Environmental Chemistry Laboratory Research Articles

Examination of the Relationship between University Students’ Perceptions Regarding the Chemistry Laboratory Environment and their Chemistry Laboratory Anxiety

This research examined the relationship between university students’ perceptions of the chemistry laboratory environment and their chemistry laboratory anxieties. The method of the study is correlational research. The study was conducted on 281 university students who enrolled in biology, physics, chemistry, and science teaching programs and took the chemistry laboratory course. The chemistry laboratory classroom environment scale and the chemistry laboratory anxiety scale were used to collect research data. The obtained data were analyzed via the structural equation model. The research results revealed that students’ perceptions of the chemistry laboratory environment were a significant predictor for their chemistry laboratory anxiety. Furthermore, it was determined that 13% of the variance in laboratory anxiety was explained by the perceptions of the laboratory environment.

Reform and Practice of Environmental Chemistry Laboratory Teaching under the Background of Emerging Engineering Education

Reform and Practice of Environmental Chemistry Laboratory Teaching under the Background of Emerging Engineering Education

The Effectiveness of Virtual Learning Process on Environmental Chemistry Laboratory Course

The impact of advanced technology is perceived in every sector, including education. As the Ministry of Education and Culture program, distance learning has become applied in Indonesia, especially with this pandemic COVID-19. The learning model used in the course will affect student understanding in this situation, especially for an experimental study that aims to enhance student skills in the laboratory. The virtual laboratory practice is an additional learning model used in Environmental Chemistry Laboratory Course. Before, the Environmental Laboratory Course used only video to deliver learning materials. This research is experimental research that aims to evaluate the additional virtual laboratory practice's impact on student grades compared to the previous method. The research result was obtained by comparing the practical course's assessment results in 2019/2020 to 2020/2021. A questionnaire was also used to collect student opinions about the new learning method. The number of samples in this research was 395 students. The results show that the average students' grades using explanatory video only is 89, then with additional virtual laboratory practice are 88. From the questionnaire, 46% of the respondent said the application increased their understanding of the learning materials, and they also enjoyed using the application. It could be concluded that the virtual laboratory practice did not improve the assessment result of the course but enhanced the student interest. Keywords: Distance learning, Laboratory course, virtual laboratory practice

Isotopic profiling of natural uranium mined from northern Nigeria for nuclear forensic application

Four mined samples of natural uranium from northern Nigeria were studied through inductively coupled plasma mass spectrometry, at the Environmental Analytical Chemistry Laboratory, University of the Witwatersrand, Johannesburg. The samples were characterised for lead, thorium and uranium isotopic concentrations, isotopic ratios and age. The objective was to obtain nuclear forensic fingerprints as baseline data to add to the Nigerian National Nuclear Forensic Library. Results showed significant variation in the isotopic concentrations of lead, thorium and uranium across the mines. Isotopic ratios of 238U/235U, 235U/238U and 234U/238U across the sample of 137.881±0.007, 7.253×10-03±2.05×10-04 and 5.540×10-05±4.08×10-07 were found to be consistent with the natural values. The age of natural uranium is comparable to the age of earth. Uranium, lead, and thorium isotopic concentrations and ratios, as well as the age of the samples characterised, provide an isotopic profile that can be used for nuclear forensic application. Significance: Given the abundant deposits of natural uranium in Africa and the consequent potential for nuclear insecurity, determining the isotopic profiles and signatures of natural uranium is important for application in nuclear forensics. Isotopic concentrations of 232Th, 238U, 235U and 234U from the respective sampling sites differed significantly, thereby providing characteristic isotopic profiles.

