一种戊二醛消毒液的消毒性能观察

目的观察一种戊二醛消毒液的杀菌效果及稳定性。方法采用载体浸泡杀菌试验和理化分析方法,对该戊二醛消毒液进行了实验室检测。结果该戊二醛消毒液浓度为22 g/L,内含2.5 g/L脂肪醇聚氧乙烯醚。以该消毒剂原液对载体上枯草杆菌黑色变种芽孢作用60 min,杀灭对数值>3.0;作用4 h以上,可达到完全杀灭。该戊二醛消毒液连续浸泡医疗器械14 d,其杀菌效果不下降;模拟现场试验对医疗器械浸泡60 min,对污染在器械上的枯草杆菌黑色变种芽孢杀灭对数值≥5.0,浸泡5 h可达到完全杀灭。该消毒液密封存放于37℃90 d,戊二醛含量下降率<10%。结论该戊二醛消毒液能在规范时间内有效杀灭细菌芽孢,加速试验性能稳定。     

一种戊二醛消毒液相关性能的研究

目的研究一种戊二醛消毒液的杀菌效果及其消毒相关性能。方法以载体定量和定性杀菌试验方法及动物试验方法,对该戊二醛消毒液进行了实验室和现场消毒试验观察。结果用浓度为20 g/L的该戊二醛消毒液对载体上枯草杆菌黑色变种芽孢作用30 min,杀灭对数值均>3.00;作用5 h对载体上枯草杆菌黑色变种芽孢达到完全杀灭,且定性培养结果无菌生长。能量试验显示该戊二醛消毒液对大肠杆菌最低合格浓度为1 000 mg/L。用该浓度戊二醛消毒液连续浸泡医疗器械14 d后,其对载体上的枯草杆菌黑色变种芽孢作用5 h,仍可完全杀灭载体上的枯草杆菌黑色变种芽孢。该戊二醛消毒液对小鼠经口毒性LD50为>5 000 mg/kg,小鼠骨髓多染红细胞致微核试验结果阴性。结论该戊二醛消毒液具有较好的杀菌效果,属于无毒级物质,无致微核作用。     

戊二醛消毒液杀菌效果及其影响因素的实验研究

目的研究戊二醛消毒液的卫生质量技术要求,为制定戊二醛消毒剂通用标准提供依据。方法采用载体浸泡定量杀菌、定性灭菌试验和理化分析方法对通用戊二醛溶液的杀菌效果及其影响因素进行了实验室观察。结果在室温条件下,以医用级戊二醛原料制备的20g/L戊二醛溶液对不锈钢圆片上的龟分枝杆菌脓肿亚种和枯草杆菌黑色变种芽孢分别作用5min和60min,平均杀灭对数值均>3.00;作用2h达到完全杀灭。该溶液连续使用14d后,达到完全杀灭细菌芽孢需要作用5h。在试验规定条件下,杀菌效果随戊二醛浓度加大、作用时间延长而增强,戊二醛原料由医用级换为生化级其杀菌效果减弱;非离子和阳离子表面活性剂对戊二醛杀菌效果有增效作用。含量20g/L戊二醛溶液密封包装经37℃条件下存放90d,其含量下降率均<10.0%;经活化后的20g/L戊二醛溶液常温下存放28d,其含量下降率均<10.0%,且pH值变化不明显。结论含量20g/L戊二醛溶液杀菌效果可靠、性能稳定;戊二醛杀菌效果受其原料级别、配方组份、浓度以及作用时间等因素的影响。     

多孔壳聚糖微球的最佳制备条件

背景:天然状态的壳聚糖大部分为粉末状,比表面积小,作为吸附载体,使载体和吸附物都难以回收,从而限制其应用.目的:分析制备多孔壳聚糖微球的最佳条件.设计、时间及地点:重复测量设计,于2006-11/2007-05在陕西理工学院应用化学实验室完成.材料:壳聚糖脱乙酰度为95.62%.方法:以环己烷作致孔剂,戊二醛作交联剂,采用反液相悬浮交联法,改变加入环己烷和戊二醛用量,调节反应温度,改变搅拌速度和提取时间.主要观察指标:观察反应温度、提取时间、搅拌速度、环己烷用量和戊二醛用量对制备多孔壳聚糖微球的影响.结果:多孔壳聚糖微球最佳制备条件为:添加10mL环己烷,戊二醛2 mL,反应温度60～70℃,搅拌速度中速(100～120 r/min)时,提取时间不小于48 h,可得到90%粒径大小为3～12 μm的多孔壳聚糖微球.结论:此制备方法具有耗时短,制备的壳聚糖微球粒径小、粒度分布窄、多孔性等特点.     

