用铬渣生产水泥消除铬消毒性的研究

本文提出了一种通过以粉煤灰（或煤矸石），石灰石，铬渣，Ａ渣为原料煅炼新型低温水泥的方法去除儿渣毒性，进行了去除铬渣毒性稳定性试验，讨论了除铬渣毒性的机理和影响去除铬渣毒性的因素，试验结果表明，该法去除铬渣毒性彻底，社会效益及经济效益显著，是处理铬渣的一种有效方法。     

铬渣作水泥矿化剂的经济及环境效应分析

铬渣的处理利用一直是铬盐行业和固体污染物处理的难点，本文介绍了用铬渣作水泥矿化剂处理铬渣这种新方法的原理，并进行了经济和环境效应分析，结果表明用铬渣作水泥矿化剂确实是一种很好的处理铬渣的方法。     

回转窑在处理危废铬渣中的应用

铬渣主要指铬盐厂生产过程中产生的有毒废渣,属于危险废物,其危害源自于所含的毒性很大的六价铬。文章介绍了危险废物处理行业中采用回转窑焚烧处理铬渣,及后续烟气净化、彻底无害化处理的工艺设计过程。为铬渣的处理提供了一套系统高效的处理方式。     

铬渣湿法解毒技术

正由河南金谷实业发展有限公司开发的铬渣湿法解毒技术,适用于铬渣及铬污染物处理。主要技术内容一、基本原理将铬渣或含铬污染物湿化研磨后,利用酸性介质将其中的酸溶性六价铬、水溶性六价铬完全转移至液相中,然后再投入还原药剂将液相中的六价铬还原至三价铬,并沉淀固定在工艺残渣中,实现铬渣及含铬污染物的无害化处置。二、技术关键全过程采用湿式液相处置工艺,用较大量的酸和还原剂,使酸溶和水溶六价铬全部还原。典型规模处理量500t/d。     

铬渣的危害与解毒技术

本文介绍了铬渣的产生过程和主要成分,以及我国铬渣的产生和污染现状;介绍了化学处理法、物理/化学法、熔烧法和固化/稳定化处理法等铬渣解毒技术原理;概括了目前国内主要的铬渣综合利用方式.     

剧毒铬渣岂能一堆了之

最近新闻报道，2005年，国家发．改委与国家环保总局联合出台的《铬渣污染综合整治方案》显示，截至当时，19个省、自治区和直辖市累计产生铬渣600万吨，其中只有200万吨得到处理，其余400万吨铬渣处于堆放状态。然而，方案没能治住超标，不仅是铬，各大重金属污染已是屡禁不止。     

铬渣湿法和干法解毒技术的应用对比

通过对国内典型铬渣处理的项目进行分析,并结合某铬渣污染治理工程实例,从反应机理、解毒工艺、工艺适应性、资源回收利用、设备选型、处理规模、场址选择、污染控制及安全生产和经济性方面对铬渣湿法解毒和干法解毒技术在实际应用中的选择进行对比,为该项目提出了更适合的解毒技术。     

铬渣处理处置技术研究进展

介绍了国内外铬渣处理处置技术的研究现状,并对各种处理处置技术的解毒机理、工艺条件及过程、优缺点、以及实践应用状况进行了分析.     

铬渣污染肇事企业擅自复产底气何来

前不久,云南曲靖铬污染事件被披露,引起全国广泛关注。8月16日,云南省环保厅要求肇事企业陆良化工实业有限公司在停产整治期间,必须完成老铬渣库和现厂内渣库堆存的全部铬渣的无害化处理,未经曲靖市环保局验收,不得恢复生产。     

三种抗生素菌渣肥的肥效研究

将通过高温水解、喷雾干燥、电子束辐照等方式去除抗生素残留的青霉素菌渣、硫红霉素菌渣、头孢菌渣制成菌渣肥,并以这三种菌渣肥作为供试材料,按500 kg/亩,1 000 kg/亩的剂量施入种植大豆及玉米的试验田中,观察在植株4个不同生长时期的土壤肥力变化.试验结果表明:施入抗生素菌渣肥后,土壤中的有机质含量有所增加,但随着...     

用微波消解-光度法测定废钻井液中的总铬

采用微波消解-光度法处理钻井液废水中的总铬。该方法克服了常规消解方法的缺点,测定步骤简单、快速,准确性高。通过实验探讨了微波功率、加热时间、样品体积对样品消解的影响。与常压的硫酸-硝酸消解法进行比较的结果表明,用微波消解-光度法处理泥浆废水可将消解时间由原来的6h缩短为20min,加标回收率由60%提高到92%,降低了工作强度,改善了工作环境。     

水泥注浆中六价铬总溶出量的影响因素研究

水泥注浆过程中析出液中的六价铬Cr(Ⅵ)易造成地下水的重金属污染,对生态和环境具有较大危害性,为了有效降低水泥注浆中Cr(Ⅵ)总溶出量,采用化学还原的方法,探讨了各种降铬剂及其掺量对降低Cr(Ⅵ)总溶出量的效果,研究了颗粒粒度、液固比对Cr(Ⅵ)总溶出量的影响.结果 表明,硫酸亚铁降铬剂的效果最显著,当用量在3％以内时...     

