Hugh McLaughlin, P.E. is an independent consultant. Below is a summary of problems solved by Organoclay. For more information on Organoclays go to http://biomininc.com

As a Chemical Engineering Consultant, I often find a significant portion of the engineering challenge is associated with cleaning aqueous effluents to acceptable levels for discharge or for recycling to reduce overall water consumption. Furthermore, having worked with activated carbon for over 30 years, I have come to appreciate that there are applications that activated carbon is sometimes the “miracle cure” or even the “only game in town”.

There are a number of applications where activated carbon alone is not efficient or is even ineffective at removing certain contaminants. Because activated carbon adsorbs the contaminants on the internal surface area of the activated carbon, it is really only able to remove organics that are soluble in water and diffuse into the carbon particles. When a separate organic phase is present, even as a relatively low level of emulsified hydrocarbon, the material has a tendency to coat the activated carbon particles on the outside — and block access to the internal surface area. It sort of reminds me of the old Sherwin-Williams slogan “Cover the Earth” — but the impact is to render the activated carbon a gooey ineffective mess, while simultaneously breaking through an unacceptable portion of the still emulsified phase.

Years ago, I was delighted to learn that Organoclays can be used ahead of the activated carbon adsorbers to effectively remove the emulsified organic phase. This pre-filter approach avoids the premature demise of the activated carbon beds, which then serve as polishing filters and operate for dramatically longer periods of time before breakthrough.

Another area where activated carbon is ineffective is in any ion exchange applications, since activated carbon has effectively no cation exchange capacity. Some activated carbon will oxidize over time to develop carboxylic acid functionalities, but the usable capacity is unaffordable. One might be tempted to try ion exchange resins in such instances, but the typical exchange capacities are unrealistic for system that are not regenerating the resins, considering the cost of the ion exchange media.

There is a growing body of experimental data and field experience that Organoclays also function to provide ion exchange capacity in many aqueous clean up applications. While the specific mechanism of ion exchange is unclear, the capacity and effectiveness for a wide range of trace ions, including fertilizers (phosphorus, nitrates) and heavy metals (chromium, arsenic, selenium — it is a long list), makes Organoclays deserving of consideration in a wide variety of ion removal applications.

The removal mechanism probably involves several possible ionic sites within the Organoclay, which are formed by modifying bentonite, with a starting ion exchange capacity of 70-90 meq/gram, with quaternary amines. The capability to remove emulsified non-aqueous phases is usually attributed to the quaternary amines, but it is likely that a significant portion of the original bentonite ion exchange capacity is still available for binding the ionized heavy metals and other ions in solution that are more highly charged than the typical background salinity of monovalent cations and anions.

In summary, just as Organoclays have become the “miracle cure of choice” for non-aqueous emulsions that vex activated carbon adsorption, there may be a growing class of instances where Organoclays effectively address a specific requirement for removing trace heavy metals and even low levels of common fertilizer anions. While the specific mechanism is complex and the capacity and effectiveness are hard to predict, the performance of Organoclays is easy to test. In those cases where Organoclays work, they often emerge as significantly less expensive than the short list of other options.

Free Oil

• Droplet size 10 microns and larger
• Will separate in a 6″ high beaker in 90 seconds
• Requires gravity separation such as API type

Dispersed

• Droplet size 149 microns to 20 microns
• Will separate in a 6″ high beaker in 80 minutes
• Requires gravity coalescing such as the OCS separator

Mechanically Emulsified Oil

• Droplet less than 20 microns in size
• Will not separate in a 6″ high beaker in 80 minutes
• Requires chemical treatment and coalescing or chemical treatment and Dissolved Air Floatation or Ultra Filtration

Chemically Emulsified Oil

• Droplet less than 20 microns in size with surfactants or emulsifiers present
• Will not separate in a 6″ high beaker in 80 minutes
• Requires chemical treatment and coalescing or chemical treatment and DAF or UF, the surfactants will pass through with the permeate

Soluble Oil

• No discernible droplet size and the ions are crossed linked in the water
• Will not separate in a 6″ high beaker in 80 minutes
• Requires chemical treatment and coalescing or chemical treatment and DAF or UF, (with solublizers staying with the permeate)

Introduction

Environmental awareness is presently manifesting itself in tightening environmental legislation throughout the world.

