珍珠贝壳生物填料的制备及表面特性

以废弃珍珠贝壳为原料,经去除角质层、分离棱柱层,得到珍珠层。然后采用机械研磨得到生物填料(ZZB),对其物相、表面元素组成、微观形貌、热稳定性及亲水、亲油性等表面特性进行分析和表征。结果表明,制备的生物填料主要成分为文石碳酸钙,呈片状,粒径大小为0.1～2μm,有机物含量约为3.87%,热稳定性良好。ZZB粉体具有亲水、亲油的双亲性,对正庚烷浸润,对水的接触角约为23.4°。     

从牡蛎壳中提取生物糖蛋白的分析研究

研究了从牡蛎壳中直接提取生物糖蛋白的工艺条件。本工艺过程中主要从盐酸酸度、盐酸用量、反应温度、反应时间、超声波辐射、中和液pH值、乙醇用量这几个因素出发,探讨提取糖蛋白的最佳工艺条件。实验结果表明,从牡蛎壳中直接提取糖蛋白的工艺条件为：盐酸酸度为pH等于0．5、盐酸用量500mL、反应温度60℃、反应时间160min、不使用超声波辐射、中和液pH值10．9、乙醇用量600mL。     

牡蛎壳粉为载体的纳米ZnO催化超声降解偶氮品红溶液

采用实验室合成的以牡蛎壳粉为载体的纳米ZnO催化剂,以偶氮品红超声降解反应为模型,研究了各种因素对偶氮品红超声降解反应的影响。结果表明,在ZnO作用下超声降解偶氮品红的效果明显优于纳米ZnO和单纯使用超声波的情况。超声波频率25 kHz,输出功率50 W,催化剂用量800 mg/L,pH值3.0,偶氮品红水溶液初始浓度20 mg/L的条件下,3 h左右降解率即可达到90%以上,COD的降低率也达到了90%。     

以牡蛎壳粉作载体对维生素C和维生素E的抗氧化包合作用研究

利用废置的牡蛎壳粉及可溶性淀粉制成包合材料对VC和VE进行抗氧化包合;以VC和VE的利用率和收率作为综合指标,研究对比溶液法、超声波法和研磨法等的包合效果。结果表明,溶液法较适宜,选用溶液法的最佳包合工艺为:主客分子的质量比10∶1,VC利用率达88.56±1.31%,收率为88.46%。     

牡蛎壳粉为载体纳米TiO2催化降解甲基橙的研究

纳米TiO2具有很好的光催化活性,对比研究了牡蛎壳粉、多孔硅胶、SiO2、分子筛等作为载体材料对纳米TiO2的固定,比较了这些材料对纳米TiO2的负载量及负载条件,相对来说,牡蛎壳粉的负载量最大。以甲基橙为模拟物,测定了各种固定化纳米TiO2的光催化性能,负载量最大的牡蛎壳粉表现出最好的催化活性。     

Preparation and Characterization of Activated Carbon from Chestnut Shell and its Adsorption Characteristics for Lead

Activated carbons were prepared from chestnut shell by phosphoric acid activation and the prepared activated carbons were used to remove lead(II) from aqueous solutions. The effects of impregnation ratio (IR) and activation temperature on activated carbon production were investigated. The produced activated carbons were characterized by N₂ adsorption, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The highest surface area (1611 m²/g) and total pore volume (0.7819 cm³/g) were obtained at a carbonization temperature of 500°C with an impregnation ratio of 3/1. The resulting activated carbon was used for removal of lead(II) from aqueous solution. The effects of temperature, contact time, and adsorbent dosage were investigated. The adsorption isotherm studies were carried out and the obtained data were analyzed by the Langmuir, Freundlich, and Temkin equations. The rate of adsorption was found to conform to the pseudo-second-order kinetic model. The Langmuir isotherm equation showed better fit for all temperatures and the maximum adsorption capacities of lead(II) was obtained as 138.88 mg/g at 45°C.     

Porous Biphasic Calcium Phosphate Granules from Oyster Shell Promote the Differentiation of Induced Pluripotent Stem Cells

Oyster shells are rich in calcium, and thus, the potential use of waste shells is in the production of calcium phosphate (CaP) minerals for osteopathic biomedical applications, such as scaffolds for bone regeneration. Implanted scaffolds should stimulate the differentiation of induced pluripotent stem cells (iPSCs) into osteoblasts. In this study, oyster shells were used to produce nano-grade hydroxyapatite (HA) powder by the liquid-phase precipitation. Then, biphasic CaP (BCP) bioceramics with two different phase ratios were obtained by the foaming of HA nanopowders and sintering by two different two-stage heat treatment processes. The different sintering conditions yielded differences in structure and morphology of the BCPs, as determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) surface area analysis. We then set out to determine which of these materials were most biocompatible, by co-culturing with iPSCs and examining the gene expression in molecular pathways involved in self-renewal and differentiation of iPSCs. We found that sintering for a shorter time at higher temperatures gave higher expression levels of markers for proliferation and (early) differentiation of the osteoblast. The differences in biocompatibility may be related to a more hierarchical pore structure (micropores within macropores) obtained with briefer, high-temperature sintering.     

