Water Lime Treatment with Sludge Recycle

Hereinafter we introduce a system of water lime treatment with sludge recycle. This system will eliminate many problems encounted in conventional water softening treatment system, such as consuming a large amount of commodity hoe and the problem of sludge disposal. In this system the sludge of calcium carbonate from the reaction Will be calcined to quicklime and partially re-used in the system itself, the surplus quicklime can be sold out. Nearly no wastewater and wasteslag are disposed during the treatment process.

某电厂再生水深度处理系统问题诊断分析

某电厂将城市污水处理厂再生水深度处理后作为循环水系统补水。由于再生水深度处理系统存在机械加速澄清池出力达不到设计值、出水水质差、污泥脱水系统无法正常运行、石灰系统下料堵塞、加药装置泄露严重且无连锁控制等问题,无法满足电厂正常使用再生水的要求。经过问题诊断,提出优化改造方案:分别对机械加速澄清池内部结构、底部排泥管路系统改造,以恢复机械加速澄清池处理能力,满足系统所需水量的要求;对污泥脱水系统进行改造,以恢复污泥脱水单元运行;对石灰加药系统进行改造,以改善石灰加药下料堵塞等问题,恢复石灰系统的稳定运行。通过以上措施澄清池出力提高,系统出水水质得以优化,有效保证了再生水深度处理系统的正常运行以及电厂用水安全。

双碱法脱硫工艺提标改造与实践

介绍了淄博铁鹰球团制造有限公司双减法脱硫工艺技术改造过程和应用实践。通过对脱硫工艺的石灰浆液制备及输送系统、SO_(2)吸收系统、石膏脱水系统、工艺水系统、电气及自动控制系统等关键环节技术创新与改造,有效解决了脱硫能力不足、压滤效果差、塔体及喷淋管路结晶严重、工艺水平衡困难等运行难题,并实现了由双减法向石灰-石膏法脱硫工艺过渡,满足了生产需要,降低了脱硫运行成本。

高速铁路路基改良土垫层对毛细水处治的经济性分析研究

路基内毛细水上升导致的翻浆冒泥、冻胀等灾害影响高速铁路安全稳定运行。为实现安全、有效、经济的治理毛细水灾害,依托铁路工程实际,开展石灰改良土和水泥改良土垫层毛细水上升实验研究,并进行经济对比分析。研究结果表明,石灰改良土垫层和水泥改良土垫层均具有抑制毛细水上升的效果,水泥改良土垫层相比石灰改良土垫层具有较高的经济效益,具有较好的路用性能和社会效益,成果可为毛细水灾害严重地区工程项目提供借鉴。

石灰纯碱法耦合聚合氯化铝预处理高矿化度矿井水的实验研究

高矿化度矿井水回用常采用膜技术进行脱盐,但运行过程中水中硬度和悬浮物会造成膜污染极大影响了膜性能,开展预处理降低矿井水硬度及浊度,对减轻膜污染、提高出水水质、降低运行费用有重要的作用。本文采用石灰纯碱法耦合PAC去除矿井水的硬度及浊度,采用单因素试验考察了药剂投加量、反应时间、沉淀时间对去除效果的影响。试验结果表明,氢氧化钙投加量为100 mg/L、碳酸钠投加量为10 mg/L、PAC投加量为20 mg/L,反应30 min,沉淀15 min,此时水样的总硬度为51.54 mg/L,总硬度去除率为48.11%,浊度去除率为98.13%。吨水药剂费用3.07元。

Efficacy of Pelletized Lime versus Limestone Sand for Forest Regeneration Enhancement in Pennsylvania, USA

