利用铁粉与磁粉载体流化床反应器处理染料废水

研究了铁粉和磁粉为流化床载体,对模拟染料废水和实际染料废水进行处理,取得了不同实验条件下染料废水的脱色效果。结果表明,经铁粉处理30min后,其色度去除率达98%左右,实际染料废水的CODcr去除率为56%左右;经磁粉处理30min后,其色度去除率为95%左右,实际染料废水的CODcr去除率为34%。     

Innovatively employing magnetic CuO nanosheet to activate peroxymonosulfate for the treatment of high-salinity organic wastewater

Magnetic CuO nanosheet(Mag-CuO), as a cheap, stable, efficient and easily separated peroxymonosulfate(PMS) activator, was prepared by a simple one-step precipitation method for the removal of organic compounds from salt-containing wastewater.The experiments showed that the removal efficiencies of various organic pollutants including Acid Orange 7, Methylene Blue, Rhodamine B and atrazine in a high-salinity system(0.2 mol/L Na_2SO_4) with the Mag-CuO/PMS process were 95.81%, 74.57%, 100% and 100%,respectively.Meanwhile, Mag-CuO still maintained excellent catalytic activity in other salt systems including one or more salt components(NaCl, NaNO_3, Na_2HPO_4, NaHCO_3).A radical-quenching study and electron paramagnetic resonance analysis confirmed that singlet oxygen(~1O_2) was the dominant reactive oxygen species for the oxidation of organic pollutants in high-salinity systems, which is less susceptible to hindrance by background constituents in wastewater than radicals(~·OH or SO_4~(·-)).The surface hydroxylation of the catalyst and catalytic redox cycle including Cu and Fe are responsible for the generation of~1O_2.The developed Mag-CuO catalyst shows good application prospects for the removal of organic pollutants from saline wastewater.     

Optimization of CO2 adsorption capacity and cyclical adsorption/desorption on tetraethylenepentamine-supported surface-modified hydrotalcite

The objective of this research was to investigate CO_2adsorption capacity of tetraethylenepentamine-functionalized basic-modified calcined hydrotalcite(TEPA/b-c HT)sorbents at atmospheric pressure formed under varying TEPA loading levels,temperatures,sorbent weight to total gaseous flow rate(W/F)ratios and CO_2concentrations in the influent gas.The TEPA/b-c HT sorbents were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectrometry(FT–IR),thermal gravimetric analysis(TGA),Brunauer–Emmet–Teller(BET)analysis of nitrogen(N_2)adsorption/desorption and carbon–hydrogen–nitrogen(CHN)elemental analysis.Moreover,a full 2~4factorial design with three central points at a 95%confidence interval was used to screen important factor(s)on the CO_2adsorption capacity.It revealed that85.0%variation in the capacity came from the influence of four main factors and the15.0%one was from their interactions.A face-centered central composite design response surface method(FCCCD–RSM)was then employed to optimize the condition,the maximal capacity of 5.5–6.1 mmol/g was achieved when operating with a TEPA loading level of 39%–49%(W/W),temperature of 76–90°C,W/F ratio of 1.7–2.60(g·sec)/cm~3and CO_2concentration of 27%–41%(V/V).The model fitted sufficiently the experimental data with an error range of±1.5%.From cyclical adsorption/desorption and selectivity at the optimal condition,the 40%TEPA/b-c HT still expressed its effective performance after eight cycles.     

Cu-Mg-Al催化剂上NOx储存及分解性能研究

采用共沉淀方法制备了Cu-Mg-Al水滑石混合氧化物催化剂,并对该催化剂及其前驱物进行了XRD表征.使用等温吸附、程序升温脱附以及C₃H₆程序升温表面反应分别考察了催化剂上NO_x储存及分解反应性能.结果表明,由于Cu-Mg-Al催化剂中CuO组分发挥了NO氧化作用,促进了进气中NO_x以硝酸盐方式吸附在催化剂上,因此该催化剂具有很好的NO_x储存性能;在富燃条件下,C₃H₆能够显著降低催化剂上硝酸盐的热稳定性,在160～360 ℃温度范围内,这些硝酸盐会迅速分解成气态NO_x,同时随着C₃H₆加入量的提高,C₃H₆也可以将少量气态NO_x进行还原.     

