title: Vermicomposting as an advanced biological treatment for industrial waste from the leather industry.
abstract: The leather industry (tanneries) generates high amounts of toxic wastes, including solid and liquid effluents that are rich in organic matter and mineral content. Vermicomposting was studied as an alternative method of treating the wastes from tanneries. Vermicompost was produced from the following tannery residues: tanned chips of wet-blue leather, sludge from a liquid residue treatment station, and a mixture of both. Five hundred earthworms (Eisenia fetida) were added to each barrel. During the following 135 days the following parameters were evaluated: pH, total organic carbon (TOC), organic matter (OM), cation exchange capacity (CEC), C:N ratio, and chromium content as Cr (III) and Cr (VI). The results for pH, TOC and OM contents showed decreases in their values during the composting process, whereas values for CEC and total nitrogen rose, indicating that the vermicompost reached maturity. For chromium, at 135 days, all values of Cr (VI) were below the detectable level. Therefore, the Cr (VI) content had probably been biologically transformed into Cr (III), confirming the use of this technique as an advanced biological treatment. The study reinforces the idea that vermicomposting could be introduced as an effective technology for the treatment of industrial tannery waste and the production of agricultural inputs.
authors.affiliation: a Institute of Chemistry of São Carlos, University of São Paulo , São Carlos , Brazil.
authors.forename: Ramom R
authors.initials: RR
authors.lastname: Nunes
authors.affiliation: a Institute of Chemistry of São Carlos, University of São Paulo , São Carlos , Brazil.
authors.forename: Rhaissa M
authors.initials: RM
authors.lastname: Bontempi
authors.affiliation: a Institute of Chemistry of São Carlos, University of São Paulo , São Carlos , Brazil.
authors.forename: Giovane
authors.initials: G
authors.lastname: Mendonça
authors.affiliation: b Center of Biological Science and Health, Federal University of São Carlos , São Carlos , Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Galetti
authors.affiliation: a Institute of Chemistry of São Carlos, University of São Paulo , São Carlos , Brazil.
authors.forename: Maria Olímpia O
authors.initials: MO
authors.lastname: Rezende
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D001938:Brazil; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007220:Industrial Waste; D009835:Oligochaeta; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013633:Tanning
chemical_list: D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants
keywords: Eisenia fetida; Vermicomposting; chromium monitoring; tannery wastes