|Brown, R - NEW MEXICO TECH INSTITUTE|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 21, 2001
Publication Date: November 2, 2001
Citation: DAO, T.H., BROWN, R.S. COMPETITIVE SORPTION OF ANIMAL WASTEWATER ANIONS BY ZEOLITE-BASED SORBENTS. AGRONOMY ABSTRACTS. 2001. Technical Abstract: Natural zeolites have a high affinity for cationic species due to their large specific surface area and high cation exchange capacity. However, zeolites have little affinity for inorganic anions such as nitrate or phosphate. Zeolites can be modified with cationic surfactants because of the high permanent negative charge capacity, which increases their ability to sorb inorganic oxyanions such as nitrate, sulfate, arsenate, and chromate. Yet little research has been conducted to determine either natural or synthetic zeolites and surfactant-modified zeolites (SMZ)' ability to retain phosphate alone and in the presence of other competing anions in a wastewater environment. Sorption isotherms of single ions were determined in a synthetic wastewater background containing chloride and sulfate. Nitrate sorption on SMZ was primarily due to anion exchange, while natural zeolite and the synthetic zeolite wastestream by-product did not have any appreciable sorption capacity for nitrate. Phosphate retentio may be attributed to surface complexation and precipitation on both sorbents. In mixed solutions of nitrate and phosphate, the presence of phosphate apparently did not change nitrate sorption, in the concentration range of 0 to 2.5 mmol/L. The results suggested the potential of SMZ and the synthetic zeolite wastestream by-product for removing environmentally sensitive anion from wastewater.