PermeOx Plus Enhanced Aerobic Biodegradation
Introduction Successful bioremediation of petroleum contamination through aerobic microbial respiration depends on a number of factors including the presence of appropriate microbes, nutrients, electron donors and terminal electron acceptors. In the aerobic metabolism of petroleum contaminants, oxygen acts as a terminal electron acceptor and petroleum contaminants act as electron donors, which are then oxidized. Often, the limiting factor in aerobic bioremediation of petroleum contaminants is oxygen. PermeOx Plus provides oxygen through a reaction of calcium peroxide and water: CaO 2 + 2H 2 O Ca(OH) 2 + H 2 O 2 2H 2 O 2 O 2 + 2H 2 O PermeOx Plus is a timed release form of calcium peroxide that releases sufficient oxygen over an extended time period to enhance the biodegradation of petroleum hydrocarbons and other biodegradable contaminants in soil and groundwater. It is well documented that the release of oxygen in the subsurface environment enhances the biodegradation of petroleum hydrocarbons. Based on extensive laboratory studies, PermeOx Plus releases oxygen at higher rates of release than other solid peroxygen products and therefore provides a useful and cost-effective mechanism for enhancing the aerobic bioremediation of petroleum contaminants. Cumulative Oxygen Release In a study conducted at FMC's Princeton, New Jersey Research Facility, the oxygen-releasing capacity of a MgO 2 -based product and PermeOx Plus were conducted over a one-year time frame. Results of the study show that PermeOx Plus released significantly more oxygen than the MgO 2 product. These charts show laboratory studies, actual performance in the field will depend on field conditions. The significance of these tests lie in the fact that hydrated calcium peroxide, which releases hydrogen peroxide and forms calcium hydroxide, was found to release its oxygen over an extended time frame while hydrated magnesium peroxide, which forms magnesium hydroxide, creates a hardened outer shell that traps available oxygen from being released. This is further supported by the fact that calcium hydroxide is 3, times more soluble than magnesium hydroxide. Cumulative Oxygen Release (mg/i) 35 3 25 2 25 1 5 PermeOx Plus vs MgO 2 -Based Product PermeOx Plus MgO2-based 2 product 5 1 15 2 25 3 35 4 Days Data provided by FMC Corporation Safety and Handling PermeOx Plus is a solid peroxygen and as such is an oxidizer. Contact with combustible material should be avoided. This includes paper, cotton, organics, wood, leather, and other reducing agents. PermeOx Plus is not flammable, however, it will release oxygen that is one of the elements of the fire triangle. Spills should be diluted in water to allow the release of oxygen and disposed of via a treatment system in accordance with governmental agency regulations. Personal Protective Equipment Mixing PermeOx Plus can be mixed with water to form a slurry for injection via direct push. The slurry may be used to form an oxygen barrier to control the leading edge of plume. In the solid form, PermeOx Plus may bed the floor of an excavation to control residual contaminants. PermeOx Plus can be slurried up to a concentration of 65% by weight. However, most slurries in the field do not exceed 45% by weight. The slurries formed by PermeOx Plus are easy to suspend and form a soft solid, that can be resuspended on stirring. Continuous agitation is needed while injecting the PermeOx Plus. PermeOx Plus represents no significant hazard with regard to adsorption, inhalation, or ingestion. Airborne dust is irritating to eyes, nose, throat, and lungs, but poses no significant long term inhalation hazard. Personal protective equipment should include, safety goggles, gloves, apron, and dust respirator. Refer to the Material Safety Data Sheet for additional safety and health requirements.
