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含氯离子废水中化学需氧量分析方法的改进 总被引:5,自引:0,他引:5
在分析工业废水的COD时,常常会遇到含氯化物较高的废水,如味精废水、保险粉废水、染料生产盐析废水、稀土矿物提炼废水等。平时分析此类废水时,我们大都采用往水样中加入硫酸汞以消除氯离子干扰的操作方法,但是由于硫酸汞剧毒,对环境和人体危害较大。我们根据日常工作的总结,提出一种用硝酸银代替硫酸汞掩蔽废水中氯离子的新的分析方法。 相似文献
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氯离子对COD测定的干扰及校正方法的研究 总被引:6,自引:0,他引:6
采用标准曲线法,对Cl^-在测定工业废水COD时的干扰进行校正。用重铬酸钾法测定不同浓度的纯NaCl溶液的COD,将测定结果绘成标准曲线,由水样测定的COD减去由标准曲线查得的Cl^-校正值,即得到水样的真实COD。该方法简捷、方便、不使用剧毒试剂HgSO4,适用于含Cl^-500-25000mg/L废水COD的测定。 相似文献
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建立了适用于高氯离子、低COD废水中COD的重铬酸钾测定方法。分别采用甘油、二氯丙醇、β,β′-二氯异丙醚和氯化钙配制模拟高氯废水,考察了氧化剂重铬酸钾溶液浓度、掩蔽剂加入量(以m(HgSO_4)∶m(Cl~-)表示)对测定效果的影响。实验结果表明:以低浓度(0.05 mol/L)重铬酸钾溶液为氧化剂时,测定数据波动范围小,相对误差也低(-1.4%~+0.4%);对于高氯低COD废水的COD测定,当COD大于100 mg/L时按m(HgSO_4)∶m(Cl~-)=10∶1加入硫酸汞掩蔽剂,当COD小于100 mg/L时按m(HgSO_4)∶m(Cl~-)=20∶1加入硫酸汞掩蔽剂,并采用浓度为0.05 mol/L的重铬酸钾溶液作为氧化剂,能较好地消除氯离子对COD测定的干扰,相对误差在5%以内;将优化后的测定条件应用于实际环氧氯丙烷生产废水COD的测定,重现性良好,当m(HgSO_4)∶m(Cl-)分别为10∶1和20∶1时,相对误差分别为+3.3%和+2.9%,COD平均回收率分别为103.4%和102.9%。 相似文献
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包头第二热电厂和呼和浩特市电厂灰排水COD超标十几倍至几十倍,是内蒙呼包电网的突出问题。自1984年四季度地方环保部门监测以来,就征收了超标排污费。为查清超标原因,我们对冲灰水水源、灰水和过滤后的灰进行了试验分析。证明灰排水COD超标是粉煤灰中未燃尽碳所致。 相似文献
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本文在实测电厂灰水中悬浮物和COD的基础上。针对悬浮物对COD的影响。通过对灰水的过滤、澄清、混匀试验以及粉煤灰对COD的降解试验,探明了灰水中COD的超标原因并提出治理措施. 相似文献
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阐明了氯离子干扰废水化学耗氧量测定的原理.从三个方面综述了近几年分析工作者对消除氯离子干扰所进行的研究加汞盐和无汞盐掩蔽消除Cl-干扰,用国家标准方法测定化学耗氧量后再减去理论上Cl-所消耗的化学耗氧量,Cl-完全氧化法测定高氯废水的化学耗氧量. 相似文献
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Kenichiro Inoue Tsutomu Uchida 《Journal of Material Cycles and Waste Management》2017,19(4):1488-1494
Research and experimental studies were carried out in relation to reduction of hazardous elements contained in sewage sludge incineration ash. A questionnaire survey was conducted in 69 Japanese municipalities with sewage sludge incineration facilities. Selenium content in bag filter ash and ceramic filter ash was relatively higher than that in ash of cyclone and electrostatic precipitators. It was assumed that selenium vaporized in the furnace was due to adsorb in the fly ash on filter when passing through the low-temperature filter. To reduce high boiling point heavy metals in the ash, sewage sludge and incineration ash were heated up using a small muffle furnace. As the result, the chrome and nickel contents were reduced. A decrease in the surface area of ash and the reduction of elements occurred at the same time in sewage sludge and incineration ashes tested in this study. 相似文献
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在反复比较的基础上,把寻找具有多官能团的有机高分子试剂和设计简单适用的工艺方法作为研究方向,开发了适用于处理水电厂高pH值、高SS浓缩池溢流灰水的有机高分子多功能试剂,有效地防止了灰水回用系统的结垢,降低了运行费用,处理灰水的药剂费用<0.03元/t。 相似文献
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Funatsuki Atsushi Yamaguchi Shuji Shiota Kenji Takaoka Masaki 《Journal of Material Cycles and Waste Management》2018,20(2):955-964
Journal of Material Cycles and Waste Management - The chemical states of arsenic contained in 4 kinds of sewage sludge incineration ash and insolubilized materials are analyzed using a leaching... 相似文献
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Leaching characteristics of rare metal elements and chlorine in fly ash from ash melting plants for metal recovery 总被引:2,自引:0,他引:2
In terms of resource recovery and environmental impact, melting furnace fly ash (MFA) is attracting much attention in Japan due to its high metal content. The study aims to obtain fundamental information on using a water extraction method not only to concentrate valuable rare metals but also to remove undesirable substances such as chlorine for their recovery from MFA. The composition and leaching characteristics of MFA was investigated. The results revealed that the metal content in MFA is nearly equal to raw ore quality. The content of Ag, In, Pd, Pb, and Zn is, in fact, higher than the content of raw ore. As for leaching behavior, Ag, Bi, In, Ga, Ge, Sb, Sn, and Te showed the lowest release at a neutral