影响高锰酸盐指数测定的主要因素

影响高锰酸盐指数测定准确性的主要因素有样品酸度、蒸馏水水质、高锰酸钾溶液浓度、水浴加热温度和滴定时间。通过环境标准样品的分析试验，考察这5个因素对高锰酸盐指数的影响程度；     

准确测定高锰酸盐指数的条件因素探讨

为了准确测定高锰酸盐指数,文中从试剂的配制、体系的酸度情况、水浴锅的温度、加热的时间、滴定时间、滴定的速度等因素,经过实验分析,得出结论：高锰酸钾标准溶液浓度的校正系数K要控制在0.980~1.000之间,加入5 mL的1＋3硫酸到溶液中,待水浴锅的温度达到100℃后,严格控制反应时间30 min,按慢-快-慢的滴定速度,在5 min内完成滴定,此时测定的结果接近真值。     

酸性法测定高锰酸盐指数的影响因素控制

水质样品高锰酸盐指数的测定过程中，高锰酸钾标准溶液试剂的配制、滴定速度、反应温度、滴定终点的判断等的诸多因素，会影响测定结果，实际操作中，应控制好上述因素的关键点，以提高测试的准确性。     

酸性法测定高锰酸盐指数的误差消除方法

高锰酸盐指数是一个相对的条件性指标，其测定结果与溶液的酸度、高锰酸盐浓度、加热温度及其时间等条件有关。因此，在测定时必须严格遵守操作的有关规定，使结果才具可比性。     

高锰酸钾降解地下水中PCE的研究

以氯代有机污染物中常见的PCE为目标污染物，以自制高锰酸钾溶液为氧化剂，采用批实验方法，探讨了高锰酸钾降解PCE的反应动力学、影响因素以及反应机理。反应结果表明，高锰酸钾降解PCE的反应符合一级动力学方程，反应活化能E为57.119 kJ/mol，在30℃条件下，反应速率常数为0.0076 min^-1，半衰期为91.20 min。在pH在3～10，离子强度在0～0.1030 mol/L之间变化时，反应速率不受明显影响。     

尿素／高锰酸钾湿法烟气脱氮的试验研究

采用高锰酸钾和尿素配制成不同浓度的吸收溶液，在填有金属鲍尔环的管式吸收反应器中，对模拟烟气进行湿法烟气脱氮的研究。试验结果表明，用尿素和高锰酸钾配制成的吸收液进行湿法烟气脱氮，可以高效地脱除模拟烟气中的氮氧化物，高锰酸钾含量的增加可以显著提高脱氮效率，是决定脱氮效率高低的重要因素，在尿素和高锰酸钾含量分别为5％和0.60g／L时可以达到91．5％的平均脱氮效率；尿素含量、吸收液有效柱高和外加的SO2气体均对脱氮效率产生不同程度的影响。     

日本工业废水中COD的测定法

前言 COD(化学耗氧量)是衡量水质污染程度的最重要的指标之一。常用J1S Kolol工业用水试验法中的酸性高锰酸钾法和重铬酸钾法进行测定。重铬酸钾法氧化力强,准确度好,但加热时间长,操作复杂。所以人们往往只好用酸性高锰酸钾法。此外,用重铬酸     

尿素/高锰酸钾湿法烟气脱氮的试验研究

采用高锰酸钾和尿素配制成不同浓度的吸收溶液,在填有金属鲍尔环的管式吸收反应器中,对模拟烟气进行湿法烟气脱氮的研究。试验结果表明,用尿素和高锰酸钾配制成的吸收液进行湿法烟气脱氮,可以高效地脱除模拟烟气中的氮氧化物,高锰酸钾含量的增加可以显著提高脱氮效率,是决定脱氮效率高低的重要因素,在尿素和高锰酸钾含量分别为5%和0.60g/L时可以达到91.5%的平均脱氮效率;尿素含量、吸收液有效柱高和外加的SO2气体均对脱氮效率产生不同程度的影响。     

乙酰丙酮光度法测定甲醛方法的改进

用乙酰丙酮溶液将CODcr反应管制成标准反应管，CODcr消解器加热回流30min，DR／2010分光光度计比色测定甲醛含量。方法精密度、准确度满足甲醛测定的分析要求。     

