Abatement of cyanide and ammoniacal-N from coke-oven wastewater using natural adsorbents: A comparative study

The present study aims at efficient abatement of pollutants from coke-oven wastewater using environment-friendly and low-cost adsorbents for a green world. The adsorbent used were native laterite soil (NLS), heat-treated laterite soil (HTLS), native shale (NS) and Heat-treated shale (HTS). One factor at a time (OFAT) approach was followed to determine the most effective condition based on the maximum removal. Heat-treated laterite soil and native shale were found most effective among their counterparts. Freundlich model was found best to analyze equilibrium data. The real coke-oven wastewater was collected and experiments were performed in batch mode. The percentage removal of cyanide (88.09% and 95.31%) and ammoniacal-N (87.28% and 92.12%) were found satisfactory when heat-treated laterite soil and native shale were used as adsorbents, respectively.     

超高效液相色谱-串联质谱法同时测定土壤中30种抗生素

土壤基质复杂,土壤中残留的抗生素种类繁多,浓度多为痕量水平,高灵敏度的仪器方法、有效的净化和富集方法、多种类抗生素的同时检测是土壤中抗生素检测的重点和难点。该研究建立了固相萃取-超高效液相色谱-串联质谱法同时测定土壤中7类(磺胺类、氟喹诺酮类、四环素类、大环内酯类、β-内酰胺类、酰胺醇类和林可酰胺类)30种抗生素的方法。首先,通过参数优化确定最佳质谱条件,选择BEH-C18色谱柱,以0.1%(v/v)甲酸甲醇溶液-0.1%(v/v)甲酸水溶液为流动相,10%(v/v)甲醇水溶液为进样溶剂。然后,通过提取条件(萃取剂种类及体积)和固相萃取条件(上样液pH、淋洗液有机溶剂比例、洗脱液种类及体积)的优化,确定使用10 mL乙腈和Na₂EDTA-McIlvaine缓冲液的混合溶液(1∶1, v/v)为萃取剂,萃取液pH调节至8.0后,采用HLB小柱进行固相萃取,并以10 mL超纯水淋洗净化,最后用10 mL甲醇-乙腈(1∶1, v/v)洗脱目标分析物。在优化的分析条件下,该方法的定量限为0.043~4.04 μg/kg,目标化合物的标准曲线线性关系良好,相关系数在0.992~1.00的范围内,在20、100、200 μg/kg的添加浓度下,大多数目标化合物的加标回收率范围为44.8%~164%,相对标准偏差为0.700%~14.8%。将该方法用于6个实际土壤样品的分析,结果显示在30种抗生素中,17种抗生素有检出,其中12种抗生素的检出率为100%。环丙沙星和诺氟沙星是土壤样品中含量最高的两种抗生素,它们的含量范围分别是13.7~32.1和15.6~43.6 μg/kg。本研究建立的方法简单、快速、溶剂使用量少,能用于土壤样品中痕量水平的7类30种抗生素的同时测定。     

灌浆理论浅析

详细分析了两种灌浆液体的类型牛顿体和宾汉姆体的力学特征以及二者之间异同和联系,介绍了岩土体结构的基本理论、灌浆的基本理论、渗透灌浆理论机制及内容、劈裂灌浆理论机制及内容、压密灌浆理论机制及内容。     

污染土壤的物化修复治理技术研究

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术进行了分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

环境化学开放性实验设计:重金属污染土壤的化学淋洗*

介绍了一个开放性环境化学实验。该实验以被重金属污染的土壤为研究对象,分别使用稀盐酸、乙二胺四乙酸、氯化钙为淋洗剂,对其进行化学淋洗修复。通过电感耦合等离子体光谱仪分析比较修复前后土壤中铅、镉的含量,用以帮助学生加深理解配合/螯合作用、酸-碱反应、离子交换反应、胶体的性质、土壤重金属形态、土壤性质与组成等相关环境化学知识。实验所用的土壤样品由学生自选,不同类型土壤的理化性质影响淋洗效果,从而增加了实验结果的不确定性。本实验贴近学科前沿且联系工程实际,可激发学生独立思考和探索精神,提高学生的科研能力与解决复杂问题的能力。     

固相萃取/气相色谱-质谱法对土壤中有机氯农药的分析及基质效应研究

建立了一种固相萃取/气相色谱-质谱法同时测定土壤中23种有机氯农药的方法,并研究了不同基质效应补偿方式。土壤样品经正己烷∶丙酮(体积比1∶1)提取,弗罗里土小柱净化,采用气相色谱-质谱仪检测。结果发现7种有机氯存在中/强程度的基质效应;在10 mL二氯甲烷∶正己烷(体积比1∶9)+10 mL丙酮∶正己烷(体积比1∶9)为固相萃取的洗脱剂,且脉冲压力为275.8 kPa条件下,可将23种有机氯的基质效应均控制在20%以内。23种有机氯农药在0.4～10μg·mL~(-1)质量浓度范围内线性良好,相关系数(r~2)均不小于0.999 2,检出限为1.0～8.6μg·kg~(-1),定量下限为4.0～34.4μg·kg~(-1);在20、60、100μg·kg~(-1)3个加标水平下空白土壤中的平均回收率为46.3%～127%,相对标准偏差(n=6)为0.68%～15%。采用该方法在某土壤样品中检出α-六六六、γ-六六六、p,p′-DDE、异狄氏剂醛、p,p′-DDT 5种有机氯农药。     