Case Study #1 Soils TPH Concentration mg/kg 16 14 12 1 8 6 4 2 Reduction of TPH by Addition of PermeOx Plus Predicted concentration during cold weather without amendments Actual concentration with PermeOx treatment 15 3 55 85 9 12 Days Data provided by FMC Corporation A spill of diesel fuel occurred in a high traffic area in the winter. Because the spill occurred on a busy highway interchange, cleanup efforts had to be quick and non-invasive, with minimal mobilizations to the site. PermeOx Plus was tilled into the top 3 feet of contaminated soil to enhance the microbial degradation of the remaining fuel contamination. After only 85 days, the total Petroleum Hydrocarbon (TPH) concentrations in soils decreased from 1,5 mg/kg to the cleanup goal of 1 mg/kg. It is noteworthy that the actual TPH degradation rate from the addition of PermeOx Plus far exceeded the anticipated rate with ambient temperatures in the 2 F range. Case Study #2 Groundwater BTEX ug/l 4 35 3 25 2 15 1 5 PermeOx Plus Injection Response in Groundwater After Addition of PermeOx Plus Dissolved Oxygen 1 2 3 4 5 Months Courtesy of Panther Technologies Dissolved Oxygen MW-8 MW-1 MW-7 MW-2 MW-4 MW-3 MW-4 25 2 15 1 5 Average Site-Wide Dissolved Oxygen mg/l A large volume of gasoline and related petroleum products had leaked from a major petroleum storage terminal over a period of time causing soil and groundwater contamination with benzene, ethylbenzene, toluene, and xylenes (BTEX) over an area approximately three acres in size. Concentrations of up to 3,7 ug/l BTEX were detected in source area groundwater on-site over the last 1 years. After several other technologies and products failed to lower site-wide BTEX concentrations, a slurry of PermeOx Plus was injected into groundwater using a grid injection strategy within the contaminant plume. The dissolved oxygen (DO) levels in groundwater rose immediately after injection and remained elevated after 15 days. After three months, the average BTEX concentration in groundwater across the site dropped 77%, to an average concentration of 258 ug/l. The most dramatic decrease in concentrations occurred in two wells, where concentrations dropped 1%, from roughly 45 ug/l to non-detectable levels. The application of PermeOx Plus as a slurry had increased the DO in groundwater to over 2 mg/l in many areas across the site. This was found to be sufficient to enhance the natural degradation process, which had stalled due to lack of oxygen.
Benefits There are many technical and commercial benefits to using this improved time release oxygen formulation. PermeOx Plus was specifically designed to enable more creative and successful use of the product in environmental applications, as compared to other solid peroxygen compounds. Several of these benefits are listed below: Cost-effective form of treatment and/or polishing step Contains 18% active oxygen vs 1% for magnesium based products Utilizes natural processes Enhances microbial growth/bioremediation processes Minimum site disruption Effective at achieving compliance end points Slurry remains workable for injections longer and does not set up like concrete Larger particle size reduces dust hazards and material handling issues in the field Increased solubility maintains formation permeability Can be applied in dilute form through existing monitoring wells without damage to wells It releases all of its available oxygen as opposed to locking up Potential Applications for PermeOx Plus * Former Source Area Building #1 Groundwater Flow Direction Building #2 Option 4 Injection Through Well Radius of Injection Option 1 Direct Application in Excavation Option 2 Plume Grid Application Contaminant Plume Injection Point Option 3 Leading Edge Injection Barrier Unnamed Tributary In order to be effective, the timed release oxygen released form PermeOx Plus must be in contact with the contaminants and the contaminant-degrading microbes. Application techniques must be customized to meet the demands of a particular site, but typically include the following: Option 1. Direct Application in an Excavation Option 2. Subsurface Injection in a Grid within the Contaminant Plume Option 3. An Injected Leading Edge Barrier Option 4. Injection into an Existing Well * The applications depicted on this drawing are for illustrative purposes only. FMC recommends that you contact a qualified remediation engineer/applicator before using this product.
Plate Count Studies Control Magnesium-Based PermeOx Plus Product Water contaminated with a mixture of diesel fuel and gasoline (17,376µg/l BTEX) was divided into three sample sets and studies were run in triplicate within each set. One set was dosed with 1,2 mg/kg of PermeOx Plus, one with 1,5 mg/kg of a magnesiumbased product, and one served as a control. Initially, a baseline Total Aerobic Plate Count (TAPC) was performed before dosing the water. The baseline TAPC was 238, colony forming units (CFU)/ml. Four weeks after dosing the samples, a.1ml and 1ml sample were taken from the water in each sample and controls and serial dilutions were made and plated for TAPC. The results are as follows: Table 1 Total Aerobic Plate Counts PermeOx Plus 1,21, CFU/ml (428% increase from baseline) Control 91, CFU/ml (62% decrease from baseline) Magnesium-Based Product 62, CFU/ml (252% increase from baseline) The plate counts clearly show that the water treated with PermeOx Plus supports more rapid growth of petroleum-degrading microbes than either the control or the water treated with a magnesium-based product. Further, the presence of a high ph product did not affect the inoculation of microbes. Manufactured by: FMC Corporation For a PermeOx Plus distributor in your area call FMC at 866-86-476 1735 Market Street Philadelphia, Pennsylvania 1913 USA Phone: 215.299.6 Fax: 215.299.675 www.fmc.com The FMC logo and PermeOx are trademarks of FMC Corporation. FMC Corporation. All rights reserved. 1/11EIT-DE 5/2/5.RS