水相和泥浆系统中地下水成分对高锰酸钾氧化TCE的影响

三氯乙烯（TCE）是污染土壤和地下水中检出率较高的氯代有机物。以TCE为研究对象，考察了地下水无机成分和腐殖酸对高锰酸钾氧化TCE的影响，研究了不同离子强度下的MnO，颗粒行为，并测定了泥浆系统中TCE的氧化效果，结果表明：当TCE初始浓度为20mg／L、高锰酸钾与TCE的摩尔比为2：1，离子浓度〈0．1mol／L时，TCE去除率可达98％以上，Na^＋、Cl^-、HCO3-对TCE的去除率影响甚微，但离子强度对MnO2的沉淀生成影响显著；0．1mol／L的K^＋对TCE的去除有一定程度的抑制；0．1mmol／L的Fe^2＋和腐殖酸对TCE的氧化有显著负面影响。泥浆系统实验进一步验证了有机质对高锰酸钾氧化TCE的影响很大。     

紫外光协助高锰酸钾降解四环素的研究

高锰酸钾氧化法在实际水处理中得到了一定的应用,但对有机污染物的去除和降解能力相对有限,为此提出了以外加紫外光照射协助高锰酸钾氧化的方法。以四环素作为模型污染物,考察了四环素浓度、高锰酸钾浓度、反应时间、初始pH条件和不同紫外光照射等的影响。结果表明,高锰酸钾能够氧化并去除四环素,紫外光照射明显提高了高锰酸钾对四环素的降解效果,并且254 nm紫外光照射对降解的促进作用远大于365 nm紫外光。在所考察的pH范围内,无论紫外光照射与否,高锰酸钾在酸性条件下的降解效率最高,中性条件较高,碱性条件次之。     

Decolorization of dyes and textile wastewater by potassium permanganate

Decolorization of 10 types of dye solutions by potassium permanganate was studied. Effects of reaction conditions on the decolorization efficiency were examined in batch experiments. The pH value had a significant effect on the decolorization efficiency. When pH value <1.5, the decolorization efficiency was very high. When pH value >4.0, the dye solutions were almost not decolorized. Concentration of potassium permanganate and temperature also showed significant effects on the decolorization efficiency. The decolorization rate of dye solutions by potassium permanganate was rapid, and most of dye solutions can be decolorized effectively. The results of total organic carbon indicated that dye solutions were degraded incompletely by potassium permanganate. The results of treatment of textile wastewater by potassium permanganate indicated that the oxidation with potassium permanganate might be used as a pre-treatment process before biological treatment.     

Removal of <Emphasis Type="Italic">Anabaena spiroides</Emphasis> by potassium permanganate pre-oxidation: effect on photosynthetic capacity and molecular weight distribution

Bench scale tests were conducted to investigate the effect of potassium permanganate pre-oxidation on the photosynthetic activity and molecular weight distribution of Anabaena spiroides. Different concentrations of potassium permanganate were added into the suspension of Anabaena spiroides, one of the dominant algae in water bloom, and after pre-oxidation of permanganate for 1 h, the results show that the removal rate significantly increases by 33.99~36.35% compared to direct coagulation. Then, the algal characteristics, including photosynthetic ability, the changes in extracellular organic matter three-dimensional fluorescence, and the distribution of molecular weight were conducted and the results show that along with increasing concentration of potassium permanganate, the photosynthetic ability of algae decreases, more extracellular organic matter is secreted, and large molecular weight matter (humic-like and fulvic-like substances) are generated. Therefore, this study demonstrates that potassium permanganate could be used in addressing the algae-rich water.     

高锰酸钾强化混凝-生物铁法处理维生素B1生产废水工艺条件研究

采用高锰酸钾强化混凝-生物铁法处理维生素B1生产废水,确定了高锰酸钾的最佳投加顺序、混凝剂的种类以及两者的最佳投药量,探讨了水力停留时间(HRT)、溶解氧(DO)和pH值对生物铁法处理效果的影响,得到了生物铁法处理维生素B1生产废水混凝出水的最佳工况条件.     

