共查询到20条相似文献，搜索用时 31 毫秒
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主要研究水流紊动对泥沙絮凝的影响。认为水处理方面的絮凝动力学理论可用于研究泥沙絮凝问题。根据试验实测资料及国外有关试验结果研究表明,在紊动状态下,泥沙絮凝存在两个阶段,每个阶段中紊动对泥沙絮凝的影响也有所不同。 相似文献
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混凝和膜分离联用处理制药废水二级出水中试试验 总被引：3，自引：2，他引：1
对东北制药总厂废水处理厂的二级出水采用混凝-超滤-反渗透膜工艺进行中试处理研究。试验结果表明：混凝工艺对浊度和COD的去除率分别在62.0％和22.3％以上;超滤工艺对浊度和COD的去除率分别在87.4％和54.5％以上;反渗透工艺产水脱盐率在97.6％以上。工艺出水满足循环用水水质指标,工艺运行稳定。 相似文献
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Zhen LIANG 《中国地球化学学报》2006,25(B08):93-94
Diosgenin is produced from Dioscrea L, mainly using D.zingiberensis as the raw material. During the process, particularly in the process of acidic hydrolysis, large quantities of high-strength wastewaters are discharged. The waste liquids are characteristic of strong acidity, usually with pH value less than 1, and high concentrations of organic matter with average CODcr （chemical organic demand） in the range of 20000-3000 mg/L. Without proper treatment, their free disposal would pose serious threat to natural ecosystem and cause considerable environmental problems. Since diosgenin wastewaters contain high load organics and acidity, appropriate pretreatment is needed before they are biologically degraded. Coagulation is a common method for eliminating colloid particles and/or high molecule organic chemicals from wastewaters. Poly-ferric sulfate is found to be most effective in removing organic matter. The objective of this study is to investigate the effectiveness and feasibility of poly-ferric sulfate to reduce CODcr and turbidity from diosgenin wastewaters. Due to its high acidic nature, the pH value of diosgenin wastewater was neutralized with Ca（OH）2 solution before being coagulated. Various factors that influence the coagulation process, such as pH value, the dosage of poly-ferric sulfate, polyelectrolyte aids and mixing conditions were examined in the experiments. 相似文献
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铁炭微电解-混凝预处理糠醛废水 总被引：1，自引：0，他引：1
采用铁炭微电解-混凝法预处理糠醛废水,研究了材料粒径、停留时间、进水pH值等相关因素对处理效果的影响。结果表明,在铁屑粒径1~2mm,活性炭粒径<1mm,进水pH值2.10~2.40,反应40min的条件下,经混凝处理后CODCr去除率可达80%以上,废水BOD5/CODC r值从0.38上升到0.70,有利于后续生化处理。 相似文献
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氯化钙体系对松香废水的絮凝处理 总被引：2，自引：1，他引：2
黄国林 《华东地质学院学报》1997,20(4):396-400
本文报道了氯化钙和硫酸铝或聚丙烯酰胺组成的处理体系对松香废水进行的絮凝研究，全面分析了福建省南平林化厂废水的物质组成和污染指标。通过正交试验，确定处理的主要影响因素。结果表明，用该体系处理松香废水，比用单一絮凝剂，能更好地降低废水的化学耗氧量，树脂及色度，为治理松香废水提供了较充分的数据。 相似文献
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重金属废水处理技术综述 总被引：33，自引：0，他引：33
综述了目前流行的各种重金属废水的实用处理技术,分析了各种处理技术的优缺点,并针对每种处理方法的缺点提出了改进措施。文章指出了微生物絮凝法处理重金属废水是一种最经济可靠的方法。 相似文献
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混凝-催化氧化处理含油污水实验研究 总被引：2，自引：0，他引：2
采用复合化学混凝及催化氧化联合工艺对油田生产废水进行了实验研究.结果表明:含油废水经混凝处理后,剩余ρ(CODcr )可以达到300 mg/L左右,剩余悬浮物质量浓度小于10mg/L;再经活性炭载Cu、Pd催化剂的深度处理,含油污水中的ρ(CODcr )值由315 mg/L降至50 mg/L以下,达到了国家的相关排放标准.催化剂可以再生重复使用. 相似文献
