Development of an extraction method for perchlorate in soils

Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils. Based on the results of this evaluation, soils should be extracted in a dry, ground (mortar and pestle) state with Milli-Q water in a 1 ratio 1 soil ratio water ratio and diluted no more than 5-fold before analysis. When sandy soils were extracted in this manner, the calculated method detection limit was 3.5 microg kg(-1). The findings of this study have aided in the establishment of a standardized extraction method for perchlorate in soil.     

钢铁企业大型低位料仓汽车卸料的粉尘控制

某钢企大型低位料仓为汽车卸料,料仓厂房内空高,跨度大,料仓上部贯通,物料落差大,卸料中产生大量粉尘,环境污染问题典型突出。通过对低位料仓汽车卸料产尘特性分析,采取加强生产管理、组织汽车有序卸料、料仓厂房有效密闭、合理设计捕尘方式和布袋除尘系统等措施,能够有效地控制粉尘污染。除尘系统具有投资及运行费用少,除尘效果明显的优点。     

A mini review of fluoride-induced apoptotic pathways

Fluorine or fluoride can have toxic effects on bone tissue and soft tissue at high concentrations. These negative effects include but not limited to cytotoxicity, immunotoxicity, blood toxicity, and oxidative damage. Apoptosis plays an important role in fluoride-induced toxicity of kidney, liver, spleen, thymus, bursa of Fabricius, cecal tonsil, and cultured cells. Here, apoptosis activated by high level of fluoride has been systematically reviewed, focusing on three pathways: mitochondrion-mediated, endoplasmic reticulum (ER) stress-mediated, and death receptor-mediated pathways. However, very limited reports are focused on the death receptor-mediated apoptosis pathways in the fluoride-induced apoptosis. Therefore, understanding and discovery of more pathways and molecular mechanisms of fluoride-induced apoptosis may contribute to designing measures for preventing fluoride toxicity.     

限氮和限磷对活性污泥合成聚羟基烷酸的影响

聚羟基烷酸(PHA)是微生物在不平衡营养条件下贮存的一种胞内聚合物,限磷和限氮两种方式均有助于活性污泥中的混合菌群合成PHA,研究考察了两种不同方式下活性污泥合成PHA的情况。实验结果表明,当C∶N为125时,活性污泥中PHA的合成量达到细胞干重的59%;当C∶P为750时,活性污泥积累的最大PHA含量占细胞干重的37%,说明限氮和限磷两种方式对活性污泥合成PHA均有很大影响,且限氮方式更有效。     

介质阻挡放电联合催化臭氧化降解甲苯

采用介质阻挡放电区后结合MnOx/Al2O3/发泡镍去除甲苯,考察甲苯进气方式、臭氧产生方法及湿度对甲苯与O3同时去除的影响。结果表明,O3是等离子体区后催化降解甲苯的主要物种,介质阻挡放电联合催化臭氧化可实现甲苯及O3的同时高效去除。输入电压为9.0 kV时,甲苯的去除效率达92.8%,在80 min内O3的去除效率维持在99%以上。水蒸气对催化剂催化分解臭氧的活性没有直接的影响,O3浓度较高时湿度对甲苯降解效率的影响很小。GC-MS分析结果表明,甲苯降解的主要气相副产物有烷烃、酸、酮和含苯环有机物,提出了甲苯的降解途径。     

PVA降解菌的复配组合及其紫外诱变处理的研究

对已筛选出的4株PVA降解菌进行不同的组合后测定PVA降解率,发现Z5与Z8菌株混合后在1周内对PVA的去除率达到了所有组合中的最高值52.07%,比单菌株提高了约22%。采用紫外照射的方法对混合菌进行诱变并利用正交实验研究其特性,结果表明,诱变后的混合菌在1周内降解了91.46%的PVA,并且碳源浓度对酶活的影响最为显著。当pH为7,碳源、氮源含量分别为1.5 g/L、0.6 g/L,NaC l浓度为1.5 g/L时,诱变菌株处于最佳生长状态。     

聚合物驱采出水中聚丙烯酰胺的微生物联合降解作用研究

通过对2株细菌的培养降解实验研究聚丙烯酰胺(hydrolyzed polyacrylamide,HPAM)降解菌对水环境下聚丙烯酰胺的降解作用,讨论协同降解机理。2株降解聚丙烯酰胺的菌株假单胞菌CJ419、枯草芽孢杆菌FA16在初始30℃废水样品上培养,定期测量细菌生物量和HPAM降解率。培养30 d后CJ419和FA16对聚合物的降解率最大值分别达到30.4%和25%,而以1∶1比例的混合菌降解率最大值达到80.3%。对2株菌胞外各组分研究表明:混合菌降解HPAM的机理主要由胞外降解酶系水解聚合物侧链基团导致HPAM降解为小分子物质,同时生长过程中降解菌还会释放非蛋白还原性物质引发氧化反应共同参与HPAM降解。     

矿山生态环境恢复治理保证金制度在迁安的实践

以迁安市矿山环境恢复治理保证金制度实施情况及效果的调查为基础,总结了迁安市的成功实践经验,强化全社会对资源环境问题的认识,健全矿山生态环境建设责任制,建立矿山生态环境保护与治理数据库,提高矿山环境治理的技术水平。     

滨州市沿海防潮工程的生态响应

地处黄河三角洲腹地的滨州沿海为风暴潮多发区,沿海防潮工程建设已取得了显著的经济社会效益,同时也带来了一些负面生态效应,主要表现在:海岸侵蚀、潮滩潮沟退化、贝壳堤岛部分丧失、鱼类回游通道截断和入海河流水质恶化等。建议今后应加强防潮工程生态影响监测与评价,海岸带生态修复和防潮工程技术研究,以充分发挥沿海防潮工程的作用。