When to Use The Manning vs. Hazen-Williams Equation
03/27/29
“When do we use the Manning vs Hazen-Williams Equation?”
People use both the Manning and Hazen-Williams equations to calculate water flow. But when is the right time to use each? Well, the Manning Equation is used for open channel or partially full sewers, while the Hazen-Williams Equation is used for full, pressurized circular pipe flow. Keep this information in mind when you think about When to Use The Manning vs. Hazen-Williams Equation.
“What’s the difference between the surface and weir overflow rate in environmental engineering?”
Environmental engineers often have to contend with surface overflow rates and weir overflow rates. But what do these mean, and how are they different? Well, the surface overflow rate measures the upward flow of water per surface area of a sedimentation tank/clarifier to determine if physical particles will settle out. In contrast, the weir overflow rate measures the flow volume moving along the length of the weir per weir length. The weir overflow rate determines how turbulent the incoming water over a weir is and how that might affect effluent quality. This is the difference between Surface Overflow Rates vs Weir Overflow Rates.
“How can we quantify the effectiveness of an air stripper at removing contaminants?”
Air stripping towers are a wonder to behold. People will want to select an air stripping tower model based on whatever has the best effectiveness. This is summarized by the Air Stripping Factor, which is proportional to the volumetric air-to-weight ratio multiplied by Henry’s constant. The higher the air stripping factor, the better the tower will perform.
“How can we create landscapes with pre-grown grass?”
People like to create grassed landscapes. However, grass can take time and resources to develop. So what if we could insert pre-made grass? Well, this is the idea behind Sod, rolls of pre-grown grass. Sod contains grass blades and dirt, with the grass’ root base. People can use sid to stabilize disturbed areas and decelerate the flow of rainwater.
“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”.
“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.
“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.
“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.
“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.
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