控释尿素对污染土壤镉有效性的影响

通过培养试验,研究了普通尿素(PU)、硫包膜尿素(SCU)和树脂包膜尿素(PCU)在最大田间持水量(湿润)和60%田间持水量(适宜湿度)对污染土壤Cd有效性的影响.结果表明,不同水分条件下包膜尿素对土壤Cd有效性的影响差异显著.培养60d后水溶态Cd含量最大田间持水量下均显著低于60%田间持水量下.最大田间持水量下施用PU、SCU和PCU均降低了水溶态Cd含量,降低程度为PCU>PU>SCU;施用SCU和PCU均降低了有效态Cd含量,降低程度为SCU>PCU. 60%田间持水量下施用PU和PCU均降低了水溶态Cd含量,降低程度为PU>PCU;施用PU、SCU和PCU均降低了有效态Cd含量,降低程度为PCU>PU>SCU.不同控释尿素和水分含量对水溶态Cd的影响较有效态Cd的影响更加突出.最大田间持水量下水溶性SO42-含量与有效态Cd含量呈显著正相关;60%田间持水量下铵态氮含量与水溶态Cd含量呈显著负相关,硝态氮含量与有效态Cd含量呈显著负相关.在Cd污染的酸性土壤旱作中,湿润状态下宜施用SCU,适宜湿度下宜施用PCU,以降低土壤Cd的有效性.     

石墨烯在环境有机污染物分析中的应用进展

石墨烯是一种全部由碳六元环构成的新型二维碳纳米材料.从2004年发现至今,其在能源、电子、复合材料、生物医学等领域中的应用都取得了重大研究进展.近年来,石墨烯在分析化学领域也表现出了巨大的应用潜力,尤其是在环境有机污染物分析方面,涌现了大量相关报道.本文简要回顾了近期石墨烯在环境有机污染物分析中的应用情况,涵盖了样品前处理、色谱、传感器、质谱等不同的技术方向,并对石墨烯在环境分析中的应用前景进行了展望.     

Polybrominated diphenyl ethers (PBDEs) in soil and dust from plastic production and surrounding areas in eastern of China

Polybrominated diphenyl ethers (PBDEs) are a class of organic pollutants. They are used as flame retardants that caused worldwide environmental concern. This study investigated the occurrence of PBDEs in soils and dusts from three plastic manufacture plants and surrounding areas in Eastern China. A total of 13 PBDE congeners were detected using gas chromatography-mass spectrometer (electron impact ionization). The total concentrations of PBDEs range from 2.21 to 558, 19.7–4916, and 8.70–18,451 ng/g dry weight in the soils of three sampling areas, with mean of 1004 ng/g d w; in dusts, the concentrations range from 7240 to 10,469, 684–4482, and 193–3989 ng/g d w, with an overall mean of 3619 ng/g d w. The most abundant congener is the BDE-209, followed by BDE-153 and BDE-85. This indicates that the brominated flame retardant added in the plastic manufacture is mainly the commodity decabromodiphenyl ether. In comparison with other polluted areas around the world, the PBDE concentrations in the soils of the plastic manufacture plants are similar to those in soils of waste plastic disposal areas and PBDEs production sites, but orders of magnitude higher than those in agricultural soils, mountain soils and rural soils. Daily exposure was estimated using the average concentrations of the pollution sites. The hazard quotient shows that the PBDEs pose considerable human health risks, especially to children, to which attention should be paid.

     

4种农药复合污染对斑马鱼仔鱼联合毒性效应

为探明农药混合污染对斑马鱼的联合毒性效应,以斑马鱼仔鱼为研究对象,开展了氯氰菊酯、咪鲜胺、马拉硫磷和杀螟硫磷等4种农药的联合毒性效应研究。研究表明,氯氰菊酯、马拉硫磷,杀螟硫磷和咪鲜胺对斑马鱼仔鱼的96 h-LC_(50)值分别为0.12、17.88、12.39和1.45 mg·L~(-1)。根据96 h-LC_(50)值采用等毒比(1∶1)进行二元及多元联合毒性试验。二元农药混合污染(氯氰菊酯+马拉硫磷、氯氰菊酯+杀螟硫磷、氯氰菊酯+咪鲜胺和杀螟硫磷+咪鲜胺)对斑马鱼仔鱼联合作用表现协同作用。马拉硫磷+杀螟硫磷对斑马鱼仔鱼联合毒性在24 h时表现为协同作用,在其他不同时间均表现为相加作用。马拉硫磷+咪鲜胺二元农药对斑马鱼仔鱼联合毒性表现为拮抗作用。氯氰菊酯、咪鲜胺、马拉硫磷和杀螟硫磷4种农药的所有三元和四元混合污染对仔鱼联合毒性作用均表现为协同作用。研究表明,在真实的环境中,农药以混合物形式存在可能增加其对水生生物的毒性效应,给生态环境造成严重影响。     