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Aquatic humic substances can be removed by chemical coagulation during water treatment. Hydrolyzing metals such as Al(III) and Fe(III), as well as commercially available cationic polyelectrolytes, can effectively remove humic substances prior to chlorination, thus reducing the formation of trihalomethanes. Synthetic waters, produced by adding soil-extracted fulvic acids to distilled water containing a clay source and various salts, have some merit in approximating the behavior of aquatic humic substances during chemical coagulation; however, caution must be exercised in the interpretation and applicability of the results. 相似文献
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药剂与粉煤灰联合处理再生造纸废水的实验研究 总被引：2，自引：1，他引：1
通过混凝实验探讨了用PAC处理再生造纸废水的最佳混凝条件.在此基础上,选用PAM为助凝剂,通过正交实验,获得了较佳的水平条件:先加PAM,质量浓度为3 mg/L,后加PAC,质量浓度为0.2 g/L,反应9 min;处理后的出水经粉煤灰过滤,ρ(COD)可降至37.383 mg/L,ρ(BOD)为20.7 mg/L,浊度为0,pH为11.12,在空气中放置24 h后pH变为8.02. 相似文献
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化学絮凝法对钛白废水的处理 总被引：1，自引：1，他引：0
详述了硫酸铝钾－聚丙烯酰胺体系处理钛白废水的研究,较全面地分析了江西赣东化工厂钛白废水的物质组成和污染负荷,对该处理体系的工艺条件进行了系统研究,确定了最佳工艺条件。结果表明,该体系处理钛白废水,能有效降低废水中污染物质,值得作进一步研究。 相似文献
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We consider the dynamic behavior of a large-scale, two-dimensional fibril fracture field embedded in a sedimentary pile which is resting on a tectonically active crustal basement. Fractures are treated statistically as a dilute gas composed of parallel, stressed fractures. The salient physical processes are annihilation/coalescence of fractures through binary collisions and their precipitation, diffusion, and advection caused by their motions. The analysis uses techniques of coagulation theory to follow evolution of fractures as they develop from small-scale, elementary ruptures (fibrils) to large-scale objects. The purpose is to study size distribution and temporal variations of emerging fractures at the sedimentary surface with fibril fractures throughout the sedimentary pile. Analysis suggests that transport and in situ coalescence/annihilation of fibril fractures through sediments may be responsible for the size spectrum and temporal variations observed in surface fractures and ruptures. We find that smaller-scale fractures advected to the sedimentary surface have a time lag relative to larger-scale precipitated fractures—suggestive of an after-shock type of behavior. We also find that annihilation reactions (approach to hydrostatic stress and/or cementation) can be effective in reducing the mean size of emerging fractures. Simple estimates indicate that if the annihilation rate is about 5–10 times the coalescence rate, then the coalescence process is virtually unable to produce any larger-scale fractures than the original elementary ruptures (fibrils). 相似文献
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采用混凝沉淀技术处理钨矿选矿废水,通过试验确定HNJY新型高效复合絮凝剂作为混凝剂最为合适,投加量为120mg/L,经处理后废水出水水质符合国家污水排放标准并能回用,废水SS约11500mg/L,处理后的出水要求为SS<10mg/L。技术经济分析,投资总费用为67.5万元,处理成本为0.60元/m3,设计工艺可靠且经济合理。本工程既防止了废水对环境的潜在污染,又解决了枯水期选矿用水不足的问题。 相似文献
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天津市近几年来新建了多座具有独特风格和景观效果的新型桥梁,本文主要介绍其中的三座斜拉桥、三座拱桥、一座自锚式悬索桥和一座集交通、观光、游览为一体的巨型摩天轮桥梁,以及三座经装修改建、使旧桥换新颜的实例。 相似文献
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考虑核电厂地基-基础的动力相互作用,应用显式动力有限差分法分析了地震作用下极软岩、较软岩、坚硬岩上核电厂建筑结构基础的地震响应特征,比较了岩石坚硬程度对基础加速度反应谱的影响。研究表明：随着岩石坚硬程度的提高,核电厂建筑物结构基础的地震响应有增加的趋势;在周期轴上,基础处的加速度反应谱曲线会随着岩石坚硬程度的提高逐渐向短周期（高频段）方向移动。在高频段,建造于较坚硬岩石上基础结构的加速度反应谱值偏大;在中等频段,建造于较软岩石上基础结构的加速度反应谱值偏大;在低频段,岩石坚硬程度对加速度反应谱的影响不显著。 相似文献
16.
