高放废液化学成分分析

概述了高放废液中25种阳离子、5种阴离子以及总蒸残物、总氧化物、密度和游离酸的分析方法。对核燃料后处理高放废液进行取样分析,其主要化学成分采用两种以上不同原理的方法作对比测定,结果相互符合情况良好,为高放废液处理处置研究设计,提供了完整、准确的基础数据。     

A novel anions and cations co-doped strategy for developing high-performance cobalt-free cathode for intermediate-temperature proton-conducting solid oxide fuel cells

The sluggish activity of cathode at intermediate-temperature limits commercialization of proton-conducting solid oxide fuel cells (H-SOFCs). In this investigation, a novel cathode of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 was successfully developed by co-doping of anion F and cations Ca, Sn, Y. We studied the effect of F⁻-doping on phase structure, electrical conductivity and electrochemical properties of the cell. Compared with Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ, F⁻-doped Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ exhibited higher conductivity. Composite cathode consisting of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 and Sm_0.2Ce_0.8O_2−δ was applied in H-SOFCs with BaZr_0.1Ce_0.7Y_0.2O_3−δ electrolyte which achieves an encouraging performance with the maximum power density of 1050 mW cm⁻² and polarization resistance of 0.04 Ω cm² at 700 °C. The result of First-principles calculations based on spin-polarized Density Functional Theory shows that doping of F⁻ reduces the activation energy required for migration of oxygen ions. These results demonstrate that the anions and cations co-doped strategy can provide a new horizon for the cathode in H-SOFCs.     

Impacts of anions on the electrochemical oxygen reduction reaction activity and stability of Pt/C in alkaline electrolyte

Pt is the benchmark oxygen reduction reaction (ORR) catalyst for the anion exchange membrane fuel cells. In this paper, we have done systematic studies on the influence of anions (F⁻, Cl⁻, Br⁻, I⁻, CO₃²⁻, SO₄²⁻, SO₃²⁻ and S²⁻) to the ORR activity and durability of Pt/C in alkaline condition. It was found that the anions have less impact to Pt/C in alkaline than in acid. I⁻, SO₃²⁻, and S²⁻ have the poisoning effect and the other anions do not influence the ORR activity significantly. In the accelerating durability test, SO₃²⁻ and S²⁻ promote the degradation of the Pt/C catalysts. It was found that the impacts of anions are relative to the standard reduction potential of the anions. The anions with low potential have poisoning impact to the activity and durability of Pt/C. This study provides fundamental understandings of the impacts of anions on Pt/C, which may give insights in design of anion exchange membrane fuel cells.     

The effect of various cations/anions for MgH2 hydrolysis reaction

MgH2 is regarded as a potential hydrolysis material for the hydrogen generation due to its high theoretical hydrogen yield,abundant source on earth and environmentally friendly hydrolysates.However,the quickly formed passive magnesium hydroxide layer on the surface of MgH2 will hinder its further hydrolysis reaction,leading to sluggish reaction kinetics and low H2 yield.In this paper,we explore the improvement of different anions and cations in solutions for the hydrolysis of MgH2.It is found that the cations in the solution promote the reaction rate of MgH2 hydrolysis through the hydrolysate-induced growth effect,among which the fastest hydrogen yield can get 1664 mL/g within a few minutes in the Fe2(SO4)3 solution.As for the anions,it enables different microstructures of the Mg(OH)2 hydrolysate which give rise to enhanced water utilization.Specially,for the mixed 0.5 M MgCl2 + 0.05 M MgSO4 solution,the water utilization rate attains the optimum value of 51.3 ％,much higher than that of the single MgCl2 or MgSO4 solutions.These findings are of great significance for the application of MgH2 hydrolysis as hydrogen generation.     

Influence of coexisting substances on the photodegradation behaviors of 17α-ethinylestradiol （EE2） in the UV/H2O2 process

The batch photodegradation reactor was used to investigate the influence of the common coexisting substances in wastewater,such as H+,anions (HCO3-,Cl-and NO3-) and organic compounds (methanol and bisphenol A),on the photodegradation behaviors of EE2 in the UV/H2O2 process.The results indicated that the addition of coexisting substances can influence the photodegradation behaviors of EE2 and it also follows the first-order kinetics.The acidic (pH 2-4) and alkaline (pH 10-12) medium benefit the photodegradation of EE2,but the photodegradation rate constant of EE2 keeps almost constant in the pH value of 4-10.The addition of anions,such as HCO3-,Cl-and NO3-,can inhibit the photodegradation of EE2,and the rate constant has a negative linear relationship with the concentration of the anions.However,the reduction degrees vary with the anions kinds,and the inhibition effect of the three anions is in the order of HCO3->NO3->Cl-.Addition of 5 mg/L methanol and bisphenol A can reduce the photodegradation rate constant of EE2by 84.31% and 72%,respectively.By comparison,the retardant effect of methanol is much more evident.In the studied concentrations range,the photodegradation rate constant of EE2 is the unary quadratic function of the organic compounds concentrations.     

