Possibilities of using waste from wastewater treatment plants to create soil-like materials

A municipal wastewater treatment plant is a complex system of technological devices and facilities designed to remove pollutants from wastewater. The operation of such plants generates a waste stream that can be classified into three types: screenings (code 19 08 01), sand trap contents (code 19 08 02), and stabilized municipal sewage sludge (code 19 08 05). Each generated waste must be managed in accordance with the applicable law. In the context of new business models within the closed-loop economy, wastewater treatment plants are viewed as a resource rich resource that can be used to reclamate degraded lands. The purpose of the study was to evaluate the physicochemical parameters of the waste, which could form the basis for the preparation of soil-forming material. The input material considered was excess digester sludge after the stabilization process, sand from the sand traps, and sand after cleaning the wastewater network. The tested sludge contained 35 % organic substances, 12 % organic carbon, 1.8 % total nitrogen, and 0.24 % potassium. The sand contained about 1 % organic matter, 1.8 % organic carbon, 0.5 % total nitrogen, and 0.02 % potassium. Sand and sludge were prepared in the following mixtures: 1:1, 1:2, 2:1. These mixtures were then assessed for their suitability in the reclamation of degraded areas.