The efficacy of limestone sand and pelletized lime for remediation of soil acidity was compared in order to determine if limestone sand was a more cost-effective alternative to pelletized lime. Between fall of 2002 and spring 2003, two forested sites in Pennsylvania were clear cut and fenced. Pelletized lime and limestone sand were applied to separate 400-m2 plots within the sites at rates of 2170 kg·ha-1 and 4335 kg·ha-1, respectively. Two additional 400-m2 plots were used as controls. A paired before-after control-impact study design was used to assess changes in soil, soil solution, vegetation and biomass after lime application. Soil samples were collected from the Oi, Oe + Oa, and A horizons before and after lime application. Woody and herbaceous vegetation was harvested from 1-m2 sub-plots before and after liming and bi-weekly soil solution samples were collected for six months following lime application. Analysis of variance procedures were used to compare changes in the treatment plots over time. Changes in soil chemistry following lime application were comparable on the limestone sand and pelletized lime plots. There was a significant increase in exchangeable Mg and Mg saturation in the Oe + Oa horizon on all of the lime treatment plots relative to controls, but a greater percentage of applied Ca and Mg was exchangeable in the O-horizon in pelletized lime plots nine months after liming. Plant biomass did not increase on the lime treatment plots relative to the control one year post treatment. The majority of applied Ca and Mg from pelletized lime and limestone sand remained in the litter layer, with little movement into the A-horizon after one growing season. These results indicated that the application of limestone sand at two times the rate of pelletized lime produced comparable changes in soil and soil solution chemistry at a fraction of the cost.

Quality Improvement of Recycled Concrete Aggregate by Accelerated Carbonation under Different Pressure

Due to the presence of old mortar (OM) and interfacial transition zone (ITZ),recycled concrete aggregate (RCA) is inferior to natural aggregate (NA).The purpose of this paper was to study the effect of accelerated carbonation on the macro-properties and micro-properties of RCA under different pressure(0.05,0.15,0.30 MPa).The macro-property tests included colour change,apparent density,water absorption,and crushing value of RCA.The micro-property tests included scanning electron microscopy (SEM),X-ray diffraction (XRD),thermogravimetry-differential scanning calorimetry (TG-DSC),and Vickers micro-hardness(VMH).The results showed that the change trends of apparent density,water absorption,and crushing value of RCA displayed exponential relationships as pressure increasing,with the optimum pressure of 0.30 MPa.SEM images indicated that the calcite caused by the hydration products in RCA and the Ca(OH)_(2) derived from saturated lime water improved the properties of RCA;as the apparent density increased,the water absorption and crushing value decreased.The results of XRD and TG-DSC indicated that,as the pressure increased,the masses of Ca(OH)_(2) in carbonated RCA gradually decreased,while those of CaCO_(3) gradually increased,which demonstrated that the carbonation degree gradually increased.Besides,ITZ-2 was the weakest phase in RCA,but its improvement degree of VMH by accelerated carbonation was higher than that of OM.However,RCA was not completely carbonated,but only carbonated in a certain depth after 24 h accelerated carbonation.

Effect of climate change on the trends of evaporation of phreatic water from bare soil in Huaibei Plain, China

When the soil condition and depth to water table stay constant, climate condition will then be the only determinant of evaporation intensity of phreatic water from bare soil. Based on a series of long-term quality-controlled data collected at the Wudaogou Hydrological Experiment Station in the Huaibei Plain, Anhui, China, the variation trends of the evaporation rate of phreatic water from bare soil were studied through the Mann-Kendall trend test and the linear regression trend test, followed by the study on the responses of evaporation to climate change. Results indicated that in the Huaibei Plain during 1991-2008, evaporation of phreatic water from bare soil tended to increase at a rate of 5% on monthly scale in March, June and July while in other months the increase was minor. On the seasonal basis, the evaporation saw significant increase in spring and summer. In addition, annual evaporation tended to grow evidently over time. When air temperature rises by 1 °C, the annual evaporation rate increases by 7.24–14.21%, while when the vapor pressure deficit rises by 10%, it changes from-0.09 to 5.40%. The study also provides references for further understanding of the trends and responses of regional evapotranspiration to climate change.

