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Effect of Aluminum (Al 3+ ) on Granulation in Upflow Anaerobic Sludge Blanket Reactor Treating Low‐Strength Synthetic Wastewater
Author(s) -
Sondhi Akash,
Guha Saumyen,
Harendranath C.S.,
Singh Anju
Publication year - 2010
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143010x12609736966603
Subject(s) - chemical oxygen demand , granulation , wastewater , agglomerate , aluminium , chloride , pulp and paper industry , chemistry , economies of agglomeration , hydroxide , metallurgy , environmental engineering , chemical engineering , materials science , environmental science , inorganic chemistry , composite material , engineering
The effect of aluminum on agglomeration in the sludge bed and chemical oxygen demand (COD) removal efficiency in laboratory‐scale upflow anaerobic sludge blanket (UASB) reactors treating low‐strength synthetic wastewater (approximately 665 to 738 mg/L of COD) was investigated. Continuous application of aluminum chloride (200 mg/L) caused poor COD removal, less sludge density, and adversely affected agglomeration in the sludge bed. An adverse effect on granulation also was observed when 300 mg/L aluminum chloride was added only during the startup, and the effect continued even after it was discontinued. A lower concentration of aluminum chloride (50 mg/L) added for 30 days after the reactors reached steady‐state did not affect the COD removal efficiency, but adversely affected the growth of agglomerates and caused temporary degeneration of existing agglomerates. The adverse effect of aluminum appeared to stem from the precipitation of aluminum hydroxide on the surfaces of agglomerates. The effect of aluminum on agglomeration was shown to be a function of influent strength.