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Oil-Contaminated Water Treatment

Sustainable Bioremediation of Industrial Wastewater

CL Solutions provides a special consortium of microbes for oil-contaminated water treatment.   Under various conditions, the oil removal rate was as much as 1,300 mg/L/day.  In some situations the remediation goal is simply to remove the visible sheen or separate-phase oil.  With aeration, CL Solutions microbes were able to remove the visible oil layer and reduce the TPH concentration from 29% to less than 1% in 30 days at a waste oil lagoon. For more information and other case studies click here.

A special consortium of microbes removed the visible oil layer from this wastewater.

Oil-Water Separator Discharge Improvement

Similar to waste water treatment in lagoons, Petrox is used to improve the performance of industrial and commercial oil-water separators by degrading dissolved-phase oil.  The treatment goal is to reduce the TPH concentration to below discharge limits to avoid fines, surcharges and potential discontinuation of service.  The Petrox organisms may be introduced into the collection and treatment system at any point,  but are usually added to the collection or equalization sump for longer contact time.  In most cases, the dissolved phase total petroleum hydrocarbons  (TPH) is reduced by 50% to 90% in a manner of days.

For example, at a large city municipal Petrox reduced the TPH discharge from 25.9 to 7.40 mg/L in three days.  At smaller retail oil-change centers the reduction was from 278 mg/L TPH to 14.1 mg/L TPH  in 21 days.  The biological treatment is maintained by adding a gallon of Petrox to the sump weekly.

The cost for maintaining discharge compliance at these applications is as little as $250 per month.

Dry Cleaner Bioremediation and Brownfield Redevelopment

Site Description

Dry cleaning solvent spills in a storage area lead to the contamination of soil and ground water on the property of a 50-year-old dry cleaners in the middle of a hot brownfield redevelopment.   After the contaminated soil was excavated for off site disposal to the most practical extent, residual perched ground water contamination impacted the redevelopment of the property.

The soil excavation was used as an infiltration gallery as part of a recirculating ground water recovery and treatment system.  The flushing reduced contaminant concentrations, but the levels were still far above the levels required to achieve no further action status.  CL-Out was added to the recirculating ground water and the cleanup goals were achieved in less than two years and were maintained through two years of  post treatment monitoring.

Site Characteristics

Geology and Hydrogeology

The site is on a fluvial terrace adjacent to the Ohio River.  The shallow soils are clayey silts to sit to eight feet deep.  An interbedded sandy zone that formed the first water-bearing zone was encountered from 8 to 12 feet deep.  Perched ground water occurred in the sandy zone at 12 feet below grade.

Ground Water Contamination

 The size of ground water plume that resulted from the spills was estimated to be 3,500 square feet.    The ground water contamination was mainly PCE with a maximum concentration of 11,000 ug/l prior to soil removal or ground water treatment.  The daughter compounds TCE and DCE were detected up to 17 and 12 ug/l respectively.  After three years of recirculation and flushing, the maximum PCE concentration was reduced to 2.3 ug/l and the daughter compounds were below detection limits.

Results

CL-Out bioaugmentation was implemented to supplement the flushing system.  By adding CL-Out on two occasions over two years, the contaminant concentrations were reduced to below drinking water standards.  During two years of post treatment monitoring the DCE concentrations rebounded to above the MCLs.  CL-Out bioaugmentation was implemented again and within three months the contaminant levels were below drinking water standards and remained below drinking water standards for nine months.  After post closure monitoring verified the cleanup goals would be maintained, the KDEP issued a “No Further Action” letter for the site.

The following chart shows the PCE contaminant trend in one of the key monitoring wells during the remediation and post closure monitoring.

Cost

The CL-Out cost during this remediation project was less than $10,000.

 

In-Situ Petroleum Bioremediation Rates With Petrox

Recent data from field applications of Petrox bioremediation show degradation rates of 100 to 500 micrograms per liter (ug/ml) per day. These degradation rates are for total petroleum hydrocarbons or total BTEX, depending on the site monitoring requirements.

Achieving high degradation rates requires high initial concentrations. Initial concentrations of 1,000 to 10,000 ug/l were used to develop these degradation rates.

At lower concentrations, the degradation rates depend on effective distribution of microbes for cell to contaminant contact. Secondly, desorption of petroleum constituents from submerged soil may cause rebound and suggest lower degradation rates. For these reasons we cannot calculate a degradation rate for petroleum at low concentrations.

Fast, Easy Drainage Ditch Cleanup

Petrox bioremediation of surface spills and TPH accumulation in drainage ditches and maintenance areas is simple. Using a simple manual sprayer, the Petrox is applied to the soil surface. The Petrox microbes begin bioremediation immediately to enhance natural digestion of the petroleum, like probiotics for petroleum destruction.  Unlike detergents that wash the visible oil deeper in the soil, Petrox microbes destroy the all of the oil.

The following chart and table show the results of the application of Petrox to petroleum-contaminated soil in a drainage ditch. After about 60 days, the TPH concentration was reduced by 67% in one location and over 90% in three locations.  A second application to the 30 ft. north area reduced the concentration even more.

The problem was solved for a total Petrox cost of $600.

houston soil treatment chart houston soil treatment table

 

 

 

Bioremediation of BTEX at an Industrial Site in Florida

Background

Petrox® bioaugmentation was used to remediate ground water contaminated by benzene, toluene, ethylbenzene and xylene (BTEX) at an industrial facility in central Florida (Facility ID No. 8521705). The bioremediation was implemented in perimeter wells around the source area where air sparging and vapor extraction was implemented. This combined approach provided cost-effective, full-site remediation by using complementary technologies.

Remediation Approach and Results

Petrox® was introduced into the contaminated ground water in the perimeter of the source area plume by injection through temporary well points. Two applications of Petrox® were completed. The initial application was in December 2007 and a subsequent application was completed in April 2008. During each application 550 gallons of Petrox® microbial slurry were injected into the ground water through 19 injection points. The treatment covered an area of approximately 7,000 square feet.

The ground water treatment results were monitored by laboratory analysis of ground water samples for the contaminants of concern. The quarterly monitoring results after the applications showed an immediate and continuous decrease in the BTEX concentrations. The following chart shows the total BTEX concentrations in three quarterly sampling events after the implementation of Petrox® bioaugmentation.

industrial-site6

Conclusions

This project demonstrates two of the benefits of aerobic bioaugmentation. Petrox® organisms were able to metabolize the BTEX compounds, which were initially at part per million levels, to below detection limits. Bioaugmentation provides active control of the site with hydrocarbon-degrading organisms compatible with air sparging and vapor extraction in the source area, where the contaminant concentrations persisted longer than in the bioaugmentation area.