上海室内外降尘磁学空间变化特征

采用磁学方法分析上海市室内外降尘样品的磁学参数在不同功能区和不同行政区的变化特征,探讨影响室内外降尘磁学性质的影响因素。研究结果表明:上海市大气降尘污染有自然和人为2种影响因素;室内外降尘样品的磁性特征均受磁铁矿控制,主要以假单畴和多畴颗粒为主;低频磁化率在功能区上呈现出工业区(553.464×10~(-8)m~3/kg)交通区(484.302×10~(-8) m~3/kg)商业区(443.216×10~(-8) m~3/kg)居住区(320.849×10~(-8) m~3/kg)清洁区(269×10~(-8) m~3/kg)的空间变化趋势在行政区上整体呈现出宝山区(558.104×10~(-8) m~3/kg)、杨浦区(464.263×10~(-8) m~3/kg)的磁化率偏高,崇明区(218.673×10~(-8) m~3/kg)、奉贤区(218.868×10~(-8) m~3/kg)、松江区(218.689×10~(-8) m~3/kg)磁化率较低。室内外降尘的低频磁化率(χ_(if))、饱和等温剩磁(SIRM)和非磁滞剩磁磁化率(χ_(ARM))的相关系数分别为0.777、0.504、0.547,有较好的正相关关系表明室内外降尘来源很可能存在一定的趋同性。对比分析不同磁学参数,可以更好地反映降尘污染状况。研究发现χ_(lf)、SIRM和χ_(ARM)可以作为上海市大气降尘磁性特征的有效参考指标。在不同行政区大气降尘磁化率和PM_(10)浓度表现出相似的空间变化趋势。降尘样品的磁学参数测量速度快,方便用于监测城市空气污染的状况,在一定程度上可以对空气污染指数有一定的指代作用。     

县域打通“绿水青山就是金山银山”理念转化通道的典型模式研究

“绿水青山就是金山银山”理念是习近平生态文明思想的重要组成部分,具有深刻的哲学内涵,本文利用代表“绿水青山”和“金山银山”的生态与经济指标聚类分析了中国1666个县(市、区),筛选出21个典型地区并分析了其“绿水青山就是金山银山”理念转化路径,总结提出5类典型模式。其中,以浙江省衢州市的6县(市、区)为案例,综合设计衢州市各县(市、区)的“绿水青山就是金山银山”理念转化典型模式实践方案,论证县域典型模式设计方法的适用性。对研究与实践中存在的问题,提出开展生态价值核算、出台县级层面的评价标准和规范、开展试点示范、出台经济激励与优惠政策等建议,进一步深化“绿水青山就是金山银山”理念探索实践。     

中国天山过去43年大气环境变化:来自冰芯草酸根记录的证据

中、低纬度地区山地冰川有机酸记录的研究是目前国际冰芯地球化学研究的前沿之一。中国天山乌鲁木齐河源一号冰川为一中纬度山地冰川。对其冰芯的草酸根含量的分析显示,其冰芯所记录的过去43 年草酸根变化的总体特征是在一个背景值基础上存在着含量的突变峰值。草酸根的背景值含量在1 ng/g左右,在部分冰芯段,其含量甚至低于测试分析的检测限;而大多数草酸根峰值的含量都达到或超过了10 ng/g。草酸根的平均含量为3.6 ±9.2 ng/g ( x±1σ, N=534),其中70%以上由峰值构成。50年代后期是草酸根的一个低值期,平均含量略高于本底值;至60-70年代达到最高值,平均含量为5.0ng/g;80年代草酸根平均含量又下降到接近50 年代后期的水平;至90年代回落到本底值附近。草酸根的主要来源是人类活动对大气所造成的污染。其过去43 年平均含量的变化大致与中国西部工业和环境保护事业的发展历程相一致,是西部区域大气污染变化的一种反应。     

我国高校创立"安全工程" 本科专业的回顾

"安全工程"作为概念的提出和被确立为我国高等教育的一个专业,前前后后已有21年之久.但因当初只是个别人参与,若论工作渠道,堪称蹊径一条,所以事情的来龙去脉缺乏文献记载.为帮助了解或研究我国安全科教发展历史,特此文奉献给读者.     

Transferral of HMs pollution from road-deposited sediments to stormwater runoff during transport processes

Ratio of turbidity and TSS (Tur/TSS) was used to characterize PSD of stormwater particles. Pb and Zn preferred to accumulate in finer RDS, while Cu, Cr and Ni in coarser RDS. HMs pollution in stormwater particles increased linearly with Tur/TSS. Dissolvability of HMs and PSD variations contribute to the differences between RDS and stormwater. Stormwater runoff, derived from the wash-off of road-deposited sediments (RDS), contains elevated heavy metal (HM) concentrations and, thus, imposes an increasing threat to urban aquatic ecosystems. In-depth understanding of the variations of HMs pollution from RDS to stormwater during transport processes facilitates the development of effective RDS and stormwater control strategies. Toward this end, the distribution of HMs (Cu, Pb, Zn, Cr, and Ni) in RDS and stormwater were investigated simultaneously. The results show a preferential accumulation of Pb and Zn in the finer (<38.5 μm) RDS, and Cu, Cr and Ni in the coarser (38.5–150 μm) RDS. For stormwater, n.d.~48.6% of HMs fractionated into the dissolved phase, and stormwater particles constitute the primary carriers of HMs. Furthermore, the accumulation of HMs in stormwater particles increased linearly with finer particle size distributions (PSD). Geoaccumulation index (I_geo) highlighted the predominant pollution of both RDS and stormwater particles by Cu, Pb and Zn. Nonetheless, Cu, Pb, and Ni mostly contributed the potential ecological risk of RDS, whereas Cu, Pb, and Zn mainly contributed that of stormwater particles. Moreover, contamination by Cu, Pb and Zn was significantly higher in stormwater particles than that in RDS. These differences are attributable to the solubility and size-dependent accumulation of HMs in RDS, as well as the PSD variations during transport processes. The study outcomes highlight the importance of very fine (nano- and submicron- scale) RDS in stormwater pollution and the necessity of control.     

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.