论“石灰投加量公式”的合理形式

本文对混凝剂投加所引起的原水水质变化及其对石灰投加量的影响进行了分析;同时也对水中Fe、H_2SiO_3的存在形态及它们对石灰用量的影响进行了分析。在分析的基础上,修正补充了现行几类石灰用量计算式。最后导出了比较符合生产实际的石灰投加量计算公式。     

基于PLC的水厂石灰投加系统的设计与应用

在自来水厂的整体净水工艺流程中石灰投加是调节pH,确保水质的重要环节,随着社会发展,人们对供水质量和生产可靠性要求不断提高,将自动控制技术融入石灰投加流程,自动化石灰投加系统的应用越来越受行业所重视.以金华仙源湖水厂为研究对象,结合其水厂升级改造实际应用,阐述可编程逻辑控制器(PLC)在石灰投加系统中的应用模式.根据石灰投加系统的功能需求和操作要求,介绍编程实现逻辑及程序源代码.在自动投加系统中,投加的控制方式对系统整体运行效果起决定性作用,仙源湖水厂结合精细投药算法,采用流量比例复合环计算控制方式,引入在线pH仪实时测量值,进行反馈对比运算,对扰动进行有效补偿,提高系统运行稳定性,投加效果更佳.经水厂实际运行验证,运用基于PLC的自动控制技术对石灰投加系统整体性能有较好提升,非常适合水厂日常生产.     

石灰曝气法处理结垢地下水试验研究

采用石灰软化曝气法考察了西安某地地下水曝气软化过程中石灰、PAC和PAM的复合处理效果,并确定药剂最佳投加量及各项运行参数。结果表明,当石灰投加量为80 mg/L时,硬度和暂时硬度的去除率为48.10%和97.22%,混凝和沉淀过程对硬度及暂时硬度的去除效果影响不大;投加石灰后浊度明显升高,当PAC投加量为20 mg/L,PAM投加量为0.5 mg/L时,在最佳运行参数条件下可使处理水浊度稳定降低至2 NTU以下。石灰曝气软化法能有效去除水中硬度、暂时硬度和浊度,处理水煮沸后不再形成沉淀和悬浮物,该方法曝气软化过程吨水运行成本约为0.589元。     

南方某水厂生产性再矿化系统设计与运行

南方地区低p H值、低硬度和低碱度的水质特点加剧了供水管道的腐蚀,导致管道渗漏、爆管以及"黄水"现象频繁发生。某水厂设计了清水池投加石灰上清液的再矿化系统对出厂水进行再矿化处理,以改善出厂水水质,提高水质化学稳定性。介绍了该水厂再矿化系统的设计方法,并在调试运行期间对再矿化实施前后出厂水p H值、浊度和余铝的变化进行比较。结果表明,再矿化系统根据进水量动态投加石灰水的运行方法可以有效提高出厂水p H值,且对出厂水浊度及其他常规指标影响较小。再矿化系统投入使用后石灰消耗量同比有小幅度的下降,主要原因在于清水池投加石灰减少了前段工艺的石灰投加量。     

散装石灰投加系统在水厂的应用

温州陈岙泵站散装石灰投加系统由石灰料仓、石灰计量及输送系统、石灰乳配制系统和石灰乳输送投加系统组成。该系统在运行过程中存在富余能力过大、石灰易形成空穴、无法掌握仓内石灰余量等问题,通过降低多螺旋给料机的给料能力、增加破拱刮片机以及统计分析实际石灰使用量等措施,较好地解决了上述问题。     

水厂全自动石灰投加系统设计及运行

为解决自来水厂传统石灰投加系统扬尘严重、工作环境恶劣、投加设备故障率高、管道结垢堵塞等问题,新建了一套全自动石灰投加系统,并在实际工程应用中取得了很好的效果。     

污泥石灰干化工艺在北京小红门污水厂的应用

介绍了北京小红门污水处理厂污泥干化项目的工艺方案、实施情况和运行费用的影响因素.通过小红门污水处理厂污泥干化项目的运行及实验室检测数据,初步研究和分析了污泥原始含水率对处理后污泥含水率的影响以及石灰投加量对杀菌效果的影响.结果表明,针对小红门污水厂的污泥,仅需添加5%的石灰,即可将大肠杆菌的含量降至未检出水平.而为了使成品污泥含水率同样达到小于60%的效果,原始污泥含水率越低,所需投加的生石灰量越少,当原始污泥含水率为80%-85%时,需要的石灰投加量为20%-30%,而原始污泥含水率为77%-78%时,仅需投加13%的石灰.     

