Application of Nanoscale Zero-Valent Iron-Loaded Natural Zeolite for Tetracycline Removal Process

Immobilized nanoscale zero-valent iron on natural zeolite (NI-NZ) was synthesized for remediation of antibiotics-contaminated wastewater. A series of characterization methods confirmed the success of preventing the agglomeration of nanoscale zero-valent iron particles, using natural zeolite as supporting media. The equilibrium data fitted well with the Langmuir and Temkin models, whereas the pseudo-second-order and Elovich kinetic models were suitable to describe the kinetic data. The versatility of NI-NZ was also tested in a coagulation-flocculation process which increased the removal of tetracycline from 10 to 75 %.     

Comparative Study of Zn2+, Cd2+, and Pb2+ Removal From Water Solution Using Natural Clinoptilolitic Zeolite and Commercial Granulated Activated Carbon. Equilibrium of Adsorption

Abstract

The aim of this work is to study the effectiveness of regional, low-cost natural clinoptilolitic zeolite tuff in heavy metal ions removal from aqueous solution, through comparative study with commercial granulated activated carbon. The equilibrium of adsorption of Cd²⁺, Pb²⁺, and Zn²⁺ on both adsorbents have been determined at 25, 35, and 45°C in batch mode. The granulated activated carbon has shown around three times higher adsorption capacity for Cd²⁺ and Zn²⁺ than natural zeolite, and almost the same adsorption capacity for Pb²⁺ as the natural zeolite. The metal ion selectivity series Pb²⁺ > Cd²⁺ > Zn²⁺, on a mass basis, has been obtained on both adsorbents. The Langmuir and Freundlich model have been used to describe the adsorption equilibrium. The thermodynamic parameters were calculated from the adsorption isotherm data obtained at different temperatures. The study of the influence of the acidity of the metal ion aqueous solution has shown an increase of metal ion uptake with increase of the pH. The sorption mechanism of Cd²⁺, Pb²⁺, and Zn²⁺ on natural zeolite changes from ion-exchange to ion-exchange and adsorption of metal-hydroxide with increase of the pH from 2 to 6 (and 7 for Zn²⁺). The preliminary cost calculation, based on adsorbents maximum adsorption capacity and their price, have revealed the potential of natural zeolite as an economic alternative to the granulated activated carbon in the treatment of heavy metal polluted wastewater.     

Removal of Tartrazine From Water by Adsorption with Electrochemical Regeneration

An innovative process has been developed at University of the Manchester in order to remove organic contaminants from wastewater using graphite intercalation compounds (GICs) as adsorbents with electrochemical regeneration. The present study has demonstrated the removal of tartrazine, from water by adsorption and electrochemical regeneration. The adsorption of tartrazine onto GIC adsorbent was shown to be a quick process, however, with extremely low adsorption capacity compared to porous adsorbents. Low adsorption capacity of the adsorbent is being compensated by rapid electrochemical regeneration associated with low energy consumption that makes the process cost-effective. Regeneration efficiency of around 100% could be obtained in an electrochemical cell by passing a charge of 18 C g^?1 for 18 min through a 10-mm thick adsorbent bed. A series of adsorption and regeneration cycles showed that there was little loss in adsorbent capacity, demonstrating that tartrazine loaded GIC adsorbent could be effectively regenerated electrochemically.     

国内外沸石处理核废水的研究现状

核能源的快速发展带来了一系列核废物安全处置的问题,其中的核废水应用固态吸附剂进行减容处理,从而由液态核废转化成固态核废物。沸石是一种性能优良的无机离子交换剂,在国内外净化核废水方面应用广泛。本文参阅了国内外相关文献,就沸石处理核废水的研究内容、研究手段、存在的问题展开了分析总结,力求对现有研究有一个较为全面系统的认识,为后续的研究工作提供一个借鉴。     

改性粉煤灰对二甲酚橙的吸附研究

研究了改性粉煤灰对二甲酚橙的吸附性能。探讨了吸附时间、溶液初始浓度、吸附剂用量及溶液初始pH对二甲酚橙去除率的影响。结果表明：在pH=11及常温条件下,改性粉煤灰用量为8g/L时对浓度为7．6mg／L二甲酚橙的去除率为85％。     

Removal of ammonium ions from aqueous solutions with coal-based activated carbons modified by oxidation

The main purpose of this work is to study the possibilities for removal of ammonium ions from aqueous solutions by the two coal-based activated carbons (one obtained from Bulgarian lignite from the Chukurovo deposit, and the second, available as commercial product) and their oxidized modifications. The porous texture and surface chemistry of the adsorbents were characterized. Adsorption of ions was investigated using solutions with different concentrations in the range 35-280 mg l⁻¹ in a static mode. Equilibrium modeling data were fitted to linear Langmuir’s and Freundlich’s equations and maximum adsorption capacities were calculated.     

