不同粒径尾矿中重金属水平迁移转化规律

针对桂北铅锌尾矿中重金属在水平方向上的释放、迁移和转化问题,利用尾矿为研究对象,通过降雨模拟装置进行径流冲刷试验,分析冲刷过程中尾矿重金属浓度和形态的变化。结果表明,在径流冲刷过程中,尾矿中重金属浓度整体呈下降趋势,深度对尾矿中重金属浓度变化的影响不明显,同一深度的尾矿,粒径与其重金属释放量呈负相关关系,粒径小于75μm时重金属Zn减少率高达24%。径流作用下,尾矿的粒径大小与迁移能力成反比。径流冲刷前后,尾矿中重金属含量下降,Cd,Zn和Pb的含量在弱酸提取态下分别减少2.4%,1.6%和0.3%。随降雨时间延长,液相可溶态重金属浓度未发生显著变化,固相颗粒态重金属浓度持续降低,液相颗粒态重金属含量减少最明显。     

变化中的参考作物蒸散量及其对气候的响应

作为重要的水文气象参数,参考作物蒸散量（ET0）在全球生态系统中发挥重要作用。为深化认识湿润气候区ET0变化,基于湖南省87个气象站1960~2015年逐月气候资料,应用Penman Monteith（P M）模型估算ET0,利用线性趋势、Mann Kendall检验、反距离加权插值等分析了ET0及主要气候因子的时空变化,采取逐〖JP〗步回归函数来确定P M方程所涉及的气候因子对ET0变化的贡献。研究表明：年均ET0降幅为-3346 mm/10 a,〖JP+1〗日照时数和风速下降是ET0减少的主要原因,而相对湿度下降提高了ET0。春、夏、秋、冬四季ET0变化幅度分别为2966、-5451、-0922、-0207 mm/10 a,春季ET0增加是由相对湿度下降和最高气温上升引起的,夏、秋、冬三季ET0减少主要与日照时数和风速下降有关。风速、相对湿度、日照时数呈下降趋势,而气温、降水、湿润指数呈上升趋势,后者表明气候暖湿化趋势。气候变化背景下ET0显示出不同时间尺度（年、季）空间分布的多样性     

Haloacetic acid removal by sequential zero-valent iron reduction and biologically active carbon degradation

An innovative haloacetic acid (HAA) removal process was developed. The process consisted of a zero-valent iron (Fe⁰) column followed by a biologically active carbon (BAC) column that were efficient in degrading tri- and di-HAAs, and mono- and di-HAAs, respectively. The merit of the process was demonstrated by its performance in removing trichloroacetic acid (TCAA). An empty bed contact time of 10 min achieved nearly complete removal of 1.2 μM TCAA and its subsequent products, dichloroacetic acid (DCAA) and monochloroacetic acid (MCAA). HAA removal was a result of chemical dehalogenation and biodegradation rather than physical adsorption. Preliminary kinetic analyses were conducted and the pseudo-first-order rate constants were estimated at ambient conditions for Fe⁰ reduction of TCAA and biodegradation of DCAA and MCAA by BAC. This innovative process is highly promising in removing HAAs from drinking water, swimming pool water, and domestic or industrial wastewater.     

污染源普查数据集成与共享平台研究与实践

应用数据仓库、商务智能等信息技术对第一次全国污染源普查数据进行了整理集成,设计开发了普查数据的共享平台,并对数据共享与服务的技术保障体系进行了研究。平台采用资源目录和标准数据集的方式对普查数据资源进行组织,并设计了数据资源的获取、发布以及申请定制等共享服务流程。平台技术保障体系主要包括数据成果的分类分级、发布策略、管理流程、质量控制规范等。     

苏州市黑碳气溶胶的污染特征分析

2012年1—12月,对苏州市区黑碳气溶胶浓度进行监测和分析。结果表明,苏州市区黑碳平均质量浓度为3.3μg/m3,且季节变化明显,即夏季的平均浓度最低,秋末、冬初、春末时段黑碳浓度易出现高值,其分布规律与春季秸秆焚烧、秋冬季逆温雾霾时期相吻合;与周围生物质燃烧和工业排放有关。日变化有明显的峰值、谷值,一般在每日的6:00—9:00、18:00—20:00出现高值,低值则出现在午后12:00—15:00;与国外城市相比,苏州黑碳浓度偏高,但与国内城市(北京、天津、沈阳、本溪)相比,则浓度相对较低。     

Urinary concentrations of organophosphorus insecticide metabolites in Japanese workers

