六价的

Using H2SO4 as acidulant,chromic sulfate with high purity was obtained by crystallization,which was applied to leather industry as chrome tanning agent .

将电镀废水中的六价铬还原成Cr，用化学沉淀法和絮凝法将其转化为Cr3沉淀，通过硫酸酸化，结晶为高纯硫酸铬，作为皮革工业的铬鞣剂。

In this research, the concentration of PbCrO4 in the reaction can be as low as 58g-L-1 without any ill influence on the experiment. Therefore, some leachate can be used to produce yellow chrome directly without concentration.

乙酸铅或硝酸铅与代替重铬酸钠溶液的铬渣滤液反应时，其用量应高于理论值，大约为理论值的1.10～1＊倍，才能使六价铬充分反应，使生成的铬黄量达到最大值。

Sodium dichromate dihydrate is an inorganic compound containing hexaalent chromium that was used in the NTP studies.

重铬酸钠是NTP在研究中使用的一种含有六价铬的无机化合物。

This article analyzed the pollutant source in everglade of Dongting Lake, based on investigate data from hydrological observation station of Dongting Lake, environmental monitor station and spots examine.

利用洞庭湖水文观测站、环境监测站和实地考察资料，分析了洞庭湖湿地的TN、TP、COD、六价铬等重金属、硫化物、氰化物、氟化物和石油类等污染物的来源和数量。

Since risk assessment is a continually improving process, PELs may need reassessment periodically, especially after the discovery of new information. The HRA ensures that workers are well protected, taking into account the latest advances in science and technology.

根据此规范流程执行并完成六价铬健康风险评估的结果，可以提供给相关单位参考应用以制订能广为接受的容许浓度标准，随著科学进步，在新的科学证据出现以前，容许浓度仍需要重新检讨与评估，以妥善维护劳工安全卫生并提升国家经济竞争力。

To establish the sensitive and rapid determination of hexavalent chrome in drinking water.

目的 建立饮用水中微量六价铬的灵敏、快速的测定方法。

In addition, we provide cadmium, l ead, mercury, hexavalent chromium, PBB and PBDE, analysis of packaging materials and

此外，我们提供的镉，1 部、汞、六价铬、多溴联苯和pbde，分析包装材料和部件为符合欧盟的规定等。

Automatic screening algorithm of abnormal data for linear regression calculation, improved algorithm for kinetic analysis and temperature calibration algorithm for enzyme analysis were successfully used in the portable spectrometer. 4. More than ten kinds of chemical reagent kits for rapid determination of environment monitoring and food safety coupled with the portable spectrometer were studied, such as Cr, Pb, Cd, NO2-,,NO3-, formaldehyde, sodium formaldehyde sulfoxylate, COD, NH4+, PO43+, CN-, F, Cl2, etc.

本文研究了六价铬、铅、镉、亚硝酸盐、硝酸盐、甲醛、吊白块、COD、氨氮、磷酸盐、氰化物、氟化物、余氯与总氯等十余种与环境监测和食品安全检测有关的快速检测试剂盒，并与目前实验室标准分析方法进行了分析化学特性的对比研究。

Restriction on the Use of Hazardous Substances bans new electronics containing more than agreed-to levels of lead, cadmium, mercury, hexavalent chromium, and polybrominated biphenyl as well as polybrominated diphenyl ether flame retardants.

在关于有毒物质使用的欧洲联邦法律限制新型电子设备中含有超标的铅、镉、汞、六价铬和多溴化联苯、多溴化二苯醚阻燃剂。

In conclusion, the sample which produced by the first modification method of treatment was in pH value of 4-10, chromium ion density of 10mg/L-100mg/L, absorb temperature of 20 degree Centigrade - 35 degree Centigrade, the surplus of green vitriol is 50% 's operation conditions according to chemistry measure, and the chromium ion has high and steady 's rate of wipe off, all can be more than 99%.

研究表明，改性灰Ⅰ在pH值4～10，六价铬离子浓度10mg/L～100mg/L，吸附温度20℃～35℃，按化学计量比硫酸亚铁余量50％的操作条件下，铬离子有较高且稳定的去除率，达到99％以上。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。