Ca(OH)2解吸并固定混合吸收液中CO2的实验研究

CO₂化学吸收法分离纯度高,技术成熟,但能耗过高及成本是困扰该技术发展的瓶颈.在常压条件下对利用Ca（OH）₂直接矿物碳酸化固定MDEA/PZ混合吸收富液中CO₂进行了一系列实验研究,考察了吸收液负荷、Ca（OH）₂投加量、pH、温度及搅拌速率等因素对解吸率的影响,并利用动态吸收-解吸循环实验研究了其CO₂吸收性能和循环使用稳定性,最后对碳酸化反应产物进行了XRD、TEM分析.结果表明,在常压条件下,Ca（OH）₂可以通过液相直接矿物碳酸化对CO₂进行直接固定,并实现吸收富液的再生;随着负荷的升高及Ca（OH）₂投加量、pH、搅拌速率的增大,解吸率随之增加;随着溶液温度升高,解吸率下降;经过5次动态吸收-解吸循环实验后CO₂吸收量可以达到并保持在0.57 mol·L^-1,显示出了良好的循环稳定性.     

纳米材料的表面修饰和表征技术

介绍了纳米粒子的表面改性及表面修饰的目的和方法,并对纳米微粒表面改性的各种方法原理及其特点进行了归纳;对纳米材料的常用分析和表征技术做了概括,主要从纳米颗粒的粒度测量、纳米微粒的表面分析、成分分析等方面进行了简要阐述;对纳米材料的表面修饰和表征技术的发展进行了展望。     

有机钙孔隙结构与脱硫性能研究

在定碳炉上对有机钙进行煅烧试验,利用氮吸附仪测定样品的微观孔隙结构,采用智能定硫仪对有机钙进行了脱硫实验研究.结果表明.900℃下煅烧.醋酸钙镁的比表面积高达46.6 m2/g,大约为普通石灰石比表面积的4倍.醋酸钙比表面积主要分布在孔径小于5 nm的微孔和中孔,醋酸钙镁比表面积主要集中在孔径为5 nm左右的中孔.醋酸钙的烧结主要发生在微孔和中孔,醋酸钙镁的烧结发生在整个孔径分布区域,有机钙表现出良好的抗烧结特性.1 000℃下按钙硫比为1添加钙基,有机钙的脱硫效率为68.28%-75.55%.比普通石灰石高1倍以上.煅烧形成的良好孔隙结构使得有机钙具有较高的脱硫效果.     

氢氧化镁对水体内源磷释放的控制作用

本研究首先通过批量实验考察了氢氧化镁对水中磷酸盐的吸附性能,再通过底泥模拟释放实验考察了氢氧化镁覆盖和添加控制底泥中磷向上覆水体释放的效果及机制.结果表明,氢氧化镁对水中磷酸盐具有良好的吸附能力,其投加量的增加有利于水中磷酸盐被其所吸附去除,与Langmuir模型相比,其对水中磷酸盐的等温吸附行为更适合采用Freundlich和Dubinin-Radushkevitch(D-R)模型加以描述.氢氧化镁覆盖可以有效地控制底泥中磷向上覆水体的释放,使得上覆水中SRP浓度处于较低的水平,即使覆盖层的结构完整性受到扰动破坏而导致覆盖材料与表层底泥的混合,氢氧化镁仍然可以有效地控制底泥中磷向上覆水体的释放.氢氧化镁覆盖和添加均可以有效地降低最上层(0～10 mm)底泥间隙水中SRP的浓度,这对于其覆盖和添加有效控制底泥中磷向上覆水体的释放是至关重要的.人工合成的氢氧化镁对水中磷酸盐的吸附性能优于商业购买的氢氧化镁,前者控制水体内源磷向上覆水体释放的效果也优于后者.以上结果显示,氢氧化镁是一种有希望用于控制水体底泥内源磷释放的活性覆盖和改良材料.     

