An investigation into the options to control hydrogen sulphide in industrial waste water treatment systems

Abstract

A research study examined the options for controlling hydrogen sulphide in industrial waste water treatment systems It was found from the study that the principal methods of controlling hydrogen sulphide in waste water treatment systems are physical, chemical, biological, or thermal systems. The physical methods include containment, dilution, combustion, adsorption, activated carbon, sand, soil, compost beds, oxygen injection, masking agents and wet scrubbers. The chemical methods include chemical oxidation, catalytic filtration, chemical adsorption, catalytic combustion, electrochemical treatment, nitrate dosing, and chemical scrubbing. Biological methods include trickling filters, aeration tanks, stripping towers, sulphur oxidising bacteria, anaerobic biological reduction and lagoons. Thermal methods are thermal conditioning, incineration and flares. The research included: • A review of available information on sulphide removal and treatment. • A review of all methods for sulphide removal to determine effectiveness, applicability and removal efficiency. • A review current of experiences in Ireland with sulphide abatement including three site visits. • Selection of a method for trial at Aughinish Alumina to abatement sulphide emissions from an industrial effluent treatment process. • Review of trial results with a view to installation of permanent system. The trial consisted of the installation of a Bio-reactor which cultured bacteria specific to the treatment of sulphide in wastewaters with low organic content and resistant to pH variations. The bacteria were cultured every day and dosed into the treatment process over a one hour period each day for seven weeks. The result was a sulphide reduction of 97%. The bacterial addition was stopped, and within a two week period, the sulphide returned to its original concentration.