Analysis of student perceptions in the learning environment chemical laboratory

This study aims to analyze the perceptions of chemistry students towards the chemistry laboratory learning environment at Universitas Negeri Jakarta, by using instrument the Chemistry Laboratory Environment Inventory (CLEI). The sample used was 400 students of the Depart of Chemistry and Chemistry Education Universitas Negeri Jakarta. The research method used is a survey method using a questionaerie, laboratory observations and interviews with students. The survey results show the dimensions of student cohesiveness, open-endedness, integration, and students’ perception rule clarity is very good, only in the open-ended dimension and environment material resulting in a multitude of answers dominance never, rarely, and sometimes

An Undergraduate Experiment to Investigate Air Pollutants Created from Lightning

Chemistry of the environment has been a long-standing and important area of scientific research. Atmospheric chemistry is of particular interest in society due to the impact that rising levels of pollutants are having on the climate. It is well-known that combustion processes create CO and NOx, which leads to the creation of other pollutants, such as ozone and CO2. There are natural processes, such as lightning, that also create a significant amount of pollutant gases. The purpose of this guided and open inquiry laboratory experiment is to provide an opportunity for students to investigate how lightning may produce pollutant gases in the atmosphere. In the guided inquiry experiment, a sealed IR gas cell containing air is exposed to a spark or corona discharge created by an Oudin coil to mimic lightning. IR spectroscopy is used to monitor the reaction progress and identify new species made after exposure to the electrical discharge. Based on the results, students draw conclusions about what types of gases are created in the two different discharge processes and how lightning may contribute to atmospheric pollutants. Students move on to the open inquiry to further investigate aspects of atmospheric gases, where they develop their own hypothesis and methods based on one of the provided suggestions, such as the effect of spark and corona discharge on pure oxygen, nitrogen, or carbon dioxide gases, the kinetics of ozone creation and decay, and the temperature dependence of NO2 dimerization. Although designed for an honors general chemistry course, this experiment can be adapted for second-semester general chemistry, environmental chemistry, analytical, and physical chemistry laboratory courses. Results from these experiments are presented, and the relevant atmospheric chemical processes are discussed. The impact of this experiment on perceived gains in knowledge, the value of inclusion in the curriculum, and the design of the experiment were assessed, and the results are discussed.

Identificação do tipo de acidez responsável pela agressividade de águas subterrâneas

O estado do Ceará localizado na região Nordeste do Brasil, encontra-se, na sua totalidade, incluído no denominado Polígono das Secas e apresenta um regime pluviométrico marcado por extrema irregularidade de chuvas. A formação geológica, com cerca de 75% de solos cristalinos, torna o potencial de águas subterrâneas bastante baixo mas não diminui sua importância como alternativa de abastecimento de água para a população. Na região é comum a captação da água subterrânea, através de poços e dependendo da agressividade da água devido à presença de acidez, situações de corrosão poderão ocorrer no concreto da estrutura da parede de proteção e segurança do poço e nas tubulações de ferro. Diante do exposto, o estudo teve como objetivo identificar o tipo de acidez responsável pela agressividade, com base no índice de saturação de Langelier em águas de poços localizados em cinco distritos de dois municípios do Estado do Ceará. As amostras foram coletadas durante os meses de janeiro, fevereiro e março de 2020 e as análises foram realizadas no Laboratório de Química Ambiental do Núcleo de Tecnologia e Qualidade Industrial do Ceará. De acordo com os resultados obtidos, concluiu-se que a agressividade das águas foi devido à acidez carbônica.

Applicability of purge and trap gas chromatography- mass spectrometry method for sensitive analytical detection of naphthalene and its derivatives in waters.

Nowadays, a wide variety of chemicals has emerged because of increasing industrial and human activities. Thus, environmental chemistry laboratories performing analytical measurements need rapid and sensitive methods more than ever to get reliable quantitative data. For this purpose, a purge and trap gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the rapid, simple, and sensitive determination of the presence of naphthalene and its derivatives in waters. The method validation was based on specificity, calibration curve linearity, limit of detection (LOD) and limit of quantification (LOQ), accuracy (recovery), precision, matrix effects (MEs), and measurement uncertainty. This method showed excellent linearity from 1.00 to 40.00 μg/L except naphthalene (0.50-40.00 μg/L) because the correlation coefficients were higher than 0.997 for all analytes. The LOQ values varied from 0.312 to 0.746 μg/L, and the LOD values changed from 0.094 to 0.224 μg/L with relative standard deviations (RSDs) for all compounds below 10% (3.12-7.46), respectively. Recoveries ranged from 81.9% to 95.6%, and repeatability and reproducibility (in terms of RSD for six measurements) were lower than 10% in all cases. F test was subjected on the related data at 95% confidence level, and no statistically significant difference was observed. There was no critical ME (recovery varied from 80% to 110% in all matrices). In measurement uncertainty, the expanded uncertainties of each analyte were changed in the range of 0.39-0.52 μg/L, and the calibration curve and repeatability had dominant effects on the combined uncertainty. The application to real samples was successfully assessed by the developed method. These results indicate that the developed method is suitable for the determination of naphthalene and its derivatives in waters.