Experimental investigation on extinguishing performance of a novel nanocomposite for gaseous fires

A novel nanocomposite was synthesized by incorporating three different types of flame-retardants and its extinguishing performance was tested for gaseous fires. The nanocomposite consists of the inorganic magnesium hydroxide (MH) nanoparticles as the dominant component, the nitrogen-based melamine cyanurate (MCA), and the phosphorus-based ODOPB. The wet mixing, dry mixing, and ultrasonic agitation were employed in the preparation process to enhance the homogeneity of the nanocomposite. The prepared powders were characterized using a series of analytical instruments including X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravity analyzer (TGA), and differential scanning calorimeter (DSC). The efficiency of various samples in extinguishing gaseous fires was investigated in a lab-scale extinguishing system. The fire extinguishing tests indicated that the nanocomposite is considerably more effective in fire extinguishing than other powders in terms of extinction time and agent mass consumed. The fire extinction time of nanocomposite was 45.2% shorter than that of commercial ABC-MAP powder. Furthermore, the consumed amount of nanocomposite was 63.2% less than that of commercial powder. In addition, the order of extinguishing mass concentrations was as follows: the novel nanocomposite (103.7 g/m³) < MH/MCA (148.1 g/m³) < MH/ODOPB (155.6 g/m³) < MH (170.4 g/m³) < commercial ABC powder (281.5 g/m³) < MCA/ODOPB (384.1 g/m³). The fire suppression mechanisms of the nanocomposite were also discussed. It was inferred that the extinguishing mechanism of nanocomposite comprised of simultaneous chemical and physical inhibition actions involving chemical inhibition action, cooling action, and asphyxiation action. This study provides a promising attempt to gain benefits from the striking features of nanotechnology and flame-retardants in extinguishing gaseous fires.     

Experimental and DFT insights into nitrogen and sulfur co-doped carbon nanotubes for effective desulfurization of liquid phases: Equilibrium & kinetic study

• Synthesis of NS-CNTS is used in a high desulfurization performance. • Synthesizing NS-CNT is considered as a novel adsorbent from low-cost precursors. • A high sulfur removal capacity for NS-CNT is attained compared with recent works. Herein, nitrogen and sulfur co-doped carbon nanotubes (NS-CNT) adsorbents were synthesized via the chemical vapor deposition technique at 1000°C by employing the camphor, urea and sulfur trioxide pyridine. In this study, desulfurization of two types of mercaptans (dibenzothiophene (DBT) and tertiary butyl mercaptan (TBM) as nonlinear and linear forms of mercaptan) was studied. In this regard, a maximum capacity of NS-CNT was obtained as 106.9 and 79.4 mg/g and also the removal efficiencies of 98.6% and 88.3% were achieved after 4 h at 298K and 0.9 g of NS-CNT for DBT and TBM, respectively. Characterization of the NS-CNTs was carried out through exploiting scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and elemental analysis (CHN). The isotherm equilibrium data could be ascribed to the Freundlich nonlinear regression form and the kinetic data was fitted by nonlinear form of the pseudo second order model. The negative values of ΔS⁰, ΔH⁰ and ΔG⁰ specify that the adsorption of both types of mercaptans was a natural exothermic process with a reduced entropy. Maintenance of more than 96% of the adsorption capacity even after nine cycles suggest the NS-CNT as a superior adsorbent for mercaptans removal in the industry. Density functional theory (DFT) calculations were also performed to peruse the effects of S/N co-doping and carbon monovacancy defects in CNTs toward the adsorption of DBT and TBM.     

利用Al（OH）3凝胶废渣生产聚合氯化铝（PAC）

介绍了对处理铝材加工含Ａｌ＾３＋的酸性废液过程中产生的二次污染物Ａｌ（ＯＨ）３凝胶废渣的应用。     

异烟酸——吡唑啉酮光度法测定水中氰化物方法的探讨

在用异烟酸-吡唑啉酮光度法测定水中氰化物时，用氢氧化钠代替，N，N-二甲基甲酰胺作为溶剂，配制吡唑啉酮作试验，结果表明，改进法代替标准法是可行的，且改进后的显色剂较原显色剂稳定。     

Filtration improvement of zinc sludge by using unconventional alkalization sequence

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板料拉深成形润滑模式研究

对板料拉深成形中的两种常用润滑模式进行了研究 ,并按膜厚尺寸对这两种润滑模式进行分类。在分析其润滑机理的基础上提出一种复合润滑模式 ,这种润滑模式使液体润滑剂和微米级粉体两种润滑介质的优势互相补充。实验证明 ,具有很好的润滑效果。另外 ,提出纳米微粒添加剂在板料润滑中的应用前景