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821.
土壤中异黄酮植物雌激素降解体系的研究   总被引:1,自引:0,他引:1  
利用睾丸酮丛毛单胞菌(菌株C.test十act5)具有消化多环芳烃类化合物这一特性,以异黄酮植物雌激素为底物筛选菌株C.test+act5降解雌激素的培养条件,使异黄酮植物雌激素在土壤中的含量相对降低,以期为高效降解环境中激素类物质奠定基础.结果表明:菌株C.test+act5降解异黄酮植物雌激素的最适质量浓度为100~200 μg/mL,最适温度为30℃,最适pH为6.0;在此条件下,降解48 h时的降解率达85%左右,72 h后几乎完全被降解.  相似文献   
822.
Shi Q  Liu GH  Yan HQ  Zhang HL 《Ambio》2012,41(5):446-455
The northern reef of Yongxing Island, the largest reef island of the Xisha Islands in the South China Sea, was in good condition with significant cover of scleractinian corals until 2002. Surveys in 2008 and 2010, however, found that coral coverage had declined rapidly and severely, implying that catastrophic coral mortality occurred during the past 8 years. A blackish mat was observed covering live and dead corals in both 2008 and 2010 that was identified as an encrusting sponge, Terpios hoshinota, by special surface morphology and spicule structure. In addition, spicule residues were found on the surface of long-dead corals, indicating a previous invasion of T. hosinota. T. hoshinota is referred to as the "black disease" because it rapidly overgrows and kills corals. Our evidence indicates that outbreaks of black disease are at least partially responsible for the massive coral mortality at the northern reef of Yongxing Island over the past 8 years, although human activities and heat-related coral bleaching cannot be discounted as minor causes for this coral decline.  相似文献   
823.

Purpose

Phosphorus amendments have been widely and successfully used in immobilization of one single metal (e.g., Pb) in contaminated soils. However, application of P amendments in the immobilization of multiple metals and particularly investigations about the effects of planting on the stability of the initially P-induced immobilized metals in the contaminated soils are far limited.

Methods

This study was conducted to determine the effects of phosphate rock tailing (PR), triple superphosphate fertilizer (TSP), and their combination (P+T) on mobility of Pb, Cu, and Zn in a multimetal-contaminated soil. Chinese cabbage (Brassica rapa subsp. chinensis) (metal-sensitive) and Chinese kale (Brassica alboglabra Bailey) (metal-resistant) were introduced to examine the effects of planting on leaching of Pb, Cu, and Zn in the P-amended soils.

Results

All three P treatments greatly reduced CaCl2-extractable Pb and Zn by 55.2?C73.1% and 14.3?C33.6%, respectively. The PR treatment decreased CaCl2-extractable Cu by 27.8%, while the TSP and P+T treatments increased it by 47.2% and 44.4%, respectively. All three P treatments were effective in reducing simulated rainwater leachable Pb, with dissolved and total leachable Pb decrease by 15.6?C81.9% and 16.3?C64.5%, respectively. The PR treatment reduced the total leachable Zn by 16.8%, while TSP and P+T treatments increased Zn leaching by 92.7% and 78.9%, respectively. However, total Cu leaching were elevated by 17.8?C178% in all P treatments. Planting promoted the leaching of Pb and Cu by 98.7?C127% and 23.5?C170%, respectively, especially in the colloid fraction, whereas the leachable Zn was reduced by 95.3?C96.5% due to planting. The P treatments reduced the uptake of Pb, Cu, and Zn in the aboveground parts of Chinese cabbage by up to 65.1%, 34.3%, and 9.59%, respectively. Though P treatments were effective in reducing Zn concentrations in the aboveground parts of the metal-resistant Chinese kale by 22.4?C28.9%, they had little effect on Pb and Cu uptake.

