Structural Analysis of Heat-Calcined Modified Sewage Sludge From WWTP in Gas Complex For Environmental Risk Assessment

Abstract

Thermal processing of sewage sludge (SS) wastewater treatment plant WWTP has received increasing attention in recent years. Heat calcination valorise the carbon rich organic fraction of SS, while effectively reducing SS volume. The refractory metals (thermally stable, i.e. Zn, Cu and Cr) are less volatile at different temperatures at 200 and 400 °C of thermal processes and they are enriched in the residues. To gain insights into mineralogical analysis, physicochemical, microstructure properties and heavy metals ( HMs ) were characterized by proximate, ultimate field emission x-ray fluorescence ( XRF ), scanning electron microscopy ( SEM ), attenuated total reflectance-Fourier transform infrared ( ATR-FTIR ) spectroscopy, x-ray diffraction ( XRD ) and UV-vis spectrophotometer. Such analysis plays a crucial role in the effective management of WWTPs and in evaluating the environmental risks associated with the disposal of wastewater sludge’s. It aids in assessing the potential value of these sludge’s as fertilizer, considering factors such as the presence of potash and iron, for agricultural purposes, or as building materials, considering the presence of silica and calcium oxide. The assessment is carried out utilizing X-ray fluorescence (XRF) technology. Furthermore, a case study is included to illustrate typical situations in a WWTP, emphasizing the main challenges and limitations linked with ships, as well as wastewater management and disposal. Additionally, the specific scenario of gas complex GP1/Z is scrutinized to suggest a wastewater treatment solution, which involves evaluating potential locations for the treatment plant and determining the appropriate treatment methods to be implemented.