拓展等效线图法评估离子液体与杀菌剂多果定之间的拮抗作用

等效线图法(isobologram)是评估化学混合物毒性相互作用的经典方法之一,然而该方法仅能评估混合物在某一特殊浓度效应水平(通常为50%的浓度效应水平,即EC50)的联合毒性作用情况。因此,拓展等效线图法并用于不同效应水平下混合物毒性的评估显得尤为必要。以杀菌剂多果定(Dod)和3种离子液体(ILs)包括溴化丁基吡啶([bpy]Br)、溴化己基吡啶([hpy]Br)和溴化辛基吡啶([opy]Br)为混合物组分,采用直线均分射线法设计3组二元混合物体系(Dod-[bpy]Br、Dod-[hpy]Br和Dod-[opy]Br)共15条射线,应用微板毒性分析法系统测定各污染物及其混合物射线对青海弧菌Q67(Vibro qinghaisiense sp. Q67,Q67)的毒性,应用拓展等效线图法分析15条混合物射线在5个不同效应水平(EC20、EC30、EC40、EC50和EC60)的毒性相互作用,并与经典等效线图法和浓度加和模型(CA)评估的结果进行比较。结果表明:以p EC50为毒性指标,3种吡啶ILs对Q67的毒性具有烷基链效应,即毒性大小顺序为Dod-[opy]BrDod-[hpy]BrDod-[bpy]Br; 3组二元混合物体系的15条射线的毒性,随农药Dod浓度比的减少而减弱;拓展等效线图法可以比较直观地表征3组Dod-ILs混合物体系在5个不同效应水平的拮抗作用,且拮抗作用强度随Dod浓度比的增加而变化,即先增强后减弱;拓展等效线图法可以有效地评估二元混合物在多个效应水平的联合毒性相互作用。     

2种经典模型对抗生素与重金属锌的蛋白核小球藻时间依赖联合毒性作用的评估比较

污染物在环境中普遍以混合物的形式存在,其累积毒性与毒性相互作用具有潜在的环境风险。因此,本研究以水环境中普遍存在的氨基糖苷类抗生素(硫酸链霉素、硫酸安普霉素和双氢链霉素)和重金属锌(Zn)为目标污染物,以蛋白核小球藻(Chlorella pyrenoidosa,C. pyrenoidosa)为指示生物,应用直接均分射线法设计3种抗生素与Zn的3个二元混合物体系,应用时间毒性微板分析法系统测定3种抗生素和重金属Zn及其二元混合物射线的时间-浓度-毒性数据,以浓度加和(concentration addition,CA)与独立作用(independent action,IA)为标准加和参考模型,分析混合物毒性相互作用及其随时间变化规律。结果表明,随着暴露时间延长,3种抗生素和重金属Zn对C. pyrenoidosa的毒性逐渐增强; 2种模型对3个二元混合物体系的毒性相互作用评估基本一致,即在低浓度区域始终呈现加和作用,而在高浓度区域随暴露时间延长由协同作用逐渐转变为加和作用;而对于同一混合物体系,CA和IA模型预测毒性之间的差距随着浓度增加而增加,且IA预测曲线始终位于CA预测曲线上方,显示了IA模型在评估具有相异组分混合物的毒性时较CA模型接近实际观测值。     