煅烧温度对牡蛎壳陶粒磷吸附效果的影响

研究主要是制备一种牡蛎壳陶粒,并考察煅烧温度对牡蛎壳陶粒除磷性能的影响。结果表明煅烧温度对牡蛎壳载体磷吸附效果的影响较大,当牡蛎壳粉末∶粘土∶九水硅酸钠=7∶2∶1,煅烧温度为450℃时,制备的牡蛎壳陶粒对磷的吸附量为0.155 mg·g-1。牡蛎壳陶粒对磷的吸附符合Langmuir等温吸附模型,且在25℃下最大吸附量为0.432 mg·g-1。最佳条件下制备的牡蛎壳陶粒具有良好的亲水性,吸水率可以达到18.64%、载体的抗压强度可以达到2.15 MPa、空隙率为41.2%、比表面积为5.71 m2·g-1、破碎率与磨损率之和为2.95%、含泥量为0.61%,这些指标均满足《水处理用人工陶粒滤料CJ/T 299-2008》的指标,可以将此牡蛎壳陶粒用到水处理当中。     

我国高吸水性树脂的制备及性能研究进展

介绍了我国近 2 0年来高吸水性树脂的研究情况。     

活化牡蛎壳固化余泥渣土及其机理分析

为实现牡蛎壳和余泥渣土两种固废资源的利用,提出了预处理的牡蛎壳经磷酸或磷酸氢二铵(DAP)活化后固化土体,制得牡蛎壳固化土。试验测定了不同配比的牡蛎壳固化土的力学性能,研究牡蛎壳固化土的边坡抗冲刷性能,并使用扫描电镜和X射线衍射仪观察固化土的微观结构,分析其固化机理。结果表明,掺磷酸、DAP能提高牡蛎壳固化土的抗压强度,其中掺加DAP的效果更好。材料最佳配比(质量分数)为:73.6%土,18.4%牡蛎壳(粒径≤1 mm),8%DAP。其烘干抗压强度达到2.14 MPa,是牡蛎壳稳定余泥渣土抗压强度的2.43 倍,软化系数达到0.5,改变了原土遇水崩解的特性。在室内边坡冲刷试验中,掺DAP牡蛎壳固化土与素土相比,有效降低了坡面冲刷的产沙量。微观结构分析表明,磷酸、DAP分别与牡蛎壳作用生成磷酸钙晶体、羟基磷灰石,两者都能胶结土粒,从而固化土体。     

水解腈纶废丝制备吸水性树脂

腈纶废丝在碱性条件下水解后,水解产物与甲醛和AlCl3进行交联反应可制得高吸水性树脂,对水解反应条件和水解物的结构进行了分析,由正交实验考察了交联反应条件对产物吸水性能的影响,研究了吸水树脂对不同水质的吸水率和吸水速率。结果表明,交联剂用量和沉淀用乙醇的浓度对产物的吸水率有较大的影响,当甲醛和AlCl3用量分别为0.3 mL和1.2 mL,交联温度为80℃,产物用60%的乙醇沉淀并在50℃下烘干时,树脂对蒸馏水的吸水率近800 g/g,有较快的吸水速率。     

高锑铅阳极泥真空还原除锑研究

介绍了一种在真空气氛下,高锑铅阳极泥还原除锑新工艺。添加3．5％聚乙烯树脂作还原剂,阳极泥蒸发率可达64％(锑脱除率大于98％)。此工艺具有流程短,处理温度低,消耗少,回收率高,劳动强度低,无三废污染等特点。     

利用天然浓缩丹宁合成新型凝胶吸附剂通过表面沉淀去除水溶液中铅

Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, removal of lead from aqueous solutions is investigated using a novel gel adsorbent synthesized from natural condensed tannin. The novel adsorbent performs in aqueous solutions as a weak base with valid basic groups of 1.2mmol·g-1 tannin gel particles and therefore results in the elevation of pH value of aqueous solutions. Even when initial pH is 3.6, final pH at equilibrium can climb up to 6.5 that is above the pH value for Pb(OH)2 precipitation formation and then lead can be removed from wastewater by this so-called surface precipitation. The adsorption isotherm can be expressed by the Langmuir equation and the maximum capacity for adsorption of Pb is up to 92 mg·g-1 (based on dry adsorbent) when initial pH value is 3.6. Hence, the adsorbent does offer favorable properties in lead removal with respect to its high adsorption capacity at low initial pH value, which     

硅藻土-沸石复合吸附剂对水中磷的吸附性能研究

本文利用硅藻土和沸石为主要原料制备硅藻土-沸石复合吸附剂,采用傅里叶变换红外光谱法(FTIR)、X射线衍射(XRD)、SEM对其进行表征,研究了静态吸附过程中的复合吸附剂对溶液中磷的吸附动力学行为和吸附等温线.结果表明,硅藻土与沸石在复合过程中基本上完全参与了化学反应,可以增加复合吸附剂的活性;复合吸附剂对磷的吸附动力学特征更符合准二级反应动力学方程;等温吸附特征与Langmuir方程拟合较好.     

