H_2O_2氧化-重量法测定氯乙酰氯生产过程产生的废酸液中的SO_4~(2-)

研究了在氯乙酰氯生产过程中产生的废酸液中的SO42-浓度的测定方法。在酸性(pH≤5.0)介质中,用过量H2O2作为氧化剂,将S2O32-和SO32-氧化为SO42-后,BaCl2沉淀重量法测总硫,根据c(SO42-)=c(总SO42-)-c(SO32-)-2c(S2O32-)关系式,计算法获得SO42-准确含量。该方法简便、可靠,对用氯化法工艺由氯乙酸生产氯乙酰氯过程中由直接水洗吸收法处理尾气所得废酸液及同类废液的分析和废液再利用,具有重要的参考意义和应用价值。     

Efficient removal of organic pollutant by activation of persulfate with magnetic Co3O4/CoFe2O4 composite

In this study, magnetic spinel Co₃O₄/CoFe₂O₄ composite were synthesized by the mechanical mixing of both powdered pristine samples. Then the catalyst was characterized by TEM, SEM, XRD, BET, XPS and VSM measurement. Next, Co₃O₄/CoFe₂O₄ composite was applied to degrade rhodamine B (RhB) in water by activating persulfate. Results showed that Co₃O₄/CoFe₂O₄ composite exhibited high efficiency for removal of RhB, and 95.59% of it could be degraded in 45 min. Besides, the effects of parameters, such as initial pH, PS dosage, Co₃O₄/CoFe₂O₄ composite dosage, initial concentration of RhB and temperture were studied. Also, the effects of coexisting anions on RhB degradation were observed and explained. Furthermore, we conducted the quenching experiment and found that sulfate radical and hydroxyl radicals were the main active radicals in the degradation process. Finally, recycle experiments proved that Co₃O₄/CoFe₂O₄ had a good stability for RhB degradation. In short, Co₃O₄/CoFe₂O₄ composite is a promising catalyst for wastewater treatment.     

Development of an Amperometric Microbial Biosensor Based on Thiobacillus thioparus Cells for Sulfide and Its Application to Detection of Sulfate‐Reducing Bacteria

This paper describes a novel electrochemical microbial biosensor based on Thiobacillus thioparus cells for sulfide detection. The morphology and electrochemical properties of the proposed biosensor were characterized by SEM and cyclic voltammetry, respectively. Working conditions of the microbial biosensor were optimized to obtain good electrochemical performances. Under the optimum conditions, analytical performances were evaluated, and the results suggested that the microbial biosensor could be used for selective detection of sulfide. The microbial biosensor was then successfully applied in detection of sulfate‐reducing bacteria by oxidizing its characteristic metabolite, sulfide, which was accumulated in culture media during bacterial growth.     

Facile One‐pot Synthesis of Substituted Dihydropyrrol‐2‐ones via Four‐component Domino Reaction of Amines,Dialkyl Acetylenedicarboxylates and Formaldehyde

A mild and efficient method for the one‐pot synthesis of substituted dihydropyrrol‐2‐one derivatives is described via four‐component domino reaction of amines, dialkyl acetylenedicarboxyaltes and formaldehyde in the presence of 1‐methyl‐2‐oxopyrrolidinium hydrogen sulfate ([Hpyro][HSO₄]) as ionic liquid catalyst. This facile approach proceeded smoothly in good to high yields and pure products are separated from the reaction mixture by simple filtration.     

Comment on the Paper: “Crystal Structure of the Bis[zinc(II)‐hydroxide‐(μ‐perchlorate‐triaqua] Complex” by Y.‐H. Li,Q. Ye,Y.‐Z. Tang,and R.‐G. Xiong (Z. Anorg. Allg. Chem. 2004, 630, 1553)

In the present comment it will be outlined that the recently published perchlorate [Zn(OH)(μ‐ClO₄)(H₂O)₃]₂ is in fact the well known sulfate ZnSO₄·4H₂O. The assumption is supported by both bond lengths considerations and structural characteristics.     

