铬污染土壤处理中的铬含量及形态变化

采用FeSO_4和Na_2S作为还原剂处理铬污染紫色土壤,研究了还原过程中铬的含量及形态的变化。实验结果表明:当FeSO_4加入量为1.5%(w,下同)时,浸出Cr(Ⅵ)含量由(1 745.13±27.93)mg/kg降至(17.65±2.28)mg/kg,浸出总铬含量由(1 768.83±57.24)mg/kg降至(69.79±8.61)mg/kg,铬形态由水溶+碳酸盐结合态转变到较稳定的铁锰结合态;当Na_2S加入量为0.4%时,浸出Cr(Ⅵ)含量由(1 745.13±27.93)mg/kg降至(25.50±0.12)mg/kg,浸出总铬含量由(1 768.83±57.24)mg/kg降至(410.87±12.83)mg/kg,铬形态由水溶+碳酸盐结合态转变到铁锰结合态和有机结合态。     

锂电池在特种设备行业中梯次利用的前景展望

特种设备行业对动力电池的要求不仅局限于功率性能,同时由于特种设备的应用场景特殊性,其环保要求和性价比同样重要。梯次利用作为应对电动汽车退役电池处理的重要手段,在电池余能利用方面发挥重要作用。现有特种设备动力来源正从燃油向电能转化,而且还有一大批鉛酸动力电池需要更新换代,梯次利用锂电池在机电类特种设备行业中的应用符合节能减排的政策导向,具有市场前景。     

Chemical Tracking and Marine Environmental Impact of Ocean Disposal of Calcium Carbonate Residue in the North Yellow Sea

The objective of this study is to determine the sedimentation rate and dispersion area of calcium carbonate residue dumped at sea and the impact to marine environment of dumping by a laboratory simulation experiment; chemical tracking in the field with the help of acoustic and optical tracking; and a comparative study of baseline conditions and marine environmental impact after dumping. Turbidity, pH and phosphate are selected as the chemical tracers to be monitored.

Results show that in the dumping area of 15 square miles with water depth of 50 m, if 217 t calcium carbonate residue is dumped (spot dumping) in the presence of a pycnocline with a current velocity of 60 cm/s (close to the maximum) the maximum dispersion distance of the calcium carbonate residue plume front is less than 2100 m; the dispersion area is less than 0.56 km²; and the maximum dispersion time is about 60 min when the turbidity and pH in the whole dispersion area return to background level. Therefore, the ocean disposal of calcium carbonate residue is feasible.     

以膨润土为载体的碳酸盐吸收剂对二氧化碳的吸收

采用膨润土为载体,KHCO3为前驱物通过喷雾-干燥法制成固体碳酸钾吸收剂,制成的固体吸收剂粒径大小为0.5—2.0 mm,密度为1.73 g.mL-1.通过K2CO3负载量、吸收温度、吸收时间、床层纵横比等因素考察固体吸收剂对CO2气体的吸收效率及循环反应特性.分析碳酸钾吸收剂对CO2的吸收机理,并与以碳酸氢钠为前驱物制备的吸收剂进行对比,比较两种吸收剂对CO2吸收效果的差异性.通过XRD测试吸收剂吸收反应前后组成的变化,BET多点法测试吸收剂比表面积,扫描电镜观察吸收剂表面形态特征.结果表明,碳酸钾吸收剂和碳酸钠吸收剂对CO2气体均具有较高的吸收量,相比而言碳酸钾吸收剂的碳酸化反应速率较快,而且经过多次循环反应后吸收效果未发生衰减,在60℃—80℃范围内,碳酸钾吸收剂对CO2的吸收能力最佳.     

石漠化地区豆科植物根瘤菌降解碳酸钙、镁能力研究

微生物对岩溶地区岩石风化、成土具有明显的促进作用,为了筛选出能够促进碳酸盐岩风化、加快成土速率的优势根瘤菌菌株,将其与豆科植物建立共生体系,进行石漠化地区修复与治理,实验以分离自云南石漠化地区的9株豆科植物根瘤菌为研究对象,将9株根瘤菌接种于加有难溶性碳酸钙或碳酸镁的液体培养液中,28.5℃、160 r·min-1摇床培养15 d,于0、1、3、6、10、15 d取样2 mL,每个样3个平行;将样品加入到10 mL体积比5∶1的硝酸高氯酸消化液中浸泡过夜,放在电热板上缓慢加热至溶液澄清透明,分别用含La3＋2%的盐酸溶液定容至10 mL,空白用同样方法处理;最后采用原子火焰吸收方法测定样品中Ca2＋和Mg2＋含量,筛选出对碳酸盐岩主要成分碳酸钙和碳酸镁具有强降解作用的根瘤菌菌株。结果表明：热带根瘤菌Rhizobium tropici （SWFU09）和根瘤菌Rhizobium sp.（SWFU02）对碳酸钙降解作用最强;对碳酸镁降解作用最好的菌株为根瘤菌Rhizobiumsp.（SWFU03）、热带根瘤菌Rhizobium tropici（SWFU05）和慢生根瘤菌Bradyrhizobium sp.（SWFU01）。溶液pH值对碳酸镁降解作用具重要的影响,对碳酸钙降解作用影响不大,说明根瘤菌代谢产生的酸性物质（有机酸、氨基酸）对碳酸钙和碳酸镁降解作用有一定影响,但不是唯一影响因素;也可能是微生物代谢产生的有机配体（基）吸附碳酸钙和碳酸镁表面,与水体中的成分形成复合物,改变溶解的平衡,置换出Ca2＋和Mg2＋。     

