Antibiotic removal from water: Elimination of amoxicillin and ampicillin by microscale and nanoscale iron particles

Zerovalent iron powder (ZVI or Fe⁰) and nanoparticulate ZVI (nZVI or nFe⁰) are proposed as cost-effective materials for the removal of aqueous antibiotics. Results showed complete removal of Amoxicillin (AMX) and Ampicillin (AMP) upon contact with Fe⁰ and nFe⁰. Antibiotics removal was attributed to three different mechanisms: (i) a rapid rupture of the β-lactam ring (reduction), (ii) an adsorption of AMX and AMP onto iron corrosion products and (iii) sequestration of AMX and AMP in the matrix of precipitating iron hydroxides (co-precipitation with iron corrosion products). Kinetic studies demonstrated that AMP and AMX (20 mg L⁻¹) undergo first-order decay with half-lives of about 60.3 ± 3.1 and 43.5 ± 2.1 min respectively after contact with ZVI under oxic conditions. In contrast, reactions under anoxic conditions demonstrated better degradation with t_1/2 of about 11.5 ± 0.6 and 11.2 ± 0.6 min for AMP and AMX respectively. NaCl additions accelerated Fe⁰ consumption, shortening the service life of Fe⁰ treatment systems.     

Regulating Industrial Stormwater: State Permits,Municipal Implementation,and a Protocol for Prioritization1

Abstract:  This research evaluated the effectiveness of regulations for stormwater pollutants originating from industrial facilities. Industrial facilities discharging stormwater are subject to General Permits implemented by state and federal agencies, which require facility operators to identify themselves and to implement pollution prevention measures. An overlying system of permits require Municipal Separate Storm Sewer System operators to identify and inspect facilities in their jurisdictions capable of discharging substantial pollutant loads into stormwater conveyances, introducing more active regulation and strategic prioritization, but with unequal implementation in different urban regions. This research evaluated the interaction between the regulations and ways in which the regulations succeed, or fail, at protecting water quality. The research evaluated potential for pollutant discharges at 136 industrial facilities in Pinellas County, Florida, using telephone interviews; off-site facility visits; and on-site facility inspections, targeting four industrial categories: wood products; stone, clay, glass, and concrete products; fabricated metal products; and electronic products. Results documented that a large proportion of facilities subject to General Permits conduct few or no activities likely to produce stormwater pollutants, indicating that the regulations’ equal treatment of all facilities may constitute overregulation. The research developed a methodology to assess facilities using intensity of industrial activities exposed to stormwater, a rational measurement that could regularize municipal agencies’ requirements and prioritize implementation toward facilities with the potential to impact receiving water quality.     

SBSE-TDU-GC/MS法同步测定饮用水源水中16种多溴联苯化合物

通过对萃取和解吸条件进行优化,实现搅拌棒吸收萃取(SBSE)-热脱附-气相色谱/质谱联用以同时测定饮用水源水中16种多溴联苯单体。此法在2~50 ng/L范围内线性良好,取10 m L水样,搅拌棒吸收萃取1 h后,16种多溴联苯单体的检出限为0.5~1.1 ng/L。对实际水样进行2个质量浓度的加标回收,平均回收率为89.2%~102%。     

银杏渣超临界甲醇解聚产物分析

考察了银杏渣粉末在超临界甲醇中的解聚反应,用傅立叶变换红外光谱仪(FTIR)和气相色谱/质谱联用仪(GC/MS)分析了解聚产物。结果表明,超临界甲醇解聚产物(SCMD)中成分十分复杂,GC/MS分析鉴定出86种有机化合物,其中59种为含氧有机化合物,有酯、酚、醚、醇和酮等,还检测出少量正构烷烃、烯烃、芳烃和含氮有机化合物,反映了SCMD的高含氧量特性。SCMD中10.65%的苯酚类物质、3.34%的芳烃类物质和5.20%的苯甲醚类化合物可能源于木质素在超临界甲醇中的解聚作用,而32.84%的甲酯及二甲酯类化合物可能是甲醇与银杏渣组成和解聚产物酯化反应的结果。由此可以推断出在银杏渣的超临界解聚过程中涉及了甲醇与银杏渣的醇解和热解的协同反应。     

室内空气中芳香烃的测定与污染源模拟

采用Ｔｅｎａｘ树脂吸附－热解吸／氢火焰气相色谱法定量测定室内空气中芳香烃类有机的。现场采样测定了某办公楼装修前后室内空气环境中芳香烃浓度。     

新型动态针捕集阱技术分析大气中低浓度的VOCs

本研究针对大气中挥发性有机物（VOCs）浓度低,难于分析等特点,以Carboxen 1000作为吸附剂,制作一种新型动态针捕集阱（needle trap）装置,可用于主动富集大气中低浓度VOCs.该装置与气相色谱-质谱（GC-MS）联用,操作简单、无需溶剂、容易定性定量.选择空气中苯系物（BTEX）为目标化合物,对needle trap装置从设计原理到实际应用进行了详细分析,将萃取条件与穿透体积等实验条件进行优化,建立了needle trap吸附提取空气中BTEX的最佳条件.结果表明,方法检出限低至0.05ng·mL-1,加标回收率为86.5%～110.5%,符合外场采样要求.     

