Leigh Wastewater Treatment Works – Amtreat® Ammonia Removal

With United Utilities decision to convert the Leigh WWTP into the regional sludge centre and to invest in a new thermal hydrolysis plant to treat the indigenous and tankered imported sludge’s. This system requires the feed sludge to be thickened to 16-22% which produces a new waste centrate stream along with the digested dewatering sludge liquors which are high in ammonia.

UU’s Tier 1 Contractor KMI were tasked with supervising the site wide upgrade including the provision of a high rate ammonia treatment solution.

ACWA’s successful solution was to design and construct its proprietary high rate (Amtreat®) ammonia removal system. With only limited space available on site this system was designed to fit into a very restricted space divided into two construction areas by the site access road. The Amtreat® system comprises of an anoxic tank constructed inside the Amtreat® reactor with a degassing column and final settlement tank along with recirculation, heating and chemical dosing systems.

This Amtreat® system is the seventh installed in the UK to date, all of which are treating high strength ammonia sludge liquors, the other plants installed are for Southern Water, Anglian Water and Severn Trent Water.

Technical Overview

Design basis:
• Turnkey M&E Project
• Flow – 805 m3/d
• Ammonia Load: 622 Kg/d
• Ammonia Removal : >95%

The Benefits

ACWA’s Amtreat® solution provides:
• High ammonia removal efficiencies in excess of 98%
• A very reliable and robust process
• Reduced capital and Whole Life Costs
• Flexible plant arrangement
• Can utilise existing assets if available
• Simple to operate and maintain