复方强化戊二醛消毒液对细菌芽孢的杀菌效果观察

为了解复方强化戊二醛消毒液对细菌芽孢杀灭效果,采用载体定量和定性杀菌试验进行了实验室观察和现场试验。结果,以含22.4 g/L戊二醛的复方强化戊二醛消毒液对载体上枯草杆菌黑色变种芽孢作用1 h,杀灭率>99.9%;作用3 h达到完全杀灭。能量试验对大肠杆菌最低有效浓度为1000 mg/L戊二醛。经模拟现场试验用含22.4 g/L戊二醛消毒液对污染在止血钳上的枯草杆菌黑色变种芽孢作用3 h达到完全杀灭。连续使用稳定性杀菌试验,14 d后达到完全杀灭细菌芽孢的效果需要作用5 h。结论,复方强化戊二醛消毒液对细菌芽孢杀灭效果较好,性能稳定。     

不同溶解方法对环磷酰胺药效影响的观察

目的：观察采用振荡和加温两种方法溶解环磷酰胺粉针剂时,在保证药效的前提下使其完全溶解的振荡时间及温度。方法：振荡溶解法：将3种不同批号的环磷酰胺西林瓶（每支200 mg）中各注入10 mL 0.9%NaCl,放在同一个振荡器上进行振荡,分别在振荡后的1、2、4、6、8、15 min取出,采用高效液相仪测定每个时间点的药物含量,进而确定振荡的时间。加温溶解法：将3种不同批号的环磷酰胺西林瓶（每支200 mg）中各注入10mL 0.9%NaCl,放入不同温度（37、50、60、65℃）的恒温箱中加温,分别在每个温度点下的1、2、4、6、8、15 min时取出,采用高效液相仪测定各时间点的药物含量,进而确定药物溶解的最佳温度。结果：加温溶解法：37℃下环磷酰胺的溶解时间为1 5 min时,含量为（94.69±1.11）%;50和60℃下环磷酰胺在溶解时间达6 min时,含量分别为（95.27±1.58）%和（97.74±0.80）%,超过6 min后,含量明显下降;在65℃时环磷酰胺在溶解时间达4 min时含量即可达（95.46±1.09）%,但其在15 min时下降至约87%。振荡溶解法：环磷酰胺完全溶解最短时间为8 min,含量为（96.09±1.67）%。结论：采用振荡溶解法环磷酰胺完全溶解的最短时间为8 min。配制环磷酰胺时温度以50~60℃为宜,时间为6 min。     

戊二醛消毒作用的影响因素

<正> 戊二醛是一种较好的消毒剂,对其理化性质、杀菌作用、作用机理及应用方法等已有专文介绍。研究证明,戊二醛的杀菌作用受微生物的种类、使用浓度、pH、温度、有机物等因素的影响。一些非离子添加物和超声波处理,对戊二醛还有增效作     