高效复合絮凝剂在喷织废水处理中的实验研究

针对喷织废水的特点,在定性试验了各种絮凝剂的絮凝效果后,定量分析破乳剂及高效复合絮凝剂的最佳投加量,在投加石灰、高效复合絮凝剂及PAM的情况下,色度去除率均可达40%以上,CODCr的去除率均可达70%以上。当pH=7.6,石灰投加量为80mg/L,高效复合絮凝剂投加量为80mg/L,PAM投加量为2mg/L时,COD及色度去除率分别可达83.1%和70%,出水直接可达《污水综合排放标准》。     

全封闭新型石灰投加系统的设计与应用

自来水厂传统石灰投加方式具有扬尘污染严重、工人劳动强度大、工作环境恶劣的不足,为此介绍了新型散装石灰投加工艺及其工艺参数设计方法.实际应用效果表明,该工艺有效地解决了石灰扬尘问题,且自控水平高,是现代化水厂的发展方向.     

水厂加碱调节pH值试验研究

对于低碱度、低pH值的原水,在水处理过程中通常投加碱调节剂,以提高出水的碱度和pH值,从而增强出水的化学稳定性。本文通过烧杯搅拌试验、中试和生产性试验,对三种碱调节剂-石灰、氢氧化钠、碳酸钠进行了对比试验,以了解三种不同碱剂的投加效果,同时对三种碱剂的投加成本进行了对比分析。     

Effect of Portland cement and lime additives on properties of cold in-place recycled mixtures with asphalt emulsion

Due to lack of previous research on applying additives in Cold In-Place Recycling (CIR) mixes in this study, Portland cement and lime were used as additives. The Portland cement was introduced in powder form and lime was utilized as hydrated lime in powder form and lime slurry, and the effects of each additive on properties of CIR mixes has been evaluated. The results showed that both lime and Portland cement can increase Marshall stability, resilient modulus, tensile strength, resistance to moisture damage and resistance to permanent deformation of CIR mixes. Use of Portland cement and lime slurry had better results than hydrated lime but due to the difficulties in producing lime slurry in practice, the use of Portland cement is recommended.     

配合比、含水率对生石灰桩径膨胀率的影响

通过对生石灰桩的理论及施工技术的研究,发现生石灰桩体材料对生石灰桩径膨胀率的影响因素研究成果较少,在前人研究生石灰用于纠偏和湿陷性黄土地基处理的基础上,通过试验进一步研究生石灰桩体材料对桩径膨胀率的影响。试验分两步,第一步研究生石灰桩体材料配合比对桩径膨胀率的影响,结果表明,石灰含量过高的生石灰桩易出现碎桩现象,石灰桩的桩径大小也对膨胀率有一定影响,通过数值回归法得到桩体材料配合比与桩径膨胀率的关系式。第二步研究生石灰桩体材料含水率对桩径膨胀率的影响,并通过数值回归法求得含水率与桩径膨胀率变化的公式。该研究为生石灰桩的膨胀理论研究提供了依据。     

水泥-石灰-粉煤灰干硬性体系的单纯型-格子研究

通过对水泥-石灰-粉煤灰干硬性体系进行单纯型-格子研究,探讨了石灰掺量对该体系早期与后期无侧限抗压强度的影响规律.结果显示:石灰掺量对水泥-石灰-粉煤灰干硬性体系早期强度的影响规律与其中的水泥掺量有关,当水泥掺量低于7%(质量分数,下同)时,掺入石灰有助于体系早期强度的提高;当水泥掺量高于7%后,掺入石灰对该体系早期强度反而存在负面作用;不论水泥掺量如何,掺入石灰均能提高该体系的后期强度.     

石灰、粉煤灰改性对盐渍土吸附石油污染物行为的影响

有效调控污染物的运移是实现污染土工程再利用的前提。考虑石油污染盐渍土的特殊性及工程利用的力学需求,优选石灰和粉煤灰为改性材料,结合静态动态试验,研究石灰和粉煤灰对滨海盐渍土中石油污染物的吸附解吸行为的影响。结果表明:单独的石灰和粉煤灰,对石油污染物的吸附率分别为26%和14%,两者联合作用时,吸附率提高到39%,在盐渍土中加入石灰和粉煤灰可有效提高对石油污染物的吸附量,加快吸附稳定速率;盐渍土、石灰+盐渍土、粉煤灰+盐渍土、石灰+粉煤灰+盐渍土对石油的吸附动力学均符合Lagergren二级动力学非线性方程,联合作用可使吸附平衡时间由400min缩短至60min;石灰、粉煤灰有利于吸附赋存于土颗粒孔隙中未被盐渍土颗粒吸附的呈自由态的石油;盐渍土、石灰+盐渍土、粉煤灰+盐渍土、石灰+粉煤灰+盐渍土对石油污染物的吸附等温线均为非线性Freundlich模式;石油被解吸的能力依次为盐渍土粉煤灰+盐渍土石灰+盐渍土石灰+粉煤灰+盐渍土,石灰+粉煤灰对石油污染物的吸附以化学吸附为主,具有不可逆性,有助于缓解环境温度的影响,增强稳定性。     

石灰形态对粉煤灰活性激发效果影响及动力学分析

生石灰和熟石灰对粉煤灰活性激发的效果是不同的。试验数据及动力学分析均表明：以等ＣａＯ 当量为比较条件,熟石灰比生石灰更有利于粉煤灰活性激发,具有技术经济优势。基本系统采用生、熟石灰的主要差别是：采用熟石灰体积安定性好、系统水灰比小、细度大,而用生石灰的消解要受到硫酸盐的抑制。     