pH range. Pd was leached constantly regardless of pH, but its concentration was quite low. On the other hand, most of the Tl was easily leached, revealing that water extraction is not appropriate for Tl recovery from MFA. Major elements Cl, Ca, Na, and K, occupying about 70% of MFA, were mostly leached regardless of pH. Base metal elements Cu, Pb, and Zn showed minimum solubility at a neutral pH. The leaching ratio of target rare metal elements and base metal elements suggests that the optimal pH for water extraction is 8-10, at which the leaching concentration is minimized. The water extraction process removed most of the Cl, Ca, Na, and K, and the concentration of rare metals and base metals increased by four or five times. 相似文献
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分析了国内水中余氯测定标准的现状,从标准适用范围、标准对象、方法原理、样品预处理、干扰物和方法的精密度等方面对现行标准进行了分析讨论,提出目前国内水中余氯测定标准存在现状复杂、技术内容重复、术语名称和定义不统一、样品预处理、保藏和运输规定与检测方法之间不协调、方法的质量指标不同等问题,并对今后余氯测定标准化工作提出建议,特别是针对标准对象名称混乱和技术内容重复等现象,对标准制/修订工作提出了及时复审或修订标准、对关键技术内容开展比对试验以探讨差异存在必要性等建议。 相似文献
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Shaohong Peng Sha Liang Mei Yu Xia Li 《Journal of Material Cycles and Waste Management》2014,16(1):178-185
A new recycling process for the supercritical CO2 (sc-CO2) extraction of polybrominated diphenyl ethers from waste high impact polystyrene (HIPS) was developed in this paper. HIPS was first dissolved in d-limonene. The remaining decabromo diphenyl ether (decaBDE) particles in solution were then removed by centrifugation, and the PBDEs in the centrifugate solution were further extracted by sc-CO2. The influence of temperature and pressure, the volume ratio of sc-CO2 to plastic solution, and the concentration of decaBDE in the solution on the separating efficiency were investigated. The decaBDE particles in 20 % of the HIPS solution can be removed by centrifugation at a speed of 10,000 r/min at 30 °C. The suitable sc-CO2 fluid conditions were 65 °C and 20 MPa, and the optimum volume ratio of the sc-CO2 to the HIPS solution was 2:1. More than 97 % of the PBDEs were successfully removed, and the concentration of PBDE residues in the recycled HIPS was reduced to lower than 0.1 % (dry) by this recycling process. 相似文献
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Ogawa Narihito Amano Takahito Koike Yuya 《Journal of Material Cycles and Waste Management》2021,23(1):158-164
Journal of Material Cycles and Waste Management - Radioactive cesium found in municipal solid waste incineration (MSWI) fly ash can be easily eluted through contact with environmentally sourced... 相似文献
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以粉煤灰(FA)为原料,采用共沉淀法制备了层状双金属氢氧化物(LDH)和层状金属氧化物(LMO,也称LDO),并采用XRD和BET技术进行了表征。比较了FA、LDH、LMO对活性红X-3B染料(X-3B)的吸附效果;考察了LMO吸附X-3B的影响因素,并探讨了吸附机理。XRD表征结果表明,LMO在吸附X-3B后重新恢复LDH层状结构。BET表征结果表明,LMO的比表面积大于LDH。吸附实验结果表明,3种吸附剂对X-3B吸附效果的优劣顺序为:LMOLDHFA;在初始X-3B质量浓度为50 mg/L、LMO投加量为2.0 g/L、吸附温度为25℃、吸附pH为7、吸附时间为30 min的条件下,X-3B去除率可达98.1%;LMO对X-3B的吸附符合Langmuir等温吸附方程,饱和吸附量为129.53 mg/g,且吸附过程可用准二级动力学方程描述。 相似文献
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The durability, of mixtures of two kinds of Spanish fly ashes from coal combustion (ASTM class F) with 0, 15 and 35% replacement of Portland cement by fly ash, in a simulated marine environment (Na(2)SO(4)+NaCl solution of equivalent concentration to that of sea water: 0.03 and 0.45 M for sulphate and chloride, respectively), has been studied for a period of 90 days. The resistance of the different mixtures to the attack was evaluated by means of the Koch-Steinegger test. The results showed that all the mixtures were resistant, in spite of the great amount of Al(2)O(3) content of the fly ash. The diffusion of SO(4)(2-), Na+ and Cl- ions through the pore solution activated the pozzolanic reactivity of the fly ashes causing the corresponding microstructure changes, which were characterized by X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). As a result, the flexural strength of the mixtures increased, principally for the fly ash of a lower particle size and 35% of addition. 相似文献