天然气脱硫工业模拟试验研究

以中原油气天然气处理厂为例 ,建立了模拟试验装置 ,通过实验得知 ,脱硫剂在 2 5℃ ,空速 12 5 0h-1,压力 0 .4MPa的工艺条件下 ,脱硫效果良好 ,为国内天然气有机硫的脱除提供了参考。同时论证了天然气脱硫的必要性以及天然气脱硫后带来的经济效益和环境效益     

改性膨润土对甲胺磷的吸附研究

探讨了经十二烷基苯磺酸钠改性并煅烧的膨润土对甲胺磷的吸附性能。结果表明改性的方法能够明显改善膨润土在水中的沉降与过滤性能 ,较大地提高了膨润土对甲胺磷的吸附能力。经1 0 %的十二烷基苯磺酸钠改性 ,30 0℃煅烧处理后所得的改性膨润土对甲胺磷的吸附量可达 1 5mg L以上 ,对浓度为 70mg L的甲胺磷废水 ,当改性膨润土的用量为 2 5g L时 ,对甲胺磷的去除率为 88%。     

Removal Of Residual Organics From Drinking Water By Ozonation And Activated Carbon Filtration: A Pilot Plant Study

The effects of ozonation, granular (GAC) and biological activated carbon (BAC) in the removal of natural organic matter and precursors of disinfection byproducts from drinking water were studied on pilot scale. Ozonation was determined to be the best method to reduce concentrations of the precursors of AOX, chloroform and mutagenicity, whereas BAC removed organic matter the most effectively. Reductions in TA100 mutagenicity were an average 40%, 4%, 26% in ozonated, GAC and BAC filtered water, respectively. Average reductions of AOX levels were similar at 48%, 7% and 35%, respectively. The chloroform formation potential always increased after GAC filtration.     

甲醛法测定工业锅炉软化水中铵离子含量的研究

研究了用甲醛法测定工业锅炉软化水中铵离子的含量,探讨了反应平衡时间、甲醛加入量及水样酸度调节指示剂等因素对测定效果的影响。实验结果表明：反应平衡时间30 min、甲醛的加入量为稀释一倍的甲醛溶液5 mL了（水样中含铵离子浓度为5.00~15.00 mg/L）、水样酸度调节指示剂选甲基红是最佳的测定条件     

CRT玻璃清洗含氟废水处理技术

含氟废水排放量逐年增长,氟污染日益受到人们的关注.因此,含氟废水处理方法与技术研究一直是国内外环保领域的重要课题.本文阐述了目前国内外电视电脑显示器(CRT)玻璃清洗过程中对含氟废水处理的方法,重点介绍了常用的化学沉淀法、混凝沉淀法、中和沉淀和混凝沉淀配合使用,并对除氟机理进行了讨论.     

湿法磷酸分解氯化铵工艺研究

通过正交试验研究了磷酸与氯化铵物质的量比、反应温度、反应时间对氯化铵分解率的影响,获得了氯化铵分解基本完全的反应条件:磷酸与氯化铵物质的量比2、反应温度250℃、反应时间2 h,氯化铵分解率大于99%。     

Resource Recovery of Waste Incineration Fly Ash: Synthesis of Zeolites A and P

The conversion of waste incineration fly ash to zeolitic compounds by hydrothermal treatment in the presence of NaOH solution has been investigated. An acid pretreatment of fly ash in addition to water washing and heating at 800°C was found to be an important process to prepare reproducible zeolitic compounds. Treatment with a low-concentration NaOH solution at 60°C and 100°–120°C successfully produced zeolites A and P, respectively, as major products. At increased concentrations of NaOH, sodalite was generated. The hydrothermal products showed uptake behavior for NH₄⁺ ions.     