戊二醛复方中辅助成分对其性能影响的研究

采用载体定量杀菌试验观察了戊二醛消毒剂复方辅助成分对其性能的影响。结果 ,在 2 0g/L戊二醛溶液中加入 5g/L亚硝酸钠 ,其pH值为 4 .5 6 ,加入 3.0g/L碳酸氢钠和 5 .0g/L亚硝酸钠时 ,其pH值为 7.73。以pH值为7.73的该液作用 4h ,对不锈钢片上枯草杆菌黑色变种芽孢杀灭率为 10 0 % ;对止血钳头上滴染的枯草杆菌黑色变种芽孢达到灭菌。将该消毒剂连续使用 14d后 ,对不锈钢片上的枯草杆菌黑色变种芽孢作用 5h杀灭率为 10 0 %。在室温下存放 7d ,其戊二醛含量下降率 >10 % ,对金属无腐蚀。在 2 0g/L戊二醛溶液中只加入 5g/L亚硝酸钠 (pH4 .5 6 ) ,对不锈钢片上枯草杆菌黑色变种芽孢杀灭率达到 10 0 %需作用 5h ,对止血钳头上滴染的枯草杆菌黑色变种芽孢达到灭菌需要 8h。在室温存放 14d后 ,其戊二醛含量下降率 <10 % ,对铜中度腐蚀。结论 ,加碳酸氢钠的碱性戊二醛杀芽孢效果好 ,但稳定性差 ,腐蚀性小 ;只加亚硝酸钠的酸性戊二醛杀芽孢效果差 ,稳定性好 ,腐蚀性增加。     

一种复合中性戊二醛消毒剂的性能观察

目的观察一种复合中性戊二醛消毒剂的消毒、灭菌、稳定性及金属腐蚀性等性能。方法采用理化和微生物检测方法对该复合戊二醛消毒剂性能进行检测。结果复合中性戊二醛含量为23.41 g/L,pH值为7.00。2年稳定性试验结果显示,戊二醛含量为23.03 g/L,下降率为1.62%。连续使用稳定性试验结果显示,7 d和14 d戊二醛含量的下降率分别为13.02%和35.56%。对染于金属片上的枯草杆菌黑色变种芽孢作用30、60和90 min的杀灭对数值均>3.00;对染菌载体作用2、4、6 h均能达到灭菌效果;浸泡5 h后,戊二醛对止血钳头上所有的芽孢杆菌完全杀灭,连续稳定性试验7 d和14 d,仍能完全杀灭止血钳头上的芽孢杆菌。消毒液对不锈钢片、碳钢片和铜片基本无腐蚀,对铝片有轻度腐蚀。结论该复合中性戊二醛是一种稳定的消毒灭菌剂,腐蚀性低,适用于医疗器械的消毒和灭菌。     

一种强化戊二醛消毒剂相关性能的试验观察

目的观察一种强化戊二醛消毒剂杀菌效果与使用安全性,为实际应用提供参考。方法采用理化分析和载体定量杀菌试验方法,对该戊二醛消毒剂的相关性能进行实验室试验。结果该戊二醛消毒剂由20 g/L戊二醛与某非离子表面活性剂以及其他辅助成分组成,其原液pH值为6.77,54℃条件下存放14 d,戊二醛含量下降率3.86%。以戊二醛浓度为20 g/L的该消毒剂对载体上枯草杆菌黑色变种芽孢作用60 min,平均杀灭对数值>3.0。戊二醛消毒液pH值降低对其杀菌效果有严重影响。该戊二醛消毒液对小鼠经口急性毒性LD50值>5 000 mg/kg(体重),对小鼠嗜多然红细胞微核试验结果阴性。结论试验表明,该强化戊二醛消毒剂对细菌芽孢具有良好的杀灭效果,属于实际无毒,无致微核作用,性能稳定。     

Adsorption behavior of magnetic bentonite for removing Hg(ii) from aqueous solutions

Bentonite is a porous clay material that shows good performance for adsorbing heavy metals and other pollutants for wastewater remediation. However, it is very difficult to separate the bentonite from water after adsorption as it forms a stable suspension. In this paper, we prepared magnetic bentonite (M-B) by loading Fe₃O₄ particles onto aluminum-pillared bentonite (Al-B) in order to facilitate its removal from water. The functional groups, skeleton structure, surface morphology and electrical changes of the prepared material were investigated by FT-IR, XRD, BET, SEM, VSM and zeta potential measurements. It was used as an adsorbent for Hg(ii) removal from aqueous solutions and the influence of various parameters on the adsorption performance was investigated. The adsorption kinetics were best fitted by the pseudo-second-order model, and also followed the intra-particle diffusion model up to 18 min. Moreover, adsorption data were successfully reproduced by the Langmuir isotherm, and the Hg(ii) adsorption saturation capacity was determined as 26.18 mg g⁻¹. The average adsorption free energy change calculated by the D-R adsorption isotherm model was 11.89 kJ mol⁻¹, which indicated the occurrence of ionic exchange. The adsorption thermodynamic parameter ΔH was calculated as 42.92 kJ mol⁻¹, which indicated chemical adsorption. Overall, the thermodynamic parameters implied that Hg(ii) adsorption was endothermic and spontaneous.

