废轮胎热裂解行业清洁生产审核方法研究

文章对废轮胎热裂解企业清洁生产指标体系和审核中元素平衡法的运用进行了研究;用实例验证了元素平衡法在裂解企业清洁生产审核中的作用。通过审核发现,裂解企业存在原料利用率低、能源浪费等问题;针对企业存在的问题提出了清洁生产方案。研究结果表明,符合裂解企业特点的清洁生产指标体系和元素平衡法在裂解企业的清洁生产审核中起到了积极的作用,为企业节能减排方案的制定提供了方法支持。     

梵净山野生红菇矿质元素分布特征及土壤相关性分析

为了开发利用梵净山自然保护区内野生红菇资源,需了解区内野生红菇中矿质元素质量比范围、分布和富集特征,并探究野生红菇菌盖和菌柄中矿质元素与土壤环境的相关性.本文采用电感耦合等离子体质谱仪(ICP-MS)测定5种野生红菇菌盖、菌柄和根际土壤中12种矿质元素K、Ca、Na、Mg、Zn、Cu、Mn、Fe、Cd、Hg、Pb、As质量比,通过转移系数(TF)评价矿质元素在野生红菇菌盖和菌柄中的分布特征,并用菌盖、菌柄生物富集系数(BCFc、BCFs)评价野生红菇菌盖、菌柄对矿质元素的富集能力,最后用pearson相关系数评价野生红菇菌盖和菌柄与土壤环境相关性.结果表明:K是野生红菇菌盖和菌柄中质量比最高的大量元素,Fe是野生红菇菌盖和菌柄中质量比最高的微量元素.野生红菇菌盖中K、Mg、Cu、Mn、Cd和Hg质量比大于菌柄(TF＞1),而野生红菇菌柄中Na质量比大于菌盖(TF＜1).野生红菇菌盖和菌柄富含人体必需常量元素和微量元素,但菌盖和菌柄中As、Cd、Hg和Pb元素质量比与国家限量标准对比,均超过限量标准,这与野生红菇的生长环境有关.梵净山野生红菇极具开发利用潜力,但在开发过程中,应重视有毒重金属带来的健康风险.     

德兴地区土壤重金属人为污染的地球化学评价

在系统采集德兴地区表层土壤样品的基础上,采用标准化方法确定了该区Cu、Pb、Zn、Cr、Cd、Hg、As的地球化学基线值,并采用富集因子对表层土壤的人为污染进行了地球化学评价.结果表明:1)土壤中7种重金属元素的基线值较江西省土壤背景值高;2)土壤中As、Hg、Cd、Cr、Pb、Zn的人为污染以轻微污染为主,Cu的人为污染为轻微污染和中度污染,人为污染的区域主要分布在德兴铜矿及其周边地区;3)土壤重金属污染源判别表明,Pb、Zn、Cd具有相似的来源,其污染与铅锌矿的采矿及冶炼活动有关,Cu的来源与德兴铜矿的采矿活动有关,其他重金属来源差异较大.     

Distribution of Platinum group elements in road dust in the Beijing metropolitan area, China

Dust samples collected from the Beijing metropolitan area （China） were evaluated to determine the distribution and the concentration of platinum group elements （PGEs）. The dust particles that were smaller than 100 mesh size fraction （150 μm） were analyzed after aqua regia digestion. Concentrations ofPt, Rh, and Pd were found to be between 3.96 and 356.3 ng/g, 2.76 and 97.11 ng/g, and 0.1 and 124.9 ng/g, respectively, in the urban areas of Beijing, whereas for the background samples collected from the suburbs of Beijing, the concentrations of Pt, Pd, and Rh were very low and ranged from 0.1 to 0.9 ng/g, 0.5 to 1.4 ng/g, and 0.8 to 2.2 rig/g, respectively. The distributions of PGEs in road dust were an accurate reflection of the levels of pollution and were found to match with the local traffic conditions. A strong positive correlation was established among all the dements found in road dust. This suggests that emissions of abraded fragments from vehicle exhausts may be the source of the high concentration of Pt, Rh, and Pd in road dust along the main roads of Beijing.     

