AFROX AFROX

Wastewater


Breathing life into aeration
Wastewater treatment plants that make use of aeration processes commonly experience challenges such as inadequate purification and rancid odours caused by anaerobic decomposition – this is a direct result of insufficient dissolved oxygen levels in the water.

By Gareth Jones,
Afrox applications engineer.

The systematic introduction of pure oxygen at critical points along the wastewater process chain can help solve purification and odor issues more effectively than industry-standard aeration alone, ensuring greater efficiency and operational flexibility.
Sub-Saharan gas market leader Afrox boasts a range of trademarked SOLVOX solutions that improve wastewater treatment plant performance without the need for costly construction or restructuring work. Often these solutions can be implemented without reducing plant capacity during the installation phase.
The SOLVOX system has been designed to transfer oxygen and disperse dissolved oxygen to all areas of works’ aeration basins or tanks. This results in a vast improvement at overloaded activated sludge plants, as more wastewater throughput can be treated, thereby improving the plant’s overall performance. This effect is supported by the decreased sludge load, as the plant can support more biomass per unit of volume. As a result, effluent from the wastewater treatment plant has lower and more consistent biological oxygen demand and chemical oxygen demand concentrations.

Oxygen advantage
Oxygen is often overlooked as a wastewater treatment solution because it is perceived to be more costly than air. However, lower capital investments, reduced energy consumption and higher oxygen transfer efficiency can be more cost effective than traditional air-based systems. Many local municipalities are unaware that SOLVOX can be retrofitted to any existing system to be used as back-up during peak demand, for example. In effect, this means that Afrox’s SOLVOX serves as a complementary support system to existing aeration systems.
The product can therefore wastewater treatment overseers money, since it negates the need to expand overloaded activated sludge plants to cope with increased pollutant loads, and the rise in oxygen needed by the micro-organisms. Moreover, transferring pure oxygen with the SOLVOX processes covers peak demands more efficiently and economically, as it eliminates the need for expansion of existing aeration systems. It also eliminates the high investment costs for larger surface aerators, additional compressors and associated equipment.
The use of pure oxygen can also reduce the production of foaming and volatile organic compound emissions caused by excess off-gas from traditional air-based systems. In certain situations SOLVOX solutions require no additional energy source to transfer oxygen into activated sludge tanks or lagoons, as there is sufficient agitation provided by the existing aeration equipment.
Bearing this in mind, wastewater levies can be reduced and wastewater can be purified without odours.

Proven performance
SOLVOX pure oxygen systems have been used to upgrade and retrofit existing aeration-based activated sludge plants treating industrial and municipal wastewater for over 30 years. This is a tried and tested method to improve final effluent quality without requiring a large upfront investment in capital and acquiring land for development for plant expansion programmes
As wastewater treatment quality regulations continue to tighten and public attitudes to pollution by poorly performing wastewater treatment facilities hardens, SOLVOX is set to add substantial value to municipal wastewater projects in the future.

SolvoxR-D injection device
Oxygen is the perfect gas for treating large quantities of wastewater, and municipalities can ensure long-term cost savings by implementing SOLVOX 9injection device pictured) as a peak demand add-on to existing aeration systems.

Gareth Jones,
Afrox applications engineer

The product can therefore wastewater treatment overseers money, since it negates the need to expand overloaded activated sludge plants to cope with increased pollutant loads

The use of pure oxygen can also reduce the production of foaming and volatile organic compound emissions caused by excess off-gas from traditional air-based systems.