慢滤柱挂膜更快,对氨氮的去除率更高。慢滤柱对氨氮的平均去除率可以达到85%以上。随着滤层厚度增加氨氮去除率升高;滤速越大去除效果越差;氨氮去除率同水温呈正相关,与进水CODMn负荷呈负相关;进水氨氮负荷较低时,去除率随负荷加大而升高,进水氨氮负荷高于0.08mg/(L·h)时,去除率基本无变化。     

生物活性滤池饮用水除氨氮的影响因素

以实际沉淀池出水进行配水,通过模型实验,探讨了生物活性滤池（BAF）除氨氮的影响因素及作用机理。结果表明,滤前水中有机物含量和滤料粒径对BAF除氨氮能力影响较大。当采用沉淀池出水中自身携带的有机物时,BAF-1除氨氮效率为97%;当沉淀池出水中另配入2 mg·L^-1牛肉膏+2 mg·L^-1蛋白胨+2 mg·L^-1葡萄糖时,由于受到异养菌对溶解氧和生存空间竞争的限制,其除氨氮效率下降至51.0%。活性炭粒径采用0.8～1.2 mm的BAF-1氨氮去除率比采用1.0～2.0 mm的BAF-2高1.5%～16.7%。当滤前水氨氮浓度低于1.60 mg·L^-1时,BAF-1的氨氮去除率接近100%;当氨氮浓度逐渐升高时,由于受到溶解氧的限制,去除率逐渐下降。对滤前水进行预曝气充氧,能提高BAF-1的除氨氮效率。滤速对BAF-1除氨氮影响不显著。反冲洗可适当提高BAF-1的除氨氮效率。     

自动反冲活性炭净水器处理饮用水的实验研究

粒状活性炭净水器是净化饮用水的经济实用的深度净化设备,自动反冲洗活性炭净水器在使用寿命和运行操作上均优于传统活性炭净水器。本文对自动反冲洗活性炭净水器处理上海某区的自来水进行实验,考察了自动反冲洗活性炭净水器在不同处理水量时对污染物的去除效率,实验发现：该净水器对CODMn、色度、浊度及余氯均有较好的处理效果;自动反冲洗装置可延长活性炭使用寿命,活性炭依靠过滤截留和吸附的共同作用去除水中的浊度,利用现场快速检测余氯浓度,可间接判断活性炭是否失效。     

袋式过滤器过滤初期阶段滤袋压力特性的实验研究

针对袋式过滤器过滤初期阶段的压力特性,选用高密度聚乙烯粉料进行了实验分析,主要考察过滤速度和入口浓度对滤袋压降的影响。实验结果表明,在过滤初期阶段滤袋的压降上升趋势很明显,这种压降的增大主要来自于残余压降;滞留在滤料内的粉尘改变了滤料内部的流道结构,从而导致了滤袋残余压降的不断升高;过滤速度和入口浓度的增加均可使残余压降增大。最后通过压降组成的分析,提出了滤袋总压降的计算模型。     

低浊度废水的微絮凝变孔隙深层过滤

研究了微絮凝变孔隙深层过滤处理低浊度废水时,滤料粒径、絮凝剂种类、投加量、滤速等因素对过滤效果的影响。试验结果表明：由于变孔隙结构等原因,该系统具有用药量省、阻力损失小、出水量大及整床过滤效能好等优点。     

THE DEVELOPMENT OF FLOCCULATION EFFECTS IN FILTER THEORY

A flocculation model of filtration was applied to estimate flocculation conditions in filter beds. The model was derived on the basis of hydraulic parameters and defined in terms of the mean velocity gradient in filter beds. The velocity gradient allows us to establish the effect of filter media density, which has not been yet described quantitatively. Presented are also relations between media density and the optimal filtration rate and filter bed depth. It was found that floes compressibility together with some other hydraulic parameters should be considered important when determining the filtration capacity of the beds. Development of the flocculation effects in filtration theory leads to the optimization of filter designing.     

Cake formation and growth in cake filtration

In this study we develop an experimental method to help understand the formation and growth of dust cakes. An on-line pressure-displacement measurement system is developed to measure the thickness of the dust cakes. A higher filtration superficial velocity resulted in a higher degree of compaction in the dust cakes and thus a higher specific cake resistance, hence a better collection efficiency could be achieved. The empirical equations for cake solidosity and specific cake resistance as a function of the filtration superficial velocity are derived. We find that the cake filter is influenced by the cake thickness and the filtration superficial velocity. The results of this study can be applied to granular bed filters for the removal of dust particulates in advanced coal-fired power systems.     

