SiREM offers competitively priced specialty chemical analytical services to monitor remediation processes and progress including:
- Dissolved hydrocarbon gases
- Volatile fatty acids
- Compound Specific Isotope Analysis
Dissolved Hydrocarbon Gas Analysis
SiREM’s custom gas chromatographic dissolved hydrocarbon gases (DHG) analysis is based on a modified RSK-175 method developed by the US EPA. DHG analysis is used to quantify aqueous concentrations of methane, ethene, ethane and can also quantify propene, propane and acetylene.
Use SiREM DHG Quantification to:
- Confirm complete dechlorination of chlorinated ethenes, ethanes and propanes
- Quantify methanogenesis
- Quantify gases used in cometabolic remediation
Volatile Fatty Acids Analysis
Volatile fatty acids (VFAs) quantification in groundwater is used to assess electron donor status in bioremediation systems. When commonly used electron donors, such as lactate, emulsified vegetable oils (EVO) or alcohols, are fermented, VFAs are often observed. Detection of VFAs confirms that electron donor fermentation is occurring and indirectly indicates that hydrogen generation, the ultimate electron donor used by most reductive degradation microbes, is likely occurring. Quantification of VFAs also provides additional insights into electron donor status compared to total organic carbon (TOC) analysis. SiREM uses a custom ion chromatographic method for VFA quantification, capable of quantifying common VFAs including: lactate, acetate, propionate, formate, butyrate and pyruvate.
Use SiREM VFA Quantification to:
- Minimize unnecessary electron donor application leading to more effective and efficient use of electron donor and reduced costs
- Confirm the fermentation of slow release and soluble electron donors
- Determine the need for additional electron donor for complete reductive dechlorination
Anion quantification in groundwater is used to assess water quality, redox conditions, and stable tracers in remediation systems. During the onset of reducing conditions during bioremediation, common polyanionic species like nitrate and sulfate are reduced to their less oxidized states (i.e., nitrogen gas and sulfide). These changes in nitrate and sulfate concentrations are often indicators that biologically mediated changes in the redox chemistry of the aquifer are occurring. The concentrations of these analytes can also impact the dosage of electron donors, as these species can consume more electron donor than site compounds of interest. Quantification of anionic tracers, such as bromide, can also be used in determining groundwater velocities or flow paths. SiREM uses a custom ion chromatographic method for anions quantification based on US EPA Method 300 to quantify chloride, bromide, nitrite, nitrate, sulfate and phosphate.
Use SiREM Anion Quantification to:
- Assess the concentrations of redox-sensitive anionic species including nitrate and sulfate
- Confirm the onset of suitable reducing conditions required for reductive dehalogenation
- Trace the groundwater velocity and flow path using stable anionic tracers, such as chloride or bromide
Compound Specific Isotope Analysis
Compound Specific Isotope Analysis (CSIA) has emerged as a powerful molecular tool for contaminant source information as isotopic signatures from stable isotopes such as carbon, hydrogen, oxygen, nitrogen, chlorine, sulfur, can be traced back to specific mechanisms and/or origin. Overall, CSIA provides a quantitative approach to differentiate between biotic and abiotic degradation reaction pathways and contaminant source and can be applied as a line of evidence for monitored natural attenuation (MNA) of contaminated sites.
Use SiREM CSIA to:
- Confirm contaminant reaction pathways
- Identify source information of individual contaminants
- Provide additional lines of evidence of MNA as a part of SiREMNA™