Classificação da água subterrânea para uso na irrigação

Em regiões que sofrem de escassez continua de água, a instalação de poços é uma pratica comum. Embora seja um meio eficaz para a obtenção de água, esse método não garante a qualidade da água. No Estado do Ceará, predomina o embasamento das rochas cristalinas e, como consequência, as águas contêm elevadas concentrações de íons que conferem uma alta salinidade a água. Uma das utilizações dessas águas é para a irrigação e, águas com alta salinidade, causam danos às espécies vegetais. Por essa razão, torna-se necessário uma avaliação da qualidade da água para esse uso. O estudo foi realizado em águas subterrâneas captadas de poços localizadas em cinco localidades de dois diferentes municípios do Estado do Ceará. As amostras de água foram coletadas durante o período de janeiro a março de 2020 e os parâmetros selecionados foram cálcio, magnésio e sódio, para o cálculo da Razão de Adsorção de Sódio (RAS) e, a Condutividade Élétrica (CE), para fazer a classificação das águas, segundo os riscos de sodificação (sódio) e salinização. As análises seguiram as metodologias descritas no Standard Methods for the Examinations of Water and Wastewater (APHA, 2012) e foram realizadas no Laboratório de Química Ambiental da Fundação Núcleo de Tecnologia Industrial do Ceará (NUTEC). Conforme os resultados obtidos para as classes de risos, pode-se concluir que as águas subterrâneas estavam impróprias para o uso em irrigação, a não ser que precauções especiais sejam tomadas para o uso.

A chemistry laboratory platform enhanced with virtual reality for students’ adaptive learning

In recent years, virtual reality system (VRS) has become more prominent among many researchers due to its capacity of providing as close as possible to real-life experience for users from diverse fields of life, such as tourism, academics, manufacturing and medicine. In this study, we present an VRS for the titration experiment in a chemistry laboratory to enable students to learn the titration experiment in a virtual laboratory environment before proceeding to the chemistry wet lab. The virtual chemistry laboratory environment was developed using the Unity Real-Time Development Platform, and the Microsoft SQL Server was used for the database to enable easy assessment of the student performance after the experiment. To evaluate our VRS, we tested it among 50 students (25 high school and 25 first-year undergraduate chemistry students). We collate their user’s experience through a structured questionnaire, and the responses from the students show that 60% agreed that it was helpful, 66% easy to interact with and 54% strongly agreed that it improved learning. Therefore, it is evidence that the proposed VR-enabled chemistry laboratory platform could be used to improve the understanding of chemistry titration practical process among students.

Influência da proximidade de um aterro sanitário na qualidade das águas

Diversos fatores contribuem para contaminação das águas tanto superficiais como subterrâneas localizadas próximas a um aterro sanitário. Isto deve-se provavelmente ao fato da formação de compostos decorrentes da decomposição da matéria orgânica do material que é depositado no aterro sanitário. Em consequência, a qualidade dessas águas são alteradas e não podem mais ser utilizadas para os diversos fins pela população. O estudo foi realizado em águas de rio e poço localizadas próximo a um aterro sanitário situado em um munícipio dentro da área metropolitana de Fortaleza, capital do estado do Ceará. Foram coletadas três amostras de água de rio e uma amostra de água subterrânea durante três meses e foram realizadas as análises dos parâmetros indicadores de qualidade estabelecidos pelas Resolução nº 357, de 17 de março de 2005 e Resolução nº 396, de 07 de abril de 2008, do Conselho Nacional do Meio Ambiente (Conama). As análises seguiram as metodologias descritas no Standard Methods for the Examinations of Water and Wastewater (APHA, 2012) e foram realizadas no Laboratório de Química Ambiental da Fundação Núcleo de Tecnologia Industrial do Ceará (NUTEC). De acordo com os resultados obtidos as concentrações de alguns parâmetros se encontraram em desacordo com os valores máximos estabelecidos pelas legislações citadas, sinalizando uma preocupação de risco para a saúde da população do local.

