Products of methotrexate during chlorination

Methotrexate(MTX)is a cytotoxic drug widely used in the treatment of tumors,autoimmune diseases and severe asthma. jen00883 This drug has been frequently detected in the aquatic environment with concentrations up to μg/L levels. The MTX present in environmental water might be transformed and removed during chlorination disinfection treatment. In this work,the fate of MTX during aqueous chlorination was investigated in laboratory batch experiments,and the transformation products of MTX were identified. Aqueous solutions of MTX(1 mg/L)were chlorinated by sodium hypochlorite solution at room temperature under neutral p H conditions. Chlorinated products were pre-concentrated with solid-phase extraction(SPE)cartridges and determined by liquid chromatography electrospray ionization tandem mass spectrometry(LC–ESI–MS/MS). The reaction of MTX chlorination exhibited pseudo-first-order kinetics and the half-life time of MTX degradation was calculated to be 1.65 min,when the initial chlorine concentration was 2 mg/L. Two chlorinated MTX congeners,4-amino-3-chlorinated-N10-methylpteroylglutamic(monochloro-MTX)and 4-amino-3,5-dichloro-N10-methylpteroylglutamic(dichloro-MTX)were found in the chlorinated solution. Monochloro-MTX was successfully fractionated by high performance liquid chromatography(HPLC)and its structure was further identified using ~1H nuclear magnetic resonance(NMR)analysis. The presence of the two products in real hospital wastewater was then examined and both compounds were detected. Finally,the effects of MTX and monochloro-MTX on the cell cycle progression in vitro were evaluated using zebrafish liver cell line. It was found that both compounds could inhibit the proliferation of zebrafish liver cells through S phase arrest and their effects on the cell cycle profile had no significant difference.     

Effects of halobenzoquinone and haloacetic acid water disinfection byproducts on human neural stem cells

Human neural stem cells(h NSCs) are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts(DBPs) is scarce. Comprehensive toxicological results are essential to the prioritization of DBPs for further testing and regulation. Therefore, this study examines the effects of DBPs on the proliferation and differentiation of h NSCs. Prior to DBP treatment, characteristic protein markers of h NSCs from passages 3 to 6 were carefully examined and it was determined that h NSCs passaged 3 or 4 times maintained stem cell characteristics and can be used for DBP analysis. Two regulated DBPs, monobromoacetic acid(BAA) and monochloroacetic acid(CAA), and two emerging DBPs, 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ) and 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), were chosen for h NSC treatment. Both 2,6-DBBQ and 2,6-DCBQ induced cell cycle arrest at S-phase at concentrations up to 1 μmol/L. Comparatively, BAA and CAA at 0.5 μmol/L affected neural differentiation. These results suggest DBP-dependent effects on h NSC proliferation and differentiation. The DBP-induced cell cycle arrest and inhibition of normal h NSC differentiation demonstrate the need to assess the developmental neurotoxicity of DBPs.     

水敏性城市设计应用研究——以佛山市高明区荷城乡镇生态规划为例

21世纪是知识经济和全球经济一体化的世纪,经济活动和生态环境的相互影响日益加深,全球性人口增长、资源短缺、环境污染和生态恶化已成为人类面临的共同难题.水敏性城市设计的出现,为各国谋求经济社会与人口、资源、环协调发展提供了思路.水敏性城市设计的核心是可持续发展,是城市设计与城市水循环的管理、保护和保存的结合,确保城市水循环管理能够尊重自然水循环和生态过程.通过介绍国内外水敏性城市设计理念与实例,结合佛山市高明区荷城乡镇生态规划方案,把污水管道,雨水管道和道路设计,景观设计相融合,将节水技术与废水资源化融入到城市生态乡镇规划中,实现对水资源的完全利用和循环利用.     

生命周期评价在环境管理中应用的局限性及其技术进展研究

生命周期评价法(Life Cycle Assessment)在国际上广泛应用于工业企业部门、政府管理部门和服务行业,但最突出的贡献是在环境管理方面的应用.LCA的技术框架分为确定目的与范围、生命周期清单分析、生命周期影响评价(LCIA)和结果解释4个部分.LCIA的方法可归纳为中点法和终点法.LCA存在数据获取、清单分配、边界选择、评价模型、时空限制,以及结果不确定性等方面的局限性.为适应环境管理和评价技术本身的要求,LCA评价技术朝系统化方向发展,目前主要有IO-LCA、ALCA、CLCA、LCC、S-LCA和LCSA等评价技术.不同的评价技术从不同侧面拓展了LCA的应用领域和回避LCA评价的局限性,使得LCA越来越成为环境管理不可或缺的工具.     

