1
|
Alexander WA. Methyl-Cyclohexane Methanol (MCHM) Isomer-Dependent Binding on Amorphous Carbon Surfaces. Molecules 2021; 26:molecules26113411. [PMID: 34200015 PMCID: PMC8200209 DOI: 10.3390/molecules26113411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
In January 2014, over 10,000 gallons of methyl-cyclohexane methanol (MCHM) leaked into the Elk River in West Virginia, in a chemical spill incident that contaminated a large portion of the state’s water supply and left over 300,000 residents without clean water for many days and weeks. Initial efforts to remove MCHM at the treatment plant centered on the use of granulated activated carbon (GAC), which removed some of the chemical from the water, but MCHM levels were not lowered to a “non-detect” status until well after the chemical plume had moved downstream of the intake. Months later, MCHM was again detected at the outflow (but not the inflow) at the water treatment facility, necessitating the full and costly replacement of all GAC in the facility. The purpose of this study is to investigate the hypothesis that preferential absorbance of one of the two MCHM isomers, coupled with seasonal variations in water temperature, explain this contrary observation. Calculated intermolecular potentials between ovalene (a large planar polycyclic aromatic hydrocarbon) and the MCHM isomers were compared to physisorption potentials of MCHM onto an amorphous carbon model. While a molecular mechanics (MM) force field predicts no difference in the average interaction potentials between the cis- and trans-MCHM with the planar ovalene structure, MM predicts that the trans isomer binds stronger than the cis isomer to the amorphous carbon surface. Semi-empirical and density functional theory also predict stronger binding of trans-MCHM on both the planar and amorphous surfaces. The differences in the isomer binding strengths on amorphous carbon imply preferential absorbance of the trans isomer onto activated charcoal filter media. Considering seasonal water temperatures, simple Arrhenius kinetics arguments based on these predicted binding energies help explain the environmental observations of MCHM leeching from the GAC filters months after the spill. Overall, this work shows the important implications that can arise from detailed interfacial chemistry investigations.
Collapse
|
2
|
Perfetto M, Kirkham SG, Ayers MC, Wei S, Gallagher JEG. 4-Methylcyclohexane methanol (MCHM) affects viability, development, and movement of Xenopus embryos. Toxicol Rep 2021; 8:38-43. [PMID: 33391995 PMCID: PMC7772722 DOI: 10.1016/j.toxrep.2020.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/17/2020] [Accepted: 12/10/2020] [Indexed: 10/26/2022] Open
Abstract
Following chemical spill disasters, it is important to estimate the effects of spilled chemicals on humans and the environment. Here we analyzed the toxicological effects of the coal cleaning chemical, 4-methylcyclohexane methanol (MCHM), which was spilled into the Elk River water supply in 2014. The viability of HEK293 T human cell line cultures and Xenopus tropicalis embryos was negatively affected, and the addition of the antioxidants alleviated toxicity with MCHM exposure. Additionally, X. tropicalis embryos suffered developmental defects as well as reversible non-responsiveness and melanization defects. The impact MCHM has on HEK293 T cells and X. tropicalis points to the importance of continued follow-up studies of this chemical.
Collapse
Affiliation(s)
- Mark Perfetto
- Department of Biology, 53 Campus Drive, University of West Virginia, Morgantown, WV, 26506, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Scotia G Kirkham
- Department of Biology, 53 Campus Drive, University of West Virginia, Morgantown, WV, 26506, USA
| | - Michael C Ayers
- Department of Biology, 53 Campus Drive, University of West Virginia, Morgantown, WV, 26506, USA
| | - Shuo Wei
- Department of Biology, 53 Campus Drive, University of West Virginia, Morgantown, WV, 26506, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Jennifer E G Gallagher
- Department of Biology, 53 Campus Drive, University of West Virginia, Morgantown, WV, 26506, USA
| |
Collapse
|
3
|
Introducing an applied reactor for treatment of wastewater containing propylene glycol. SN APPLIED SCIENCES 2019. [DOI: 10.1007/s42452-019-1638-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
4
|
Chaudhuri S, DiScenza DJ, Verderame M, Cromwell B, Levine M. Colorimetric detection of polycyclic aromatic hydrocarbons using supramolecular cyclodextrin dimer-squaraine constructs. Supramol Chem 2019. [DOI: 10.1080/10610278.2019.1579332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - Dana J. DiScenza
- Department of Chemistry, University of Rhode Island, Kingston, RI, USA
| | - Molly Verderame
- Department of Chemistry, University of Rhode Island, Kingston, RI, USA
| | - Benjamin Cromwell
- Department of Chemistry, University of Rhode Island, Kingston, RI, USA
| | - Mindy Levine
- Department of Chemistry, University of Rhode Island, Kingston, RI, USA
| |
Collapse
|
5
|
Affiliation(s)
- Teresa L. Mako