Evaluation of selected heavy metals on the artisanal gold mining sites in North Rift Region, Kenya

ASGM activity significantly contributes to the economies of developing countries with a consequent impact on the socio-ecological systems. The impacts are largely due to the wide use of mercury in the extraction processes. It also deforestates the exploited areas with consequent loss of biodiversity and ecosystem functions. ASGM has varied impacts of adverse health effects and it is said that mercury has more significant health effects than other heavy metals (Cd, Pb, As, and Cr). Due to dearth in the studies on artisanal mining in Kenya, the study sought to evaluate the concentration levels of selected heavy metals on the artisanal mining sites in Nandi and West Pokot Counties of Kenya in order to determine their nature, concentration levels and suggest mitigation measure. The study was done in two artisanal gold mining sites in Kapsaos in Nandi County and Sekker in West Pokot County in Kenya and employed a comparative analysis to examine the attributes of these locational spaces. Thirteen samples were randomly collected from tailings at different points from the tailing disposal site in Kapsaos areas and Sekker site. The samples were transported prepared and stored at Environmental Chemistry Laboratory, the University of Eldoret where it was subjected to Atomic Absorption Spectroscopy (AAS). The laboratory analysis results showed that the samples from both artisanal gold mining sites contained several heavy metals which included Chromium, Cadmium, and Lead. Overall, the mining sites in Nandi County had the following concentration of Cr, 0.4195 ppm, Cd, 0.2470 ppm, and Pb, 0.6300 ppm, while the mining sites in West Pokot county had the following concentrations: Cr, 0.1790 ppm; Cd, 0.0050 ppm; and Pb, 0.7400 ppm. Besides, the concentrations levels of Lead and Cadmium were above the WHO guidelines. A casual look at the concentration levels indicates that the mining sites in Nandi County have higher concentration levels of selected heavy metals (Pb, Cd and Cr) that in West Pokot County which was attributable to the ASGM activities. The study concluded that ASGM activities excavates, destabilizes the stables states of elements and then concentrates them. Finally, the study recommends that ASGM be upscaled instead of being frowned upon. Further studies on the potential socio-economic impacts on the ASGM activities in Western Kenya because the activity is considered a complementary/supplementary economic activity. Keywords: Artisanal and small scale gold mining (ASGM), artisanal mining, selected heavy metals, mercury, heavy metal pollution DOI: 10.7176/JEES/10-6-12 Publication date: June 30 th 2020

Ruination Science: Producing Knowledge from a Toxic World

The multiple environmental crises our planet is experiencing forces us to change the ways we engage with it, especially the ones developed by scientific disciplines such as toxicology. In particular, widespread degradation should lead us to develop scientific practices that take environmental ruination as a framework condition, not only as an object of analysis. In doing so, we should take into account the practice of science at laboratories located in the peripheries of global science, institutions that have coexisted with extensive environmental and material decay from their very onset. Contributing to this task, this paper analyzes the case of Centro Nacional del Medio Ambiente (CENMA), an environmental chemistry laboratory located in Santiago, Chile. Established in mid-1990s, decades of continual budget cuts left it in a state of almost terminal ruin. In its struggle to remain relevant, CENMA developed an alternative kind of scientific practice, ruination science. Although always precarious, ruination science also tends to be well adapted to engage with impurity, resilient but fragile, and ethically entangled, prioritizing attachment and compromises over the application of certain standard recipes or procedures. Beyond its particularities, CENMA’s ruination science provides us with several valuable keys to better deal with worlds facing multiple kinds of anthropogenic degradation.