Cosolvent-enhanced chemical oxidation of perchloroethylene by potassium permanganate

A laboratory study was conducted to examine cosolvent-enhanced in-situ chemical oxidation (ISCO) of perchloroethylene (PCE) using potassium permanganate (KMnO4). The conceptual basis for this new technique is to enhance permanganate oxidation of dense non-aqueous phase liquids (DNAPLs) with the addition of a cosolvent, thereby increasing DNAPL solubility while avoiding mobilization. Among 17 cosolvent candidates screened, tertiary butyl alcohol (TBA) and acetone were the most stable in the presence of KMnO4, both of which increased PCE aqueous solubility significantly, and therefore are suitable to be used as cosolvent in this study. Batch experiments indicated that the second-order rate constant for PCE oxidation by potassium permanganate was 0.043+/-0.002 M(-1) s(-1) in the purely aqueous (no cosolvent) solution. In the presence of 20% cosolvent (volume fraction=fc=0.2), the rate constant decreased to 0.036+/-0.003 M(-1) s(-1) with TBA and to 0.031+/-0.002 M(-1) s(-1) with acetone. However, in the presence of free-phase PCE, chloride ion concentration from PCE oxidation in acetone/water solutions (fc=0.2) was about twice that in aqueous solutions, indicating that the increase in PCE solubility more than compensated for the decrease in reaction rate constant, such that the oxidation efficiency of PCE was increased with cosolvent. A complete chlorine mass balance was observed in the aqueous system, whereas approximately 70% was obtained in TBA/water or acetone/water (fc=0.2). In soil columns containing residual DNAPL and subjected to isocratic flushing with step-wise increases in f(c) cosolvent, TBA at fc=0.2 resulted in PCE mobilization, whereas acetone at fc相似文献   

生态环境监测中高锰酸盐指数测定影响因素分析研究

文中从水浴时间、计时开始方式和溶液酸度3个方面,对环保部标准样品研究所低、中、高3个已知浓度标准样品进行实验分析。结果表明,在加入5 mL 1+3硫酸,从每锅第一个样品放入水浴锅开始计时和最佳水浴时间为29 min条件下,所测定的高锰酸盐指数值具有较高的准确度和精密度。     

应用改进分光光度法测定多组分水样的COD

提出改进分光光度法测定多组分水样的化学需氧量(COD)。以多种物质的吸光曲线回归方程,将实时测得的水样吸光度分解成多种物质的吸光度,利用多元一次方程进行求解并计算出COD的方法。新方法对含邻苯二甲酸氢钾和丙烯酰胺水样测量的COD,误差平均值为+5.0%,对更多组分的水样测量紫外吸光度误差较大,通过引入修正系数修正后误差大幅下降,10次测量的变异系数约0.5%,精密度较好。通过分析新方法实际运用时存在的优劣之处,提出综合高锰酸盐指数(CODMn)来弥补其测量上不足的新型废水监测模式,以实现监测的快速测量、低耗能、低污染和实时性。     

Bench-scale visualization of DNAPL remediation processes in analog heterogeneous aquifers: surfactant floods and in situ oxidation using permanganate

We have conducted well-controlled DNAPL remediation experiments within a 2-D, glass-walled, sand-filled chamber using surfactants (Aerosol MA and Tween 80) to increase solubility and an oxidant (permanganate) to chemically degrade the DNAPL. Initial conditions for each remediation experiment were created by injecting DNAPL as a point source at the top of the chamber and allowing the DNAPL to migrate downward through a water-filled, heterogeneous, sand-pack designed to be evocative of a fluvial depositional environment. This migration process resulted in the DNAPL residing as a series of descending pools. Lateral advection across the chamber was used to introduce the remedial fluids. Photographs and digital image analysis illustrate interactions between the introduced fluids and the DNAPL. In the surfactant experiments, we found that DNAPL configured in a series of pools was easily mobilized. Extreme reductions in DNAPL/water interfacial tension occurred when using the Aerosol MA surfactant, resulting in mobilization into low permeability regions and thus confounding the remediation process. More modest reductions in interfacial tension occurred when using the Tween 80 surfactant resulting in modest mobilization. In this experiment, capillary forces remained sufficient to exclude DNAPL migration into low permeability regions allowing the excellent solubilizing properties of the surfactant to recover almost 90% of the DNAPL within 8.6 pore volumes. Injection of a potassium permanganate solution resulted in precipitation of MnO2, a reaction product, creating a low-permeability rind surrounding the DNAPL pools. Formation of this rind hindered contact between the permanganate and the DNAPL, limiting the effectiveness of the remediation. From these experiments, we see the value of performing visualization experiments to evaluate the performance of proposed techniques for DNAPL remediation.