HUBER Technology highlighted the Grit Trap GritWolf compact grit and grease removal system at WEFTEC this year. This aerated grit trap is designed to reliably remove the grit from the wastewater flow while also capturing particulate lipophilic substances (grease) to keep floatable particles from settling or overflowing in downstream treatment systems.

Fine grit with grain size of 75 µm micrometers or above is difficult to capture in conventional aerated longitudinal grit traps because rising air counteracts the continuous sedimentation of small particles, according to the manufacturer. This means long, wide and high-volume structures are required.

The Grit Trap GritWolf consists of an aerated chamber and a separate unaerated chamber. In the first smaller chamber, the wastewater is exposed to fine-bubble aeration. Floatable particles rise to the water surface where they accumulate forming agglomerates. A paddle system removes these from the grit trap surface just before the outlet.

The unaerated chamber is equipped with stacked plates. With a deep flow approach and a lamella separator, it removes 90 percent of grit grains 75 µm and larger. The system is available in different sizes for flow rates from 1 to 20 mgd and requires much less space than conventional systems.

The grit trap tank is usually made of concrete, although stainless steel tanks for flows up to 4 mgd are available as an option. The system can be integrated into existing grit trap chambers. The horizontal grit conveyor, the lamella packages and the paddle system for grease removal are made from corrosion-resistant material.

The grit is removed axially by a time-controlled horizontal screw conveyor. A grit pump delivers the grit-water mix to a HUBER Coanda Grit Washer RoSF4 that produces clean grit.