M. D. Sharma 《Journal of Earth System Science》2004,113(2):247-257
Three dimensional scattering of near-field is studied for dilatation and rotation in the time domain. The perturbation method
is applied to solve the equation of motion for the first order scattering from a weak inhomogeneity in an otherwise homogeneous
medium. The inhomogeneity is assumed close enough to the point source so that the near-field intermediate wave is dominating
over the far-field sphericalP andS pulses. The integral expressions are derived to relate dilatation and rotation of scattering to the radial fluctuations of
velocities and density in the inhomogeneity. These integrals are solved to calculate the strains of scattering from (a part
of) an inhomogeneous spherical shell of arbitrary curvature. Variable curvature may allow the shape of inhomogeneity volume
element to change uniformly from spherical to rectangular. Rotation of scattering from a spherical shell is independent ofP wave velocity inhomogeneity. Dilatation of scattering does not involveS wave velocity inhomogeneity but its gradient. The back scattering results are obtained as a special case. Strains are computed
numerically, for hypothetical models to study the effects of various parameters viz., velocity inhomogeneity, distance of
source from inhomogeneity and from receiver, and thickness of inhomogeneity. The curvature of the spherical shell is varied
to study the effects of the shape of inhomogeneous volume element on scattering. 相似文献
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地震次生地质灾害风险评估集对态势分析 总被引：2，自引：0，他引：2
5．12四川汶川8级强震引发了大量次生地质灾害,加剧了灾情并严重影响抗震救灾。地震次生地质灾害受多重因素制约,其孕育与致灾过程具有不确定性。利用集对分析原理与方法,对地震次生地质灾害进行同异反态势分析,拟定了风险评估的集对分析同一度、差异度、对立度等指标体系的构建原则与赋值标准,对承灾体系统的不确定性及其作用作了刻画与分析,建立了不同风险分区代表性的集对分析联系度表达式,为地震灾害研究提供了可资借鉴的新思路和技术方法。 相似文献
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Ivan V. BRAGIN Georgy A. CHELNOKOV Oleg V. CHUDAEV Natalia A. KHARITONOVA Sergey V. VYSOTSKIY 《《地质学报》英文版》2016,90(1):276-284
Studied waters belong to warm(T=30-50℃),alkaline(pH=8.9-9.3),low mineralized(TDS235 mg/1)Na-HCO_3 or Na-SO_4-HCO_3 thermal waters with high content of SiO_2(up to 81 mg/l)and F(up to 3.9 mg/1),occur on modern volcano-tectonic rejuvenated areas of Eastern Sikhote-Alin orogenic belt.Low~3He concentration as well as N_2/O_2 and N_2/Ar ratios exclude influence of deep mantle fluid.New rare earth element data constrain our understandmg of water-rock interaction occurring in the water source region.Meteoric origin of waters is proved by stable isotope values varying from-71‰to-136.1‰and from-10.8‰to-18.8‰forδ~2U andδ~(18)O respectively.REE patterns reflect high pH,resultfing from water-rock interaction and oxidative conditions.Calculations of deep aquifer temperature using Na-K and quartz geothermometers show 116.8-131.1°C and 82.2-125.8℃respectively.Presence of deep faults both with abnormal thermal gradient(~45-50 K/km)define unique geochemical shape of thermal waters of Sikhote-Alin,area,where no present volcanic activity is registered. 相似文献