Acid Volatile Sulfides (AVS) in Sediment: An Environmental Chemistry Experiment

Brouwer, Henry

doi:10.1021/ed072p182

Cited by 13 publications

(5 citation statements)

References 4 publications

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“…First and foremost, to our knowledge, it is the first laboratory experiment for undergraduate students to quantify microplastic (with an emphasis on microfibers) pollution in soil samples. Environmental concerns are of major importance to many students, and although there are many published environmental chemistry laboratory experiments, some of which deal with plastics, there are none that allow students to quantify microplastics pollution in their environment. − Second, this laboratory experiment incorporates several key topics (pH, solution concentration calculations, etc.) learned in virtually any nonmajors’ or majors’ chemistry course within a single laboratory experiment.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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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 affecting the food chain. This laboratory experiment uses current, research-based methods such that the students can determine the extent of microplastic pollution in local soil samples. This laboratory experiment can be used as either a 2 or 3 week mini-research-project for first-year undergraduate students in either an introductory chemistry course for nonmajors or a general chemistry course for majors. The laboratory experiment gives students exposure to sieving, density gradients, and exposure to the Fenton reagent to isolate microplastics from soil samples, which are then analyzed and quantified under stereomicroscope magnification. Several general chemistry topics common to most first-year chemistry courses (density and solution concentration calculations, etc.) are emphasized during the laboratory experiment. From postexperiment assessments, students showed a marked improvement in select skill sets and knowledge of the microplastic pollution problem, and some students recognized their misconceptions concerning research following the completion of this laboratory experiment.

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Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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“…These sulfides likely dominate the CRS within the gabbros. As mentioned previously, the AVS is reduced sulfur contained within unstable products that almost always form as a result of microbial activity at low temperatures (<120°C; Brouwer, 1995; Rickard & Morse, 2005), this may be also the case for the THF and means that the AVS in the study area originated mainly from low‐temperature microbial activity, indicating that the AVS in the gabbro samples formed when the cooled gabbro was close to or exposed at the seafloor.…”

Section: Discussionmentioning

confidence: 65%

“…Sulfur occurs in three main forms: acid‐volatile sulfur (AVS), chromium‐reduced sulfur (CRS), and sulfate–sulfur (SS). AVS has been experimentally defined and represents the amount of reduced sulfur (H 2 S) released by acidification (Brouwer, 1995). Rickard and Morse (2005) suggested that AVS is reduced sulfur contained within unstable products that almost always form as a result of microbial activity.…”

Section: Introductionmentioning

confidence: 99%

Sulfur sources for ultramafic‐hosted sulfide mineralization in the Tianzuo hydrothermal field, 63.5° E, South‐west Indian Ridge: Insights from sulfur and carbon isotopes

et al. 2022

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To date, discovered ultramafic-hosted seafloor massive sulfide (UM-SMS) deposits are rare, remain poorly understood in terms of their genesis, and typically form along slow-and ultraslow-spreading mid-oceanic ridges. The Tianzuo hydrothermal field (THF) is the only UM-SMS deposit identified so far along the ultraslow-spreading South-west Indian Ridge (SWIR). This study presents new detailed mineralogical and S-C isotopic data for serpentinized peridotite, gabbro, serpentinite, and sulfide ore samples from the THF and to provide new insights into the processes that formed the deposit. Chromium-reduced sulfur (CRS) and sulfate-sulfur (SS) in samples of serpentinized peridotite have positive δ 34 S values (up to 10.22‰ and 20.67‰, respectively). The CRS formed through thermochemical reduction of seawater sulfate during reactions between seawater and ultramafic rocks, whereas the SS most likely occurred as dissolved sulfate phases in seawater occupying the pore space of serpentinized peridotite after exposure at the seafloor. The serpentinite samples contain SS with δ 34 S values of 19.21‰-20.9‰, indicating infiltration by seawater that led to the deposition of seawater sulfate. The sulfide ores have acid-volatile sulfur (AVS), CRS, and SS δ 34 S values of 10.99‰-12.07‰, 2.34‰-10.98‰, and À4.13‰ to 2.76‰, respectively, indicating that the AVS and CRS within the samples are dominated by sulfur reduced from seawater sulfate (e.g., anhydrite) and leached from the surrounding wall rocks, although the re-oxidization of microbial-reduced sulfur most likely generated the sulfate with low and negative δ 34 S values. The total carbon and total organic carbon δ 13 C values of the THF samples are negative and range from À21.99‰ to À0.34‰ and À26.7‰ to À21.02‰, respectively, further suggesting that the samples record microbial activity. Gabbro samples have strongly negative AVS (À10.69‰) and CRS (À7.2‰) δ 34 S values, indicating that microbial-reduced sulfur derived from shallow levels in the crust was incorporated into the hydrothermal system that circulated through the deeper-seated gabbroic units. Our results suggest

