羟基镧改性树脂的制备及其对氟离子的吸附

采用共沉淀法制备了羟基镧改性D101树脂复合吸附剂,利用扫描电子显微镜及能谱分析仪、红外光谱和比表面积分析仪对复合吸附剂的结构和形貌进行了分析,并对水溶液中氟离子(F~-)进行吸附研究,探讨了该复合吸附剂对F~-的吸附特性,并将其应用于实际含氟废水的处理。结果表明:在25℃、F~-初始质量浓度为10 mg/L、吸附剂量为0.4 g/L、溶液pH=5时,F~-吸附量最大,为24.45 mg/g;复合吸附剂对F~-的吸附动力学数据遵循拟二级动力学反应模型,整个吸附反应为多级控制过程;复合吸附剂对F~-的吸附符合Langmuir吸附等温模型,在10℃、25℃和35℃下,吉布斯自由能(ΔGo)均小于0,焓变(ΔHo)大于0,熵变(ΔSo)大于0,表明该吸附反应为自发吸热熵增过程。采用羟基镧改性D101树脂复合吸附剂可以有效去除实际含氟废水中的氟化物,实现废水的达标排放。     

某尾矿库泄漏次生突发水环境锑污染事件的应急处置

2015年11月,由于E省某尾矿库2^#排水井拱圈盖板破裂,导致大量尾矿浆从涵洞口喷出,进入A河,并沿河顺流进入B河、C江,使得C江沿线部分水厂停水。在此次突发事件中,E、F、G省采用断污染源、截污、清淤、投药降污、水库调蓄、水利稀释、饮水保障等工程手段,经过71 d的应急处置,受污染河道全线达标。通过现场试验,确定了0~2 ℃条件下应对锑污染的河道投药降污技术。在硫化钠、聚合硫酸铁投药技术的基础上,通过硫化钠+聚合硫酸铁(硫化钠法)混凝沉降法,使得锑去除率分别从12.3%、36.8%提高到95.1%。     

淋洗-废水解毒工艺处理氰化物污染土壤

综合分析当前氰化物污染土壤处理方法的特点,提出异位筑堆淋洗-废水解毒工艺处理氰化物污染土壤的技术方法。采用装柱淋洗-废水解毒工艺对天津某氰化物污染土壤开展实验研究,结果表明：采用pH值10~11的石灰水,控制淋洗强度60 L·（m2·h）-1,淋洗时间22 d时,土壤中总氰化物平均含量从47.91 mg·kg-1降低至3.73 mg·kg-1,达到土壤污染风险筛选指导值中住宅类用地小于9.86 mg·kg-1的要求;采用碱性氯氧化法对淋洗产生的废水进行了处理,在局部氧化阶段反应pH值12.5,漂白粉用量3.5 g·L-1,反应时间1.5 h;完全氧化阶段漂白粉用量4.5 g·L-1,反应pH值8.0,反应时间1.0 h的条件下,废水中总氰化物含量可由83.9 mg·L-1降低至0.33 mg·L-1,达到GB 8978-1996中小于0.5 mg·L-1要求。研究结果初步表明,采用异位筑堆淋洗-废水解毒工艺处理氰化物污染土壤具有实际应用可行性。     

Enhancing sensitivity of microbial fuel cell sensors for low concentration biodegradable organic matter detection: Regulation of substrate concentration, anode area and external resistance

The relatively low sensitivity is an important reason for restricting the microbial fuel cell (MFC) sensors’ application in low concentration biodegradable organic matter (BOM) detection. The startup parameters, including substrate concentration, anode area and external resistance, were regulated to enhance the sensitivity of MFC sensors. The results demonstrated that both the substrate concentration and anode area were positively correlated with the sensitivity of MFC sensors, and an external resistance of 210 Ω was found to be optimal in terms of sensitivity of MFC sensors. Optimized MFC sensors had lower detection limit (1 mg/L) and higher sensitivity (Slope value of the linear regression curve was 1.02), which effectively overcome the limitation of low concentration BOM detection. The essential reason is that optimized MFC sensors had higher coulombic efficiency, which was beneficial to improve the sensitivity of MFC sensors. The main impact of the substrate concentration and anode area was to regulate the proportion between electrogens and nonelectrogens, biomass and living cells of the anode biofilm. The external resistance mainly affected the morphology structure and the proportion of living cells of the anode. This study demonstrated an effective way to improve the sensitivity of MFC sensors for low concentration BOM detection.     

