Chemical Waste Minimization & Treatment

Did you know that the CU Boulder Hazmat unit strives to be a leader in hazardous waste reduction among universities? Do you want to help? This section will briefly describe some of the efforts the unit makes to reduce hazardous wastes and how campus research and operations employees can help.

The Hazmat unit works closely with CU Boulder Green Labs to find new ways of reducing the impact of research operations have on the environment. The wastes generated by research operations are unique and we’ve come up with some unique ways to help reduce this waste. Please read on to find out more. If you have any ideas for waste reduction in your research operations we’d love to hear them!

The Chemical Waste Treatment System at EH&S

Three waste streams have been identified for treatment at the EH&S waste treatment facility by using the application of different types of technology including ion exchange, neutralization, and oxidation.

  1. Silver recovery in photographic wastewater solutions
  2. Neutralization of acidic & basic corrosive aqueous solutions
  3. Decomposition of trace organic compounds in aqueous solutions

After proper treatment, the hazards once present in the wastewaters are eliminated. What remains is pre-treated industrial water that can be sent to the City of Boulder wastewater treatment system where it is treated further and then eventually discharged to Boulder creek.

General Processes Description

1. Silver Recovery/Recycling

“Great for jewelry, but not for drinking water.”

Silver compounds found in photographic solutions are removed using an ion exchange system.

The silver is trapped in a cartridge and eventually sent offsite for recycling.

2. Neutralization

“Sodium Hydroxide & Hydrochloric Acid to Water & Sodium Chloride.”

[NaOH + HCL → H2O + NaCL]

Inorganic acids and bases in aqueous solutions can be used to neutralize each other, in effect canceling out their corrosive characteristics. All that remains after the reaction is water and common salt compounds. Sodium chloride and potassium sulfate are two examples of the non-hazardous salts that remain.

3. Oxidation

O3 or ozone oxidation can be used to split various carbon bonds that compose organic toxins. Organic compounds are reduced to a manageable form that can be handled by city wastewater treatment systems. Further purification is conducted by ultraviolet light, leaving only non-toxic, drain disposable components.

How to help EH&S Treat More Waste

The easiest and most effective ways to maximize the chemical waste treatment system at CU Boulder is to properly identify your wastes and keep certain wastes segregated from each other. As obvious as this sounds it is not an easy task in this busy world.  Many people worry about their wastes only until it leaves their lab – then it becomes someone else’s problem. However, it should take just a small amount of time to segregate certain wastes when they can be easily segregated to greatly increase their potential for treatment by EH&S.

Proper Identification

The hazardous materials/wastes generated on the CU Boulder campus are picked up after a Hazardous Materials/Waste (HMW) Tag is submitted to EH&S. The HMW Tag is fairly simple, but filling it out thoroughly is crucial to ensure the safe disposal of hazardous materials/wastes from your laboratory.

The treatment processes performed at the University are configured based on a specific waste stream or characteristic.  There is no simple process whereby waste is converted into industrial waste water.  For example, suppose a lab mixed a color film solution containing selenium into a black & white film solution waste and then said nothing about this mixture on the waste tag. When this mixture is pumped into the treatment system at EH&S, the selenium ion will displace the silver ion and contaminate the entire batch, which will cause delays, extra costs, and damage to the exchange columns.

In order to effectively treat hazardous materials/waste, we must know with a fine degree of accuracy what is contained in the materials sent to us. We are dealing in milligrams per liter of contamination—visualize one drop of cream in a tanker truck of coffee—everything counts. We need to know (to the best of your knowledge) what is in the waste before we can treat it.

Segregation

Another thing that waste generators can do to maximize the amount of waste that EH&S is able to treat is to separate out (as best as possible) any heavy metals in solutions.

Metals that we would prefer to see separated (aka, the RCRA Eight) are:

  • Arsenic
  • Barium
  • Cadmium
  • Chromium
  • Lead
  • Mercury
  • Selenium
  • Silver

In addition, the City of Boulder regulates:

  • Copper
  • Molybdenum
  • Nickel
  • Zinc

We appreciate that many manufacturers are reluctant to disclose the precise nature of their products which can make it difficult to let us know exactly what is in waste materials that are sent to us. However, if at a minimum these “proprietary” wastes can be segregated from other treatable wastes such as photography solutions, acids/bases, and trace organics we can maximize the amount of wastes treated and reduce the impact to both natural resources and the environment.  We thank you for all your efforts in helping us reduce the University’s impact on the environment.  If you have any questions concerning treatment, please always feel free to contact the Chemical Treatment Specialist at 303-492-3675.

EH&S Involvement with Other Waste Minimization Programs

Acetone Recycling Program

The CU Boulder Hazmat unit has teamed up with the CU Boulder Chemistry and Biochemistry Department on an acetone recycling effort. Funds for a fractional distillation unit were supplied from the Sustainable CU FundsCU Boulder Facilities Management Office of SustainabilityChemistry and Biochemistry Department, and the EH&S Department.

Labs within the CU Boulder Chemistry and Biochemistry Department collect their rinse acetone generated from research operations and send it through the program which is overseen by Dr. Jacquie Richardson, Director of the CU Boulder Organic Chemistry Teaching Labs. The acetone is purified in the distillation unit which enables it to be recycled and used by undergraduate students in the organic chemistry labs.

Since its inception in the summer of 2013, it has been a very successful program and has reduced the amount of solvent wastes being sent off campus as a hazardous waste. Cost reductions in the first year of operation were over $2,500. This figure represents the combined cost savings to the Chemistry Department for the reduction of purchased acetone and also cost savings to EH&S for the disposal of acetone wastes.

Ethanol Reuse Program

Through the collaborative efforts of the CU Boulder Institute for Artic and Alpine Research (INSTAAR), CU Green Labs, the Chemistry and Biochemistry Department, and EH&S, an ethanol reuse program was born in the spring of 2013. This innovative program allows ethanol that has been used in cold traps within INSTAAR and contaminated with only water to be reused as a disinfecting solution within Bio-Safety Cabinets within the Chemistry and Biochemistry Department’s Cell Culture Facility. EH&S safely transports dedicated containers between the labs, which are located in different buildings on east campus. This program has saved, on average, approximately $1,500/year in avoided ethanol purchases for the cell culture facility. It also reduces the amount of ethanol that EH&S ships offsite as a hazardous waste.

Segregation of Solvent Wastes

Although it is difficult to recycle or reuse most of the solvent wastes generated on campus, there are still ways to minimize the cost of its disposal and utilize the Btu value for a beneficial use. When possible, we send all non-halogenated organic solvent wastes for use as cement kiln fuels. This allows the Btu value of the solvents to be utilized in the manufacture of cement rather than to be simply incinerated for destruction.

There are a few simple steps you can take to ensure we can use organic solvents as a fuel:

  • No Halogens or Heavy Metals (Absolutely no Hg!)
  • No organic or inorganic acids. (Keep the pH between 4 – 10)
  • Keep significant amounts (>10%) of aqueous wastes out.
  • Please be sure to list all constituents on the hazardous waste tag.

Carboy Re-use Program

The Hazmat unit consolidates most of the liquid wastes that are generated on campus. The containers that held the liquid wastes are emptied into drums and then rinsed within the EH&S hazardous waste facility. Whenever the Hazmat unit empties and rinses 5 gallon carboys that are suitable for reuse, they are transported back to the ChemStores within the Chemistry and Biochemistry Department for reuse as a hazardous waste storage container. Since its inception in 2013 the program has facilitated the reuse of over 200 carboys per year.