Ro Recovery Rate Calculation

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RO Recovery Rate Calculator

GPM / LPM
GPM / LPM

Calculation Result

0%

function calculateRORecovery() { var permeate = parseFloat(document.getElementById('permeateFlow').value); var concentrate = parseFloat(document.getElementById('concentrateFlow').value); var resultArea = document.getElementById('roResultArea'); var displayPercent = document.getElementById('recoveryPercentage'); var displayFeedback = document.getElementById('roFeedback'); var displayTotal = document.getElementById('totalFeedRate'); if (isNaN(permeate) || isNaN(concentrate) || permeate <= 0 || concentrate < 0) { alert("Please enter valid positive numbers for flow rates."); return; } var totalFeed = permeate + concentrate; var recoveryRate = (permeate / totalFeed) * 100; resultArea.style.display = "block"; displayPercent.innerHTML = recoveryRate.toFixed(2) + "%"; displayTotal.innerHTML = "Total Feed Flow Calculated: " + totalFeed.toFixed(2) + " units"; var feedback = ""; if (recoveryRate = 15 && recoveryRate 40 && recoveryRate <= 75) { feedback = "This is a high recovery rate, usually seen in multi-stage industrial systems. Ensure you are using appropriate anti-scalants to prevent membrane fouling."; } else { feedback = "Extremely high recovery. Caution: Operating at this level significantly increases the risk of scaling and membrane damage unless high-end treatment and monitoring are in place."; } displayFeedback.innerHTML = feedback; }

Understanding RO Recovery Rate

In water treatment, the RO Recovery Rate is a critical metric that measures the efficiency of a Reverse Osmosis system. It represents the percentage of feed water that is successfully converted into purified permeate water rather than being discharged as concentrate (brine).

The RO Recovery Formula

Recovery Rate (%) = [Permeate Flow / (Permeate Flow + Concentrate Flow)] × 100

Alternatively, if you already know your Total Feed Flow:

Recovery Rate (%) = (Permeate Flow / Total Feed Flow) × 100

Why Does Recovery Rate Matter?

  • Water Conservation: Higher recovery means less water is sent to the drain.
  • Membrane Health: As recovery increases, the concentration of salts in the waste stream increases. If the recovery is too high, minerals like calcium and magnesium will precipitate, causing "scaling" on the membrane surface.
  • Operating Costs: Higher recovery can reduce water costs but may increase chemical costs (anti-scalants) and maintenance frequency.

Example Calculation

If your RO system produces 10 Gallons Per Minute (GPM) of purified water and sends 30 GPM to the drain (concentrate):

  1. Calculate Total Feed: 10 (Permeate) + 30 (Concentrate) = 40 GPM.
  2. Apply Formula: (10 / 40) = 0.25.
  3. Convert to Percent: 0.25 × 100 = 25% Recovery Rate.

Typical Recovery Ranges

System Type Standard Recovery
Residential Undersink RO 15% – 25%
Commercial Single Stage 35% – 50%
Industrial Multi-Stage 50% – 75%
Seawater Desalination 35% – 45%
Pro Tip: Never increase your recovery rate beyond the manufacturer's specification for the specific membrane and water quality. Always perform a projection using software (like WAVE or ROSA) when designing high-recovery systems.

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