硅改性花生壳生物炭对水中磷的吸附特性

为实现花生壳资源化利用,通过硅酸钠溶液对花生壳进行浸渍改性,再热解制备成硅改性花生壳生物炭（Si-PSBs）,探究Si-PSBs对水中磷的吸附特性.结果表明,相比于未改性花生壳生物炭（PSB）,Si-PSBs对磷的吸附量明显增大,8%硅酸钠溶液改性的生物炭（8% Si-PSB）对磷的吸附量是改性前的3.9倍.SEM、FTIR和XRD等结果表明8% Si-PSB上有二氧化硅生成,二氧化硅影响吸附过程中源于生物炭的碳酸钙形态,提高了生物炭自身所含金属离子Ca²⁺的反应活性.强酸强碱环境中,8% Si-PSB对磷均具有良好的吸附效果.反应平衡后,8% Si-PSB和PSB对磷的吸附量分别在2.79 mg ·g^-1和0.71 mg ·g^-1上下浮动,对磷的吸附均更符合准二级动力学模型,说明反应以化学吸附为主.等温吸附实验数据采用Langmuir模型拟合度更高,说明8% Si-PSB和PSB对磷的吸附均以单层吸附为主.溶液中腐殖酸（HA）的存在抑制8% Si-PSB和PSB对磷的吸附.8% Si-PSB是一种低成本的新型除磷材料,可提高花生壳自身金属钙离子的利用程度.     

GROUND WATER OF THE ISLAND OF MONTREAL,CANADA1

ABSTRACT: The geochemistry and nature of the flow of ground water not only control the supply potential but constitute clues to the whole geology of an area. A study has been made of the largest available assemblage of data from 161 wells for the Island of Montreal collected by the Geological Survey of Canada in 1951–53. Data indicated that the system is generally subartesian, flowing from the principal topographically high areas towards the shores of the Island. As the probable use is about 13% of the estimated recharge of 140 million liters per day, most wells could be supplied by local recharge. The study has confirmed the predominance of calcium bicarbonate ground water from the carbonate sequence. The waters appeared to be saturated with respect to CaCO₃ in all but 10 wells. The presence of other types of waters suggests the effects of the igneous intrusions of the area, the post-glacial marine submergence and the upward movement of waters from deep sources through fault and other structural zones. Confirmation of the significant variations in chemical composition in some neighboring wells indicated the future need for repetitive sampling from specific horizons for chemical and isotopic analyses.     

Mechanical Properties and Lipase-Catalyzed Biodegradation of α-Methyl, ε-Caprolactone/ ε-Caprolactone Copolymers Obtained by Chemical Modification of Poly(ε-caprolactone)

Novel (-caprolactone)-based copolymers of different compositions were synthesized by allowing methyl iodide to react with the polycarbanion that resulted from the action of lithium diisopropylamide on poly(-caprolactone) in THF at –70°C under argon atmosphere. The copolymers were characterized by various techniques, namely ¹H nuclear magnetic resonance, size exclusion chromatography, differential scanning calorimetry, x-ray diffraction and viscoelasticimetry. They were submitted to hydrolytic and lipase-catalyzed enzymatic degradation in comparison with genuine PCL. The Young modulus depended on the degree of methylation. In contrast, loss angle and glass transition temperature did not depend on this parameter. It is shown that the lipase-catalyzed degradation of methylated PCL is much slower than in the case of genuine PCL.     

锂的用途及其资源开发

锂在原子能工业中具有十分独特的地位 ,被誉为“高能金属” ;它推动着能源工业 ,尤其是电池技术的发展 ,无愧于“能源金属”和“推动世界前进的金属”的称谓。随着技术的发展 ,世界锂业的传统格局和市场分布发生了较大的变革 ,盐湖提锂技术的进步打破了半个世纪以来锂资源的分布和供应格局 ,而澳大利亚、俄罗斯、加拿大和津巴布韦等硬岩型锂资源大国将失去其在世界锂资源和锂盐供应市场上的优势。智利、中国、阿根廷和玻利维亚等国将成为世界拥有锂资源大国。盐湖工业生产的锂产品适应于当今知识经济时代的需求 ,市场前景广阔。笔者介绍了金属锂的一些重要用途 ;分析了锂资源开发的现状 ;指出我国盐湖卤水提锂技术已取得了重大突破 ;透露了作为国家计委批准的西部高技术产业化示范工程项目有关信息 ,年产 30 0 0吨碳酸锂生产线 ,将于2 0 0 5年 6月正式投产。     

碳酸钙在补钙食品中的利用和开发

简要介绍了钙在机体内的吸收情况，并就碳酸钙在食品领域目前的应用及可能的开发途径进行了介绍，预测了今后碳酸钙在食品领域的发展方向。