不同添加剂处理柞树叶青贮对延边黄牛体外发酵瘤胃降解率和微生物菌群的影响

本研究旨在分析不同添加剂处理柞树叶青贮对延边黄牛体外发酵瘤胃降解率和微生物菌群的影响。选择4头平均体重为(443.3±26.7)kg、装有永久性瘤胃屡管的延边黄牛公牛为瘤胃液供体。将青贮的柞树叶按照添加发酵添加剂的不同分为糖蜜组(M)、乳酸菌组(LAB)、EM菌组(一种混合菌一般包括光合菌、酵母菌、乳酸菌等有益菌类)(EM)、石灰水组(LW)、乳酸菌+糖蜜组(LAB-M)以及EM菌+糖蜜组(EM-M),每组3个重复。体外发酵48 h后,计算中性洗涤纤维降解率、干物质降解率以及粗蛋白质的降解率,并提取瘤胃液中的细菌总DNA,进行PCR扩增后用Illumina Hi Seq 2500测序平台进行高通量测序。结果表明:各青贮柞树叶试验组的干物质、粗蛋白质以及中性洗涤纤维的降解率均较对照组显著升高(P<0.05),EM组和EM-M组降解率增加最显著。LW组的干物质降解率、粗蛋白质降解率和中性洗涤纤维降解率显著低于其余的5个组(P<0.05)。不同发酵添加剂的青贮柞树叶对延边黄牛体外发酵瘤胃微生物菌群无显著影响(P>0.05)。在门水平上,变形菌门、拟杆菌门以及厚壁菌门是反刍动物瘤胃内的主要微生物菌群。在属水平上,不动杆菌属、普氏菌属、弓形杆菌属是主要微生物菌群。综上所述,不同添加剂可以有效地改善瘤胃降解环境,提高瘤胃降解率。其中,EM组和EM-M组效果较好,且各试验组对于延边黄牛瘤胃微生物整体区系构成、微生物多样性以及微生物的丰度均无显著影响。

抗剥落剂对沥青混合料水稳定性影响研究

为改善沥青混合料水稳定性,采用消石灰和水泥两种抗剥落剂改良沥青混合料,并通过室内试验研究抗剥落剂对沥青混合料水稳定性影响规律。结果表明,掺抗剥落剂的沥青混合料抗水损害能力提高,抗剥落剂掺量每增加1%,沥青混合料冻融劈裂抗拉强度比降低不超过2.6%;消石灰掺量1%时,沥青混合料残留稳定度最大,较未掺抗剥落剂的沥青混合料残留稳定度提高11.4%以上;抗剥落剂可减小沥青混合料浸水飞散损失,抗剥落剂掺量≥1%时,石灰和水泥掺量增加1%,沥青混合料浸水飞散损失分别平均增大9.5%、9.6%。

不同水分管理措施配施生石灰对大米硒及其他金属元素积累的影响

【目的】硒、铜、锌等微量元素通过酶参与人体内多种反应,是机体保持健康不可或缺的重要元素,而重金属元素(Cd、Pb、Hg、As)通过食物链作用于人体,是危害人体的有毒物质。大米作为国民主粮是人体摄入这些元素的重要渠道。本试验探究不同农艺措施与石灰改良剂对水稻籽粒中重金属积累及微量元素含量变化影响。【方法】选用莲红香占为对象,使用不同浓度(10,20,30,40 g/桶)的石灰及不同的水分管理措施(淹水、湿润、间歇灌溉)的盆栽试验,研究对大米中微量元素(Se、Mn、Fe、Zn、Cu)及重金属元素(Cd、Pb、Hg、As)变化影响。【结果】湿润灌溉模式可显著提高大米中总硒含量,当湿润灌溉且石灰添加量为10 g/桶与30 g/桶时,大米中的总硒含量显著增加。采用双因素方差分析结果显示,灌溉方式与生石灰用量二因素单独及交互皆对大米总硒含量影响极显著。在间歇灌溉模式下,添加不同含量的石灰对稻谷籽粒中Zn含量增加影响效果显著。生石灰用量因素对大米中Zn含量影响效果极显著,灌溉方式与生石灰用量交互对Zn含量影响效果极显著。湿润灌溉时添加石灰可显著降低稻谷中Cd浓度,灌溉方式与生石灰用量交互对Cd含量影响效果极显著。淹水灌溉模式下添加20 g/桶至40 g/桶石灰,对籽粒中Pb含量降低影响效果显著。【结论】在水稻种植过程中采用正确水分管理措施配合适宜浓度石灰改良剂促进水稻微量元素Se与Zn富集及减少重金属元素Cd与Pb对水稻的危害具有重要作用。

