Calculate removal efficiency and logarithmic reduction
Enter value in mg/L, ppm, or count
Enter value in same units as above
Please enter valid numeric values. Initial concentration must be greater than zero.
Removal Efficiency:0%
Remaining Percentage:0%
Absolute Reduction:0
Log Reduction Value (LRV):0
function calculateRemovalRate() {
// Get input values
var initialInput = document.getElementById('initialConc');
var finalInput = document.getElementById('finalConc');
var resultBox = document.getElementById('rrResult');
var errorBox = document.getElementById('rrError');
// Parse values
var cin = parseFloat(initialInput.value);
var cout = parseFloat(finalInput.value);
// Validation
if (isNaN(cin) || isNaN(cout)) {
errorBox.style.display = 'block';
resultBox.style.display = 'none';
errorBox.innerHTML = "Please enter valid numbers in both fields.";
return;
}
if (cin <= 0) {
errorBox.style.display = 'block';
resultBox.style.display = 'none';
errorBox.innerHTML = "Initial concentration must be greater than zero to calculate a rate.";
return;
}
if (cout 0) {
logReduction = Math.log10(cin / cout);
} else {
// If cout is 0, technically infinite log reduction, but we display notation
logReduction = Infinity;
}
// Formatting results
document.getElementById('efficiencyResult').innerHTML = removalEff.toFixed(2) + "%";
document.getElementById('remainingResult').innerHTML = remainingPct.toFixed(2) + "%";
document.getElementById('reductionResult').innerHTML = absReduction.toFixed(2) + " units";
if (logReduction === Infinity) {
document.getElementById('logResult').innerHTML = "> 6 (Total Removal)";
} else if (logReduction < 0) {
document.getElementById('logResult').innerHTML = "N/A (Accumulation)";
} else {
document.getElementById('logResult').innerHTML = logReduction.toFixed(3);
}
// Show result box
resultBox.style.display = 'block';
}
Understanding Removal Rate Calculation
The Removal Rate (often referred to as Removal Efficiency) is a critical metric used in environmental engineering, water treatment, air filtration, and chemical processing. It quantifies the effectiveness of a treatment process by measuring the percentage of a specific substance (contaminant, particulate, or chemical) removed from a system.
The Removal Rate Formula
To calculate the removal rate, you need the initial concentration (inflow) and the final concentration (outflow). The standard formula is:
Efficiency (%) = [ (Cin – Cout) / Cin ] × 100
Where:
Cin: The concentration of the substance entering the system (Inflow).
Cout: The concentration of the substance leaving the system (Outflow).
Interpreting the Results
The calculator provides several key metrics to help you analyze process performance:
Removal Efficiency: This is the primary percentage indicating how much contaminant was removed. For example, a 95% efficiency means 95% of the pollutant was trapped or destroyed.
Remaining Percentage: The percentage of the original contaminant that passed through the system untreated.
Log Reduction Value (LRV): Commonly used in microbiology and filtration. A 1-log reduction is 90%, 2-log is 99%, 3-log is 99.9%, and so on. This is crucial for determining if water is safe to drink.
Example Calculation
Imagine a wastewater treatment plant receiving water with a suspended solids concentration of 500 mg/L. After the primary clarifier, the concentration drops to 50 mg/L.
The calculation would be:
Input (Cin): 500
Output (Cout): 50
Math: (500 – 50) / 500 = 0.90
Result: 0.90 × 100 = 90% Removal Rate
Applications
This calculator is applicable in various industries:
Water Treatment: Measuring the removal of heavy metals, bacteria, or nitrates.
Air Quality: Calculating the efficiency of HEPA filters or industrial scrubbers in removing particulate matter.
Chemical Engineering: determining the yield of separation processes like distillation or extraction.