Keywords: municipal sewage sludge, sewage treatment plants, leachate testing, heavy metals, Australia, reuse potential, agricultural applications, agriculture, sewage sludge reuse
Sustainable reuse potential of municipal sewage sludge in south–east Australia
With the aim of reusing municipal sewage sludge, this paper presents the chemical and organic properties of sludge from a major sewage treatment plant in south–eastern Australia. The results show that the concentrations of all OCPs and majority of PAHs were below or close to laboratory detection limits. Concentrations of heavy metals in sludge samples were compared with typical sludge testing results from the USA and UK. Concentrations of heavy metals from the south–eastern Australian sludge samples were noted to be much lower than concentrations of same metals reported in the UK but slightly higher than in the USA. Concentrations of lead in south–eastern Australian sludge samples were however found to be lower than the US sludge samples. Results on the leachate testing on aerated and nitrogen purged samples revealed minor differences in the results. Potential reuse options for the sewage sludge in agricultural applications are also discussed.