Sludge

Industrial Municipal WWT | Sludge | Drinking Water | Surface & Groundwater |VOC Recovery | Defoamers | Amines | Analytical Laboratories

Aerobic Sludge Digestion
Aerobic Sludge Digestion (ASD) can be used to reduce waste sludge biosolids, in both secondary and primary sludges. Oxy-Dep SD, an ASD process enhanced by the use of high purity oxygen, allows the following:

partial disinfection and pathogen kill by operation at thermophilic temperatures (45 – 65°C)

the production of a stable sludge with excellent dewatering properties

much reduced digester retention times (and so smaller digester volumes) compared with conventional aerated ASD or anaerobic digestion

good process control to reduce odours, VOCs and foam.

The process is used widely in municipal and industrial sludge applications.

Retrofitting Jet Aerators with Oxygen
The treatment capacity of an existing wastewater system fitted with conventional (air based) Jet Aerators can be increased substantially by converting aerators to pure oxygen operation. This is usually a simple and inexpensive conversion.

The rate at which oxygen dissolves is proportional to the purity at which it is used. By changing from air to oxygen the purity increases five times giving much higher oxygen transfer rates.

A further benefit is the much reduced VOC stripping from the effluent system due to much lower volumes of gas leaving the basin.

Emergency Oxygenation
Dissolved Oxygen (DO) shortage can cause catastrophes in both natural waters and aerobic waste water treatment plants. In periods of high BOD and COD loading, or high ambient temperatures where biological activity and oxygen uptake rate are high, DO can fall to zero levels. At such times, higher aquatic life dies, odours can cause nuisance, and waste water discharges can exceed consent levels.

High purity oxygen brings immediate relief to oxygen shortfall. Air Products’ rapid response oxygen supply via Oxy-Dep jet mixing equipment or Fine Bubble Diffusers can be installed on site quickly and effectively, often within 48h of request.

Aerator Performance Testing
The performance of aeration equipment is critical to the successful operation of an activated sludge process. Often, in building a new plant, the performance of such equipment must be tested against the manufacturers specification in terms of power used for the quantity of oxygen transferred to the water.

Standard clean water Oxygen Transfer Efficiency (OTE) tests using nitrogen to purge oxygen out of the water, so reducing the Dissolved Oxygen (DO) concentration to zero, allow multiple tests to be carried out on new aeration equipment in a short time, giving data based on consistent methodology using a zero DO baseline.