大宝山尾矿重金属形态及其潜在迁移能力分析

以大宝山槽对坑尾矿库、新鲜尾矿排放口和铁龙尾矿库3个不同区域尾矿为研究对象,采用Dold七步分级化学提取法研究了4种重金属Cu、Pb、Zn、Mn的化学形态特征,并分析了其潜在迁移能力.结果表明,Cu、Pb在所有尾矿中以原生硫化态和残渣态为主;Zn在槽对坑尾矿和新鲜尾矿中以原生硫化态和残渣态为主,在铁龙尾矿中水溶态、可交...     

两级混合稳定表流湿地处理生活污水

为了提高一级稳定表流湿地(stable surface flow wetland,SSFW)的出水水质,在单级稳定表流湿地后串联一级潜流人工湿地,构成两级混合稳定表流湿地(two steps hybrid stable surface flow wetland,TSHSSFW),研究气候变化对其净化效果的影响,并同一级潜流人工湿地(one step subsurface flow wetland,OSSFW)进行对比。研究表明,气候变化对TSHSSFW的COD和总磷去除率影响较小,去除率均在80%左右;而对氨氮和总氮的去除率影响比较大,夏季TSHSSFW的氨氮和总氮去除率分别为87.77%和77.74%,而冬季氨氮和总氮的去除率分别为54.07%和48.84%。相比单级潜流人工湿地(OSSFW),有SSFW作为前处理的潜流人工湿地对氨氮和总氮的去除率较高。     

The potential environmental risks of pharmaceuticals in Vietnamese aquatic systems: case study of antibiotics and synthetic hormones

Presently, many pharmaceuticals are listed as emerging contaminants since they are considered to be great potential threats to environmental ecosystems. These contaminants, thus, present significant research interest due to their extensive use and their physicochemical and toxicological properties. This review discusses a whole range of findings that address various aspects of the usage, occurrence, and potentially environmental risks of pharmaceuticals released from various anthropogenic sources, with emphasis on the aquatic systems in Vietnam. The published information and collected data on the usage and occurrence of antibiotics and synthetic hormone in effluents and aquatic systems of Vietnam is reported. This is followed by a potential ecological risk assessment of these pollutants. The extensive use of antibiotics and synthetic hormones in Vietnam could cause the discharge and accumulation of these contaminants in the aquatic systems and potentially poses serious risks for ecosystems. Vietnam is known to have extensively used antibiotics and synthetic hormones, so these contaminants are inevitably detected in aquatic systems. Thus, an appropriate monitoring program of these contaminants is urgently needed in order to mitigate their negative effects and protect the ecosystems.     

Occurrence of free estrogens,conjugated estrogens,and bisphenol A in fresh livestock excreta and their removal by composting in North China

An efficient pretreatment and analytical method was developed to investigate the occurrence and fate of four free estrogens (estrone (E1), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinylestradiol (EE2)), four conjugated estrogens (estrone-3-sulfate sodium salt (E1-3S), 17β-estradiol-3-sulfate sodium salt (E2-3S), estrone-3-glucuronide sodium salt (E1-3G), and 17β-estradiol-3-glucuronide sodium salt (E2-3G)), and bisphenol A (BPA) in three livestock farms raising beef cattle, cows, sheep, swine, and chickens in Qi County, which is located in North China. The results demonstrated that one cow and one beef cattle excreted 956.25–1,270.41 and 244.38–319.99 μg/day of total (free and conjugated) estrogen, respectively, primarily through feces (greater than 91 %), while swine excreted 260.09–289.99 μg/day of estrogens, primarily through urine (98–99 %). The total estrogen excreted in sheep and broiler chicken feces was calculated to be 21.64–28.67 and 4.62–5.40 μg/day, respectively. It was determined that conjugated estrogens contributed to 21.1–21.9 % of the total estrogen excreted in cow feces and more than 98 % of the total estrogen excreted in swine urine. After composting, the concentration of total estrogen decreased by 18.7–59.6 %; however, increased levels of BPA were measured. In treated compost samples, estrogens were detected at concentrations up to 74.0 ng/g, which indicates a potential risk of estrogens entering the surrounding environment.     

城市垃圾焚烧渗沥液中Ca2＋对厌氧EGSB处理效果的影响

研究了城市生活垃圾焚烧厂渗沥液中Ca2＋对厌氧颗粒污泥膨胀床反应器（EGSB）处理效果的影响,并采用静态实验方法考察了Ca2＋对厌氧颗粒污泥产甲烷活性的影响。实验结果表明,进水COD为17000mg／L的条件下,当Ca2＋浓度低于6000mg／L时,EGSB对COD去除率达93％以上;当Ca2＋浓度高于6000mg／L时,COD去除率随运行时间明显下降,并在污泥中形成大量沉淀。静态实验结果表明,废水中低浓度Ca2＋促进了厌氧颗粒污泥的产甲烷活性,但高浓度Ca2＋明显抑制了其产甲烷活性,这是导致高Ca2＋浓度条件下EGSB对COD去除率降低的主要原因。研究表明,颗粒污泥产甲烷活性恢复程度随Ca2＋浓度增加而减弱。     

