陕西省汉中市汉台区2011年农村土壤中重金属铅、镉监测结果分析

目的了解该区土壤中重金属铅、镉的含量。方法按照《土壤质量铅、镉的测定石墨炉原子吸收分光光度法》(GB17141-1997)规定的方法进行检验。结果铅最低22.40 mg/kg,最高41.60 mg/kg,达到二级合格率为100%;镉最低0.02 mg/kg,最高2.30 mg/kg,达到国家标准二级合格率为75%。结论该区抽检的20份土样,目前未受到重金属铅的污染;25%已经受到重金属镉的污染。

微波消解—原子吸收光谱法测定岗梅根茎中铅、镉的含量

【目的】建立岗梅根、茎中铅、镉的含量测定方法。【方法】采用微波消解—原子吸收光谱法测定不同产地及不同生长年限岗梅根、茎中铅、镉的含量,消解体系是浓硝酸。【结果】方法的精密度分别为3.5%、2.1%,重复性分别为4.3%、3.5%(N=6);平均回收率分别为96.8%、97.2%,sR分别为4.2%、3.6%(N=6)。12个产地的岗梅药材根、茎中铅、镉含量普遍超标,且随着生长年限的不同,岗梅根、茎中铅、镉含量也不同。【结论】本方法准确、快速、简便,适用于岗梅根、茎中铅、镉2种重金属的含量测定。

2011-2012年马山县农村土壤重金属铅、镉监测结果分析

目的为掌握马山县农村环境土壤重金属铅、镉污染状况及动态变化,客观地评价该县农村环境卫生状况,为政府制定政策措施提供科学依据。方法对马山县2011-2012年农村环境土壤重金属铅、镉监测资料进行描述性流行病学分析,以《国家土壤环境质量标准》(GB 15618-1995)二级标准作为评价依据。结果 2011-2012年共监测土壤40份,土壤中铅含量全部符合国家《国家土壤环境质量标准》(GB 15618-1995)二级标准;2011-2012年85.00%的村土壤中镉含量超标,最高值分别为4.48 mg/kg和7.32 mg/kg,超过土壤二级标准限值分别为14.9倍和24.4倍,污染最为严重的地区是石丰村和杨圩村。结论马山县农村环境土壤大部分村中镉含量超过土壤二级标准,属重度污染,每年需重点对超标行政村加强监测。

Transcriptome Sequencing and Analysis of Agaricus blazei Mycelia Under Cadmium Stress

To explore the mechanism of Agaricus blazei Murrill enrichment of the heavy metal cadmium,we employed Illumina high-throughput sequencing to analyze the transcriptomes of A.blazei mycelia treated with and without exogenous cadmium addition,and then the differentially expressed genes(DEGs)of the strains with high and low cadmium enrichment between the control and cadmium treatment were screened out.The results showed that the DEGs were mainly involved in steroid biosynthesis,antibiotic biosynthesis,protein processing in endoplasmic reticulum,glutathione metabolism and other pathways.Carbon metabolism and glutathione metabolism may play an important role in the response of A.blazei mycelium to cadmium stress.

Effect of rhamnolipids on cadmium adsorption by Penicillium simplicissimum

The effect of rhamnolipids （RL） on Cd^2＋ adsorption by Penicillium simplicissimum （P. simplicissimum） was studied. The maximum adsorption capacities of Cd^2＋ were obtained at pH 6.0 for the intact P. sirnplicissimurn and at pH 5.0 for the RL-pretreated P. simplicissimum, respectively. The adsorption equilibrium was reached after about 4 h. The experimental adsorption isotherms were in good agreement with the Langmuir model. The maximum adsorption capacities （qmax） for the intact P. simplicissimurn and for the RL-pretreated P. simplicissimum were 51.6 and 70.4 rag/g, respectively. The interactions between Cd^2＋ and functional groups on the cell wall surface of the P. simplicissimum were identified by SEM, EDAX and FTIR analysis. It is indicated that carboxyl, amino and hydroxyl groups play major roles in the Cd^2＋ adsorption. The results suggest that the RL-pretreated P. simplicissimum is a promising candidate for the removal of Cd^2＋ from aqueous solutions.

Isolation, identification and characterization of cadmium-resistant Pseudomonas aeruginosa strain E_1

Strain E1 with resistance to 18 mmol/L cadmium （Cd）, isolated from Cd-contaminated soil was identified by morphological observation, biochemical and physiological characterization and 16S rDNA sequence analysis. The resistance to heavy metals Cd, Cu, Co, Mn, Pb, Zn and 12 antibiotics was examined. The ability of removing Cd from solution was studied. The characterizations show that strain El is affiliated to Pseudomonas aeruginosa （P aeruginosa）. Strain E1 has high resistance to heavy metals and the order is found to be Cd〉Mn〉Zn〉Cu〉Pb〉Co in solid media. Strain E1 also exhibits the resistance to 12 antibiotics. Both living and non-living cells of strain E1 can remove Cd from solution, and living cell has better biosorption than non-living cell.

石墨炉原子吸收法测定土壤中的铅和镉含量

目的探讨用石墨炉原子吸收法测定土壤中的铅和镉含量。方法采用盐酸-硝酸-氢氟酸-高氯酸混合酸消解技术对样品进行消解，用石墨炉原子吸收法测定铅和镉。结果铅在0～80ng／mL，镉在0～5ng／mL范围内呈良好线性关系，铅相关系数r=0．9981～0．9996，回收率90．5％～104．0％，RSD〈5％，最低检出限为0．02mg／kg；镉相关系数r=0．9990～0．9997，回收率90．5％～105．8％，RSD〈3％，最低检出限0．005mg／kg。结论该方法测定土壤中铅和镉能满足分析要求。