Many industries discharge liquid waste contaminated with hydrocarbon or oil-like pollutants. Sources of such waste include petroleum and petrochemicals refining and processing, tramp oils from machine tool coolants, utility operations, sanitary sewage, bilge and ballast water, contaminated surface runoff.

Oil discharges into the environment typically have deleterious effects. Oily waste discharge creates potential safety hazards and consumes dissolved oxygen necessary to aquatic life.

Toxic effects of oil fall into two categories (Laws, 1981):

1. Effects due to smothering or coating of animals or plants with oil. Coating effects are most noticeable when large amounts of free oil are present as in an oil spill. Coating effects are not usually found when only parts per million (ppm) are present, as is the case of an industrial plant effluent.

2. Disruption of animal’s or plant’s metabolism due to the ingestion of oil and incorporation of oil into the organism’s fatty tissues. Generally, toxic compounds are not water-soluble but are oil soluble, thus tending to accumulate in body fat and damaging animals or human beings.

This paper introduces the oil-in-water separation theory and the basic criteria for selection and design of a separation system, presenting an up-to-date overview of technologies currently available and of their capabilities in terms of achievable discharge levels.

2. Background

Oil can exist in water in several forms:

• Free Oil is composed by oil droplets with a diameter exceeding about 30 microns. It rises quickly to the water surface when given a sufficient quiescent settling period.
• Mechanical dispersions are distributions of fine oil droplets ranging in size from less than 1 micron to 30 microns and having stability due to electrical charges and other forces, but not due to the presence of surface active materials.
• Chemical emulsions are distributions of oil droplets similar to mechanical dispersions, but which have additional stability due to chemical interactions typically caused by surface active agents present at the oil/water interface.
• Dissolved oil is dissolved in a chemical sense; the removal by normal physical means is impossible.
• Oil that adheres to the surface of particulate materials is referred to as oil-wet solids.

The degree of an oil/water separation problem depends on the oil droplet size distribution. Separation problems also involve chemicals other than oil, which have an effect on the treatment required.

The degree of the dispersion/emulsion of the oil is difficult to assess, but steps can be taken to discourage its formation by:

1. Preventing from using detergents, which may cause stable chemical emulsions.

2. Ensuring an adequate size piping to avoid the possibility of turbulence and formation of fine droplet dispersions.

3. Avoiding devices such as pumps, especially centrifugal ones, valves, especially globe ones, and other restrictions in flow, such as elbows, tees, etc., or simply unduly small line sizes, which may create shear stresses and enhance the formation of mechanical dispersions. As a matter of fact, where an oil and water mixture has to be presented to the separation equipment, it is of the utmost importance to select a pump which imparts the lowest amount of energy to the mixture, as any excess energy thus created has to be removed by the equipment. For this reason, the use of high speed centrifugal pumps, although relatively cheap and small, should be avoided and pumps of low shear characteristics, such as peristaltic or progressive cavity, used.

Ideal inlet conditions for an oil-water separator are:

1. Gravity flow (not pumped) in the inlet piping.
2. Inlet piping sized for minimum pressure drop.
3. Inlet piping straight for at least ten pipe diameters upstream of the separator (directly into nozzle).
4. Inlet piping containing a minimum of elbows, tees, valves, and other fittings.
5. Inlet piping should be as smooth as possible to avoid turbulence caused by pipe roughness. Smooth PVC is preferable to rough concrete. Nevertheless it must be pointed out that a slight amount of turbulence (i.e. at Reynolds numbers close to translation) is likely to increase the probability to coalescence with other oil droplets.

The importance of viscosity

From Stokes’ Law, the lower the water viscosity, the faster the oil rises in water.

