Removal of ammonia from a smelting wastewater by cyclic stripping and acid adsorption: Kinetics study

Abstract

Air stripping is an effective method for the removal of ammonia from high‐concentration wastewater. The traditional open stripping process is expensive due to high consumptions of alkali reagent and energy. This study proposed a novel cyclic stripping‐acid adsorption system for ammonia removal. The stripped ammonia gas flowed into the stripping tower, and no fresh air was added during the cyclic stripping process. The kinetics model of ammonia removal from the smelting wastewater in a pilot‐scale cyclic stripping tower was investigated. The influences of stripping temperature (T), wastewater pH, air to liquid ratio (R), and acid spray flow (F) on the ammonia removal rate were discussed. The kinetics equation was determined as G = 4.14 × 10−3 × pH1.83 × T0.27 × F0.98 × R−0.49 when pH = 9.80–12.29, T = 19–35°C, F = 58–76 m3·h−1, and R = 1329–1725. The equation can be used to predict the removal rate of ammonia during operation. The ammonia concentration of the effluent decreased from 5951 mg·L−1 to 13 mg·L−1 within 15 h. Ammonia can be removed rapidly and economically from wastewater via the cyclic stripping process. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

Mechanism of calcium hydroxide-reinforced magnesium-loaded clinoptilolite/phosphoric acid-modified biochar for NH3-N removal from rare earth element tailing wastewater

“…12 The stripping process is expensive due to high equipment and energy costs. 13 Adsorption has proven to be an effective method in wastewater treatment. Clinoptilolite 14 and biochar 15 are widely used as adsorbent materials and have no toxicity to the subsequent biological treatment systems.…”