The kinetics of ilmenite beneficiation in a fluidised chlorinator

The beneficiation of ilmenite, the preferential removal of the iron oxides by selective chlorination, has been studied in a fluidized bed reactor. Temperatures from 700°C–950°C, inlet mole ratios of carbon monoxide (the reducing agent used) to chlorine (the oxidizing agent used) from 1–2, and a wide range of values of the ratio of initial bed weight to gas-flow rate were investigated. The volumetric average rate of solid and chlorine consumption were followed as a function of elapsed time from the start of a run. Rate equations correlating the results for both rates are presented. The rates being found functions of temperature but not strongly dependent upon other operating conditions.     

Jet pulsed filters as chemical gas/solid reactors—Experiment and model prediction

A recently introduced generations filter model [A. Kavouras, G. Krammer, Distributions of age, thickness and gas velocity in the cake of jet pulsed filters—application and validation of a generations filter model, Chem. Eng. Sci. 58 (2003) 223–238] allows one to determine from macroscopic experimental data the distribution of cake thickness versus filter area and in consequence the complete filter behaviour. Based on a simplified assumption this generations filter model is employed in a predictive way to estimate operating points of imperfectly cleaned filters. However, filter behaviour in terms of the fraction of the filter area cleaned when jet pulsed cannot be predicted yet without experimental data. This is due to the variable cleaning properties of the cake, which are dependent on the filter operating parameters.

Combining the predictive filter model and a model for the chemical reactions in the fixed bed of the filter cake [A. Kavouras, B. Breitschaedel, G. Krammer, A. Garea, J.A. Marques, A. Irabien, SO₂ removal in the filter cake of a jet pulsed filter: a combined filter and fixed bed reaction model, Ind. Eng. Chem. Res. 41 (2002) 5459–5469], the filter performance as a gas/solid reactor can also be simulated in a predictive way. It is found that the pressure drop across the filter has a weak influence on filter performance as a gas/solid reactor.     

烧结复合式烧结金属丝网颗粒移动床过滤器研究

A new gas clean-up process called “integrated sintered metal screen moving granular bed“ (ISMSMGB) for the integrated gasification combined cycle (IGCC) and pressured fluidized bed combustion (PFBC) was developed on the basis of a sintered metal candle filter and a cross-flow moving granular bed filter. This is a combination of the surface and deep bed filtering processes. A set of facilities was established and a series of cold model tests were carried out. The dust removal efficiency and the pressure drop of the filter were measured and analyzed. The results show that this process features the advantages of the moving bed for high capacity as well as high inlet dust load and the surface filter for high efficiency. Meanwhile, the granules moving downward cleans the cake on the screen surface, so that the system is operated at steady state.     

炭砂滤池新旧滤料的对比分析

对清泰水厂更换过的粒度为8×20目柱状破碎炭的6#炭砂滤池进行研究,分析和总结其工艺去除率和炭砂滤池运行参数,探讨深层取样方法。结果表明:新活性炭滤料水质去除率良好,耗氧量约55.7%,浊度约99.7%,氨氮约86%,亚硝酸盐约97%;粒度为8×20目的煤质柱状活性炭比8×30的颗粒活性炭跑炭更少,细颗粒所占比例也更少;实际运行中,活性炭滤料高度在175~177 cm更为合理。     

Effects of biocide and nutrient availability on microbial contamination of surfaces in cooling-water systems

The results of an evaluation of the effects of different factors on formation, growth and removal of biological films are reported. Experiments have been performed both on laboratory equipment and a test system located on a cooling-water system at an industrial site. The effects of temperature, nutrient availability and surface material of construction are discussed in relation to film formation. Experiments concerning continuous biocide treatment are assessed in relation to biofilm removal. A pure culture of Pseudomonas fluorescens was used to grow biological films in the laboratory under identical hydrodynamic conditions but at different temperatures. Drastic reductions in film thickness were noted at temperatures 5°C above and below the optimum temperature for growth of the organism. The effects of nutrient loading under similar hydrodynamic conditions have been studied in the laboratory. The maximum biofilm thickness was reduced by 55% when no air was present and by 80% when neither air nor nutrient were supplied. Biofilm growth at the industrial site was unexpectedly more pronounced on brass than mild steel. Examination of destruction of existing biofilms in the laboratory showed that at a concentration of 4 parts 10^?-6 free chlorine (sodium hypochlorite) the initial rate of film removal was four-to-six times higher than that at 2.5 parts 10^?-6 free chlorine. A higher velocity of sodium hypochlorite solution over the biofilm resulted in a higher rate of removal. The results are discussed in the light of published data in related tests.