Increasing the temperature will significantly reduce water viscosity. For example, oil droplets in water at 4 degrees C (40 degrees F) will rise at only half the rate as if they were at 32 degrees C (90 degrees F), if other parameters remain the same.

The importance of specific gravity and oil droplets diameter

From Stokes’ Law, the greater the difference in specific gravity between oil and water, the faster the oil droplet rise in water. For example, a fuel oil that has a specific gravity of 0.8 will rise twice as fast as oil with a specific gravity of 0.9.

The importance of both oil droplet diameter and specific gravity is pointed out in the following table where it may be seen the travel time for a 10 cm (4 in.) vertical distance for various values of the two parameters. Time is expressed in hr.min.sec.

Determination of specific gravity, viscosity and oil droplet size

Water viscosities as well as specific gravities of water and oil are readily obtained from literature data. It must be pointed out that, in the design phase of separation devices, a wide variety of temperatures (and therefore of viscosities and specific gravities) have to be considered to take into account summer and winter conditions as well as possible process upsets.

Oil droplet size is much more difficult to be determined. The most common way to measure it is by particle size counters such as laser light scattering analyzers.

This treatment sequence requires a reaction tank and a pH adjustment tank. The salts and polymers that break the emulsions are added to the tank by means of metering pumps and mixed with mechanical mixers, or injected in line prior to the tank and the pump, using the pump as the mixer. Metals can be removed in the second tank. The final polishing step again consists of a tank filled with organoclay. Activated carbon use is optional.

Either of these systems depends on a final polishing step with organoclay to allow zero discharge and recycling of the wastewater. Wastewater treatment costs range around $0.5-0.10/gallon, which is considerably cheaper than hauling it away, particularly if the wastewater is hauled over long distances. There are no liabilities such as those involved with hauling wastewater and the potential of spills due to accidents. Zero discharge and recycling implies near zero dealings with local water authorities.

Techniques For Splitting Oily Emulsions

The design of oil/water separators is based on Stoke’s Law, the lighter oil droplets impact on the slant ribs of the media, coagulate, and rise to the surface. The principle of air flotation is that oil droplets will adhere to air and gas bubbles and rise to the surface of the tank. Chemically emulsified oil can be removed by heating the water from 150-220 degrees F, which can become expensive. Evaporators remove the water and leave the oil behind. This is expensive and results in difficult clean ups of the elements of the evaporator. The addition of salts, polymers, bentonite powders and pH adjustment are the most difficult, but also most successful method of breaking emulsions and removing the oil.

When chemical treatment is applied, prior bench testing is required. The first step is addition of an inorganic salt, such as magnesium or aluminum sulfate, which may be sufficient to break emulsions, or de-emulsify the oil, if sodium soaps are the emulsifier. If that is not successful, a cationic coagulant may be added. The purpose is to neutralize the charges on the oil droplet caused by the emulsifier, ie. drive the zeta potential towards zero. If this step is not successful, the pH may have to be adjusted downward to 3.5 with sulfuric acid, which results in the break up of the surfactant. Coagulants and flocculants may then be added to remove the oil. This step is followed by passing the water through a bed of organoclay to remove the last traces of oil (polymers are not economical below 30 ppm), adjustment of the pH to 5 or higher, and a pass through an activated carbon bed. Now the water can be reused.

Breaking emulsions and getting the right pH will increase performance. pH can be used to increase capacity. When the absorbate is neutral (no ionic charge) it will fit into the long hydrocarbon chains in the Quat and the micro pores in carbon. The closer you get the absorbate to its saturation concentration the better it will adsorb. For example, benzoic acid is soluble at 1-2 grams ,but benzoate ionic form is 50 grams soluble per liter of water.

Figure A in Technical Bulletin #46 shows the schematic diagram for an aluminum can manufacturers wastewater treatment system. Their treatment added surfactants to wash oil off aluminum sheets. They used hydrofluoric acid to separate the oil from the surfactant.