新生MnO2对茜素红吸附脱色的研究

以新生MnO2为吸附剂,对水中茜素红染料进行了脱色研究,探讨了影响吸附的因素。结果表明,降低pH值、增加吸附剂投加量,有利于新生水合二氧化锰对茜素红染料的脱色。当新生态水合MnO2浓度为300 mg/L,茜素红浓度为400 mg/L,pH=2,反应时间为60 min时,茜素红脱色率达90%以上。实验还发现对茜素红染料吸附较好符合Freundich吸附等温式,吸附速率较快。     

Hydroxyl Radical Oxidation Processes For The Removal Of Triazine From Natural Water

The purpose of this study was to point out processes that can provide triazine oxidation via hydroxyl radical production in a water treatment line. We focus our attention on:

- oxido-flocculation, using Fe²⁺, H₂O₂

- inter-oxidation, using O₃, H₂O₂ and eventually an heterogeneous catalyst.

- disinfection, using UV, O₃ and H₂O₂ combinations.

Results show that triazines can be removed by all these processes with different efficiencies. At full scale, the O₃/H₂O₂ process presents the best performances from an economical and technical point of view.     

聚磷酸铵阻燃聚丙烯的研究

采用聚磷酸铵(APP)对聚丙烯(PP)进行了填充改性，研究了APP对PP阻燃性能和力学性能的影响，还研究了200℃下APP对PP阻燃复合材料的流变行为及结晶性能的影响。结果表明：在PP中加入适量的APP，可改善体系的阻燃性能，同时对材料的力学性能会产生影响，使复合体系的弯曲强度与弯曲模量明显提高，却使断裂伸长率，特别是冲击强度降低；在200℃时，较低剪切速率范围内，APP的加入有利于复合材料流动性能的改善，但在高剪切速率范围内对复合材料的流动性能影响不大；APP在PP中具有成核剂作用，可使PP的结晶过程在较高温度下进行，结晶速率也大大提高，但对PP的结晶度和熔点影响不大。     

电感耦合等离子体发射光谱法测量青海地区矿泉水中锶含量的不确定度

采用电感耦合等离子体发射光谱(ICP-AES)法测定矿泉水中锶的不确定度。分析了标准溶液配制过程及仪器测定过程的各种不确定度影响因素,对各不确定度分量进行了评定与计算,当锶的质量浓度为0.8373 mg/L时,测量结果的扩展不确定度为0.0192 mg/L(k=2)。该法适合于以线性回归法得出检测结果的不确定度评估。     

Adsorption and Microbiological Mechanisms for Removal of Natural Organics in Granular Activated Carbon Columns

Performance data for GAC columns treating surface water are analyzed to determine the relative importance of physical adsorption and biological activity, with and without pre-ozonation. Kinetic and equilibrium adsorption parameters for the source water are used in the Homogeneous Surface Diffusion model to predict GAC performance over 83 weeks. The model underestimates removal of TOC for ozonated and unozonated streams by 46% and 28%, respectively, which is attributed to omission of biological removal in the model.     

缺氧氨氧化脱氮研究

现阶段国内外脱氮研究热点：厌氧氨氧化,严格定义应为缺氧氨氧化;介绍缺氧氨氧化机理;简述国内外缺氧氨氧化研究现状;并介绍了作者的试验设计方案及初步成果。     

缔合法磷酸二铵氨化反应特征的研究

研究了氨和磷酸缔合物生成磷酸一铵的化学反应特征。其反应式为：（Ｒ３ＮＨ）Ｈ２ＰＯ４＋ＮＨ３→Ｒ３Ｎ＋（ＮＨ４）Ｈ２ＰＯ４获得了两个温度范围的反应速率方程：２０～５０℃：－γＡ＝８．６７８×１０３·ｅｘｐ（－１．９５６４×１０３·１／Ｔ·Ｃ０．３Ａ５０～８０℃：－γＡ＝０．４２０３×１０２·ｅｘｐ（－０．９７８０×１０３·１／Ｔ·Ｃ０．３Ａ方程计算与实测在相同与不同温度时的平均误差分别为－４．２９％和－０．３２％。研究结论：反应级数ｎ＝０．３;反应为受液膜控制的快速反应;生成磷酸二铵的反应有一慢速区,反应分为两段进行较为经济。