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Acid characteristics of dissolved organic matter in wastewater
Author(s) -
Wang Jianmin,
Huang C.P.,
Allen Herbert E.,
Takiyama Luis R.,
Poesponegoro Ira,
Poesponegoro Haryanto,
Pirestani Dan
Publication year - 1998
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 - 10.2175/106143098x123372
Subject(s) - chemistry , dissolved organic carbon , wastewater , titration , dissolution , environmental chemistry , organic matter , sewage treatment , chemical oxygen demand , inorganic chemistry , nuclear chemistry , environmental engineering , organic chemistry , environmental science
The presence of dissolved organic matter (DOM) in a wastewater treatment system can significantly affect the uptake of heavy metals by sludge particulates. The characteristics of DOM, its concentration, and the solution pH are important parameters governing the heavy metals uptake reaction. The characteristics of DOM of various wastewater and sludge (primary, secondary, and tertiary) samples collected from four municipal wastewater treatment plants were investigated. Results showed that the dissolution of DOM from sludge is significantly affected by pH and suspended solids concentration. Results also showed that DOM contains two discrete acid groups that are available for metals complexation. The site concentration and acidity constants were determined by an alkalimetric titration method. For all DOM samples studied, the acidity constants, pK ab and pK aB , were 5.3 and 9.5, respectively. Based on the acidity constants and the Fourier transform infrared spectra, it is believed that the acid sites consist of carboxylic and amino functional groups. The density of the first acid site was approximately 10 −5 mol/mg chemical oxygen demand for all samples studied. However, the density of the second acid site varied significantly among the DOM samples investigated.