Photolytic reaction mechanism and impacts of coexisting substances on photodegradation of bisphenol A by Bi2WO6 in water

Bi₂WO₆ displayed great photolytic degradation efficiency to bisphenol A (BPA) under simulated solar light irradiation but its reaction mechanism and the impacts of coexisting substances on the degradation remain unclear. In present study, the reaction mechanism was investigated using DMPO spin-trapping ESR spectra and experiments with scavengers of hydroxyl radicals (OH) and holes. The results supported that hole oxidation mainly governed the photodegradation process. As a common humic substance in natural water, humic acid accelerated the degradation of BPA when its concentration was 1 mg/L, while the photodegradation was impeded with the increase of humic acid concentration in the range of 5-20 mg/L. Almost all anions, including NO₃⁻, HCO₃⁻, Cl⁻, SO₄²⁻ inhibited the degradation of BPA by Bi₂WO₆ and their inhibition effects followed the order of SO₄²⁻ > Cl⁻ > HCO₃⁻ > NO₃⁻. Cations of Na⁺, K⁺, Ca²⁺ and Mg²⁺ displayed slight suppressing effect on BPA degradation mainly due to the impact of Cl⁻ coexisting in the solution. However, Cu²⁺ hindered the BPA photodegradation heavily. Fe³⁺ and H₂O₂ affected the photodegradation in a complicated way: they suppressed or promoted the photodegradation depending on their concentrations. This could be the result of competition between photolyitc hole generated by Bi₂WO₆ and OH produced by Fe³⁺ or H₂O_2.     

油田注入水中Cl~-、SO_4~(2-)和Ca~(2 )、Mg~(2 )的快速现场测定—离子色谱法

将ZIC-ⅡA型离子色谱仪改装为双输液泵、双流路、双检测系统以后,可以同时用稀释100倍的油田注入水、双柱离子色谱(带电渗析抑制器)法测定Cl~-、SO_4~(2-),用稀释20倍的水样、单柱离子色谱法测定Ca~(2 )、Mg~(2 )。方法简便快速、准确可靠,已用于中原开采油田现场分析。     

The effects of some anions on metastable pitting of 316L stainless steel

The effects of PO₄³⁻, CrO₄²⁻, SO₄²⁻ and NO₃⁻ anions on metastable pitting of 316L stainless steel in NaCl solutions were investigated using potentiostatic and potentiodynamic polarization tests. The four anions all retard nucleation of metastable pitting. The inhibition effect decreases in the order: PO₄³⁻>CrO₄²⁻>SO₄²⁻>NO₃⁻. The propagation rates of metastable pits are also decreased by the anions tested. Both metastable pitting potential E_m and stable pitting potential E_p increase almost linearly with the increase of each anion concentration, and have very close increasing slopes.     

Influence of coexisting substances on the photodegradation behaviors of 17α-ethinylestradiol (EE2) in the UV/H2O2 process

The batch photodegradation reactor was used to investigate the influence of the common coexisting substances in wastewater,such as H +,anions(HCO3-,C1-and NO3-)and organic compounds(methanol and bisphenol A),on the photodegradation behaviors of EE2 in the UV/H2O2 process.The results indicated that the addition of coexisting substances can influence the photodegradation behaviors of EE2 and it also follows the first-order kinetics.The acidic(pH 2-4)and alkaline(pH 10-12)medium benefit the photodegradation of EE2,but the photodegradation rale constant of EE2 keeps almost constant in the pH value of 4-10.The addition of anions,such as HCO3-,Cl-and NO3-,can inhibit the photodegradation of EE2,and the rate constant has a negative linear relationship with the concentration of the anions.However,the reduction degrees vary with the anions kinds,and the inhibition effect of the three anions is in the order of HCO3-＞ NO3-＞ C1-.Addition of 5 mg/L methanol and bisphenol A can reduce the photodegradation rate constant of EE2by 84.31％ and 72％,respectively.By comparison,the retardant effect of methanol is much more evident.In the studied concentrations range,the photodegradation rate constant of EE2 is the unary quadratic function of the organic compounds concentrations.     

SiC微粉表面阴离子含量的分析研究

本文首次采用超声波水萃取-离子色谱法(超声波水萃取-IC法)对SiC微粉表面阴离子含量进行准确测量,并对测量不确定度进行评估。主要是针对氟离子、氯离子、溴离子、硝酸根离子等无机阴离子进行研究。结果表明,SiC微粉表面含有微量的无机阴离子,特别是卤素。