Assessment of cytotoxicity and toxicity for phosphonium-based deep eutectic solvents

In this work, the cytotoxicity and toxicity of phosphonium-based deep eutectic solvents (DESs) with three hydrogen bond donors, namely glycerine, ethylene glycol, and triethylene glycol were investigated. The cytotoxicity effect was tested using brine shrimp (Artemia salina). The toxicity was investigated using the two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity of tested DESs was much higher than that of their individual components, indicating their toxicological behavior was different. It was also found that there was toxic effect on the studied bacteria, indicating their potential application as anti-bacterial agents. To the best of our knowledge, this is the first time the cytotoxicity and toxicity of phosphonium-based DESs were studied.     

Removal potential of anti-estrogenic activity in secondary effluents by coagulation

Anti-estrogenic activity in wastewater is gaining increased attention because of its endocrine-disrupting function. In this study, the level and removal efficiency by coagulation of anti-estrogenic activity in secondary effluents of domestic wastewater treatment plants were studied. Anti-estrogenic activity was detected in secondary effluent samples at a tamoxifen (TAM) equivalent concentration level of 0.38–0.94 mg-TAM L⁻¹. Dissolved organic matters (DOM) with the molecular weight (MW) less than 3000 Da in hydrophobic acids (HOA) and hydrophobic neutrals (HON) fractions of the secondary effluent were the key fractions related to anti-estrogenic activity. Coagulation with FeCl₃ and polyaluminium chloride (PAC) can remove the anti-estrogenic activity of the secondary effluents, but the removal efficiency was limited. The removal efficiency using FeCl₃ coagulant was higher than that induced by PAC. Dissolved organic carbon was continuously removed with increased coagulant dose (0–120 mg L⁻¹ FeCl₃ or 0–60 mg L⁻¹ PAC). However, the removal of anti-estrogenic activity was not enhanced further when the coagulant concentration was beyond a critical value (30 mg L⁻¹ FeCl₃ or 10 mg L⁻¹ PAC). The highest removal of anti-estrogenic activity was about 36% by FeCl₃ and 20% by PAC. Size exclusion chromatography results indicated difficulty in removing DOM with MW less than 3000 Da in the secondary effluent during coagulation even at a high coagulant concentration, which led to low removal efficiency of anti-estrogenic activity.     

Analysis of Organophosphorus Pesticides in Whole Milk by Solid Phase Microextraction Gas Chromatography Method

Solid phase microextraction (SPME) was used for the extraction of residual coumaphos and dichlorvos in whole milk. The residues were analyzed by capillary gas chromatography equipped with nitrogen phosphorus detector (GC-NPD). A manual SPME holder with a 100-μm polyacrylate fiber was used. The optimized conditions for extraction by SPME method were: sample agitation, absorption temperature of 30°C, absorption time of 40 min, desorption time of 10 min, and sample volume was 16.0 mL in the vial. Under these conditions, the calibration graphs were linear in the range of 0.17 μgL^?1 to 1.75 μgL^?1 for coumaphos and 0.69 μgL^?1 to 6.90 μgL^?1 for dichlorvos. Precision was good with RSD values of 13% for coumaphos and 14% for dichlorvos. The detection limits (LOD) were 0.060 μgL^?1 for dichlorvos and 0.052 for coumaphos. The quantification limits (LOQ) were 0.086 μgL^?1 for dichlorvos and 0.066 μgL^?1 for coumaphos. The results obtained in this study suggest that SPME is a suitable technique for residual pesticide analysis of milk. The data demonstrate that particular OP pesticides used in dairy farming in the region of Minas Gerais were found to contaminate cow whole milk, and the residues are not removed by treating the milk by boiling.     

液膜法处理硫普罗宁废水的研究

采用W／O型乳状液膜法提取水溶液中的硫普罗宁,考察了载体、温度、硫普罗宁浓度以及油内比、试剂比、乳水比对提取率的影响,并得出了液膜法提取硫普罗宁的最佳乳液配方：油内比＝1：1,乳水比＝1：2,试剂比＝6－8,载体浓度＝5％,温度20℃,转速＝240－250r.min^-1,其提取率高达90％。     

BOD5 Estimation by Using UV Absorption and COD for Rapid Industrial Effluent Monitoring

The study dealt with the method to predict the BOD₅ in effluent from industrial wastewater by using the UV absorption from two wavelengths, 260 and 550 nm. The interference from suspended solids was reduced. In the same time, COD was used as the secure value to calculate BOD₅. From the representative wastewater treatment plants, the estimated effluent BOD₅ of wastewater from the Para rubber industry showed an average error at ±2.97 mg/l. While it was at ±3.31 mg/l, for frozen seafood industry. The simple mathematic equations in this study gave the assuring method for BOD₅ estimation without time consuming.     

Distribution of Ultraviolet solar Radiation at Riyadh Region, Saudi Arabia

The ultraviolet UV solar radiation flux is monitored over a fixed time interval to study the daily, monthly and annual variations for a nearly one decade in Riyadh. Mathematical expressions will be presented based on a comparison between theoretical and experimental values. It is believed that the present analysis of UV radiation suggest that the environmental effects led to a better understanding of UV scattering, UV reflection, ozone and clouds layers in Riyadh and other selected areas in the mid-east region.     

预应力锚索抗滑桩中锚索预应力的计算方法及对比研究

在预应力锚索抗滑桩的设计计算中,锚索预应力的取值对抗滑桩的内力计算影响较大,其计算方法仍然是一个需要深入研究的课题,笔者在总结锚索预应力计算方法的基础上,介绍了锚索与桩变形的协调原理,并结合工程实例对其中的3种计算方法进行了对比研究.     

毛细管柱气相色谱法测定水质五氯酚

用乙酸酐衍生,正己烷液一液萃取,毛细管柱气相色谱-电子捕获检测器对地表水、废水中五氯酚进行了测定,确定五氯酚浓度范围在5．0—500μg/L之间时,样品的测定精度、回收率及方法检出限均能满足要求。     

吹扫—捕集／气相色谱法测定水中挥发性有机物

为提高样品分析效率,研究并建立了吹扫-捕集／气相色谱／氢火焰检测器联用同时测定水中1,2-二氯乙烷、苯、甲苯、氯苯、乙苯、对-二甲苯、间-二甲苯、苯乙烯、邻-二甲苯、异丙苯、1,4-二氯苯、1,2-二氯苯、硝基苯、1,3,5-三氯苯、1,2,4-三氯苯、1,2,3-三氯苯、六氯丁二烯17种挥发性有机物的分析方法。结果表明,当进样体积为25．0ml时,最低检出限为0．0034-0．1088μg/L,相对标准偏差为1．8％～6．4％,加标平均回收率为97．6％-105．8％。该方法可快速、简便、准确、高灵敏度的测定水中17种挥发性有机物,并适用于饮用水和地表水中挥发性有机物的测定。     

气相色谱法同时测定水中28种多氯联苯单体

采用液液萃取-浓硫酸磺化净化-气相色谱电子捕获检测器同时测定水中28种多氯联苯单体,必要时利用质谱选择离子监测模式定性,考察了萃取溶剂种类和体积及盐析效应对测定的影响,比较了硫酸磺化和弗罗里硅土柱对萃取液的净化效果。方法在1.00μg/L~47.6μg/L范围内线性良好,当取样体积为200 mL时,方法检出限为0.001μg/L~0.002μg/L,基体加标回收率为95.8%~103%,相对标准偏差≤18.7%。