Treatment of lagooned sewage sludge in situ using electrokinetic geosynthetics

The treatment and disposal of sewage sludge constitute one of the most problematical issues affecting wastewater treatment in the developed world. Water companies have in the past deposited large volumes of digested sewage sludge in lagoons adjacent to water treatment works, and continue to do so. A lagoon has a potential for causing smell nuisance, represents a major hazard, and frequently occupies a potentially valuable site. Currently no technology exists for treating these lagoons that will both reduce the volume of the problem and allow post-treatment redevelopment of the site. Electrokinetic geosynthetics (EKG), polymer-based materials containing conducting elements, formed as wick drains offer one novel solution. The paper describes a field trial on lagooned sewage sludge using EKG, and discusses the results in the context of a full-scale treatment, considering the power consumption, electrode design, electrode array configuration, length of required treatment time and economic implications.