大型常压储罐在用检验技术与策略

介绍了钢制立式焊接常压储罐主要的损伤机理、主要检测标准和各种无损检测方法在储罐检验中的应用特点以及基于风险检验的理念,提出了储罐在用检验的技术方法和策略。     

脱硫类水滑石衍生复合氧化物不同方法的制备与表征

采用尿素水解法和共沉淀法制备了MgAl类水滑石,高温焙烧获得衍生复合氧化物.采用X射线衍射(XRD)、热重分析(TG-DTG)、扫描电镜(SEM)、N2-吸附/脱附和CO2程序升温脱附(CO2-TPD)等手段对所制备的复合氧化物结构特征进行表征,并研究其对SO2脱除性能的差异.结果表明,共沉淀法制备的MgAlO复合氧化物比尿素法具有更大的比表面积(148.1m2·g-1)和更多碱性位,这些特点可能促使该方法制备的复合氧化物具有更高的SO2储存容量和反应速率.采用尿素法和共沉淀法制备的MgAl水滑石复合氧化物在700℃温度下SO2吸附容量分别可达0.55g·g-1和0.79 g·g-1.     

Rates of particulate pollution deposition onto leaf surfaces: Temporal and inter-species magnetic analyses

Evaluation of health impacts arising from inhalation of pollutant particles <10 μm (PM₁₀) is an active research area. However, lack of exposure data at high spatial resolution impedes identification of causal associations between exposure and illness. Biomagnetic monitoring of PM₁₀ deposited on tree leaves may provide a means of obtaining exposure data at high spatial resolution. To calculate ambient PM₁₀ concentrations from leaf magnetic values, the relationship between the magnetic signal and total PM₁₀ mass must be quantified, and the exposure time (via magnetic deposition velocity (MV_d) calculations) known. Birches display higher MV_d (∼5 cm⁻¹) than lime trees (∼2 cm⁻¹). Leaf saturation remanence values reached ‘equilibrium’ with ambient PM₁₀ concentrations after ∼6 ‘dry’ days (<3 mm/day rainfall). Other co-located species displayed within-species consistency in MV_d; robust inter-calibration can thus be achieved, enabling magnetic PM₁₀ biomonitoring at unprecedented spatial resolution.     

环境磁学在城市污染研究中的应用

环境磁学是一门介于地学、磁学和环境科学之间的新兴边缘学科。在简要阐述环境磁学原理的基础上，集中介绍其在城市污染研究中的主要应用，包括环境污染指示、重金属污染监测、大气污染颗粒物来源及污染历史研究等。     

磁性分散固相萃取-气相色谱法测定水中氯苯类化合物

采用磁性分散固相萃取技术富集水中氯苯类化合物,用气相色谱法测定,并对萃取剂的用量、萃取时间、解吸溶剂、氯化钠加入量等条件进行优化。试验表明,方法在0．001 mg/L～2．50 mg/L 范围内,氯苯类化合物各组分线性良好,方法检出限在0．600μg/L～5．00μg/L范围内。地表水实际水样的加标回收率为83．1％～93．4％,RSD为4．8％～7．3％。     

磁铁矿区河流沉积剖面中磁化率与重金属含量相关性分析

选择广东省铁帽顶铁矿区下游一河流沉积剖面为研究对象,测定沉积物的磁化率与元素含量并作相关性分析,以考察磁铁矿床周边沉积物磁化率指标对重金属富集程度的指示作用。结果显示,该剖面中低频质量磁化率χlf为0. 87×10-6m~3/kg～184. 93×10-6m~3/kg,频率磁化率χfd为0. 5%～7%。χlf仅与Fe2O3呈现极显著的正相关关系,与其他重金属元素相关性差;χfd与Mn、Pb、Cd及REE均呈正相关;元素Cu、Zn、As等与χlf、χfd的相关性都很差。表明在该种磁化率和重金属元素含量背景值均高的特殊地区,简单地利用磁化率指标指示重金属污染水平需谨慎。