施用城市污泥堆肥对土壤微生物群落结构变化的影响简

在温室条件下进行了15周的盆栽实验,考察了施用城市污泥堆肥后,土壤中养分含量的变化规律,重点研究了施用城市污泥堆肥对土壤微生物群落结构变化的影响。实验发现,污泥堆肥能改善土壤养分,有机质和氮、磷含量得到显著提高。经PCR-DGGE分析,施肥1周后土壤中细菌和真菌的群落结构均发生了较大的变化。随着施肥时间的延长,细菌在富含有机质及氮、磷等养分的土壤环境下大量生长,多样性提高,其优势菌群属于γ变形菌、α变形菌和芽单胞菌;随着有机质的不断消耗,细菌的生长活性受到抑制,最终由于养分的缺乏,细菌种群多样性呈现小幅度的降低,优势菌群变为绿弯菌门、γ变形菌亚纲和厚壁菌门。对于真菌,其多样性指数在堆肥前3周逐渐提升,在第3~12周的监测中呈现相对稳定的变化趋势,优势菌群主要为座囊菌纲和散囊菌纲。     

重金属-多氯联苯复合污染土壤同步洗脱

电子垃圾拆解区土壤具有重金属与有机物复合污染的特性,尤其以Cu、Pb、Cd和多氯联苯(PCBs)的复合污染较为突出。为了同步脱除土壤中重金属与PCBs,选用增溶物质:Tween 80、TX-100、SDBS、β-环糊精与螯合剂柠檬酸依次组合进行复合污染土壤淋洗实验,应用批量平衡震荡法研究它们对重金属(Cu、Pb、Cd)与PCBs(Aroclor 1254)的洗脱效果。通过比较洗脱效果、环境友好性等方面,得出非离子表面活性剂Tween 80与天然螯合剂柠檬酸2种淋洗剂复合最佳;进一步研究两者的淋洗先后顺序、浓度配比、洗脱时间及淋洗剂p H对污染土壤洗脱效果的影响,结果表明,在Tween 80和柠檬酸均为10 g/L、p H=6、淋洗时间12 h时淋洗效果达到最佳,对Cu、Pb、Cd及PCBs的洗脱率分别达到98.77%、55.92%、66.82%和58.01%。因此,利用Tween80和柠檬酸组合可同时有效去除土壤重金属和PCBs,是复合污染土壤淋洗修复的有效淋洗剂。     

RO浓水-废水联合培养小球藻的实验研究

为了实现微藻培养基的低成本化和废水资源化利用多重目的的耦合,对反渗透浓缩液(RO浓水)作为培养基培养小球藻(Chlorella sp.)的可行性及其影响因素进行了探讨。实验取一级、二级处理出水和消化反应上清液及3种废水与RO浓水混合液制成6种培养基培养小球藻,探究最佳培养基;在此基础上探究浓度与温度对小球藻生长的影响。结果表明,培养15 d后,3种添加了RO浓水的培养基比3种纯废水培养基更有利于小球藻的生长,其中消化反应上清液-RO浓水混合液是最佳培养基;浓水浓度0%~90%的该混合液中小球藻生物量增加315%~780%,且小球藻的生物量表现为随RO浓水浓度的增大先增加后减小的变化趋势,30%是小球藻最佳培养浓度;在10、20和30℃下,浓度0%~90%的培养基中小球藻生物量增加了140%~570%,各浓度中的小球藻均在20℃下生长最好。     

SBR快速实现短程硝化及影响因素

基于建立的序批式反应器(SBR),探索实现城市生活污水短程硝化的主要控制因素。研究结果表明,废水温度维持在(30±1)℃、p H值为7.8~8.2的条件下,采用间歇曝气的运行方式,仅驯化培养29 d,成功实现短程硝化,亚硝氮积累率为95%左右。通过对比发现,间歇曝气方式优于连续曝气方式,间歇曝气能有效地将溶解氧(DO)浓度控制在1.0mg/L以下,从而有利于进行短程硝化反应。此外,温度和p H可以影响亚硝氮的积累效果;当温度在25~35℃、进水p H为7.8~8.2时,亚硝氮的积累情况较好,积累率在91%以上。     

Satellite monitoring for carbon monoxide and particulate matter during forest fire episodes in Northern Thailand

This study explored the use of satellite data to monitor carbon monoxide (CO) and particulate matter (PM) in Northern Thailand during the dry season when forest fires are known to be an important cause of air pollution. Satellite data, including Measurement of Pollution in the Troposphere (MOPITT) CO, Moderate Resolution Imaging Spectroradiometer aerosol optical depth (MODIS AOD), and MODIS fire hotspots, were analyzed with air pollution data measured at nine automatic air quality monitoring stations in the study area for February–April months of 2008–2010. The correlation analysis showed that daily CO and PM with size below 10 μm (PM₁₀) were associated with the forest fire hotspot counts, especially in the rural areas with the maximum correlation coefficient (R) of 0.59 for CO and 0.65 for PM₁₀. The correlations between MODIS AOD and PM₁₀, between MOPITT CO and CO, and between MODIS AOD and MOPITT CO were also analyzed, confirming the association between these variables. Two forest fire episodes were selected, and the dispersion of pollution plumes was studied using the MOPITT CO total column and MODIS AOD data, together with the surface wind vectors. The results showed consistency between the plume dispersion, locations of dense hotspots, ground monitoring data, and prevalent winds. The satellite data were shown to be useful in monitoring the regional transport of forest fire plumes.