Solar drying of wastewater sludge: A review

摘要: Abstract Drying constitutes an important process for wastewater sludge management, as it can reduce the mass and volume of product consequently cost storage, handling transport. During constant operating conditions, drying kinetic has shown mainly: a rate, one or two falling rate periods final short period with variations along physical properties appearance shrinkage cracks phenomena. Solar was benefit using free solar energy operation. On other hand, plays role pathogen reduction until Environmental protection Agency (EPA) recommendations. In some studied cases, value 1000 CFU g −1 DS, which represents EPA Class A requirement, fecal coliform attained. The general design used dryers constituted of: greenhouse made transparent material floor, where is speared in thick layers. Furthermore, fans ventilations be order to have homogeneous distribution air inside replacement humidified fresh one. Automatic handle mix once several times day. increase performances system, ways such heating floor water heater, infrared lamps, heat pumps adding thermal storage systems were also tested. Covered given better results than open drying. However, origin affects obtained results. Alternatively, modeling effectuated balances, applied dried product. satisfactory