Evaluating granulometry and metal content in sludge from UASB reactors treating sugarcane vinasse

Author(s)

Alves, Inae ; Del Nery, Valeria ; Barbosa, Moara Yuri Utino ; Damianovic, Marcia Helena Rissato Zamariolli ; Pires, Eduardo Cleto

• Document type: Journal article
• Source: JOURNAL OF WATER PROCESS ENGINEERING; v. 51, p. 8-pg., 2023-02-01.

Abstract

Few studies have been carried out on sludge blankets in treatment systems. However, the sludge blanket in a UASB system is the area where microorganisms responsible for converting organic matter into biogas are concentrated. Considering its importance, the present research aimed to study the sludge blanket of three UASB reactors used in the treatment of sugarcane vinasse (pilot scale). The main difference between them was the applied effluent recirculation rate (100 %, 200 %, and 400 %). The research objective was to analyze the sludge blanket of these reactors: to determine the granulometry; the concentration of zinc, lead, cadmium, nickel, iron, manganese, copper, total chromium, calcium, magnesium, sodium, and potassium; and the organic and inorganic contents, aiming to identify the physical-chemical alterations in the sludge caused during the operational period. A reduction in the granular diameter was observed in all systems up to the range between 0.4 and 1 mm, provided by the increase in the hydraulic load, the organic loading rate and biogas production, and the increase in the mineral fraction in the sludge blanket, associated with the metal contribution of vinasse to the sludge blanket. Metal accumulation such as magnesium, sodium, calcium, and potassium was not detrimental to the methanogenic process due to the strategy of adapting biomass to vinasse, by gradually increasing the vinasse load, and the effects of antagonisms between magnesium and sodium and between potassium and sodium, which reduced its toxic effects. (AU)

• FAPESP's process: 13/17591-1 - Biogas production by sugar cane vinasse anaerobic digradation: investigation of hydraulic and organic rates applied to the up flow anaerobic sludge blanket reactor for process optimization
• Grantee: Eduardo Cleto Pires
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants