Comparison of the effect of AlCl3 and Al13 on sludge conditioning in water supply plant
LI Mingshuang1,2,, XU Hui1,2,,, WANG Dongsheng1,2, WANG Xi1,2, YU Junjie1,2 1.State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 2.University of Chinese Academy of Sciences, Beijing 100049, China
Abstract:The sludge of water supply plant are conditioned by AlCl3 and Al13, and the performance of them are evaluated by measuring capillary suction time (CST), specific resistance to filtration (SRF), dissolved organic matter content (DOC), residual aluminum of conditioned sludge’s supernatant, the particle size and fractal dimension of flocs and analyzing the composition and content of organics by three-dimensional excitation emission matrix fluorescence (3D-EEM). The optimal dosage of Al13 is 0.336 g?L?1 while AlCl3 is 0.800 g?L?1 (measured by aluminum content). Under the optimal dosage, the CST of the sludge after Al13 and AlCl3 conditioning is 33.1 and 34.8 s, and the SRF is 4.98×1012 and 5.45×1012 m?kg?1, respectively. Al13 can achieve a good dewatering effect under the condition of less dosage. The results of SEM and the dynamic change of particle size indicated that the flocs conditioned by Al13 are small, while the flocs conditioned by AlCl3 are large. DOC and residual aluminum of the sludge conditioned by Al13 are 14.27 mg?L?1 and 1.20 mg?L?1, respectively, which are less than 21.93 mg?L?1 and 154.00 mg?L?1 of AlCl3. Therefore, the supernatant of the sludge conditioned by Al13 is more suitable for reuse. The results of this study shows that Al13 has an advantage over AlCl3 in water supply plant sludge conditioning, and it can give an idea for optimizing the sludge conditioning process. Key words:AlCl3/ Al13/ aluminum speciation/ water supply plant sludge conditioning/ sludge dewatering.
图1不同浓度Al13和AlCl3调理后的污泥的CST和SRF Figure1.CST and SRF of sludge treated with different concentrations of Al13 and AlCl3
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1.State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 2.University of Chinese Academy of Sciences, Beijing 100049, China Received Date: 2020-08-17 Accepted Date: 2020-10-23 Available Online: 2021-03-24 Keywords:AlCl3/ Al13/ aluminum speciation/ water supply plant sludge conditioning/ sludge dewatering Abstract:The sludge of water supply plant are conditioned by AlCl3 and Al13, and the performance of them are evaluated by measuring capillary suction time (CST), specific resistance to filtration (SRF), dissolved organic matter content (DOC), residual aluminum of conditioned sludge’s supernatant, the particle size and fractal dimension of flocs and analyzing the composition and content of organics by three-dimensional excitation emission matrix fluorescence (3D-EEM). The optimal dosage of Al13 is 0.336 g?L?1 while AlCl3 is 0.800 g?L?1 (measured by aluminum content). Under the optimal dosage, the CST of the sludge after Al13 and AlCl3 conditioning is 33.1 and 34.8 s, and the SRF is 4.98×1012 and 5.45×1012 m?kg?1, respectively. Al13 can achieve a good dewatering effect under the condition of less dosage. The results of SEM and the dynamic change of particle size indicated that the flocs conditioned by Al13 are small, while the flocs conditioned by AlCl3 are large. DOC and residual aluminum of the sludge conditioned by Al13 are 14.27 mg?L?1 and 1.20 mg?L?1, respectively, which are less than 21.93 mg?L?1 and 154.00 mg?L?1 of AlCl3. Therefore, the supernatant of the sludge conditioned by Al13 is more suitable for reuse. The results of this study shows that Al13 has an advantage over AlCl3 in water supply plant sludge conditioning, and it can give an idea for optimizing the sludge conditioning process.