Conclusions

The results indicated that all P treatments were effective in immobilizing Pb. The effect on the immobilization of Cu and Zn varied with the different P treatments and evaluation methods. Metal-sensitive plants are more responsive to the P treatments than metal-resistant plants. Planting affects leaching of metals in the P-amended soils, specially leaching of colloid fraction. The conventional assessment on leaching risks of heavy metals by determining dissolved metals (filtered through 0.45-??m pore size membrane) in leachates could be underestimated since colloid fraction may also contribute to the leaching.  相似文献   
824.
为实现DB 12/356-2008《天津市污水综合排放标准》(CODCr≤60mg/L)要求,大港油田对原有的废水生化处理工艺进行技术升级改造,优选生物活性炭曝气滤池工艺作为工程改造的主体技术方案。现场实施后,各项水质指标均达到了天津市标准的要求,对大港油田工业废水深度处理工作具有实践指导意义。  相似文献   
825.
确立了气相色谱法测定丙溴磷残留量的检测方法.采用该方法,丙溴磷在土壤、植株、糙米、稻壳和田水中的平均添加回收率为87.2%~103.6%,变异系数为3.20%~11.50%,最低检测质量浓度:田水为0.005 mg/kg;土壤、植株、糙米和稻壳为0.050 mg/kg.残留动态研究表明,丙溴磷在田水、植株和土壤中的半衰...  相似文献   
826.
利用ICP-AES分析了潞城市采暖期和非采暖期4个不同功能区PM10样品中16种化学元素,对不同元素的时空分布特征进行了研究,并采用富集因子和主成分分析初步研究了潞城市PM10中元素的主要来源。结果表明,潞城市PM10中重金属污染较为严重,且各元素在采暖期的平均浓度均明显高于非采暖期。PM10中Ca、V、Cr、As、Ni、Mn、Cu、Zn、Al和Pb的富集因子EF〉10,主要来源于人为污染;而Na、Mg、Si、Fe和K的EF〈10,除部分来自人为活动外,主要来自土壤风沙等自然来源。主成分分析结果显示,潞城市PM10中元素的主要来源按贡献率大小依次为:煤烟尘和工业粉尘50.39%,自然源34.37%和机动车尾气15.24%。  相似文献   
827.
一体化A/O生物膜反应器脱氮特性研究   总被引:1,自引:0,他引:1  
采用新型的一体化A/O生物膜反应器,对生活污水进行脱氮处理实验.研究了溶解氧(DO)质量浓度对硝化和反硝化作用的影响,并对反应器的脱氮特性和降解机理进行了探讨.结果表明:DO对一体化A/O反应器脱氮影响较大,随着好氧区DO的增加,NH3-N和TN的去除率相应增加.当DO为2~4 mg/L时,发生同步硝化反硝化作用,NH...  相似文献   
828.
杂多酸水溶液脱除烟气中SO2的性能研究   总被引:1,自引:0,他引:1  
合成了H3PMo12O40、H4SiW12O40、H3PW12O40、H4PMo11VO40、H5PMo10V2O40和H6PMo9V3O406种杂多酸,分别采用红外光谱(FT-IR)和X射线衍射(XRD)表征杂多酸的结构,并采用气相色谱仪对6种杂多酸水溶液进行脱硫实验测试.实验结果表明:制备的6种杂多酸具有良好的Ke...  相似文献   
829.
Fenton和类Fenton氧化处理地下水中BTEX及其动力学   总被引:2,自引:1,他引:1  
研究比较Fenton试剂和类Fenton试剂氧化处理地下水中苯、甲苯、乙苯和二甲苯(BTEX)的效果及动力学.结果表明,Fenton氧化处理BTEX较类Fenton效果好,且反应过程中体系均处于强氧化环境,pH值维持在3左右;Fenton和类Fenton氧化去除BTEX过程均符合二级反应动力学方程:1/C=kt+1/C...  相似文献   
830.
根据清洁生产原理、间二硝基苯生产工艺及废水产生情况,提出了重结晶废水直接回用于精制,精制废水蒸馏后回用于精制洗涤和重结晶的清洁生产工艺;经小试4次和中试3次废水循环套用后产品均为优等品,证明清洁生产工艺对产品质量无不良影响,可实现工艺废水零排放。  相似文献   
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