A recent development in analytical chemistry has enabled us to monitor systemic organophosphorus insecticide (OP) exposure at individual levels. At present, however, limited data are currently available on urinary OP metabolite levels worldwide. The purpose of this study was to assess urinary dialkylphosphate (DAP) concentrations in Japanese workers. Urine samples were collected in both summer and winter from 339 Japanese adults who worked as food distributors (FDs, n = 164), apple farmers (AFs, n = 147) and pest control operators (PCOs, n = 28). DAPs were measured by gas chromatography-mass spectrometry after derivatization with pentafluorobenzylbromide. Dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP) and diethylthiophosphate (DETP) were detected in the urine of over 87% of the studied populations in both seasons. The geometric mean values of total DAPs (nmol g⁻¹ creatinine), DMP, DMTP, DEP and DETP (μg g⁻¹ creatinine) in summer and winter were 106.7 and 98.3, 7.0 and 3.8, 3.4 and 4.5, 0.8 and 1.5, and 0.3 and 0.2 for the FDs, 440.8 and 197.7, 33.1 and 10.8, 10.1 and 5.8, 4.2 and 4.7 and 1.6 and 0.8 for the AFs, and 473.4 and 284.6, 28.9 and 22.2, 17.6 and 4.6, 3.5 and 4.4, and 0.5 and 0.6 for the PCOs, respectively, thereby revealing significantly higher concentrations in AFs and PCOs groups than in the FDs in both seasons except for winter DMTP. These DAP concentrations were approximately the same or at lower levels compared with those reported in the previous literature. This is one of the first studies to demonstrate urinary DAP concentrations in Japanese adults.     

Increased urinary 8-hydroxy-2��-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.     

油气输送焊管残余应力测试与安全评价方法研究

针对油气输送焊管残余应力测试与评估技术难题,采用机械切割应力释放法对不同成型工艺和状态焊管的残余应力进行了测试分析对比,结果表明:UOE焊管的残余应力分布水平较低;ERW焊管次之;SSAW焊管的残余应力分布范围较广,有高有低。不同管型和成型工艺及水压试验状态具有明显不同的残余应力分布特征,在进行焊管安全评价时必须区别对待。根据残余应力实测结果提出了焊管安全评价时残余应力的取值建议。研究结果对管道设计、安全分析与评价、焊管残余应力的改善、控制及焊管合理选用具有重要工程意义。     

消油剂使用对水下溢油分散效果的研究

消油剂的水下使用是水下溢油应急处置的一种潜在的有效手段,但是消油剂对水下溢油分散效果的定量评估还比较少见。本研究采用自制的1 m×1 m×2 m（长×宽×高）的水下溢油模拟实验装置,开展消油剂作用下的蓬莱19-3原油水下喷射实验,以油滴体积分布和体积中值粒径为指标,考察不同消油剂使用量对水下溢油油滴破碎的影响。结果表明,与不使用消油剂相比,使用消油剂时的水下溢油分散效果更加显著,表现为油滴体积分布最高点向小粒径方向移动,大粒径油滴的体积分数减小;消油剂使用量越大,大粒径油滴的体积分数越小,最终完全消失。油滴体积中值粒径也随消油剂使用量的增加逐渐减小。     

基于MERIS影像的洪泽湖叶绿素a浓度时空变化规律分析

叶绿素a(Chl-a)浓度是衡量藻类生物量及评价水体营养状态的重要指标.基于洪泽湖2016年7月、2016年12月共49个实测水质参数与同步光谱数据,验证了5种可应用于MERIS/OLCI数据的Chl-a遥感估算模型(包括波段比值模型、三波段模型、FLH模型、MCI模型以及UMOC模型)在洪泽湖水域的适用性.结果表明,UMOC模型是最适用于洪泽湖水域的Chl-a浓度估算模型,其平均相对误差为32.30%,低于波段比值模型的75.17%,三波段模型的62.44%,FLH模型的45.87%和MCI模型的56.95%.进而利用UMOC模型,结合MERIS数据,获取了洪泽湖2002~2012年Chl-a浓度遥感估算产品,并分析了洪泽湖Chl-a浓度的时空变化规律.洪泽湖Chl-a浓度具有明显的时空差异性.依据水体像元长时间序列月平均Chl-a浓度的差异,将洪泽湖水体分为了区域A、区域B和区域C这3种类型.区域B和区域C水体无明显的变化趋势,区域A则显著增加.与气象因子的相关性分析表明,区域B和区域C年平均Chl-a的波动主要受年降水量的影响,反映了该2个区域Chl-a浓度的变化主要受湖流强度的控制,区域A年平均Chl-a浓度的变化与年平均风速呈显著负相关性,风速下降的气候大背景可能会加重这一区域的富营养化程度,威胁南水北调的水质安全.此外,在汛期(7~9月)洪泽湖水体Chl-a浓度与离淮河入湖口的距离呈显著的正相关关系,证明了这一时期淮河对洪泽湖藻类浓度具有明显的抑制作用.