Properties of Portland Cement Pastes Incorporating Nanometer-Sized Franklinite Particles Obtained from Electric-Arc-Furnace Dust

The present work presents preliminary results concerning ordinary portland cement (OPC) blended with electric-arc-furnace dust (EAFD) obtained from steel-smelting plants. The powder obtained after acid treatment of the EAFD consisted basically of nanometer-sized particles of ZnFe₂O₄. Incorporation of the EAFD in the OPC produced retardation of the setting process. Nevertheless, after 7 d, the compressive strength of the OPC/EAFD pastes was superior to undoped OPC, and, after 28 d, the extent of hydration of the OPC/EAFD pastes was equivalent to undoped OPC. A compressive strength of 72 MPa was attained after 42 d for OPC doped with 10 wt% EAFD.     

纤维素系高吸水性树脂的研究进展

高吸水性树脂是一种新型功能高分子材料,具有优异的性能和广泛的用途,目前已研究出淀粉系,纤维素系和合成树脂系三类高吸水材料。文章着重介绍了纤维素系高吸水性树脂的制备、吸水机理以及发展状况。     

Removal of lead from water by adsorption on a kaolinitic clay

The possible use of kaolinitic clay, Giru clay, from Nigeria as an adsorbent for the removal of lead from water was investigated. Studies were carried out as a function of contact times, concentrations, temperatures and pH. The kinetics of adsorption as well as adsorption isotherms at different temperatures were equally studied. The results show that lead removal is favoured by low concentration, high temperature and acidic pH. The reasons for these observations are adduced.     

Removal of Lead Ions from Aqueous Solutions by Different Types of Industrial Waste Materials: Equilibrium and Kinetic Studies

Abstract

A comparative study of the adsorbents prepared from several industrial wastes for the removal of Pb²⁺ has been carried out. Fertilizer industry waste viz. carbon slurry and steel plant wastes viz. blast furnace (B.F.) slag, dust, and sludge were investigated as low‐cost adsorbents after proper treatment in the present study. The adsorption of Pb²⁺ on different adsorbents has been found in the order: B.F. sludge>B.F. dust>B.F. slag>carbonaceous adsorbent. The least adsorption of Pb²⁺ on carbonaceous adsorbent even having high porosity and consequently greater surface area as compared to other three adsorbents, indicates that surface area and porosity are not important factors for Pb²⁺ removal from aqueous solutions. The adsorption of Pb²⁺ has been studied as a function of contact time, concentration, and temperature. The adsorption has been found to be exothermic, and the data conform to the Langmuir equation. The kinetic results reveal that the present adsorption system follows Lagergren's first order rate equation. Since all three waste products from the steel industry show higher potential to remove lead from water, therefore, it is suggested that these metallurgical wastes can be fruitfully employed as low‐cost adsorbents for effluent treatment containing toxic metal ions.     

Removal of inorganic mercury from mine waste water by ion exchange

The present study has been undertaken to investigate a process that might remove inorganic mercury from mine waste water streams by use an ion exchange resin system. A number of commercial resins have been evaluated as ion exchangers and the mercury content of the waste water, ranging from 70 to 90 ppm, is reduced to a permitted level of 34 ppb. Dowex XZS‐1, a strong cationic ion exchanger in a gel Form, has the most pronounced selectivity for mercury. The loaded resin was regenerated efficiently using HCl solutions, due to increased competition between Hg and hydronium ions and formation of an HgCl ₄ ²⁻ ionic complex. © 2000 Society of Chemical Industry     

聚丙烯酸-海藻酸钠吸水树脂的制备及性能研究

以丙烯酸为单体,海藻酸钠为接枝物,添加丙烯酰胺,通过溶液聚合法制备复合型耐盐高吸水性树脂。研究了聚丙烯酸-海藻酸钠高吸水树脂的吸水性能。结果表明,在蒸馏水、生理盐水中吸水倍率分别达到830 g/g、81 g/g。天然高分子海藻酸钠具有很好的耐盐性,海藻酸钠的加入,提高了高吸水性复合材料的耐盐性。