Multifunctional metal-organic frameworks in oil spills and associated organic pollutant remediation

The release of toxic organic compounds into the environment in an event of oil spillage is a global menace due to the potential impacts on the ecosystem. Several approaches have been employed for oil spills clean-up, with adsorption technique proven to be more promising for the total reclamation of a polluted site. Of the several adsorbents so far reported, adsorbent-based porous materials have gained attention for the reduction/total removal of different compounds in environmental remediation applications. The superior potential of mesoporous materials based on metal–organic frameworks (MOFs) against conventional adsorbents is due to their intriguing and enhanced properties. Therefore, this review presents recent development in MOF composites; methods of preparation; and their practical applications towards remediating oil spill, organic pollutants, and toxic gases in different environmental media, as well as potential materials in the possible deployment in reclaiming the polluted Niger Delta due to unabated oil spillage and gas flaring.

     

铁炭微电解-Fe2+/K2S2O8降解甲基橙

针对偶氮类有机物废水具有色度大,难降解的特点,以对二甲基氨基偶氮苯磺酸钠(甲基橙)为模拟研究对象,对水体系中铁炭微电解-Fe2+/K2S2O8降解甲基橙的方法进行了研究。通过正交实验确定出该方法各因素的影响程度,进一步通过单因素影响实验确定该方法的最佳条件是:铁炭微电解填料、FeSO4和K2S2O8投加量分别为300 g/L、1.3mmol/L和0.7 mmol/L,初始pH值为7.0。在最佳条件下,甲基橙COD和色度去除率分别能达到64.7%和68.2%。     

典型重化工园区产能增加对城市O3浓度影响

重化工园区产能增加将加大园区挥发性有机物(VOCs)排放总量,进而影响本地及周边城市O₃浓度.珠三角实施的“VOCs倍量替代”政策可在城市层面有效抵消重化工园区VOCs排放量上升的不利影响,还可进一步降低城市VOCs排放总量,实现区域O₃浓度下降.以惠州市某大型重化工园区为例,编制2018—2020年重化工园区产能增加以及实施“VOCs倍量替代”政策的污染物排放清单,基于WRF-CMAQ模拟体系,定量分析多种情景下园区在基准年(2017年)7—10月气象条件下对惠州市及周边城市O₃影响程度.研究表明,重化工园区增产而增加VOCs排放4101.96 t,“VOCs倍量替代”综合减排余量7298.97 t;“VOCs倍量替代”政策可有效解决重化工园区增产对O₃浓度的不利影响,其中7月最为显著,主导东南风下风向的深圳市及惠州市大亚湾管委会站点O₃浓度降幅最大,分别为3.9μg·m^-3(下降率2.97%)和7μg·m^-3(下降率4.95%);...     

固定污染源废气中磷酸雾测定方法研究

目前,对固定污染源废气中磷酸雾的检测并无统一的方法,相关含磷污染物的控制指标主要是磷化氢、单质磷以及五氧化二磷。在调研国内外分析方法及相关文献的基础上,通过对几种典型含磷污染源的实样测试,提出了固定污染源废气中磷酸雾的检测方法。结果表明,使用石英滤筒捕集固定污染源废气中的磷酸雾,采样效率可达98%以上。捕集到的总磷酸雾不仅包含磷酸,还包含磷酸盐以及含磷氧化物等,是一项综合指标。该指标能够反映含磷污染物的排放特征,可为未来此类污染物的排放控制提供依据。     

化学镀镍废水中磷和镍的同步去除

为有效去除化学镀镍废水中的主要污染物质磷与镍,采用H₂O₂氧化、芬顿氧化、铁碳处理、次氯酸钙氧化4种方法进行同步除磷去镍效果研究。结果表明：H₂O₂可有效去除废水中的镍,但单独氧化除磷效果不佳,芬顿氧化可增强其对磷的去除率,在一定的反应时间下达到良好的同步除磷去镍的效果;铁碳处理可基本达到同步除磷去镍的效果,但反应时间长;次氯酸钙可快速去除水中的磷与镍,是一种理想的同步除磷去镍试剂。通过分析可知,4种方法对化学镀镍废水中的磷与镍的去除均具有一定效果,且各具优势。研究为实现化学镀镍废水中同步除磷去镍的目标提供参考。     

面向寒冷地区城镇污水处理厂提标改造的ASM模拟优化及其应用

为指导和支撑寒冷地区城镇污水厂升级改造,采用GPS-X软件的ASM1模型,构建了河北某污水处理厂CASS工艺提标改造模型,分别对污泥回流比(R_S)、反应区体积比(R_V)、充水比(λ)、运行周期(T)和不同水温的CASS运行方案等进行了数值模拟优化;同时,综合模拟结果,提出了升级改造技术方案,并予以实施。冬季运行结果表明,改造后的CASS工艺出水指标COD、氨氮和TN的浓度分别为(23.23±2.76)、(1.16±0.76)、(9.83±1.4) mg·L⁻¹,能够稳定达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标准。     

