Research Projects

Why from sewage sludge?

Sewage sludge is an unavoidable byproduct of the treatment of wastewaters and exists in a huge amount around the world.
These huge amounts of waste materials, consequently, cause major handling and disposal problems.
These waste material are available almost free of cost to be used in other forms for various applications.
Usually these materials are reutilized in agriculture, incineration, land filling, compost manufacture, bio gas production, manufacture of adsorbents.
If the solid wastes are used as low cost adsorbents/catalysts, it will provide a twofold environmental advantage.
The sludge-exhausted material is carbonaceous in nature and rich in organic materials.

Major Findings

The presence of carbon materials accelerates the decomposition of ozone.
hydroxyl radicals have a great role on the removal of organic compounds.
The treatment efficiency could be enhanced by combining two processes in one reactor (simultaneous adsorption and catalytic oxidation)
Applying the process for complex matrices and real process water.
Applying other oxidants/catalysts to generate hydroxyl radicals for in-situ oxidation

Potential application:

The outcomes of this research will help to design in-situ oxidation processes for passive and semi-passive treatment approaches such as wetlands and pit lakes.

Project Significance and Potential Applications

Solar-driven electrochemical oxidation can be considered as a promising treatment option for process water given that it can lead to improved biodegradability and reduced toxicity of process water while maintaining the economic feasibility.
The lower voltages required for the treatment and the use of relatively inexpensive and abundant electrode materials will result in a sustainable and environmental friendly process that can be operated by solar energy and applied in constructed wetlands/pit lakes.
In the case where the electric field is turned off, the TiO2 can still work as a photo-catalyst.
The exclusion of the need for chemicals addition will prevent the production of any additional hazardous wastes.

Project Significance

The established ozonation-biofiltration process can efficiently remove naphthenic acids from process water. The semi-passive process can potentially be scaled up, such as the development of engineered wetlands for process water treatment.
Bacterial from Rhodococcus genus may play a crucial role during the naphthenic acids biodegradation, which can potentially be selected for the development of genetically-modified-organisms (GMOs) based biofiltration process.

Potential Applications

The biofiltration process can be scaled up for process water treatment, such as the establishment of engineered wetlands for the treatment of process water inflow to pit lakes or outflow out of a pit lake .