A review of sewage sludge dewatering and stabilisation in reed bed system: towards the process-based modelling

Abstract

The sludge treatment reed bed is a sustainable sewage sludge management technology that offers promising sludge dewatering and stabilisation, due to its low energy and labour requirements, and minimal operating and maintenance costs. Despite numerous existing studies and increasing applications of sludge treatment reed bed in both developed and developing countries, the lack of standard system configurations and operating regimes led to several operational problems, including bed clogging and poor dewatering and mineralisation efficiency. Sludge dewatering and stabilisation in STBRs are complex processes governed by system- and operation-related factors such as the substrate media, macrophytes, loading regime, sludge characteristics, and climate conditions. Rather than the complex experimental study, process-based modelling has become a promising approach to investigating the influence of specific factors on the efficiency of sludge dewatering and stabilisation. This paper presents an overview of the critical system and operating parameters in sludge treatment reed beds and a summary of the interactions between the factors. Then, a framework of process-based modelling is proposed, which provides a useful platform to study the interactions of operating parameters and other factors in the complex processes of sludge dewatering and stabilisation, which supports the system design and optimisation of sludge treatment reed beds.

Conversion of Sewage Sludge into Biofuels via Different Pathways and Their Use in Agriculture: A Comprehensive Review

“…Ideally, the conversion technologies for energy efficiency improvement and the production of sustainable energy from sewage sludge should be improved [5,68,69]. Sewage sludge has different physical-chemical characteristics compared to typical solid fuels (biomass or coal), making its treatment more complex [70][71][72]. It generally contains N and P compounds, low-toxic organic substances, hazardous heavy metals (Pb, Ni, Cd, Hg, and As), organic contaminations (dioxins, pesticides, and aromatic hydrocarbons), pathogens, inorganic substances (Si, Ca, and Mg compounds), and a varying concentration of water.…”