Determination of urine-derived odorous compounds in a source separation sanitation system

Source separation sanitation systems have attracted more and more attention recently.However, separate urine collection and treatment could induce odor issues, especially in large scale application. In order to avoid such issues, it is necessary to monitor the odor related compounds that might be generated during urine storage. This study investigated the odorous compounds that emitted from source-separated human urine under different hydrolysis conditions. Batch experiments were conducted to investigate the effect of temperature, stale/fresh urine ratio and urine dilution on odor emissions. It was found that ammonia, dimethyl disulfide, allyl methyl sulfide and 4-heptanone were the main odorous compounds generated from human urine, with headspace concentrations hundreds of times higher than their respective odor thresholds. Furthermore, the high temperature accelerated urine hydrolysis and liquid–gas mass transfer, resulting a remarkable increase of odor emissions from the urine solution. The addition of stale urine enhanced urine hydrolysis and expedited odor emissions. On the contrary, diluted urine emitted less odorous compounds ascribed to reduced concentrations of odorant precursors. In addition,this study quantified the odor emissions and revealed the constraints of urine source separation in real-world applications. To address the odor issue, several control strategies are recommended for odor mitigation or elimination from an engineering perspective.     

Assessment of estrogen disrupting potency in animal foodstuffs of China by combined biological and chemical analyses

Food has been documented as one of major routes for human exposure to environmental estrogens（EEs）, but information on the occurrence of EEs in animal foodstuffs is still scarce.This study analyzed estrogenic activity in 16 types of animal foodstuffs（n = 142） collected from four cities（Wuhan, Guangzhou, Wenzhou and Yantai） of China by combined yeast estrogen screen（YES） bioassay and chemical analysis. By bioassay, all samples＇ extracts were found to induce estrogenic activities and the bioassay-derived 17β-estradiol equivalent（EEQbio） ranged from 8.29 to 118.32 ng/g. In addition, the samples were analyzed by liquid chromatography coupled to tandem mass spectrometry for further chemical analysis. 17β-Estradiol was found in all samples in this survey at levels of 0.44 to 15.04 ng/g.All samples had 33.1% detection rate of 17α-ethinylestradiol（EE2）, and the maximum concentration was 2.80 ng/g. Bisphenol A and 4-nonylphenols were detected in 83.8% and83.1% of samples, with concentrations up to 12.56 ng/g and 35.76 ng/g, respectively.However, the concentrations of estrone, diethylstilbestrol and 4-t-octylphenol were found to be below the limit of detection. A comparison of EEQbiomeasured from the YES assay and EEQchemcalculated from chemical analysis showed good correlation（R2= 0.84）. Based on the results, the YES assay can be used as a rapid pre-screening method for monitoring the levels of estrogenic activity in large numbers of animal foodstuffs, and chemical analysis used in combination can be used for the identification of specific EEs.     

粉煤灰增强超声/H2O2降解左氧氟沙星的实验研究

研究粉煤灰对超声/H2O2体系降解左氧氟沙星的增强效果,考察了粉煤灰添加量、H2O2浓度、溶液初始pH值、左氧氟沙星初始浓度等对降解效果的影响.结果表明,与单独超声,H2O2氧化,超声/H2O2,超声/粉煤灰,粉煤灰/H2O2氧化相比,粉煤灰有效增强了超声/H2O2体系对左氧氟沙星的降解,降解反应符合一级反应动力学.粉煤灰添加量为1.5g/L,H2O2浓度为15.0mmol/L,pH=7.16,超声功率325W,左氧氟沙星初始浓度20mg/L,反应160min,左氧氟沙星的去除率达到99.12%,TOC去除率为17.37 %.利用荧光探针法对不同体系产生的·OH浓度进行了分析比较,粉煤灰作为非均相催化剂,主要在于发生类Fenton反应.采用HPLC/MS/MS方法对3种反应产物进行了分析,结果表明左氧氟沙星主要是通过喹诺酮环失去-C2,哌嗪环去亚甲基化以及·OH进攻喹诺酮环发生降解.     

GC／MS法测定自来水中挥发性有机化合物

应用ＧＣ／ＭＳ联用仪对自来水中挥发性有机化合物进行了测定,实现了了吹扫－捕集装置与联用仪的连接,并由ＤＰＦＣ控制,使整个过程自动化。检测的自来水样中,主要有氯甲烷类,溴氯甲烷类和苯类等挥发性化合物。