Bentonite is a porous clay material that shows good performance for adsorbing heavy metals in wastewater remediation. Magnetic bentonite (M-B) was prepared and it was successfully used as an adsorbent to remove Hg(ii) from aqueous solutions in this paper.     

An efficient and robust exfoliated bentonite/Ag3PO4/AgBr plasmonic photocatalyst for degradation of parabens

Efficient visible-light-driven heterojunction photocatalysts have attracted broad interest owing to their promising adsorption and degradation performances in the removal of organic pollutants. In this study, a mesoporous exfoliated bentonite (EB)/Ag₃PO₄/AgBr (30%) photocatalyst was obtained by stripping and exfoliating bentonite as the support for loading Ag₃PO₄ and AgBr. The particle size ranges of Ag₃PO₄ and AgBr were about 10–30 nm and 5–10 nm, respectively. The exfoliated bentonite could greatly improve the dispersion and adsorption of Ag₃PO₄ and AgBr, and significantly enhance the stability of the material during paraben photodegradation. 0.2 g L⁻¹ methylparaben (MPB) was completely decomposed over the EB/Ag₃PO₄/AgBr (30%) in 40 min under visible light irradiation. In addition, the photocatalytic activity of EB/Ag₃PO₄/AgBr (30%) remained at about 91% after five recycling runs manifesting that EB/Ag₃PO₄/AgBr (30%) possessed excellent stability. Radical quenching tests revealed that holes (h⁺) and hydroxyl radicals (·OH) were the major radicals. They attacked the side chain on the benzene ring of parabens, which were gradually oxidized to the intermediates, such as benzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, azelaic acid, and eventually became CO₂ and H₂O. The enhancement of photocatalytic activity and photo-stability could be ascribed to the stable structural characteristics, enlarged surface area, high absorption ability, and improved light absorption ability from loading Ag₃PO₄ onto EB. Meanwhile, the matched energy levels of Ag₃PO₄ and AgBr made the photoelectron–hole pairs separate and transfer effectively at the interfaces. As a result, the photocatalytic properties of EB/Ag₃PO₄/AgBr (30%) composites were enhanced.

A mesoporous exfoliated bentonite (EB)/Ag₃PO₄/AgBr (30%) photocatalyst was designed to combine various functions to achieve efficient photodegradation of parabens.     

Preparation of high-performance toluene adsorbents by sugarcane bagasse carbonization combined with surface modification

A series of activated carbons were prepared by carbonizing sugarcane bagasse combined with surface modification, which showed an excellent performance of adsorbing toluene (522 mg g⁻¹ at 30 °C). The results demonstrated that the enhancement of the activated temperature was benefit to promote the porosity and specific surface area (BET) of ACs. Thus, AC-800 showed optimal adsorption and its toluene adsorption performance was better than that of most ACs in the literature. Five consecutive adsorption–desorption cycles presented that AC-800''s toluene adsorptive capacity was as high as 522 mg g⁻¹ (30 °C), and toluene adsorptive capacity was only decreased by 4.5%. According to the fraction of N-containing functional groups and the binding energy of toluene on N-containing functional groups, pyridinic-N (N-6) was believed to contribute more to toluene adsorption. Moreover, the Bangham model was considered as the best model of describing toluene adsorption on AC-800. Therefore, both surface adsorption and pore diffusion were the two mechanisms of toluene adsorption, and the diffusion of toluene molecules in the pores was considered as the key factor that affected the adsorption rate.

A series of activated carbons were prepared by carbonizing sugarcane bagasse combined with surface modification, which showed an excellent performance of adsorbing toluene (522 mg g⁻¹ at 30 °C).     