- Department of Chemistry, University of Rhode Island, 140 Flagg Road, Kingston, Rhode Island 02881, United States
| | - Joan M. Racicot
- Department of Chemistry, University of Rhode Island, 140 Flagg Road, Kingston, Rhode Island 02881, United States
| | - Mindy Levine
- Department of Chemistry, University of Rhode Island, 140 Flagg Road, Kingston, Rhode Island 02881, United States
| |
Collapse
|
6
|
Horzmann KA, de Perre C, Lee LS, Whelton AJ, Freeman JL. Comparative analytical and toxicological assessment of methylcyclohexanemethanol (MCHM) mixtures associated with the Elk River chemical spill. CHEMOSPHERE 2017; 188:599-607. [PMID: 28917212 DOI: 10.1016/j.chemosphere.2017.09.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/01/2017] [Accepted: 09/06/2017] [Indexed: 05/27/2023]
Abstract
On January 9, 2014, a chemical mixture containing crude methylcyclohexanemethanol (MCHM) contaminated the water supply of Charleston, West Virginia. Although the mixture was later identified as a mix of crude MCHM and stripped propylene glycol phenyl ethers, initial risk assessment focused on 4-MCHM, the predominant component of crude MCHM. The mixture's exact composition and the toxicity differences between 4-MCHM, crude MCHM, and the tank mixture were unknown. We analyzed the chemical composition of crude MCHM and the tank mixture via GC/MS and, based on identified spectra, found that crude MCHM and the tank mixture differed in chemical composition. To evaluate acute developmental toxicity, zebrafish embryos were exposed to 0, 1, 6.25, 12.5, 25, 50, or 100 parts per million (ppm; mg/L) of 4-MCHM, crude MCHM, or the tank mixture. The percent mortality and percent hatch, larval morphology alterations, and larval visual motor response test were used to establish toxicity profiles for each of the chemicals or mixtures. The acute toxicity differed between 4-MCHM, crude MCHM and the tank mixture with significant differences in survival, hatching, morphology, and locomotion at levels as low as the short-term screening level of 1 ppm, suggesting a need for further research into human health risks. This study is the first to evaluate the developmental toxicity of the tank mixture and highlights that studies evaluating risk should not assume the effects of 4-MCHM or crude MCHM are representative of the Tank 396 mixture.
Collapse
Affiliation(s)
| | - Chloe de Perre
- Department of Agronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Linda S Lee
- Department of Agronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Andrew J Whelton
- Lyles School of Civil Engineering and Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Jennifer L Freeman
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, USA.
| |
Collapse
|
7
|
Cozzarelli IM, Akob DM, Baedecker MJ, Spencer T, Jaeschke J, Dunlap DS, Mumford AC, Poret-Peterson AT, Chambers DB. Degradation of Crude 4-MCHM (4-Methylcyclohexanemethanol) in Sediments from Elk River, West Virginia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12139-12145. [PMID: 28942635 DOI: 10.1021/acs.est.7b03142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In January 2014, approximately 37 800 L of crude 4-methylcyclohexanemethanol (crude MCHM) spilled into the Elk River, West Virginia. To understand the long-term fate of 4-MCHM, we conducted experiments under environmentally relevant conditions to assess the potential for the 2 primary compounds in crude MCHM (1) to undergo biodegradation and (2) for sediments to serve as a long-term source of 4-MCHM. We developed a solid phase microextraction (SPME) method to quantify the cis- and trans-isomers of 4-MCHM. Autoclaved Elk River sediment slurries sorbed 17.5% of cis-4-MCHM and 31% of trans-4-MCHM from water during the 2-week experiment. Sterilized, impacted, spill-site sediment released minor amounts of cis- and up to 35 μg/L of trans-4-MCHM into water, indicating 4-MCHM was present in sediment collected 10 months post spill. In anoxic microcosms, 300 μg/L cis- and 150 μg/L trans-4-MCHM degraded to nondetectable levels in 8-13 days in both impacted and background sediments. Under aerobic conditions, 4-MCHM isomers degraded to nondetectable levels within 4 days. Microbial communities at impacted sites differed in composition compared to background samples, but communities from both sites shifted in response to crude MCHM amendments. Our results indicate that 4-MCHM is readily biodegradable under environmentally relevant conditions.
Collapse
Affiliation(s)
- Isabelle M Cozzarelli
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Denise M Akob
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Mary Jo Baedecker
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Tracey Spencer
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Jeanne Jaeschke
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Darren S Dunlap
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | - Adam C Mumford
- U.S. Geological Survey, National Research Program, Reston, Virginia 20192 United States
| | | | - Douglas B Chambers
- U.S. Geological Survey, Virginia-West Virginia Water Science Center, Charleston, West Virginia 25301 United States
| |
Collapse
|