title: Influences of volatile solid concentration, temperature and solid retention time for the hydrolysis of waste activated sludge to recover volatile fatty acids.
abstract: The study evaluated influences of sludge concentration, temperature and solids retention time (SRT) for the hydrolysis of waste activated sludge (WAS) in anaerobic digesters. The results indicated that volatile fatty acids (VFA) production increased when the concentration of mixed liquor volatile suspended solids (MLVSS) was higher. When SRT was 48 h, VFA concentration increased 8.43 times from 4.57 to 23.78 gMLVSS/L. VFA generation was significantly affected with different temperature and SRT. When the temperature changed from 40 to 50°C, it induced 1.65-fold increase in VFA yield. The optimal SRT was 48 h. As VFA concentration decreased only 1.31 times compared with maximum VFA production at SRT of 120 h. Iso-valeric acid, acetic acid and n-butyric acid were the dominant VFA produced and would improve ployhydroxyvalerate proportion in polymer. The feasibility of nitrogen and phosphorus recovery and the risk of metal ion released depended on the nature of WAS.
authors: School of Environment, Tsinghua University, Beijing 100084, China.
authors: Huilei
authors: H
authors: Xiong
authors: Jinluan
authors: J
authors: Chen
authors: Hui
authors: H
authors: Wang
authors: Hanchang
authors: H
authors: Shi
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D003247:Conservation of Natural Resources / Q000379:methods*; D005232:Fatty Acids, Volatile / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D044367:Phase Transition; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000382:microbiology*; D013696:Temperature
chemical_list: D005232:Fatty Acids, Volatile; D012722:Sewage