氨基甲酸酯类农药对蛋白核小球藻联合毒性作用特点及机制

氨基甲酸酯类农药广泛应用于农业生产中,其在环境中的残留及其对非靶标生物的毒性作用引起关注。以5种氨基甲酸酯类农药包括残杀威、灭多威、抗蚜威、涕灭威和呋喃丹为研究对象,以蛋白核小球藻为受试生物,应用微板毒性分析法系统测定每种农药及其五元混合物对蛋白核小球藻在不同暴露时间(12、24、48、72和96 h)的生长抑制作用,并同步分析农药对蛋白核小球藻的生理特性如叶绿素含量、蛋白质含量、超氧化物歧化酶(SOD)活性和脂质过氧化物丙二醛(MDA)含量的影响。结果表明,5种农药对蛋白核小球藻的浓度-效应均具有明显的时间依赖性,农药抗蚜威在中低浓度促进绿藻生长,呈现非单调J型浓度-效应曲线(CRC)特征,其余4种农药的CRC呈现经典S型;以半数效应浓度的负对数(p EC50)为毒性大小指标,5种农药在96 h时毒性大小为:呋喃丹(p EC50=3.43)残杀威(p EC50=2.76)抗蚜威(p EC50=2.12)灭多威(p EC50=2.11)涕灭威(p EC50=1.89)。浓度为EC50的5种农药处理后的蛋白核小球藻中叶绿素和蛋白质含量随暴露时间的延长而减少,但不同农药处理的绿藻中叶绿素和蛋白质含量减少率随暴露时间延长变化趋势稍有不同; SOD酶活性随着暴露时间延长逐渐下降,MDA含量逐渐增加,这说明藻细胞受到破坏,脂质过氧化的损害程度超过细胞修复能力,SOD活性被抑制,细胞的抗氧化能力下降,藻细胞内的H2O2不断积累,导致MDA含量升高。五元混合物对蛋白核小球藻的毒性也具有一定的时间依赖性,并表现出刺激作用,即hormesis现象,且混合物毒性与组分浓度比具有良好的线性相关性;暴露于混合物的小球藻均在96 h出现了刺激效应,其叶绿素与蛋白质含量随暴露时间延长不断增加,SOD活性不断升高,MDA含量不断减少;五元混合物均在96 h呈现出拮抗作用,且与混合物的浓度和组分浓度比相关。     

武陵山片区旅游经济时空差异与影响因素研究

以武陵山片区县域为研究尺度,基于标准差、变异系数和旅游经济发展水平梯度探析了旅游经济发展水平的差异特征与演变规律,并借助GWR模型对旅游经济空间分异的影响因素进行了分析。结果表明:(1)武陵山片区71个县域旅游经济发展水平在时间上呈绝对差异逐年上升,而相对差异波动下降的演变趋势。(2)2014—2018年间旅游经济发展水平欠发达区数量下降,并呈西北和东北部明显高于其他区域的空间分布格局。(3)人均GDP、第三产业占GDP比重、3A级以上景点数、国家级非物质文化遗产数、公路密度、3星级以上宾馆数是影响武陵山片区旅游经济发展水平的主要因素。     

RTCA与CCK-8法用于检测柴油废气颗粒物致支气管上皮细胞毒性的比较研究

运用实时无标记细胞分析系统(RTCA)和Cell Counting Kit-8(CCK-8)法分别检测柴油废气颗粒物(DEP)致支气管上皮细胞(HBE)细胞毒性,从而对2种方法进行比较研究.分别以浓度为0、3.5、7、14、28和56 mg·L-1 2种柴油废气标准参考颗粒物(Standard Reference Material 1650b,SRM 1650b;Standard Reference Material 2975,SRM 2975)对 HBE 细胞进行暴露处理,分别暴露6、12、24和48 h后,检测不同DEP致HBE细胞毒性,比较各组之间细胞存活率或标准化细胞指数(normalized cell index,NCI)值的差异,考察2种方法的优缺点.并用细胞凋亡实验检测各差异组之间的凋亡率.在相同染毒浓度及暴露时间,与SRM 1650b相比,SRM 2975对HBE细胞的毒性更强.在RTCA检测DEP致HBE细胞毒性时,低浓度DEP组的NCI值已经表现出与对照组有统计学差异(P＜0.05),而相同时间条件下,CCK-8法在更高浓度的DEP组才检测出显著的细胞活性下降(P＜0.05).且由细胞凋亡实验证实,与对照组相比,低浓度DEP组的细胞凋亡率已经有统计学差异.相对于CCK-8法,RTCA更适用于检测DEP致贴壁HBE细胞毒性.CCK-8法更适用于检测DEP致悬浮细胞的细胞毒性或与气液暴露装置联用时的贴壁/悬浮细胞毒性.     

Assessment of future climate change impacts on water-heat-salt migration in unsaturated frozen soil using CoupModel