高炉矿渣—石灰复合改良膨胀土工程特性试验研究

针对传统石灰改良膨胀土能耗高、污染大的缺点,应用工业固体废物高炉矿渣替代部分石灰对河北地区膨胀土进行改良。通过击实试验及无侧限抗压强度试验分析高炉矿渣-石灰改良土的击实特性、水敏特性、力学特性和水稳特性,并将其与相同掺量的石灰改良膨胀土进行对比。结果表明:相同击实功下,改良土的最大干密度随高炉矿渣占比的增加呈上升趋势,最优含水率呈下降趋势;改良土未浸水和浸水无侧限抗压强度、弹性模量随高炉矿渣占比的增加呈先增后减趋势,高炉矿渣占比为0.75时达到最大值。高炉矿渣占比为0.25,0.5,0.75时,改良土未浸水和浸水无侧限抗压强度、弹性模量均高于石灰改良土。改良土水稳系数随高炉矿渣占比的增加而呈下降趋势。

含砷酸性废水除砷工艺现状与展望

综述了当前含砷废水主要处理方法如石灰法、石灰-铁盐法、硫化法以及臭葱石法的运行现状和研究动态。通过详细分析含砷酸性废水除砷工艺研究现状,着重探讨了上述除砷技术的反应原理、除砷效果、工艺特点,并对含砷酸性废水未来处理技术的发展趋势及研究方向进行了展望,为有色金属行业清洁高效除砷工艺选择及改进提供参考借鉴。

熟石灰掺量对矿粉-粉煤灰二元碱激发胶凝材料性能影响

文中研究熟石灰掺量(2%、4%、6%、8%)对矿粉-粉煤灰二元碱激发胶凝材料微观形貌、强度、化学结合水含量及凝结时间的影响。结果表明,SF-8的28 d抗压强度能达到30.56 MPa,与SF-2相比,其抗压强度和化学结合水含量均已提高,凝结时间缩短,熟石灰适宜掺量能促进矿粉-粉煤灰二元碱激发胶凝材料水化,提高浆体致密性。

混凝压滤-熟石灰处理包装印刷废水

包装印刷废水是一种COD、NH_(3)-N,色度都很高的工业废水,废水成分主要来源于纸箱生产过程中使用的水性版油墨和淀粉粘合剂,通常使用PAC结合PAM进行混凝预处理。经实验对比,采用熟石灰混凝压滤后,COD去除率在60%以上,色度去除率在90%以上,价格便宜,处理成本低,由于处理溶液维持在偏碱性环境,腐蚀性低,处理设备可采用碳钢结构,投资成本较低,适用于大规模生产的纸箱生产企业。

磁加载石灰混凝预处理市政中水的研究

本文主要研究了磁加载石灰混凝在中水预处理中的可行性与效能。研究结果表明,聚合氯化铝(PAC)、阴离子聚丙烯酰胺(PAM)、石灰和磁种的最佳投加量分别为250、375、0.75和375 mg·L^(-1)时,可以实现水中悬浮物100%去除,溶解性有机物的去除率高达26.7%,显著降低了水的硬度。进一步研究了磁种的投加顺序对絮体形态的影响,讨论了磁加载石灰混凝的机理。研究发现,磁种先于混凝剂投加,可以有效改善絮体结构,在增强絮体沉降性能的同时实现污泥减量。该技术可以强化溶解性污染物的去除效果,同时实现在线控制与装备集成,在中水回用中具有广阔的应用前景。