Characterization of biocompatible pig skin collagen and application of collagen-based films for enzyme immobilization

Based on the excellent biocompatibility of collagen, collagen was extracted from pig skin by acid-enzymatic method. The films were prepared by the self-aggregation behavior of collagen, and the catalase was immobilized by adsorption, cross-linking and embedding. The experiment investigated the effects of glutaraldehyde on the mechanical properties, external sensory properties, and denaturation temperature of the films. The results showed that self-aggregating material could maintain the triple helix structure of pig skin collagen. The self-aggregation treatment and cross-linking treatment can improve the mechanical properties to 53 MPa, while the glutaraldehyde cross-linking agent can increase the denaturation temperature of the pig skin collagen self-aggregating membrane by 20.35% to 84.48 °C. This means that its application to immobilized catalase has better stability. The comparison shows that the catalase immobilized by the adsorption method has strong activity and high operational stability, and the cross-linking agent glutaraldehyde and the initial enzyme concentration have a significant effect on the immobilization, and the activity can reach 175 U g⁻¹. After 16 uses of the film, the catalase was completely inactivated. This study provides a reference for the preparation of a catalase sensor that can be used to detect hydrogen peroxide in food by a catalase sensor.

Based on the excellent biocompatibility of collagen, collagen was extracted from pig skin by acid-enzymatic method.     

Preparation and Properties of a Cephalosporin Acetylesterase Adsorbed onto Bentonite

A cephalosporin acetylesterase produced by Bacillus subtilis was immobilized by adsorption onto bentonite. The immobilized enzyme (E(I)) and the soluble enzyme (E(S)) exhibited Michaelis-Menton kinetics with 7-aminocephalosporanic acid (7-ACA): K(m) = 2.8 x 10(-3) M and K(m) = 3.2 x 10(-3) M, respectively. Similar kinetics were observed with 7-(thiophene-2-acetamido)cephalosporanic acid (cephalothin), but the K(m) value measured with E(I) (3.7 x 10(-3) M) was less than one-half that measured with this substrate and E(S). The reduction in K(m) value was correlated with the ability of bentonite to adsorb cephalothin. The reaction products, acetate and deacetyl-7-ACA, were weak competitive inhibitors of E(S) and E(I). The K(i) values for E(I) were 5.0 x 10(-2) M for acetate and 3.6 x 10(-2) M for deacetyl-7-ACA. Similar values were measured with E(S) and these substrates. E(I) retained about 80% of its initial activity after 3 weeks of storage in solution at 25 C. However, the enzyme dissociated from the bentonite particles during the deacetylation reaction. This dissociation was minimized by cross-linking E(I) with glutaraldehyde or bis-dimethyladipimidate, or by adding Al(OH)(3) to the suspension. With the latter addition, E(I) was stabilized so that it could be reused nine times before one-half of the initial activity was lost.     

Synthesis,characterization and corrosion inhibition behavior of 2-aminofluorene bis-Schiff bases in circulating cooling water

In this work, two new bis-Schiff bases, namely 2-bromoisophthalaldehyde-2-aminofluorene (M1) and glutaraldehyde 2-aminofluorene (M2), were synthesized, and their structures were characterized and confirmed by infrared spectroscopy, Fourier transform mass spectrometry and UV-visible spectroscopy. Their corrosion inhibition performance on carbon steel in simulated circulating cooling water was investigated by weight loss measurements and electrochemical measurements. The potentiodynamic polarization curves confirmed that two bis-Schiff bases are anode-type inhibitors; electrochemical impedance spectroscopy tests showed that M1 and M2 possess the best inhibition efficiencies of 96.25% and 99.15% at the optimal concentration of 2.50 mmol L⁻¹, respectively. The weight loss results showed that M1 and M2 exhibit maximum η_w values of 92.62% and 96.31%, respectively. Scanning electron microscopy showed that the inhibitors inhibited carbon steel corrosion. The adsorption isotherm measurements indicated that the two inhibitors exhibited physicochemisorption mechanisms and followed Langmuir adsorption isotherms. The relationships between the molecular structure and inhibition behavior of the inhibitors were explored by density functional theory, frontier molecular orbital studies, and Fukui index analysis, which affirmed that M2 possesses higher corrosion inhibition efficiency than M1.

