含碳酸盐水溶液中扑热息痛的光解研究

采用动力学方法研究了环境浓度范围内的扑热息痛在含碳酸盐溶液中的光解,比较了碳酸盐自由基和羟基自由基对扑热息痛的光解效果,探讨了pH值、硝酸根离子、腐殖质、氯化钠、钙镁离子等因素对扑热息痛光解的影响.利用GC/MS技术鉴定了扑热息痛的光解产物,并探讨了扑热息痛在碳酸根体系中可能的光解途径.结果表明,扑热息痛与碳酸盐自由基反应的二级反应速率常数为 k.=5.0×107L·(mol·s)-1,低于与羟基自由基反应的二级反应速率常数kb=8.1×109L·(tool·s)-1,但是由于天然水体中碳酸盐自由基的稳态浓度较高,所以碳酸盐自由基对扑热息痛光解的影响和羟基自由基大致相当.提高体系pH值,加入硝酸根离子、氯化钠或者钙镁离子都会加快扑热息痛的光解速率;而加入Suwannee河富里酸则会降低光解速率.     

1株扑热息痛降解新菌株的选育及其代谢特性研究

通过选择性富集培养,从活性污泥样品中选育到1株能以扑热息痛为唯一碳源生长的好氧细菌F1.根据菌株F1的形态特征、生理生化特性、16S rRNA基因序列分析及和Biolog测试,初步鉴定为亲铜(Cupriavidus necator)菌属.菌株F1降解扑热息痛最适pH值和温度分别为7.0和30℃;菌株降解扑热息痛的过程遵...     

Admissions to the Cardiff Poisons Unit involving paracetamol poisoning (1989–2002)

In this study, the trends in paracetamol poisoning were examined over more than a decade in Cardiff and compared with patterns for other substances taken in overdose. All data concerned patients aged 14 years and over of both genders, who were referred to the Cardiff Poisons Treatment Unit between 1989 and 2002. The Chi-squared test for trend was used. During the 14-year study period, there were 18,834 admissions to the hospital, involving poisoning either with pure paracetamol or paracetamol in combination with other drugs (37%, N = 6975), and the proportion of admissions with paracetamol poisoning increased from 36% in 1989 to 44% in 2002. Paracetamol was the second most common drug associated with admissions related to poisoning to the Cardiff Poisons Treatment Unit (37%), after alcohol (48%). Thus, paracetamol poisoning remains a major public health concern in the UK.     

扑热息痛在硝酸根溶液中的光解研究

以中压汞灯为光源模拟阳光,研究了环境浓度范围内的硝酸根溶液中扑热息痛（paracetamol）的光解;探讨了pH值、硝酸根浓度以及天然水体中广泛存在的腐殖质、碳酸盐等因素对扑热息痛间接光解的影响.结果表明,扑热息痛的光解符合一级动力学,提高硝酸根浓度,其光解速率可由0.79×10^-3 min^-1增至8.90×10^-3 min^-1.提高体系pH值,加入碳酸氢根或高浓度的Suwannee河富里酸（SRFA）会促进扑热息痛的间接光解;而加入Nordic湖腐殖酸(NOHA)或低浓度的SRFA产生抑制作用.采用分子探针方法鉴定了硝酸根在光照过程中产生的羟基自由基.利用GC/MS技术鉴定了扑热息痛的光解产物,探讨了扑热息痛在硝酸根体系中可能的光解反应历程.     

Investigation of acetaminophen adsorption with a biosorbent as a purification method of aqueous solution

ABSTRACT

Pharmaceutical compounds are considered emerging environmental pollutants that have a potential harmful impact on environment and human health. In this study, the spiky green horse-chestnut shell was used for the biosorption and removal of acetaminophen from aqueous solution. It was analysed how the parameters, like contact time, pH, mass of biosorbent and temperature, influence the effectiveness of acetaminophen removal from aqueous solutions. The equilibrium was quickly achieved after 10?min (～60%). The amount of acetaminophen adsorption slightly increased with the increase of the mass of biosorbent, and for example for an aqueous solution containing 10?mg/L of acetaminophen adsorption was increased from 62% to 81%. The promising results obtained at pH ranged between 2 and 9, which shows that the adsorption of acetaminophen did not depend on the pH and it may be a consequence of the predominant microporous sorbent and its surface charge. The result is better correlated to a pseudo-second-order kinetic model of type 2 (r ²?=?0.9992) than pseudo-first-order. A sorption mechanism of acetaminophen on biosorbent was also proposed. The sorption of acetaminophen over biosorbent is mainly preceded by hydrophilic interactions between hydroxyl and carbonyl groups in pharmaceutical molecules and hydroxyl and carboxyl groups on the surface of biosorbent.     

亚硫酸氢盐强化微量Fe2+活化过二硫酸盐降解扑热息痛

Fe²⁺可激活过二硫酸盐（PDS）快速产生硫酸根自由基（SO₄^-·），但Fe²⁺会快速转化为低活性的Fe³⁺，且Fe²⁺的投加量普遍较大，限制了该体系的广泛应用.采用亚硫酸氢盐（BS）强化微量Fe²⁺-PDS体系降解水中的扑热息痛（APAP）.结果表明，投加BS可促进Fe²⁺-Fe³⁺的循环，明显改善Fe²⁺-PDS体系对APAP的降解效果，在最优条件下（PDS=0.6 mmol·L^-1；BS=0.4 mmol·L^-1；Fe²⁺=10 μmol·L^-1；pH=4）下，APAP （4 μmol·L^-1）可在180 s内被完全降解.同时，APAP的降解速率随BS （0~0.6 mmol·L^-1）和PDS （0.2~1.5 mmol·L^-1）浓度的增大而升高，适量提高Fe²⁺浓度可促进APAP的降解，但增加BS的投加次数对降解速率影响不大.HCO₃^-与HPO₄^2-明显抑制了体系降解APAP的效率，Cl^-和NO₃^-有轻微抑制作用，腐殖酸（HA）则影响不大.通过淬灭实验和电子顺磁共振波谱检测，证实了体系中SO₄^-·、·OH和单线态氧的产生，其中SO₄^-·是降解APAP的主要活性物种.利用三维荧光光谱技术对APAP降解过程进行了表征，表明APAP降解产物具有荧光特性.此外，还鉴定出5种中间产物，并提出了3种可能的降解途径.体系在实际水体中的效能低于超纯水中的表现，但延长反应时间可明显增强降解效果，表明BS-Fe²⁺-PDS体系是一种有前景的有机污染物降解方法.     

活性炭催化臭氧氧化扑热息痛的机制研究

采用活性炭催化臭氧处理典型解热镇痛药扑热息痛,研究了活性炭/臭氧体系的协同效应,优化了工艺参数,分析了降解产物并探讨了降解机制.结果表明:在臭氧活性炭体系下,反应60 min后,TOC的去除率为55.11%,效果明显优于臭氧体系的20.22%和活性炭体系的27.39%之和,具有明显的协同作用,并且BOD5/COD比值从反应前的0.086提高到反应后的0.543,可生化性显著提高.研究了pH、臭氧投加量、污染物初始浓度和活性炭投加量等操作参数的作用规律.在此基础上,探讨了臭氧活性炭体系在不同pH下的催化反应机制,发现在酸性条件下是吸附和臭氧直接氧化共同作用,在碱性条件下以活性炭催化臭氧氧化为主.