改性莴笋叶渣净化空气中甲醛

通过对莴笋叶2种处理吸附甲醛,得出简便高效的碱热烫处理,并采用二次正交旋转回归组合对其优化,得出煮沸时间25 min、水浴温度80℃、水浴时间2.5 h,莴笋叶渣对甲醛吸附率可达37.05%,实测值36.4%,二者吻合.通过与活性炭、硅藻纯吸附效果比较,优化处理莴笋叶渣与硅藻纯吸附效果相当,均优于活性炭.电镜观测知优化莴笋叶渣与活性炭、硅藻纯均具粗糙、皱褶、疏松结构,傅里叶红外光谱分析出—C=C—基团在甲醛吸附中起主要作用.     

渗透坝对丹江口库湾水体氮磷负荷削减的应用

为了解决丹江口库湾局部水体富营养化问题,以水体氮、磷削减负荷为目标,利用渗透坝对库湾水体进行净化,促进库湾水体流动循环。该技术以渗透坝为主体,包括提水风车、生态塘和布水系统,设计进水负荷为16.7 L·min-1。结果表明,三级坝系统对水体中TP、TN、NH4+-N和NO3--N负荷平均削减率分别为48.3%、46.8%、56.9% 和52.1%,进水中NO3--N负荷量的标准偏差较大,为2.01,出水氮磷负荷量波动比较稳定,TN削减负荷量标准偏差较大,为1.08。TSS出水负荷量出现升高现象,分析表明TSS主要成分为固体颗粒物质。该技术的应用对库湾水体氮磷负荷具有显著的削减作用,同时能够增强库湾水体的流动循环,可有效防止水体富营养化现象发生。     

蟛蜞菊水提液对水华蓝藻——卵孢金孢藻的化感作用研究

为探究陆生植物对水华蓝藻的化感作用,本文采用不同浓度的蟛蜞菊(Wedelia chinensis)水提液对卵孢金孢藻(Chrysosporum ovalisporum)进行了为期6 d的室内培养试验,结果发现:蟛蜞菊水提液对卵孢金孢藻的化感作用总体上呈"低促高抑";当蟛蜞菊水提液浓度大于6 g·L~(-1)时,将显著降低卵孢金孢藻光合作用有效量子效率(YⅡ)、最大量子产量(Fv/Fm)、叶绿素a(Chla)含量和藻细胞生物量(P0.01);当浓度大于8 g·L~(-1)时,单位藻细胞内的超氧化物歧化酶(SOD)、谷胱甘肽-S-转移酶(GST)活性显著高于对照组(P0.05),表明蓝藻细胞受到较强的胁迫作用;透射电镜观察结果表明:高浓度蟛蜞菊水提液会破坏细胞膜,导致藻细胞内的类囊体、羧基体、气囊等超微结构受损,并最终导致藻细胞溶解、藻丝断裂和死亡。此外,本文利用Logisitic模型研究了蟛蜞菊水提液对卵孢金孢藻的半效应浓度(EC50),其24 h、48 h、72 h和144 h的EC50分别为:3.78 g·L~(-1)、4.47 g·L~(-1)、4.72 g·L~(-1)和6.55 g·L~(-1)。本研究为中国湖泊蓝藻水华的防治增添了基础数据和新的技术思路。     

The health hazards of potentially toxic metals in the daily diets of adults and children from a mining and smelting region (Hezhang County) in southwestern China

Toxic metals accumulated in the human body are predominantly absorbed by the digestive tract in non-occupationally exposed populations. In the current study, we collected plowed soil samples, and investigated the varied food compositions in a mining and smelting area in southwestern China, to measure the concentrations of ten potentially toxic metals—As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sr, and Zn. We collected information on the daily intakes of these metals to assess the health risks associated with their exposure among children and adults. The urine concentrations of the metals were also measured to obtain data on the amounts present in the body. The results showed that the hazard indexes (HIs) of As, Ba, Cd, Cr, Ni, Pb, and Sr were all larger than 1, for both adults and children; the Zn and Cu values were comparatively higher in children. The intake of staple foods of the region posed the greatest health risk, while drinking water only posed risks clearly associated with As exposure. The urine samples of local residents contained larger amounts of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn, confirming the hazards in the health risk assessment. Obvious differences in the urine metal concentrations between men and women were confirmed. In conclusion, higher concentrations of metals in the surface soil and rain water were the predominant cause of elevated exposure through home-grown crops and produce to accumulate in local residents’ bodies.