环境中铬污染的生态效应及其防治

从生态效应的角度介绍了重金属铬在环境中的迁移、转化规律，重点论及了铬污染对人体健康厦水生生物等其他生物的影响、对水体自净作用的影响，指出Cr^6＋的生态效应远比Cr^3＋大的多。目前治理含铬工业废水和受铬污染土壤几种有效方法，旨在引起人们对环境中铬污染的生态效应产生足够的重视和防范。     

用差示分光光度法测定高浓度皮革废水中铬的方法探讨

介绍了应用差示分光光度法直接测定高浓度皮革废水中Cr的方法，通过与原实验方法分析结果的对比，获得了满意的结果，能基本满足环境监测的要求。     

苎麻脱胶废水预处理研究

通过采用自制的苎麻脱胶废水混凝剂、去杂脱色剂对苎麻脱胶废水进行预处理，实现了苎麻脱胶废水COD（mg／L）、BOD（mg／L）、SS（mg／L）下降到生化处理的要求，为废水生化处理打下基础。通过微波处理废水滤渣，使其达到快速干燥、炭化，并能作为自制脱色剂组成成分之一，实现了滤渣的资源化利用并降低了废水的处理成本。     

Genotypic Variation in the Phytoremediation Potential of Indian Mustard for Chromium

The term “phytoremediation” is used to describe the cleanup of heavy metals from contaminated sites by plants. This study demonstrates phytoremediation potential of Indian mustard (Brasicca juncea (L.) Czern. & Coss.) genotypes for chromium (Cr). Seedlings of 10 genotypes were grown hydroponically in artificially contaminated water over a range of environmentally relevant concentrations of Cr (VI), and the responses of genotypes in the presence of Cr, with reference to Cr accumulation, its phytotoxity and anti-oxidative system were investigated. The Cr accumulation potential varied largely among Indian mustard genotypes. At 100 μM Cr treatment, Pusa Jai Kisan accumulated the maximum amount of Cr (1680 μg Cr g⁻¹ DW) whereas Vardhan accumulated the minimum (107 μg Cr g⁻¹ DW). As the tolerance of metals is a key plant characteristic required for phytoremediation purpose, effects of various levels of Cr on biomass were evaluated as the gross effect. The extent of oxidative stress caused by Cr stress was measured as rate of lipid peroxidation. The level of thiobarbituric acid reactive substances (TBARS) was enhanced at all Cr treatments when compared to the control. Inductions of enzymatic and nonenzymatic antioxidants were monitored as metal-detoxifying responses. All the genotypes responded to Cr-induced oxidative stress by modulating nonenzymatic antioxidants [glutathione (GSH) and ascorbate (Asc)] and enzymatic antioxidants [superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)]. The level of induction, however, differed among the genotypes, being at its maximum in Pusa Jai Kisan and its minimum in Vardhan. Pusa Jai Kisan was grown under natural field conditions with various Cr treatments, and Cr-accumulation capacity was studied. The results confirmed that Pusa Jai Kisan is a hyperaccumulator of Cr and hypertolerant to Cr-induced stress, which makes this genotype a viable candidate for use in the development of phytoremediation technology of Cr-contaminated sites.     

Arsenic and chromium removal by mixed magnetite–maghemite nanoparticles and the effect of phosphate on removal

Adsorption of arsenic and chromium by mixed magnetite and maghemite nanoparticles from aqueous solution is a promising technology. In the present batch experimental study, a commercially grade nano-size ‘magnetite’, later identified in laboratory characterization to be mixed magnetite–maghemite nanoparticles, was used in the uptake of arsenic and chromium from different water samples. The intent was to identify or develop a practical method for future groundwater remediation. The results of the study showed 96–99% arsenic and chromium uptake under controlled pH conditions. The maximum arsenic adsorption occurred at pH 2 with values of 3.69 mg/g for arsenic(III) and 3.71 mg/g for arsenic(V) when the initial concentration was kept at 1.5 mg/L for both arsenic species, while chromium(VI) concentration was 2.4 mg/g at pH 2 with an initial chromium(VI) concentration of 1 mg/L. Thus magnetite–maghemite nanoparticles can readily adsorb arsenic and chromium in an acidic pH range. Redox potential and pH data helped to infer possible dominating species and oxidation states of arsenic and chromium in solution. The results also showed the limitation of arsenic and chromium uptake by the nano-size magnetite–maghemite mixture in the presence of a competing anion such as phosphate. At a fixed adsorbent concentration of 0.4 g/L, arsenic and chromium uptake decreased with increasing phosphate concentration. Nano-size magnetite–maghemite mixed particles adsorbed less than 50% arsenic from synthetic water containing more than 3 mg/L phosphate and 1.2 mg/L of initial arsenic concentration, and less than 50% chromium from synthetic water containing more than 5 mg/L phosphate and 1.0 mg/L of chromium(VI). In natural groundwater containing more than 5 mg/L phosphate and 1.13 mg/L of arsenic, less than 60% arsenic uptake was achieved. In this case, it is anticipated that an optimum design with magnetite–maghemite nanoparticles may achieve high arsenic uptake in field applications.