Evaluation of processed sludge as a sustainable and efficient soil conditioner and organic fertiliser for Qatari soil

Abstract

Qatar is implementing the use of treated sludge as a sustainable resource in the green infrastructure. The study employed an experimental research design where five samples (two kilograms each) of pelletised sludge of both class A and class B were collected randomly from Doha North Sewerage Station. Results showed that Aspergillus flavus was present in class A biosolids while class B biosolids samples had Aspergillus flavus and Aspergillus niger. Class A and class B biosolids were indicted by the number of total coliforms, faecal coliforms, and E. coli. It was found that no pathogenic indicators in class A pelletised sludge were present, while class B sludge had a trace amount of total coliforms. Moreover, As, Cd, Co and Sn were not detected. Furthermore, in the pot experiment, results revealed a very healthy, vigorous plant growth for the sludge treatment with both 5, 10 kg/sqm in rows, by achieving elongation in leaves from 20 cm to 60 cm and a width development from 0.15 to 0.55, with significant differences in the overall conditions, number and the thickness of leaves base. Copyright 2022 Inderscience Enterprises Ltd.