Phosphorus recovery from biogas slurry by ultrasound/H2O2digestion coupled with HFO/biochar adsorption process.
Phosphorus (P) recovery from biogas slurry has recently attracted considerable interest. In this work, ultrasound/H2O2digestion coupled with ferric oxide hydrate/biochar (HFO/biochar) adsorption process was performed to promote P dissolution, release, and recovery from biogas slurry. The results showed that the optimal total phosphorus release efficiency was achieved at an inorganic phosphorus/total phosphorus ratio of 95.0% at pH 4, 1mL of added H2O2, and ultrasonication for 30min. The P adsorption by the HFO/biochar followed pseudo second-order kinetics and was mainly controlled by chemical processes. The Langmuir-Freundlich model matched the experimental data best for P adsorption by HFO/biochar at 298 and 308K, whereas the Freundlich model matched best at 318K. The maximum amount of P adsorbed was 220mg/g. The process was endothermic, spontaneous, and showed an increase in disorder at the solid-liquid interface. The saturated adsorbed HFO/biochar continually releases P and is most suitable for use in an alkaline environment. The amount of P released reached 29.1mg/g after five extractions. P mass balance calculation revealed that 11.3% of the total P can be made available.
Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Xuemeng
X
He
Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. Electronic address: taozhang@cau.edu.cn.
Tao
T
Zhang
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu, China.
Hongqiang
H
Ren
Key Laboratory of Plant-Soil Interactions of Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Guoxue
G
Li
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu, China.
Lili
L
Ding
Faculty of Environmental Engineering, Lublin University of Technology, Lublin, Poland.
Lucjan
L
Pawlowski
D000327:Adsorption; D056804:Biofuels / Q000032:analysis*; D002606:Charcoal / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis*; D014465:Ultrasonics; D018505:Waste Management / Q000379:methods*
D056804:Biofuels; D005290:Ferric Compounds; C540010:biochar; D002606:Charcoal; C000499:ferric oxide; D010758:Phosphorus; D006861:Hydrogen Peroxide
Biogas slurry; Ferric oxide hydrate/biochar (HFO/biochar); Nutrient recovery; Phosphorus; Ultrasound/H(2)O(2)