Two new bis-Schiff bases, namely 2-bromoisophthalaldehyde-2-aminofluorene (M1) and glutaraldehyde 2-aminofluorene (M2) were synthesized and were characterized, the potentiodynamic polarization curve confirmed that they were anode type inhibitors.     

Fast removal of Co(ii) from aqueous solution using porous carboxymethyl chitosan beads and its adsorption mechanism

Porous carboxymethyl chitosan (PCMC) beads were synthesized via ionic coacervation/chemical crosslinking, using polyethylene glycol (PEG) as a porogen and calcium chloride and glutaraldehyde as physical and chemical cross-linkers. The as-synthesized PCMC beads were characterized using SEM, EDS, BET, TGA, FTIR and XPS analysis and then tested for the removal of Co(ii) from aqueous solution. The effects of the initial pH, Co(ii) concentration and temperature were investigated. It was found that the adsorption equilibrium is reached within 6 h and the maximum adsorption capacity is 46.25 mg g⁻¹. In addition, the kinetics and equilibrium data are well described by pseudo-second-order kinetics and the Langmuir isotherm model. Moreover, the desorption and re-adsorption performance was also studied, and the results revealed that the prepared new adsorbent still showed good adsorption performance after five cycles of regeneration. Finally, the adsorption mechanism, including chemical and physical adsorption, was proposed on the basis of the microstructure analysis, adsorption kinetics and isotherm results, and chemical adsorption was found to be the main adsorption mechanism during the process of the removal of Co(ii).

The as-prepared adsorbent exhibits excellent adsorption capacity and fast kinetics for Co(ii).     

Eco-friendly synthesis of graphene–chitosan composite hydrogel as efficient adsorbent for Congo red

A simple approach was utilized to synthesize graphene/chitosan-based hydrogel using glutaraldehyde as crosslinking agent in room temperature. The composite aerogel was used for removal of cationic and anionic dyes from aqueous solution. It showed high adsorption capacity towards Congo red as an anionic dye. Adsorption experiments were performed based on various parameters, such as initial Congo red concentration, solution pH and contact time. The kinetics data were analyzed using four different models and the pseudo-second-order model best described the adsorption of Congo red aerogel. The Equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm. The maximum dye adsorption capacity calculated from the Langmuir isotherm equation was 384.62 mg g⁻¹. Moreover, the aerogel was stable and easily recovered, and adsorption capacity was about 100% of the initial saturation adsorption capacity after being used three times.

Graphene/chitosan-based hydrogel was synthesized using glutaraldehyde as crosslinking agent in room temperature and it used for removal of Congo red dye from aqueous solution.     

Reusable bentonite clay: modelling and optimization of hazardous lead and p-nitrophenol adsorption using a response surface methodology approach

In this work, bentonite clay (BC) calcined at 500 °C was used as an adsorbent (BC-500) for the adsorption of Pb²⁺ and p-nitrophenol. The ability of BC-500 for the removal of Pb²⁺ and p-nitrophenol has been investigated. The adsorption studies tailored well the pseudo-first-order and the Langmuir model for Pb²⁺ and p-nitrophenol both. In addition, the optimal removal of Pb²⁺ and p-nitrophenol was found at pH 5 for Pb²⁺ and pH 6 for p-nitrophenol. However, the change of temperature (20–60 °C) was found to have a negative effect on the adsorption process on BC-500. Based on the Dubinin–Radushkevich model the adsorption occurs via a physical process. Accordingly, the adsorption mechanism was proposed using N₂-physisorption analysis before and after adsorption of Pb²⁺ and p-nitrophenol. The reusability of BC-500 was examined and the outcomes recommended that BC-500 had good potential as an economic and proficient adsorbent for Pb²⁺ or p-nitrophenol from contaminated water. Finally, the experimental Pb²⁺ and p-nitrophenol removal efficiency were found to be 90.93 ± 2.15% and 98.06 ± 1.87% while the predicted value by model equals 91.28 ± 1.68 and 97.24 ± 2.54, respectively, showing that the predicted model values are in good agreement with the experimental value.

In this work, bentonite clay (BC) calcined at 500 °C was used as an adsorbent (BC-500) for the adsorption of Pb²⁺ and p-nitrophenol.