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“…In addition, the interference of HS – has been studied here for the first time. Hydrogen sulfide is a common component of the coastal environment generated by bacterial metabolism. , Sulfide is found under anaerobic conditions such as the sediment covered with or inundated by seawater. When CO 2 levels in these environments need to be determined, H 2 S will cause interference to the traditional Severinghaus CO 2 probe because it is able to diffuse through the gas permeable membrane as a neutral species as well and change the pH of the inner NaHCO 3 in analogy to CO 2 .…”

Section: Resultsmentioning

confidence: 99%

Non-Severinghaus Potentiometric Dissolved CO₂ Sensor with Improved Characteristics

Xie

Bakker

2013

Anal. Chem.

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A new type of carbon dioxide sensor comprising a pH glass electrode measured against a carbonate-selective membrane electrode based on a tweezer type carbonate ionophore is presented here for the first time. No cumbersome liquid junction based reference element is utilized in this measurement. The sensor shows an expected nernstian divalent response slope to dissolved CO(2) over a wide range covering the routine environmental and physiological PCO(2) levels. Unlike the conventional Severinghaus CO(2) probe for which the response is substantially delayed to up to 10 min due to diffusion of carbon dioxide into the internal compartment, the ion-selective CO(2) sensor proposed here shows a response time (t(95%)) of 5 s. When used together with a traditional reference electrode, the sensor system is confirmed to also monitor sample pH and carbonate along with carbon dioxide. A selectivity analysis suggests that Cl(-) does not interfere even at high concentrations, allowing one to explore this type of sensor probe for use in seawater or undiluted blood samples. The CO(2) probe has been used in an aquarium to monitor the CO(2) levels caused by the diurnal cycles caused by the metabolism of the aquatic plants and shows stable and reproducible results.

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Acid Volatile Sulfides (AVS) in Sediment: An Environmental Chemistry Experiment

Abstract: Experimental procedure for measuring acid volatile sulfides in environmental samples.

Cited by 13 publications

References 4 publications

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

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

Sulfur sources for ultramafic‐hosted sulfide mineralization in the Tianzuo hydrothermal field, 63.5° E, South‐west Indian Ridge: Insights from sulfur and carbon isotopes

Non-Severinghaus Potentiometric Dissolved CO₂ Sensor with Improved Characteristics

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Acid Volatile Sulfides (AVS) in Sediment: An Environmental Chemistry Experiment

Abstract: Experimental procedure for measuring acid volatile sulfides in environmental samples.

Cited by 13 publications

References 4 publications

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

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

Sulfur sources for ultramafic‐hosted sulfide mineralization in the Tianzuo hydrothermal field, 63.5° E, South‐west Indian Ridge: Insights from sulfur and carbon isotopes

Non-Severinghaus Potentiometric Dissolved CO2 Sensor with Improved Characteristics

Contact Info

Product

Resources

About

Non-Severinghaus Potentiometric Dissolved CO₂ Sensor with Improved Characteristics