F-500 Granular Activated Carbon Adsorber — Winston Water Engineering

F-500Granular Activated Carbon Adsorber

Carbon does not filter — it adsorbs. Organics stick to the internal surface of the grain, and a band of partly-loaded carbon travels slowly down the bed. When that band reaches the outlet, the bed is spent, however clean it still looks.

Cutaway — Granular Activated Carbon Adsorber

WaterOrganicsTreated

How it works

Adsorption, not filtration — A carbon grain has a huge internal surface — several hundred square metres per gram. Organics leave the water and stick to that surface. Nothing is strained out, so a carbon bed can look perfectly clean and be completely spent.
The mass transfer zone — Adsorption is not instant. The top of the bed saturates first, and a band of partly-loaded carbon — the mass transfer zone — travels slowly downward. Above it the carbon is exhausted; below it, untouched.
Contact time — EBCT is the bed volume divided by the flow. Give the water 10–30 minutes and the MTZ stays short. Rush it and the zone stretches, so it reaches the outlet while much of the bed is still unused — you throw away carbon you paid for.
Breakthrough — When the leading edge of the MTZ reaches the underdrain, organics appear in the effluent. That is breakthrough, and it is the end of the run. Lead–lag vessels in series let you run the lead bed to full exhaustion while the lag one guards the outlet.
The gravity contactor — An open concrete cell, fed by gravity and vented to atmosphere. You can see the bed, which matters more than it sounds — carbon fouling, mounding and channelling are all visible before they show up in the outlet. Loading is limited to about 12 m/h because the available head is whatever the hydraulic profile gives you.
What governs it — Capacity and load set how long the bed lasts; EBCT sets how much of that capacity you actually get. Drop the contact time and watch the MTZ stretch and utilisation fall — the same carbon, a shorter life, for no saving at all.

Design parameters

The panel opposite runs the same correlations as the F-500 design sheet, so the animation and the calculator cannot disagree. Every parameter below is live — drag one and the picture responds.

Parameter	Unit	Default	Range
Contactor configuration
Type		Gravity contactor	3 options
An upflow bed cannot blind, so it takes a dirtier feed — but the expansion mixes the bed axially and lengthens the mass-transfer zone, which wastes carbon.
Duty
Flow	m³/h	36	5 – 400
Vessel diameter	m	2.4	0.8 – 4.5
Bed depth	m	2	0.8 – 4
Influent TOC	mg/L	2	0.2 – 20
Carbon capacity	mg/g	25	5 – 120
Bed density	kg/m³	480	350 – 600

Open the full F-500 design sheet for the other four inputs, all twenty-three results with their envelopes, the six equations printed beside the numbers they produce, and a calculation record you can export and put in a design file.

Live parameters

Six of the ten inputs the F-500 design sheet takes.

Contactor configuration

Type

An upflow bed cannot blind, so it takes a dirtier feed — but the expansion mixes the bed axially and lengthens the mass-transfer zone, which wastes carbon.

Duty

Flow 36 m³/h

Vessel diameter 2.4 m

Bed depth 2 m

Influent TOC 2 mg/L

Carbon capacity 25 mg/g

Bed density 480 kg/m³

You have an estimate. The design sheet is the justification.

This page sizes the unit on six variables and tells you whether the headline numbers land in range. That is enough to sketch with, and it stays free. What it will not do is survive a design review: it does not show you the equation behind any number, it checks the obvious limits rather than all of them, and there is nothing to file.

The F-500 design sheet runs the same physics on ten inputs, reports twenty-three results against their envelopes, prints the six governing equations beside the numbers they produce, and exports the lot as a calculation record for the design file.