Figure B shows how Biomin improved the process. Since the aluminum can manufacturer adds acid for etching the cans, adding more acid was not necessary… Biomin simply added a vessel of Organoclay followed by a vessel of activated carbon. The Organoclay removed the surfactant and oil and activated carbon functioned as a polisher, removes traces 1 PPM or less dissolved oil.

Surfactants used for this application should be non-ionic, like Union Carbide’s Triton 150 which provides pH 3-5 maximun breakage of the oil-surfactant binding. Organoclay has high capacity for oils and surfactant and activated carbon removes the traces. Anionic and cationic surfactants interfere with oil removal capacity. Laboratory studies with “Column Test Methods” have demonstrated these oil capacity changes.

A Biomin Column Treatment Tutorial is provided to show you how Biomin column data can be used to design a treatment system for a wastewater stream.

Biomin Organoclay Courses

George Alther, president of Biomin, provides practical courses on “Principles and Practices of Organoclay.” Courses are also provided in conjunction with the International Activated Carbon Conference in Los Angeles CA on April 27-28, 2010 and Pittsburgh PA October 5-6, 2010.

View Technical Bulletin #46 here

During the course entitled “Organoclay Principles and Practices”, Mr. Alther will provide the tools to successfully use organoclays including what they are made of, how they work, their chemistry and how to select the best organoclay for specific applications. Different applications of organoclays will be discussed including non-ionic procedures used to remove oil and sheen from water and polar procedures to remove humic acids, THM’s and chelates from water. Waste water cleanup success in an economically acceptable manner depends on an understanding of pre-polishers and post polishers. Organoclays are also used as post polishers for oil/water separators, DAF units and oil skimmers.

Recycling of wastewater is becoming more prevalent in water starved areas, especially in developing countries and organoclays can help achieve what those above mentioned units cannot by themselves. Biomin International has patent methodologies for organoclay technology. “It is always an exciting experience to participate in international conferences regarding global waste water treatment as there are many advancements being made globally and this is an opportunity to meet friends and attendees and promote our product line”, said Alther. “In actuality, the global end user is the beneficiary of using my Organoclay for water decontamination and soil stabilization in the future”. George is an internationally recognized expert on organically modified clays and their use in environmental applications and has participated in many international conferences during his career.

Biomin International is currently developing international contacts for synergistic markets associated with its patented Oilsorb technologies and has successfully signed distribution agreements with Nigeria, Qatar and India. Joseph P. Cool, International Business Development/Export Director said “We are currently working with both domestic and international companies for development and implementation of Oilsorb methodologies and synergistic technologies for worldwide utilization including specific SE Michigan applications. International conferences such as these provide forums for identifying potential Partners for follow up discussions in the development of global business opportunities for successful water treatment globally using the Oilsorb technology”.

About Biomin, Inc. (www.biomininc.com)

Biomin International, Inc. manufactures state-of-the-art water filtration media and flocculants for removal of oil, grease, and other organics (i.e. PCBs, PNAH, PCP, and color/tannin) from water.  Biomin’s products include OilSorb^TM, ColorSorb^TM, Clayfloc^TM, EC-300, and EC-400.  Biomin filtration products are used throughout the world and have been approved for use by the U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Department of Defense, U.S. Department of Energy, the Iowa Department of Transportation, and other federal and state environmental protection departments. Its products have documented case study results that indicate cost savings up to 50% while bringing customer facilities into compliance with governmental discharge requirements.

Biomin International, Inc., an Oak Park, MI-based oil and water separation/filtration company participated in the first meeting of the Macomb Manufacturers Survival Group at the invitation of Express Employment Professionals. The meeting was held at the Express Employment Professionals office located on Morley Road, Clinton Township on 9 July 2009.