离子色谱法测定放射性废液中硫酸根

采用取样量较少的离子色谱法测定了放射性废液中硫酸根含量.放射性废液先经稀释1 250倍,然后进行离子色谱测定.进样量为100 μL,将硫酸根标准溶液加入于试样基体溶液中制作工作曲线.试样的基体溶液系在放射性废液中加入钡离子使其中硫酸根完全生成硫酸钡沉淀除去后制成.由于采用了上述的高倍稀释方法,不但使废水样的放射性大大降低,而且还避免了溶液中共存的金属离子生成沉淀而堵塞色谱柱的干扰因素.分别在从两个试样制备的基体液中加入硫酸根标准溶液制作工作曲线,算得其相关系数分别为0.998 6和0.997 4,方法的检出限为18.9 μg·L-1.根据测量峰面积计算所得的相对标准偏差为1.46%,回收率试验的结果在96.7%～103.8%之间.     

Enhanced Interfacial Electron Transfer by Asymmetric Cu-Ov-In Sites on In2O3 for Efficient Peroxymonosulfate Activation

Enhancing the peroxymonosulfate (PMS) activation efficiency to generate more radicals is vital to promote the Fenton-like reaction activity, however, how to promote the PMS adsorption and accelerate the interfacial electron transfer to boost its activation kinetics remains a great challenge. Herein, we prepared Cu-doped defect-rich In₂O₃ (Cu-In₂O₃/O_v) catalysts containing asymmetric Cu−O_v−In sites for PMS activation in water purification. The intrinsic catalytic activity is that the side-on adsorption configuration of the O−O bond (Cu−O−O−In) at the Cu-O_v-In sites significantly stretches the O−O bond length. Meanwhile, the Cu-O_v-In sites increase the electron density near the Fermi energy level, promoting more and faster electron transfer to the O−O bond for generating more SO₄⋅⁻ and ⋅OH. The degradation rate constant of tetracycline achieved by Cu-In₂O₃/O_v is 31.8 times faster than In₂O₃/O_v, and it shows the possibility of membrane reactor for practical wastewater treatment.     

Selective Removal of Sulfate from Water by Precipitation with a Rigid Bis-amidinium Compound

A simple, readily prepared biphenyl bis-amidinium compound ( 1⋅Cl₂ ) is able to selectively precipitate sulfate from water. The precipitant is effective at concentrations as low as 1 mM and shows complete selectivity against monovalent anions, and high selectivity even against CO₃²⁻ and HPO₄²⁻. It is highly effective (>90 % sulfate removed) in both seawater and highly acidic conditions relevant to mining waste-streams. X-ray crystallography reveals that 1⋅SO₄ forms a tightly packed, anhydrous, structure where each sulfate anion receives eight hydrogen bonds from amidinium N−H hydrogen bond donors.     

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

Two new lanthanum sulfates DySO₄(OH) 1 and Eu₂(SO₄)₃(H₂O)₈2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) Å, b=10.945(5) Å, c=8.164(4) Å, α=90°, β=93.619(6)°, γ=90°, V=713.0(5) Å³, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) Å, b=6.7676(8) Å, c=18.318(2) Å, α=90°, β=102.265(2)°, γ=90°, V=1642.7 (4) Å³, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner.     

Noncentrosymmetric K2Mn3(SO4)3F2·4H2O and Rb2Mn3(SO4)3F2·2H2O with pseudo-KTP structures

Two fluoride sulfates,K₂Mn₃(SO₄)₃F₂·4H₂O(Ⅰ) and Rb₂Mn₃(SO₄)₃F₂·2H₂O (Ⅱ) are obtained by water solution method.Single-crystal X-ray diffraction analysis indicated that they crystallize in space groups of Cmc2_1.Their structures feature a pseudo-KTP structure consisting of interconnecting[Mn₃(SO₄)3F₂(H₂O)2]_∞ layers,which are further packing along the a axis with alkali metal cations balancing the charges.The structure relationships between the two compounds are discussed.Secondharmonic generation measurements manifest that Ⅰ and Ⅱ have similar second-harmonic generation responses of about 0.2 and 0.25 times that of KH₂PO₄.