旱伞草修复镀锌厂含铬废水的研究

前期的筛选实验发现,旱伞草对铬具有良好的修复效果,以此为基础,采用溶液培养法,研究了旱伞草在不同总铬质量浓度、不同p H条件下的生长情况及对镀锌厂含铬废水的修复效果.研究结果表明:在10~30 mg/L的实验质量浓度范围内,旱伞草对镀锌厂含铬废水具有较强的耐受性和修复效果,能使废水中的铬和锌的质量浓度显著降低,达到国家农田灌溉水质标准.     

电镀废水中铬的去除和回收

从电镀厂的含铬淤泥中分离获得一株抗铬的脱硫弧菌(SRI)。研究SRI菌去除铬(Ⅵ)的机制和条件。进行了SRI菌去除铬(Ⅵ)的小试和中试。结果表明:SRI菌对废水中总铬的去除率为99.7％;工艺对铬的回收率大于80％。     

火焰原子吸收法中有机络合剂对铬的增感效应的研究

本文研究了火焰原子吸收法中有机络合剂对铬的增感效应。在空气-乙炔富燃焰中,0.5%的柠檬酸钠、酒石酸钠、酒石酸钾钠使铬的吸光度增加70%,并能消除钾、钠、钙、镍、铜、锡、锰镁的干扰。探讨了增感效应的机理,认为有机络合剂存在时,气溶胶离子的收缩效应增大、侧向扩散减少是增感的主要原因。     

铬系白口铸铁相间腐蚀机理的探讨

为了探讨铬系白口铸铁在腐蚀介质中的相间腐蚀机理,对试验合金应用定向凝固技术,采用提取相表面富集法制备了碳化物试样;依据电偶腐蚀原理,建立了亚共晶铬系白口铸铁相间腐蚀原电池模型;测定了试验合金组成物偶接前、后的腐蚀速度。试验结果表明：（1）亚共晶铬系白口铸铁相间腐蚀可分为主、次相同腐蚀原电池、主相间腐蚀速度是次相间腐蚀速度的2倍左右;(2) 随铬碳比的增加,试验合金组成组的腐蚀速度均显著下降,但共晶基体的腐蚀速度仍然是初生基体腐蚀速度的2倍左右;（3）碳化物与基体两相间的腐蚀电位差是相间腐蚀的驱动力,在此腐蚀过程中,高电位的碳化物被保护,低电位的基体被加速腐蚀,提高基体的腐蚀电位,不仅可以降低相同腐蚀速度,而且可以大幅度提高铬系白口铸铁的耐蚀性。     

钨渣低铬铸造磨球的研制及应用

通过理论分析和实验,研究了钨渣低铬铸造磨球的制造工艺,通过与高铬铸铁相比较,对此钨渣低铬铸造磨球进行了经济和社会效益分析。     

连续流泡沫分离法去除水中的Cr(Ⅵ)

采用连续式泡沫分离法处理废水中的Cr（Ⅵ），考察了pH值、阳离子表面活性剂质量浓度、气量、回流量、进水流量、液位高度等因素对Cr（Ⅵ）去除率的影响规律．分析发现最佳的操作条件是pH值为4．00、气量为0．10m^3／h、回流量15．0L／h、进水1．0L／h、表面活性剂质量浓度为300．0mg／L、液位高为105．0cm,此时去除率88．5％．实验结果表明，连续式泡沫分离技术处理水中的Cr（Ⅵ）效果比较稳定．     

淬火介质对高铬铸铁磨球性能的影响

研究了高铬铸铁磨球在不同介质淬火的冷却曲线、温度场、淬火裂纹、断面上硬度分布以及φ６０磨球的跌落冲击试验．结果表明空淬未能淬硬，水淬产生裂纹，油淬对小于φ１００的磨球不产生裂纹．采用有机淬火介质Ａ１得到良好的综合机械性能，无机介质Ｂ１经适当整调也能满足要求。     

Structural dependences of the η~6 complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring (1) or the unsubstituted ring (2) and their precursor 3-amino-9-ethylcarbazole (AECz). The second-order hyperpolarizability γ of the compounds 1 and 2 were found to be 42.9×10-31 and 35.9×10-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds 1 and 2 was explored in detail based on the three-level model and the density functional theory (DFT) calculation. The theoretical results indicate that the spatial distri-bution of electron density has the profound role in the third-order nonlinear optical properties.     

An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr<Superscript>3+</Superscript> removal capacity

A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr(Ⅲ) from aqueous solutions with relatively low initial concentrations of Cr(Ⅲ) (5–100 mg·L-1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr(Ⅲ) removal capacity highly depends on the initial pH value and concentration of Cr(Ⅲ) in the solution. The maximum removal capacity of Cr(Ⅲ) was evaluated to be 85.1 mg·g-1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(Ⅲ) concentration of 5 mg·L-1. This approach enables a higher removal capacity at lower concentrations of Cr(Ⅲ), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(Ⅲ) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(Ⅲ).     

电镀废铬液回收利用技术的研究

应用化学处理技术将电镀废铬槽液经过絮凝、沉淀、分离等过程,提纯为高纯度的Cr(Ⅳ）液,复配为高浓度的鞣革铬液,并应用于鞣革。结果表明,应用化学处理技术可将电镀废铬液回收为铬鞣剂,用于鞣革,各项技术指导已达到与国内标准铬粉的同等水平,实现了电镀污水零排放。