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Effects of Nano‐Copper(II) Oxide and Nano‐Magnesium Oxide Particles on Activated Sludge
Author(s) -
Liu Guoqiang,
Wang Jianmin
Publication year - 2012
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 - 10.2175/106143012x13373575830593
Subject(s) - activated sludge , biodegradation , chemistry , magnesium , nitrification , nitrite , nuclear chemistry , biochemical oxygen demand , chemical oxygen demand , environmental chemistry , nano , hydrolysis , inorganic chemistry , nitrogen , wastewater , environmental engineering , biochemistry , nitrate , chemical engineering , organic chemistry , engineering
Effects of nano‐copper(II) oxide (nano‐CuO) and nano‐magnesium oxide (nano‐MgO) particles on activated sludge endogenous respiration (aerobic digestion), biochemical oxygen demand (BOD) biodegradation, and nitrification were investigated through respiration rate measurement. For comparison, the effects of Cu(II) and Mg(II) ions on activated sludge were also studied. Results indicated that soluble Cu(II) has half maximum inhibitory concentration (IC 50 ) values of 19, 5.5, 53, and 117 mg Cu/L for endogenous respiration, BOD biodegradation, ammonium oxidation, and nitrite oxidation, respectively. However, nano‐CuO only inhibited BOD biodegradation at 240 mg Cu/L or more, and its associated toxicity was primarily caused by soluble Cu(II). In contrast, soluble Mg(II) was not toxic to activated sludge in the experimental concentration range, but nano‐MgO inhibited BOD biodegradation and nitrification with IC 50 values of 70 and 143 mg Mg/L, respectively. Further study indicated that the toxicity of nano‐MgO resulted primarily from increased pH following MgO hydrolysis.