Open AccessThermophilic (55°C) and moderately hyperthermophilic (65°C) fermentation of poultry manure triggers release of high heavy metal concentrations leading to enhanced genotoxicity
Author(s) -
Anjum Reshma,
Sebök Stefan,
Krakat Niclas
Publication year - 2016
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201500096
Subject(s) - pollutant , digestate , genotoxicity , chemistry , fermentation , anaerobic digestion , environmental chemistry , manure , food science , fertilizer , pulp and paper industry , agronomy , biology , methane , organic chemistry , toxicity , engineering
Proper disposal of waste from poultry industries may be done by thermophilic anaerobic digestion. Particularly, thermophilic fermentation exhibits pivotal advantages. However, not only the accrued waste material (digestate) serves as organic fertilizer but also poses environmental problems when the pollutant release is poorly synchronized with the environmental demand. To minimize environmental risks, additional hyperthermophilic (moderately hyperthermophilic) treatment of animal by‐products is necessary, but concurrent release of pollutants is notably increased. To estimate the quantity and quality of pollutants released, we analyzed various organic compounds as well as 21 metals and tested their genotoxic/mutagenic potential by using the Allium cepa assay and the Ames test. As, Cd, Ni, and W were not detected or had low concentration (0.01–0.47 mg/kg) and were considered of little relevance. Co, Cr, Ni, Pb, and Mo were detected at concentrations up to 5.76 mg/kg. Fe, Mn, Zn, and Cu had the highest concentrations and were accumulated to inhibitory levels. Phenolic compounds were detected in negligible concentrations. We found that approximately 30% of onion root chromosomes were permanently damaged by high heavy metal concentrations released from the digestates. Higher temperatures and longer fermentation times fostered an increased release of pollutants above permissible limits.