G-TAD^™
Process

Take Control of Aerobic Digestion

The Gravity Thickened Aerobic Digestion (G-TAD^™) process is a reliable and efficient solution for meeting Class B stabilization requirements.

This patented, non-clog, single-drop diffuser system integrates the operation of a gravity sludge thickener and two or more aerobic digesters. It thickens solids up to 2%, reducing aerobic digestion volume, footprint, and energy costs. The G-TAD system enhances pathogen destruction, reduces solids retention time, and improves pH and temperature control, resulting in stabilized biosolids with minimal operator intervention.

Learn more Ask an expert SUPPORT / PARTS & SERVICES

A GRADE-A SOLUTION TO HANDLE CLASS B SOLIDS

THE PROBLEM

Every day, approximately 16,000 U.S. facilities treat about 34 billion gallons of wastewater. Achieving effective pathogen destruction and reducing solids retention time is a challenge in municipal wastewater treatment. Traditional methods often result in high maintenance costs–between 30% and 60%–and inadequate pH and temperature control.

THE OVIVO SOLUTION

The G-TAD process offers a reliable and efficient solution for achieving Class B biosolids.

By integrating gravity thickening with aerobic digestion, this system enhances pathogen destruction, reduces solids retention time, and improves pH and temperature control. And that results in smaller sludge volumes for disposal and lower operational costs.

The G-TAD process is ideal for both new plants and existing plants looking to retrofit.

REDUCES YOUR AEROBIC DIGESTION VOLUME, FOOTPRINT, AND ENERGY COSTS

HOW IT WORKS

G-TAD technology consists of two aerobic digester basins operating in conjunction with a pre-mix basin and a gravity thickener to treat raw sludge.

The raw sludge enters the premix basin, where it is mixed and aerated to increase microbial activity and dissolved oxygen concentration.

The sludge then overflows to the gravity thickener, where solids settle to the bottom without aeration, creating an anoxic stage for denitrification to occur. This stabilizes the pH.

The supernatant is removed and returned to the head of the plant.

The thickened sludge is then airlifted to the in-loop digester, where nitrification occurs with less aeration than normally required because of alternating anoxic/aerobic phases.

Scum is collected in the gravity thickener and also airlifted to the in-loop digester.

Digested sludge overflows back to the pre-mix, completing the loop and continuously decanting and thickening the sludge.