高效液相色谱–串联质谱法同时测定土壤中8种杀菌剂残留

建立高效液相色谱-串联质谱法同时测定土壤中戊唑醇、腈菌唑、腈苯唑、氟硅唑、三唑酮、丙环唑、烯唑醇、苯醚甲环唑8种杀菌剂残留量的方法。采用QuEChERS样品前处理方法对土壤样品进行提取、净化和富集,用电喷雾离子源、正负离子扫描,以多反应监测(MRM)模式进行定性和定量分析。在优化的实验条件下,8种杀菌剂的质量浓度在0.01~0.50 mg/L范围内与色谱峰面积均成良好的线性关系,相关系数均大于0.995,方法检出限为0.005~0.010 mg/kg。样品平均加标回收率为85.6%~102.2%,测定结果的相对标准偏差为4.6%~13.2%(n=5)。该方法操作简便,灵敏度和准确度高,满足土壤中戊唑醇等8种杀菌剂残留量的测定要求。     

Phytochemical Analysis and Habitat Suitability Mapping of Glycyrrhiza glabra L. Collected in the Hatay Region of Turkey

The growth and quality of licorice depend on various environmental factors, including the local climate and soil properties; therefore, its cultivation is often unsuccessful. The current study investigated the key factors that affect the contents of bioactive compounds of Glycyrrhiza glabra L. root and estimated suitable growth zones from collection sites in the Hatay region of Turkey. The contents of three bioactive compounds (glycyrrhizic acid, glabridin, and liquiritin), soil factors (pH, soil bearing capacity, and moisture content), and geographical information (slope, aspect, curvature, elevation, and hillshade) were measured. Meteorological data (temperature and precipitation) were also obtained. An analysis of variance (ANOVA) and multivariate analysis of variance (MANOVA) were performed on the data. The soil bearing capacity, moisture content, slope, aspect, curvature, and elevation of the study area showed statistically significant effects on the glycyrrhizic acid and liquiritin contents. A habitat suitability zone map was generated using a GIS-based frequency ratio (FR) model with spatial correlations to the soil, topographical, and meteorological data. The final map categorized the study area into four zones: very high (15.14%), high (31.50%), moderate (40.25%), and low suitability (13.11%). High suitability zones are recommended for further investigation and future cultivation of G. glabra.     

Simple Derivatization–Gas Chromatography–Mass Spectrometry for Fatty Acids Profiling in Soil Dissolved Organic Matter

Dissolved organic matter is an important component of the global carbon cycle that allows the distribution of carbon and nutrients. Therefore, analysis of soil dissolved organic matter helps us to better understand climate change impacts as it is the most dynamic and reactive fraction in terrestrial ecosystems. Its characterization at the molecular level is still challenging due to complex mixtures of hundreds of compounds at low concentration levels in percolating water. This work presents simple methods, such as thermochemolysis– or derivatization–gas chromatography, as an alternative for the analysis of fatty acids in dissolved organic matter without any purification step. The variables of the protocols were examined to optimize the processing conditions for the C₉–C₁₈ range. As a proof of concept, fatty acid distributions of soil percolating water samples from a long-term field experiment were successfully assessed. The variability of dissolved organic acid distributions was pronounced through depth profile and soil treatment but no major change in composition was observed. However, although the optimization was done from C₉ to C₁₈, detection within the C₆-C₃₂ fatty acids range was performed for all samples.     

Enantioselective separation and dissipation of pydiflumetofen enantiomers in grape and soil by supercritical fluid chromatography–tandem mass spectrometry

Pydiflumetofen is registered in many countries and is widely used in crop production in the racemate form. However, the environmental behavior of the enantiomers has not been studied. An effective and sensitive chiral analytical method was first established for analyzing the pydiflumetofen enantiomers by supercritical fluid chromatography with tandem triple quadrupole mass spectrometry. The enantiomers could be separated and detected using the Chiralcel OD‐3 column in less than 3 min. The separation conditions were as follows: mobile phase, CO₂/methanol (80:20); flow rate, 1.0 mL/min; column temperature, 30°C, auto back‐pressure regulator pressure, 2000 psi with modified quick, easy, cheap, effective, rugged, and safe sample treatment method. The average recoveries of analytes from both matrices at three spiking levels were in the range of 84.1–103.0%. The limit of quantitation for each enantiomer was 0.005 mg/kg with a baseline resolution of approximately 1.64. The method was applied to monitor the enantioselective dissipation of pydiflumetofen in grape and soil. In grapes, (?)‐pydiflumetofen was degraded more rapidly than (+)‐pydiflumetofen. In soil, (+)‐pydiflumetofen was preferentially degraded. The data provided useful references for the risk assessment and rational use of pydiflumetofen in agriculture.