PM2.5暴露对小鼠肝脏能量代谢的影响

通过细颗粒物(particulate matter 2.5,PM_(2.5))的暴露,探讨其对小鼠肝脏能量代谢方式的影响及作用机制.采用透射电镜(TEM)观察肝脏组织中线粒体超微结构的改变,并检测了三磷酸腺苷(ATP)、丙酮酸和乳酸含量的变化,同时用实时荧光定量-聚合酶链式反应(RT-PCR)检测糖酵解相关基因果糖-2,6-二磷酸酶(PFKFB3)和乳酸脱氢酶(LDHB)及三羧酸循环(TCA)相关基因丙酮酸脱氢酶(PDHA1)、柠檬酸合成酶(CS)和延胡索酸酶(FH)的表达情况.此外,还对活性氧(ROS)的水平进行检测.结果表明,PM_(2.5)暴露对小鼠肝脏组织中的线粒体造成损伤,导致ATP的下降,丙酮酸和乳酸的积累.此外,PDHA1、CS和FH的表达明显降低,PFKFB3和LDHB的表达显著升高,这些结果共同表明PM_(2.5)改变了小鼠肝脏的能量代谢方式.同时ROS水平明显升高,表明PM_(2.5)暴露可能是通过ROS抑制三羧酸循环,增强糖酵解方式来为机体提供能量,从而对肝脏的能量代谢产生影响.     

不同诱导模式下CAST工艺的亚硝酸盐型反硝化除磷能力

实验采用改良型CAST工艺,考察了不同诱导模式下系统的除磷脱氮性能.结果表明,在缺氧条件下投加亚硝酸盐对系统反硝化除磷性能的抑制作用较大,投加量为5 mg·L~(-1)时系统除磷性能变差.相比较,好氧投加亚硝酸盐的CAST系统更稳定,当亚硝酸盐投加浓度为5、10、15 mg·L~(-1)时各工况初期除磷性能均有小幅波动,但分别经过10、6、34 d驯化后,除磷率迅速回升并稳定在95%以上,出水磷浓度均小于0.5 mg·L~(-1);投加量为20 mg·L~(-1)时工艺除磷性能急速恶化,但污泥的亚硝酸盐型缺氧吸磷能力是驯化前的10.4倍,说明投加一定浓度亚硝酸盐导致的除磷性能恶化可以解除,且长期投加有利于富集以NO_2~-为电子受体的反硝化聚磷菌.实验还发现,好氧投加一定浓度亚硝酸盐系统污泥沉降性能良好且污泥浓度不断降低,这对污泥减量具有一定指导意义.     

生活污水快速渗滤处理现场试验研究

在濮阳市进行了历时３个月的污水快速渗滤现场试验，试验土层为粉细砂。结果表明，快速渗滤系统对氮及有机污染物具有良好的去除效果，去除率分别大于９５％和８０％；在系统动转初期，存在微生物的适应期；通过调整水力负荷，可使系统达到最优的污染物去除效果，同时保证具有一定的水力负荷。     

海河流域碳、氮、硫、磷及生态环境数据库

介绍了海河流域碳、氮、硫、磷及生态环境数据库的建库目标,指导系统分解的概念模型,选择录入数据的指标体系,数据库系统构成及所含6个子库典型输出表。做为数据库的必要功效补充,还建立了地理信息系统。整个数据库系统是在DBASE-Ⅲ、汉化地理信息系统工具和FORTRAN-77统计与模式程序包支持下,在PC/AT微机上实现的。     

浙江白垩系的深化研究与新进展

根据岩石地层学、生物地层学和年代地层学资料，将浙江省陆相白垩系划分为３统、５群、１７组，并将其所含化石划分为建德、水康、衢江三个生物群。以综合地层学手段研究了白垩系的区域地层对比框架。在多学科综合研究，特别是在对一些岩石地层成因机制进行深层次研究的基础上，对浙江白垩系主要的关键性、疑难性地层问题，提出了一些新的认识：（１）“塘上组”底部砾岩为与火山爆发有成因联系的湖泊重力流沉积，并非底砾岩，因而“天台群”不是“新的构造亚层”，而基本上是火山岩型永康群；（２）“塘上组”、“小平田组”等人山活动成因的“组”，都是中白垩世时局部性火山事件形成的不等时、不连续的地质体，不是层位固定的岩石地层单位；（３）中戴组、方岩组、“赤城山组”都是晚白垩世早期地壳重力均衡调整作用中，在不同地区形成的同一套类磨拉石建造，并非层位不同的“三套”类磨拉石建造。     

我国城市汽车行驶工况调查研究

在５ 个典型城市进行汽车行驶工况试验的基础上，对建立城市汽车行驶工况模式的方法和必要性作了详细的描述。该行驶工况对有效地控制我国城市汽车排放污染提供重要依据