Solar Greenhouse Drying of Wastewater Sludges Under Arid Climate
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- 作者：Mohamed Oussama Belloulid ; Hassan Hamdi ; Laila Mandi…
- 关键词：Wastewater sludge ; Solar drying ; Arid climate ; Greenhouse ; Activated sludge ; Bacteriological quality
- 刊名：Waste and Biomass Valorization
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：8
- 期：1
- 页码：193-202
- 全文大小：
- 刊物类别：Engineering
- 刊物主题：Engineering, general; Environment, general; Renewable and Green Energy; Industrial Pollution Prevention; Waste Management/Waste Technology; Environmental Engineering/Biotechnology;
- 出版者：Springer Netherlands
- ISSN：1877-265X
- 卷排序：8
文摘
Wastewater sludges were dried in an open greenhouse pilot in order to provide experimental data about solar greenhouse drying under an arid climate during hot and cold periods. Climatic conditions, solids contents and geometric dimensions were constantly measured. The shape change of samples was constantly recorded with digital scan. The results indicated that solar greenhouse drying reduced the moisture content from about 4 kg water/kg DS to 0.08 kg water/kg DS in hot period and to 0.2 kg water/kg DS in cold period in only 72 h. The higher values of drying rate were obtained in hot season. The maximum ranges obtained were 0.2 kg water/kg DS.h and 0.13 kg water/kg DS.h in hot and cold campaigns, respectively. Furthermore, a large volume reduction representing at least 80 % of initial volume was observed in both periods after 72 h of drying process. Also, shrinkage and cracks phenomena took place inside sludges. An improvement of the microbial condition of treated sludges was noted in hot campaign with a decrease by one order of magnitude after only 24 h for total and fecal coliforms and after 72 h for Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus contents. These pathogenic bacteria were almost constant for fresh and dry sludges in cold period. The paper recommends the solar drying in hot as in cold periods under arid climate considering its average drying rate outside the rainy periods.