Analysis of Pesticides in Plant Foods by QuEChERS and Gas Chromatography–Mass Spectrometry: An Undergraduate Laboratory Experiment

Undergraduate students in an environmental chemistry laboratory course were taught QuEChERS (quick, easy, cheap, effective, rugged, and safe), a sample preparation procedure that is commonly used i...

Detecting Microplastics in Soil and Sediment in an Undergraduate Environmental Chemistry Laboratory Experiment That Promotes Skill Building and Encourages Environmental Awareness

Environmental pollution is both a worldwide and a local issue, and microplastic pollution in particular is receiving increased attention due to its prevalence and bioaccumulation potential affectin...

Recycling Metals from Spent Screen-Printed Electrodes While Learning the Fundamentals of Electrochemical Sensing

A laboratory experiment in which students recycle silver and platinum selectively from spent screen-printed platinum electrodes is described. The recovered silver in solution is used to show its spontaneous redox reaction with a copper sheet. The recovered platinum is electrodeposited onto a screen-printed carbon electrode to develop a sensor for hydrogen peroxide quantification in a commercially available hair lightener. The experiment is designed for a 3 h laboratory period and can be adapted for upper-division undergraduate education, graduate education, or even research students in electrochemistry, environmental chemistry, analytical chemistry, materials science, chemical engineering, or physical chemistry laboratories. It allows students to train in adequately handling strong acids, working in fume hoods, and neutralizing acid gases. It also allows one to teach the basics of metal recycling and enables students to learn the fundamentals of electrochemical sensing. The experiment also helps to raise student awareness of waste disposal problems and how recycling can help to reduce the amount of waste that we create.

Learning environment in the undergraduate chemistry laboratory courses in Beirut

The undergraduate chemistry laboratory is an ideal place for meaningful learning to occur, and the laboratory work is considered as an integral part of most chemistry courses; however, a significant proportion of laboratory experiments remain highly prescriptive and fail to challenge undergraduate students. This study investigated the chemistry laboratory environment among 170 undergraduate students at a private university in Beirut, Lebanon. Data were collected using the Chemistry Laboratory Environment Inventory with its both versions: Actual Chemistry Laboratory Environment Inventory and Preferred Chemistry Laboratory Environment Inventory. The findings of this study showed that the students prefer a chemistry learning environment with greater levels of integration and material environment, but less level of open-endedness. Suggestions for improving chemistry laboratory learning environments are provided.
 Keywords: Chemistry, laboratory, undergraduate courses, learning environment.

Project-Based Learning in Undergraduate Environmental Chemistry Laboratory: Using EPA Methods To Guide Student Method Development for Pesticide Quantitation

Presented is a project-based learning (PBL) laboratory approach for an upper-division environmental chemistry or quantitative analysis course. In this work, a combined laboratory class of 11 environmental chemistry students developed a method based on published EPA methods for the extraction of dichlorodiphenyltrichloroethane (DDT) and its environmental degradation products (dichlorodiphenyldichloroethane [DDD] and dichlorodiphenyldichloroethylene [DDE]) through Soxhlet extraction and quantitation using gas chromatography–mass spectrometry (GC–MS). From the derived procedures, the students spent the remainder of the semester performing extractions and analyses to detect pesticide drift from the San Joaquin Valley of California into the Sierra Nevada Mountain Range. The EPA methods used allow for a multitude of research-level questions which could be answered within a similar course with a specific question appropriate to student interest and regional environmental issues. This pedagogical approach provide...

Students’ perceptions of a project-based Organic Chemistry laboratory environment: a phenomenographic approach

Students can perceive the laboratory environment in a variety of ways that can affect what they take away from the laboratory course. This qualitative study characterizes undergraduate students’ perspectives of a project-based Organic Chemistry laboratory using the theoretical framework of phenomenography. Eighteen participants were interviewed in a semi-structured format to collect their perspectives of the Organic Chemistry lab. Eight qualitatively different ways in which students perceived the lab were uncovered and an outcome space was derived. The findings of this work are intended to inform the design of the undergraduate laboratory curriculum in chemistry that facilitate better student learning. Implications and suggestions for design of laboratory courses based on the results of this work are also presented.

Editorial introductions

Editorial introductions