掺超贫铁矿石混凝土力学性能及微观结构研究

这是一篇陶瓷及复合材料领域的论文。对超贫铁矿石进行加工处理,将良好级配的超贫铁矿石作为骨料,制备新型的蒸压加气混凝土砌块,进而研究不同骨料的掺量、水灰比和蒸压时间对蒸压加气混凝土性能以及微观结构的影响。结果表明:随着水灰比,石灰掺量、骨料取代率和蒸压时间的增大,混凝土的抗压强度均呈现先增大、后减小的趋势;超贫铁矿石骨料的取代率为40%,粉煤灰掺量为10%、石灰掺量为18%、水泥掺量为60%,水灰比为0.45和蒸压时间为5 h时,混凝土的性能达到较佳。同时,超贫铁矿石的掺入对新物相的产生和混凝土自身以及孔隙结构具有较大的影响。

火电厂再生水深度处理系统诊断分析与应用

为了解决火电厂再生水深度处理系统出力不足、水质不达标等问题,将“自动排泥+污泥均质”污泥预处理方法、主动外循环定量活性污泥供给方法、带回流及双馈调节“湿法”石灰投加方法有效结合,对再生水深度处理系统进行技术改进。并在北方某电厂工程应用,恢复了系统设计出力。运行结果表明,出水浊度为0.71 NTU,暂硬为0.65 mmol/L,总硬度为4.11 mmol/L,暂硬去除率为84%,总硬去除率为32%,出水水质优于回用要求,自来水取水量每年节约288万t。恢复后再生水深度处理系统能够大幅减少新鲜水的取用量,提高再生水重复利用率,达到节水减排的目的,保障火电厂的供水安全。

皖北平原不同土壤水分养分差异性研究

黄潮土和砂姜黑土面积占皖北平原总面积的87%。砂姜黑土内部含有钙质结核,严重影响土壤性质进而降低作物产量。从土壤理化性质、土壤水力学参数和土壤水分等方面探讨两种土壤差异性,并结合水文气象因素分析影响黄潮土和砂姜黑土土壤水分变异的驱动因素。结果表明:黄潮土和砂姜黑土的pH值和密度存在显著差异,全氮、全磷、碱解氮含量差异不大;黄潮土0~50 cm的有效持水量显著大于砂姜黑土,保水性更好。黄潮土土壤含水率随深度增加逐渐降低,砂姜黑土土壤含水率随深度增加逐渐增大。影响黄潮土土壤含水率变化的主要驱动因素是地下水埋深和降水量;影响砂姜黑土土壤含水率变化的主要驱动因素是地温、地下水埋深和相对湿度。该研究可为进一步改善砂姜黑土土壤性质、提高作物产量提供参考。

石灰与水泥改良给水厂污泥进行资源化利用的研究

给水污泥资源化利用是近年来的研究热点,但目前对给水厂污泥资源化利用存在难度大、成本高、技术不成熟等问题。采用生石灰和水泥作为固化剂对给水厂污泥进行改良,制成石灰水泥综合稳定土,以期用于市政管道施工的垫层。试验得到石灰水泥综合稳定土的最优质量配比为给水厂污泥∶生石灰∶水泥=100∶24∶6,最佳含水率为74%,最大干密度为0.760 g/cm3。该方法为解决给水厂污泥的处置问题提供了新途径,处理价格低廉,处理1 t给水厂污泥的材料费用仅144元,且不会造成二次污染,实现了污泥的“稳定化、无害化、资源化”的处理处置,社会、经济和环境效益明显。