Arsenic Ion Removal from Water Solutions Using Magnesium-Aluminium Layered Double Hydroxides

The results of laboratory scale studies were presented on efficacy of arsenic ion removal from model water solutions containing As(III) and As(V). For this purpose, magnesium-aluminium layered double hydroxides (LDHs) prepared by chloride and nitrate-chloride methods were applied. The studies demonstrated that both materials were effective in respect of arsenic(V) removal, whereas differed with regard to arsenic(111) removal. The latter was significantly better removed with the use of LDH received by chloride method. Based on the literature value of magnesium arsenate(V) solubility product it was estimated that at pH about 10 arsenic(V) removal occurred via adsorption and/or precipitation of magnesium arsenate(V). In contrast, arsenic(111) removal resulted solely from adsorption of these ions.