基于集成学习的改进灰色瓦斯浓度序列预测

为有效提高煤矿瓦斯浓度动态预测精度,基于微分方程理论和最小二乘法,从灰色预测模型静态灰色作用量出发,优化灰色作用量,推导幂指数型灰色作用量的改进灰色瓦斯浓度预测算法,推导基于集成学习不同灰色作用量幂指数型灰色瓦斯预测模型,进而研究吉林八连城长期和短期瓦斯浓度监控数据预测精度.结果表明:瓦斯浓度时间序列近似线性时,基于集...     

筑坝蓄水过程对高原湿地拉市海湖滨植被的影响

选择滇西北高原湿地拉市海湿地湖滨作为研究区域,采用传统的野外植被调查和定位观测相结合的方法对该区域植被特征、分布格局及受筑坝蓄水过程的影响进行分析和研究。结果表明：研究区共有维管束植物97种,隶属于34科76属,可划分为2个植被类型,3个植被亚型,10个群落类型;拉市海筑坝蓄水过程对研究区植物群落分布格局和组成结构产生明显的影响,草甸植被、沼泽植被和湖泊水生植被占研究区面积比重分别从2009年的4454%、1869%和3676%变为2011年的3259%、1368%和5359%,草甸植被和沼泽植被的面积不断缩小,湖泊水生植被面积持续扩大,狗牙根〖WTBX〗（Cynodon dactylon）逐渐取代蒿属（Artemisia）〖WTBZ〗植物在草甸植被中的优势地位,而李氏禾群落（Com.Leersia hexandra）成为了研究区湖滨带水生植物的主要成分;研究区植被在筑坝蓄水过程的胁迫下呈草甸植被（杂草群落、狗牙根群落Com.Cynodon dactylon）,沼泽植被（葱状灯心草群落Com.Juncus allioides、菖蒲群落Com.Acorus calamus、刚毛荸荠群落Com.Eleocharis vallcculosa、水蓼群落Com.Polygonum hydropiper）,湖泊水生植被（李氏禾群落Com.Leersia hexandra、两栖蓼群落Com.Polygonum amphibium、满江红群落Com.Azolla imbricata、鸭子草 穗状狐尾藻群落Com.Potamogeton distinctus Myriophyllum spicatum）的演替格局;拉市海植物群落受筑坝蓄水过程影响发生的逆向演替,从理论上延长了湿地的服务年限,但蓄水过程对鱼类的生存和繁殖、越冬水禽的生境及整个湿地生态系统结构和功能的影响是长期的,还有待深入的研究     

基于矿井通风三维仿真系统的多级机站通风系统优化与应用

为分析总结多级机站通风方式实际应用中存在的影响通风效果的共性问题,以某大型机械化铁矿通风系统为研究对象,应用能适用多台风机串并联运行的"矿井通风三维仿真系统(简称3DVS)"软件进行应用研究。结果表明,3DVS软件可以快速地实现多级机站通风系统中不同型号多台风机联合作业下的风机选型。采用安装在运输巷道两侧的硐室型风机机站技术能有效解决大压差、大断面运输巷道不安装风门、不掘绕道设置风机机站的关键问题,实现风流有效分配,且具有较好的灵活性,其成功应用,不但为多级机站通风方式的应用提供了技术和经验支持,而且增强了多级机站通风方式的适应性和稳定性,可以减少风机机站维护工作量,不影响行人和运输,促进多级机站技术发展与推广。     

基于熵权的防灾工程项目融资方式评价决策模型

对防灾工程项目融资方式的评价决策问题进行了讨论,分析了项目评价决策中的客观信息和评价决策者个人经验的主观信息,提出在量化打分的基础上整合为一个复合权重集,建立了基于熵权的防灾工程项目融资方式评价模型和方法。通过实例计算,结果表明该模型在融资方式的评价、优劣排序和选择方面具有较强的可行性和可操作性。     

Effects of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the swimming behavior,population growth and reproduction of the rotifer Brachionus plicatilis

Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE(BDE-47)and deca-BDE(BDE-209) were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that:(1) The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS(Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations.(2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.(3) Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females(OF/NOF), the ratio of mictic females/amictic females(MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.     

海河流域近500年大旱大涝时空特征及趋势预测

作者选择记录年代较长、系统性较好、分布均匀的十八个站作为海河流域的代表站，分别统计了近５００年及每世纪、各年代大旱大涝的出现频数，探讨了它的时空分布特征。还根据天文、气候背景制作了１９９５～２０１０年旱涝趋势预测。研究表明，１９９５～２０１０年海河流域大致处于太阳活动２３周的黑子低值位相和第２４周的高值位相之间，同时又处在太阳黑子世纪周期的下降段。从全国旱涝型指数和北京地区旱涝等级变化曲线看，目前海河流域正处于持续下降期，未来将进入湿润多雨阶段