Abstract
The cultivation of grasses in sewage sludge (SS) with aeration has the potential for stabilization of sludge organic matter in the production of organic fertilizer. Thus, the objective of this work was to evaluate the cultivation of Urochloa brizantha and Pennisetum purpureum under aerated system on the chemical and biological attributes of SS to obtain a matured organic fertilizer. The study was conducted in a randomized block design in a 2x2+2 factorial scheme with four replications. Factors consisted of cultivation of P. purpureum or U. brizantha in SS, with or without intermittent aeration. Control treatments were SS without cultivation, with or without aeration. Sewage sludge was collected in layers and the chemical and microbial attributes were evaluated. There was no significant difference between treatments for grass dry matter. The C/N ratio was not matched with organic fertilizer stabilization due to similar losses of C and N (~7%). However, microbial activity was reduced in the presence of plant cultivation demonstrating improvement in the properties of the organic fertilizer produced. Through uni- and multivariate analysis, organic fertilizer produced from SS aerated and cultivated with P. purpureum showed matured organic matter.
Highlights
The high volume of sewage sludge (SS) produced at the wastewater treatment plants (WWTP) has burdened the disposal of this waste in landfills, since its management may reach 60% of the operating costs of a WWTP (Godoy, 2013)
Production of the dry matter of the aerial part (DMAP), root (DMR) and total (DMT) of P. purpureum and U. brizantha were similar between treatments with or without aeration in sewage sludge after 90 days of cultivation (Table 2)
The average total biomass of P. purpureum corresponded to 68 g per plant, with a density of 50 plants per m2, were considered lower than that obtained by Oliveira et al (2018), who found a total biomass of 150 g per plant, with a density of 25 plants per m2, at 90 days of cultivation in sewage sludge
Summary
The high volume of sewage sludge (SS) produced at the wastewater treatment plants (WWTP) has burdened the disposal of this waste in landfills, since its management may reach 60% of the operating costs of a WWTP (Godoy, 2013). SS may contain contaminants such as heavy metals (Oliveira et al, 2018), toxic organic compounds (Alvarenga et al, 2017), and pathogens (Oliveira et al, 2019) It may not present stabilized organic matter, it needs some technique for its maturation. In Brazil, the agricultural and forestry use of SS is regulated by the National Council of the Environment (Conselho Nacional do Meio Ambiente - CONAMA) thought the resolution 498/2020 (Brasil, 2020a). This resolution establishes limits of heavy metal and pathogens organisms, classifying the SS, where, in which culture, and how it can be applied. There are suggestions of how the organic matter of SS can be stabilized and contaminants reduced
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
