用废旧锌锰电池制备锰锌铁氧体的研究

用水热法以废旧锌锰电池为原料对制备锰锌铁氧体进行了研究。探索了制备过程的影响因素,如水热反应的pH值、水热温度及水热时间等。结果表明,在溶液的pH值为10,水热温度为210℃,水热时间为2～24h时,均能有效制备无杂相的锰锌铁氧体;提高反应温度和延长反应时间,均有利于锰锌铁氧体的晶化过程。研究还发现,加入铁粉是一个既能高效除汞,又能制备高性能锰锌铁氧体的关键所在。      

核废物的安全和环境影响

本论述了核废物特性,核废物安全管理原则,核废物的安全处理、处置技术、废放射源的安全管理、乏燃料的安全管理和核废物的环境影响等6方面问题。特别强调了废物管理9条原则,核废物最少化,豁免和清洁解控,核废物处理、处置技术的发展动向,我国核废物管理40字方针,国际社会关注的废放射源和乏燃料安全处理和处置等,并以我国大亚湾和秦山核电站为例,说明核废物可以被安全地控制和管理,保证环境的安全。     

废弃SCR催化剂中钒和钨的浸出及回收

采用NaOH溶液一次性浸出废弃SCR催化剂中的钒和钨,并用硫酸对浸出液进行除杂,再利用NH4Cl和硫酸分步对浸出液中的钒和钨进行沉淀回收。在NaOH质量分数40%、液固比8、浸出时间4 h、浸出温度90℃的最佳碱浸条件下,钒和钨的浸出率分别达到90.44%和84.49%。除杂过程的铝去除率达到100%,硅去除率达到77.56%。在沉钒pH为8.0、n(NH_4~+)∶n(V)为4的最佳沉钒条件下,钒回收率达到82.79%。在n(SO_4~(2-))∶n(W)为2的最佳沉钨条件下,钨回收率达到76.41%。     

氨基磺酸溶液浸出废锂离子电池负极活性材料中的锂

随着锂离子电池的广泛应用,产生了大量废锂离子电池,其负极活性材料中积累了高品位的锂。锂作为一种稀有金属,对其进行回收利用很有意义。选取了无毒、稳定性好的氨基磺酸作为浸出剂,浸取废锂离子电池负极活性材料中的锂,考察了预处理方式对负极活性材料成分和结构的影响以及浸出条件对锂浸出率的影响。结果表明:600℃下煅烧4 h,可完全去除附着在负极活性材料表面的有机物;在氨基磺酸浓度0.75 mol/L、固液比5 g/L、浸出温度40℃、浸出时间45 min的最佳浸出条件下,负极活性材料中锂浸出率达97.2%。     

Earthworms to assess the innocuousness of spent biomixtures employed for glyphosate degradation

In this study, the innocuousness of different biomixtures employed for glyphosate degradation was tested through Eisenia fetida earthworms. Eight biomixtures were prepared with local materials: alfalfa straw (AS), wheat stubble (WS), river waste (RW) and two different soils (A and B). Each biomixture was divided into two equal portions: one without glyphosate application (control substrate) and the other was sprayed with a commercial glyphosate formulation of 1,000 mg glyphosate a.i. kg^?1 biomixture (applied substrate). The bioassay started when all sprayed biomixtures reached high percentages of glyphosate degradation (spent biomixtures). Three parameters were studied: survival, adults and juveniles biomass and reproduction. The results allowed the identification of three biomixtures (AWS, BWS and BWSRW) for good maintenance and development of E. fetida. In addition, at the end of the bioassay two of the viable biomixtures (AWS and BWS) showed the highest performance of juvenile earthworms compared to a reference soil. The Principal Component Analysis (PCA) indicated that the biomixtures containing high silt and clay percentages and minor density renders higher values of earthworm growth and reproduction. Therefore, these innocuous biomixtures can be used as organic amendments or recycled materials for new treatments on biobeds.     

废无汞碱性电池极性材料制备锰锌铁氧体磁性纳米颗粒

以硝酸浸取废无汞碱性电池极性材料,再加入硝酸铁及蔗糖生成前驱体,最后通过焙烧制得锰锌铁氧体磁性纳米颗粒。优化了酸浸和焙烧条件,采用FTIR和DTA-TG技术研究了前驱体的形成和热解过程,采用XRD、FTIR、TEM技术和振动样品磁强计对锰锌铁氧体进行了表征。结果表明:废无汞碱性电池极性材料酸浸的最佳条件为H_2O_2加入量3%(w)、液固比10 mL/g、稀硝酸浓度4 mol/L、浸取温度40℃,该条件下浸取10 min锰和锌的浸出率均可达100%;所得前驱体为葡萄糖酸盐,其最佳焙烧条件为焙烧温度450℃、焙烧时间2 h;最佳条件下所得锰锌铁氧体为尖晶石型Mn_(0.5)Zn_(0.5)Fe_2O_4,其颗粒为球形、大小均匀,且磁性能优良。     

微波焙烧法与马弗炉焙烧法处理废脱硝催化剂的效果比较

用Na_2CO_3作为助溶剂、Na_2O_2作为消解剂,采用微波焙烧法和马弗炉焙烧法消解处理废钒钨钛脱硝催化剂。通过XRF、BET、XRD和NH_3-TPD技术对两种消解方法制得的钛钨粉样品进行了表征。表征结果显示,与马弗炉焙烧法相比,微波焙烧法得到的钛钨粉纯度更高,TiO_2与WO_3含量之和大于96.7%(w),且该钛钨粉还具有更高的比表面积和酸性,可以作为钒钨钛脱硝催化剂的生产原料再利用。     

乙烯废碱液的再生

开发了除油-苛化-脱硫组合技术处理乙烯废碱液工艺,考察了影响各级处理效果的主要因素.实验结果表明:经石英砂-聚丙烯腈纤维膜-强碱性阴离子交换树脂组合装置除油后,碱液中油类物质质量浓度小于2 mg/L,NaOH,Na_2CO_3,Na_2S等无机组分含量基本不变;经苛化-脱硫处理后碱液中Na_2CO_3和Na_2S质量浓度分别小于4 430 mg/L和4 480 mg/L;再生碱液的流体力学性质及对酸性气体的吸收性能均可满足乙烯裂解气碱洗要求.     

Removal of 2, 4‐D from aqueous solution by the adsorbents from spent bleaching earth

Abstract

The removal of 2, 4‐D (2, 4‐ dichlorophenoxyacetic acid) from aqueous solutions by activated spent bleaching earths (SBE) was studied at 20 °C. Experiments were performed as a function of time, initial concentration, dose and particle size of the adsorbent. The Langmuir and Freundlich adsorption equations were fitted by the adsorption data obtained. The values of Langmuir and Freundlich constants were determined. The adsorption kinetic was found to follow Lagergren equation. Both the boundary layer and intraparticle diffusion played important roles in the adsorption rate of 2, 4‐D. As the size of the adsorbent increased, the time to reach equilibrium increased but adsorption capacity decreased.