PHYTOTOXICITY OF SEWAGE SLUDGE BIOCHARS PREPARED AT DIFFERENT PYROLYSIS CONDITIONS

摘要

Pyrolysis of sewage sludge was carried out at three different lab-scale reactors and conditions: an Auger reactor forrnsewage sludge pyrolysis at low temperature (300℃), a stirred batch reactor (530℃) and a fluidised bed reactorrn(530℃). The starting material is anaerobically digested and thermally dried sewage sludge from a wastewaterrntreatment plant located in Spain. A preliminary study to assess the feasibility of application to soil of the threernbiochars was performed using two germination tests and a greenhouse experiment. Water soluble compounds fromrnbiochar did not affect seed germination, but volatile compounds reduced germination of more sensitive seeds.rnBiochar applied to soil at agricultural rates (20 t/ha) reduced growth and development of a corn crop. No differentialrneffects of the three pyrolysis conditions were found.