title: Composting sewage sludge amended with different sawdust proportions and textures and organic waste of food industry--assessment of quality.
abstract: The quality of compost made from dewatered sewage sludge, sawdust (SD) and organic wastes of a potato-processing industry (OW), in terms of chemical and biological properties, was assessed. Mixtures of the sludge, SD and OW were composted for 57 days in insulated containers at two C:N ratios (approximately 30 : 1 and approximately 20 : 1) and SD textures (coarse- and fine-textured SD). The parameters monitored over this period were pH, electrical conductivity (EC), C:N ratio, CO2 evolution and two spectrophotometric ratios (Q2/6 and Q2/4). All the studied parameters were in general similarly influenced by initial C:N ratio and texture of SD except for EC, Q2/6 and Q2/4. At high C:N ratio of both textures, the EC of the final products increased but were less than those of low C:N ratio of both textures. Thus, final product can be used alone as growth medium without the need for grinding or blending with other materials. The spectrophotometric ratios (Q2/6 and Q2/4) dramatically decreased two weeks after composting and then slightly increased at the end of composting process. However, coarse-textured SD at the low C:N ratio and fine-textured SD at both C:N ratios resulted in lower Q2/6 and Q2/4 ratios, reflecting a better degree of aromatic condensation and organic matter humification. Considering these parameters, co-composting sludge with fine-textured SD and OW at high initial C:N ratio would represent the best compromise.
authors.affiliation: Department of Water Resources and Environmental Management, Faculty of Agricultural Technology, Al-Balqa' Applied University, Al-Salt, Jordan. tarekamm@yahoo.com
authors.forename: Tarek G
authors.initials: TG
authors.lastname: Ammari
authors.forename: Qusai
authors.initials: Q
authors.lastname: Al-Omari
authors.forename: Bassim E
authors.initials: BE
authors.lastname: Abbassi
mesh_terms: D002244:Carbon / Q000032:analysis; D004553:Electric Conductivity; D019649:Food Industry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D009584:Nitrogen / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage; D012987:Soil; D011198:Solanum tuberosum; D013053:Spectrophotometry; D014934:Wood
chemical_list: D007220:Industrial Waste; D012722:Sewage; D012987:Soil; D002244:Carbon; D009584:Nitrogen