Category: Earth/Climate science

Hydroxyl Radicals

Hydroxyl Radicals

Hydroxyl Radicals

03/15/2026

“Why is there a molecule called “the detergent of the atmosphere”?“

Hydroxide ions (OH-), also called Hydroxyl Radicals, are molecules made up of one oxygen atom, one hydrogen atom, and a single unpaired valence electron. This valence electron makes hydroxyl radicals very reactive and potent in neutralizing stable organic chemicals like toxic pollutants. Hydroxyl radicals also readily oxidize troposphere pollutants like methane, carbon dioxide, and VOCs, earning hydroxyl radicals the nickname as “the detergent of the atmosphere”.

Fugacity

Fugacity

Fugacity

03/14/2026

“How can we quantify how much a substance wants to escape from its mixture?”

Different substances have different levels of internal stability. Some very much want to escape their mixture, while others are happy where they are. So how can we quantify this? Well, scientists developed Fugacity theory to explain this phenomenon. Fugacity is defined as the empirically measured vapor pressure rather than the ideal vapor pressure. Chemicals will move between substances like air and water until their fugacity potentials are equal.

TCLP — Toxicity Characteristic Leaching Procedure

TCLP — Toxicity Characteristic Leaching Procedure

TCLP — Toxicity Characteristic Leaching Procedure

03/08/2026

“How can we determine if waste will leach toxic chemicals when it rains?”

Surface waste management has to account for a lot of variables. One of them includes determining if the waste will leach toxic chemicals when it rains. SO what if we were to grind waste down like it was in a landfill, mix the waste with a weak acidic solution similar to acid rain, tumble the mixture for 18 hours, and chemically analyze the leachate output for contaminant limits? Well, these are the steps behind the TCLP — Toxicity Characteristic Leaching Procedure, an EPA RCRA procedure to determine the potential toxicity of waste leachate. 

Image credit: http://www.btlliners.com

Underground Storage Tanks for Waste

Underground Storage Tanks for Waste

Underground Storage Tanks for Waste

03/06/26

“Why do people use underground storage tanks for waste?”

Waste is a massive problem for communities all over the world. Storing it above ground can take up space, cause public health problems during inclement and windy weather, emit perilous odors, and destroy visual aesthetics. So how can we use our engineering and planning mindsets to solve this? Well, what if we were to store waste underground? This can come in the form of Underground Storage Tanks for Waste. According to the U.S. EPA, underground storage tanks for waste are tanks and any underground piping system connected to the tank where at least ten percent of the combined volume is underground. Underground storage tanks for waste can address the aforementioned problems associated with surface-based waste management, and can store fluid waste more easily. However, waste managers must take extreme precaution with underground waste storage tanks because their structures can corrode or break and leak into the surrounding soil and groundwater, creating health crises. It’s best to choose long-lasting materials for building underground waste storage tanks.

Image credit: https://rivcoeh.org/

Soil Infiltration vs Transmission Rates

Soil Infiltration vs Transmission Rates

Soil Infiltration vs Transmission Rates

03/05/26

“What is the difference between soil infiltration and transmission rates?”

Soil infiltration and transmission rates are often discussed interchangeably. However, there are big differences between them. Infiltration rate measures how quickly water enters soil from the surface, while transmission rate calculates the movement rate of water through soil. Soil infiltration rate is influenced by surface conditions and the level of soil inundation, while transmission rates are governed by soil permeability. This is the difference between Soil Infiltration vs Transmission Rates.

Resource Conservation and Recovery Act (RCRA)

Resource Conservation and Recovery Act (RCRA)

Resource Conservation and Recovery Act (RCRA)

03/01/26

“How does the U.S. federal government regulate solid and hazardous waste disposal?”

Solid and hazardous waste needs proper disposal and maintenance to protect public health. In 1976, the U.S launched the Resource Conservation and Recovery Act (RCRA) to administer “cradle to grave” requirements for hazardous waste landfill/disposal criteria for non-hazardous solid wastes.  

Resource Conservation and Recovery Act (RCRA) Sampling

Resource Conservation and Recovery Act (RCRA) Sampling

Resource Conservation and Recovery Act (RCRA) Sampling

02/28/26

“How do we sample waste to make sure it isn’t hazardous?”

Proper waste disposal is important for keeping the local environment clean. Under the US Resource Conservation and Recovery Act (RCRA), waste generators must determine if their waste is hazardous. If there’s uncertainty about the waste composition, then waste generators must take samples to labs to determine if the waste is ignitable, corrosive, reactive, and/or toxic. Because waste samples can vary widely in contaminants, the waste generator must apply statistical sampling procedures. This means determining the mean, standard deviation, probability of detecting contamination if it truly exists, confidence that our conclusion is correct, the smallest difference from the regulatory standard that we want to detect, and the number of samples needed. Resource Conservation and Recovery Act (RCRA) Sampling is a vital part of determining waste hazards in the U.S.

Suspended Growth Wastewater Treatment

Suspended Growth Wastewater Treatment

Suspended Growth Wastewater Treatment

02/27/26

“How can we treat wastewater with free-floating microorganisms?”

There are many ways to go about wastewater treatment. One of the most common categories is for microorganisms to float freely in wastewater and consume pollutants. This Suspended Growth Wastewater Treatment is an effective way to treat wastewater through mixing the right microorganisms. Activated sludge treatment and aeration lagoons are examples of suspended growth wastewater treatment.

Image credit: https://www.waterandwastewater.com/