• A model coupling water-heat-salt of unsaturated frozen soil was established. • Future temperature, precipitation, and evaporation increase in freeze–thaw period. • Soil water, heat, and salt transport are closely coupled during freeze–thaw period. • Freeze–thaw cycles and future climate change can exacerbate salinization. The transport mechanisms of water, heat, and salt in unsaturated frozen soil, as well as its response to future climate change are in urgent need of study. In this study, western Jilin Province in north-eastern China was studied to produce a model of coupled water-heat-salt in unsaturated frozen soil using CoupModel. The water, heat, and salt dynamics of unsaturated frozen soil under three representative concentration pathway (RCP) scenarios were simulated to analyze the effects of future climate change on unsaturated frozen soil. The results show that water, heat, and salt migration are tightly coupled, and the soil salt concentration in the surface layer (10 cm) exhibits explosive growth after freezing and thawing. The future (2020–2099) meteorological factors in the study area were predicted using the Statistical Downscaling Model (SDSM). For RCP2.6, RCP4.5, and RCP8.5 scenarios, future temperatures during the freeze–thaw period increased by 2.68°C, 3.18°C, and 4.28°C, respectively; precipitation increased by 30.28 mm, 28.41 mm, and 32.17 mm, respectively; and evaporation increased by 93.57 mm, 106.95 mm, and 130.57 mm, respectively. Climate change will shorten the freeze–thaw period, advance the soil melting time from April to March, and enhance water and salt transport. Compared to the baseline period (1961–2005), future soil salt concentrations at 10 cm increased by 1547.54 mg/L, 1762.86 mg/L, and 1713.66 mg/L under RCP2.6, RCP4.5, and RCP8.5, respectively. The explosive salt accumulation is more obvious. Effective measures should be taken to prevent the salinization of unsaturated frozen soils and address climate change.     

有机污泥改制含碳吸附剂工艺及应用

采用先干燥再浸溃活化流程对有机污泥进行了改制含碳吸附剂工艺研究。试验结果表明,有机污泥在活化温度为５００℃,活化剂浓度为４２％,活化时间为４０ｍｉｎ,污泥与活化溶液重量比为１：３．５的条件下,可以改制成碘值为５１２ｍｇ／ｇ以上的含碳吸附剂;并利用其处理俯含电泳漆废水和含苯酚放心水,均取得优良的净化效果。     

应用GIS技术研究车流量与交通噪声相关性

对无锡建成区交通噪声等效声级(L_(eq))与车流量进行监测,应用GIS技术分析交通噪声与车流量的空间分布,为交通噪声污染防治工作提供科学参考。结果表明:噪声L_(eq)峰值及车流量峰值均集中在高速公路出入口必经路段,此区域为噪声污染防治重点区域。同时发现,噪声L_(eq)与车流量在空间分布上并非成正比关系,在时间趋势上车流量上升但噪声值下降,说明在机动车保有量不断攀升的背景下,采取多种防治措施可以有效缓解甚至改善交通噪声污染。     

有机垃圾的处理和资源化技术进展

有机垃圾具有易腐烂、热值低、有机质含量丰富等特点,常规的填埋和焚烧难以妥善处理。文章在分析各类有机垃圾组成和特性的基础上,认为堆肥化处理、厌氧发酵和综合利用应是有机垃圾处理和处置的发展趋势,这不仅有利于消除污染、保护环境,还能最大程度地实现物质和能量的自然循环。     

Health risk assessment of heavy metals in soil-plant system amended with biogas slurry in Taihu basin,China

Biogas slurry is a product of anaerobic digestion of manure that has been widely used as a soil fertilizer. Although the use for soil fertilizer is a cost-effective solution, it has been found that repeated use of biogas slurry that contains high heavy metal contents can cause pollution to the soil-plant system and risk to human health. The objective of this study was to investigate effects of biogas slurry on the soil-plant system and the human health. We analyzed the heavy metal concentrations (including As, Pb, Cu, Zn, Cr and Cd) in 106 soil samples and 58 plant samples in a farmland amended with biogas slurry in Taihu basin, China. Based on the test results, we assessed the potential human health risk when biogas slurry containing heavy metals was used as a soil fertilizer. The test results indicated that the Cd and Pb concentrations in soils exceeded the contamination limits and Cd exhibited the highest soil-to-root migration potential. Among the 11 plants analyzed, Kalimeris indica had the highest heavy metal absorption capacity. The leafy vegetables showed higher uptake of heavy metals than non-leafy vegetables. The non-carcinogenic risks mainly resulted from As, Pb, Cd, Cu and Zn through plant ingestion exposure. The integrated carcinogenic risks were associated with Cr, As and Cd in which Cr showed the highest risk while Cd showed the lowest risk. Among all the heavy metals analyzed, As and Cd appeared to have a lifetime health threat, which thus should be attenuated during production of biogas slurry to mitigate the heavy metal contamination.