镍钴转运酶NiCoT基因的克隆表达及基因工程菌对镍离子的富集

利用PCR技术从Staphylococcus aureus/ ATCC6538基因组中扩增出大小为1?053 bp的镍钴转运酶基因NiCoT gene,将其连接到pET-3c载体上构建重组质粒,并转化至E.coli BL21.筛选阳性菌并经酶切分析和PCR扩增双重鉴定.核苷酸序列测定及分析结果与GenBank中报道的同类基因相似性高达97%以上,表明其具有正确的NiCoT基因核苷酸序列.重组菌的SDS-PAGE结果图谱中,在相对分子量为39?000附近有特异性蛋白条带,大小符合预测值,表明NiCoT基因在E.coli BL21中成功表达.基因工程菌在IPTG用量为1.00 mmol·L^-1,诱导时间为4 h的条件下培养对镍离子的富集能力最高.在不同镍离子浓度时,基因工程菌对溶液中Ni²⁺的平衡富集量为11.33 mg·g^-1,与原始宿主菌相比提高了3倍.对基因工程菌吸附镍和钴的实验表明,Staphylococcus aureus ATCC6538的NiCoT对镍具有较高的特异性和富集容量,属于第Ⅲ类镍钴转运酶.     

安全——生命的第五元素

短短两个月的时间里,我最要好的朋友和姐姐的相继离世,使我的心情异常沉重.     

小白菜对猪粪中高Cu和Zn的富集与转运

近年来,规模化养猪中Cu和Zn广泛应用于饲料添加剂,导致猪粪含大量的cu和Zn.猪粪土地利用中高Cu和Zn导致的环境污染和植物效应已引起了人们的高度关注.研究高Cu和Zn的猪粪施入土壤后典型蔬菜对Cu和Zn的富集和转运,可为有机蔬菜安全生产和品质提高提供科学依据,对粪便中重金属的健康风险评价具有重要的参考价值.本研究以...     

含钛矿渣的生产及综合利用新进展

高炉法冶炼钒钛磁铁矿过程中生产了大量含TiO225%左右的高钛渣,总结了高钛高炉渣提钛技术和制备新材料方面取得的新进展,指出了高钛高炉渣综合利用的难点,比较有发展前景的工艺及应该遵循的原则。针对转底炉预还原-电炉熔分方法处理钒钛磁铁矿生产出的TiO2品位在40%左右的钛渣,提出了两步调渣法新工艺,并进行了理论分析,为钛资源的综合利用提供一条新途径。     

Plant coexistence can enhance phytoextraction of cadmium by tobacco （Nicotiana tabacum L.） in contaminated soil

A mesocosm experiment was conducted to investigate whether plant coexistence affects cadmium (Cd) uptake by plant in contaminated soil.Tobacco (Nicotiana tabacum L.var.K326) and Japanese clover (Kummerowia striata (Thunb.) Schindl.) were used.Cadmium was applied as 3CdSO 4 ·8H 2 O in solution at three levels (0,1,and 3 mg/kg soil) to simulate an unpolluted soil and soils that were slightly and moderately polluted with Cd.Tobacco (crop),Japanese clover (non-crop),and their combination were grown under each C...     

Catalytic oxidation of gas-phase elemental mercury by nano-Fe2O3

Heterogeneous oxidation of gas-phase Hg0 by nano-Fe2O3 was investigated on a fixed bed reactor, and the e ects of oxygen concentration, bed temperature, water vapour concentration and particle size have been discussed. The results showed that Hg0 could be oxidized by active oxygen atom on the surface of nano-Fe2O3 as well as lattice oxygen in nano-Fe2O3. Among the factors that a ect Hg0 oxidation by nano-Fe2O3, bed temperature plays an important role. More than 40% of total mercury was oxidized at 300°C, however, the test temperature at 400°C could cause sintering of nano-catalyst, which led to a lower e ciency of Hg0 oxidation. The increase of oxygen concentration could promote mercury oxidation and led to higher Hg0 oxidation e ciency. No obvious mercury oxidation was detected in the pure N2 atmosphere, which indicates that oxygen is required in the gas stream for mercury oxidation. The presence of water vapour showed di erent e ects on mercury oxidation depending on its concentration. The lower content of water vapour could promote mercury oxidation, while the higher content of water vapour inhibits mercury oxidation.