The meeting was attended by several local SE Michigan companies with the goal of introducing local manufacturing companies for exploration and development of global opportunities. The group of attendees included Representatives of Biomin International, Express Employment Professionals, PAT Engineering Enterprises, Target Equipment Leasing, Drake Enterprises and Bermar Associates. The meeting consisted of company introductions and a presentation entitled “Going Global: The Survival of Local Manufacturing in Macomb County – An Overview of Strategies”. Joseph P. Cool, International Business Development/Export Director of Biomin International gave the presentation which included interaction with the audience.

JoAnn Wiegand, Owner/General Manager of Express Employment Professionals is very knowledgeable regarding the changes in the manufacturing industry in Macomb County and initiated the invitation to Cool as Speaker based on his extensive experience globally. Wiegand said of the event “This was a great start. Thanks to Cools’ presentation, I now see limitless possibilities for Macomb Manufacturers to increase market share”. One of the goals of this first meeting was to develop local connections in several manufacturing sectors for further connections globally.

George Alther, President/Founder of Biomin International said “Based on future orders of the Biomin product line globally, additional personnel will be required for our Oak Park manufacturing facility which is our synergy with Express Employment Professionals to provide personnel”. Biomin International and PAT Engineering have recently signed an exclusive agreement for distribution of Biomin’s global waste water treatment solutions for Qatar and India initially based on a recent factory visit by PAT Engineering Representatives from Qatar.

Biomin International is very interested in developing local and international contacts for synergistic markets in SE Michigan dedicated to global waste water treatment processes. Cool said “I strongly believe there are many synergistic connections in local SE Michigan manufacturing market sectors and subsequent conversations and discussions will provide a very good platform for future global development of not only Biomin International but also local manufacturing companies”.

About Biomin, Inc. (www.biomininc.com)

Biomin International, Inc. manufactures state-of-the-art water filtration media and flocculants for removal of oil, grease, and other organics (i.e. PCBs, PNAH, PCP, and color/tannin) from water.  Biomin’s products include OilSorb™, ColorSorb™, Clayfloc™, EC-300, and EC-400.  Biomin filtration products are used throughout the world and have been approved for use by the U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Department of Defense, U.S. Department of Energy, the Iowa Department of Transportation, and other federal and state environmental protection departments. Its products have documented case study results that indicate cost savings up to 50% while bringing customer facilities into compliance with governmental discharge requirements.

About Express Employment Professionals  (www.expresspros.com/clintontownshipmi)

JoAnn Wiegand has been providing staffing solution since 1994 for business in Sterling Heights and Clinton Township as an Express Employment Professionals franchisee/owner. The business has evolved from providing temporary employees with clerical or light industrial experience. Today the full service office provides a broad range of human resource assistance to local businesses including payroll processing, professional searches, skilled trade placements, skills testing, training programs, writing handbooks and safety audits.

Improves the Uniformity and Performance of Organoclay to Preferentially Adsorb and Sequester a Wide Range of Hydrocarbon and Petroleum based Contaminants in a Remediation Setting

AquaBlok, Ltd., a manufacturer of innovative clay-based composite materials, in cooperation with Biomin, Inc. is pleased to offer a new way to deliver Biomin’s proven
organoclay product in a way that is low cost and provides for ease of delivery and improved performance.

AquaBlok® + ORGANOCLAY provides the following primary benefits, compared to the use of conventional powdered or pelletized organoclay products:

1. More efficient use of organoclay through use of a thin coating on a substrate/core
2. Greater product effectiveness through higher organoclay surface area
3. Improved delivery to sediments through a standing water column
4. Lower cost per pound for a target volume
5. Ease of handling and placement

View the rest of this bulletin as a PDF

During the day-long conference, three session tracks were provided for Participants to attend in which local expert engineers and scientists provided information for interactive discussions regarding solutions to the State’s most pressing water issues.

“We have to protect our resources. That is why we were able to bring together an impressive group of individuals to share their knowledge and start a dialogue on how we can engineer a solution. This successful event was the starting point of an important journey.” Brenda Moragne, Director of Conferences, the Engineering Society of Detroit.

For the full story, view the PDF.