古建筑修复用熟石灰性能优化及机理研究

研究了矿渣、循环流化床锅炉燃烧脱硫灰(CFBC脱硫灰)和硅灰对熟石灰性能的影响及作用机理,并与理想的古建筑修复材料——强度等级为NHL2的天然水硬性石灰(简写为NHL2)进行性能对比,探讨了改性熟石灰用于古建筑修复的合理性.结果表明:由于火山灰反应及对熟石灰微观结构的影响,矿渣、CFBC脱硫灰和硅灰均可明显改善熟石灰的力学性能、防水性和耐候性;与NHL2相比,掺矿渣的熟石灰力学性能、防水性、耐候性和柔性均有所提高,掺CFBC脱硫灰的熟石灰性能优势较小,掺硅灰的熟石灰抗压强度和耐候性能较好,但防水性和柔性较差.在古建筑修复中,可利用质量分数为20%的矿渣作为熟石灰的添加剂.     

The role of carbide lime and fly ash blends on the geotechnical properties of clay soils

Carbide lime is a by-product obtained during the manufacturing of acetylene from the reaction of calcium carbide and water. A major portion of carbide lime is dumped in waste deposition areas, creating an environmental problem. Carbide lime and fly ash have possible applications in slope stabilization, subgrade improvement of roads, and soil treatments under shallow foundations. A series of Atterberg limits tests, compaction tests, unconfined compressive strength tests, ultrasonic pulse velocity tests, and wetting–drying tests were performed on carbide lime and fly ash treated clay soils to evaluate the effects of additive content, curing time, strength development, and the effects of wetting and drying. A total of 8% of carbide lime constituted the fixation point, and peak strength was achieved at 12% carbide lime content. A total amount of 25% additive was found as a threshold changing the Atterberg limits. Test results indicated that the strength of the treated soil improved by the existence of carbide lime and fly ash; best performance was observed in 28-day specimens with 10% carbide lime and 20% fly ash content reaching to 8 times larger strength than untreated soil. The failure patterns of the specimens reflected the curing time and wetting–drying effects. Although, the application of wetting–drying cycles deteriorated the treated soil, the presence of carbide lime partially prevented the strength loss. New relationships between normalized strength and curing time depending on carbide lime content were proposed. Furthermore, a linear relationship between the unconfined compressive strength and the ultrasonic pulse velocity of the treated soils was established.

     

石灰土的工程特性试验研究

石灰土是一种在土建工程中得到广泛应用的建筑材料。石灰具有改善土质性能的作用,针对具体的土质及灰质,通过大量室内试验,探讨不同灰土比、密实度、含水率等因素对石灰土直剪强度的影响;同时,试验分析了养护石灰土的工程特性,特别是探讨了养护龄期及冻融循环对石灰土无侧限抗压强度的影响。通过试验研究,进一步了解了石灰土的特有工程性能,从而可为工程设计提供可靠的参考依据。     

Bearing ratio and leachate analysis of pond ash stabilized with lime and lime sludge

Recycling of industrial waste is one of the effective ways to overcome their disposal problem. Ash produced by thermal power plants and lime sludge produced by paper mills require huge disposal land and may create environmental problems such as dusting and leaching of harmful heavy metals. Stabilization of the ash can improve its engineering properties and address the environmental problems. This paper reports the laboratory test results of a Class F pond ash stabilized with lime (2%, 4%, 6% and 8% by weight) alone and in combination with lime sludge (5%, 10% and 15% by weight). The X-ray diffraction (XRD) and scanning electron micrograph (SEM) tests were also performed to identify the possible formation of crystalline phases after stabilization. The effects of lime sludge on the unsoaked and soaked bearing ratios of pond ash with different lime contents, after 7 d, 28 d and 45 d of curing, were observed. Test results indicated that the bearing ratio increased considerably up to a 4% lime content which can be taken as the optimum lime content. Further increase in lime content increased bearing ratio gradually but at a slower rate. The effect of lime sludge was more pronounced at the optimum lime content, particularly at a low curing period. Lime sludge improved the bearing ratio in soaked condition significantly. Leachate analysis of stabilized ash was performed using toxicity characteristic leaching procedure (TCLP-1311) method. The concentrations of toxic elements Zn, Cu, Cd, Ni and Cr in the stabilized mixes were lower than those in the unstabilized waste. The results indicated that the pond ash-lime-lime sludge mixes have potential application as road subbase material.     

Characterization and lime treatment of olive mill wastewater

Seventeen olive mill wastewater (OMW) samples were characterized. For characterization of the samples, amount of total, fixed, volatile, suspended, volatile-suspended solids, COD, oil-grease, polyphenol, volatile phenol, nitrogen and reducing sugar were determined. Effects of lime treatment on the waste samples were investigated. Reduction of contents of the samples treated with the lime was described. The effect of the addition of lime on an artificial phenolic mixture was also examined.