Effective Removal of Nitrates Ions from Aqueous Solution Using New Clay as Potential Low-Cost Adsorbent

Abstract

In the present study, we investigated the performance of clay mineral originated from a dam situated in Morocco (Agadir city), as natural, low-cost, alternative and eco-friendly adsorbent for removal of nitrates ions from aqueous solution within a batch process. The clay was characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Dispersive Energy of Spectroscopy (EDS), Fourier Transform Infrared (FTIR) and surface area analysis (BET). The effects of various experimental parameters are examined such as contact time, initial concentration of pollutant, adsorbent mass and solution pH. The removal of nitrate was 71.89% at natural pH (pH = 5.1) using 1 g/l of adsorbent in 500 ml of nitrate solution having initial concentration of 300 mg/l (effect of contact time). Adsorption kinetic study revealed that the adsorption process followed first order kinetic. Theoretical correlation of the experimental equilibrium adsorption data for the NitrateNew Clay system was properly explained by the Langmuir isotherm model. The maximum adsorption capacity was Qm, exp = 244.06 mg/g at 20˚C and at natural pH (with Q m, cal = 250 mg/g). An increase in adsorbent dosage increased the percent removal of nitrate, R = 1 g/l was considered as optimum dose and was used for further study. The pH heavily affected the adsorption capacity, and the percentage removal was found to decrease with increase in pH. The obtained results indicated that this New Clay (NC) was very good adsorbent for 3 NO − , interesting alternative material with respect to more costly adsorbent used, and could be used as a highly efficient adsorbent for the separation of nitrate from drinking or waste water.

Nitrate removal from aqueous solutions by adsorption onto hydrogel‐rice husk biochar composite

“…The initial swing adsorption rate of nitrate can be attributed to the availability of free binding sites on the surface of the composite (Ouardi et al, ). The rate of adsorption declined as the active sites became saturated.…”

“…The pseudo‐first‐order model explains adsorption of solid adsorbent in solid‐liquid systems, while the pseudo‐second‐order kinetic model considers chemical adsorption including the electron sharing between the adsorbent and adsorbate in liquid solutions (Ouardi et al, ).…”

“…The Freundlich isotherm model defines multilayer adsorption at different binding sites and characteristic heterogeneous surfaces (Ouardi et al, ). The Freundlich model has been stated by the following equation:where, q e (mg/g) is the quantity of nitrate adsorbed at equilibrium, K f and n are the Freundlich constant.…”

“…Nitrate separation in aqueous solutions is complicated owing to its high solubility and stability in water. Therefore, numerous physical, chemical, and biological techniques have been applied to assist in the nitrate removal from water such as biological denitrification (Schipper & Vojvodić‐Vuković, ), chemical reduction (Hu, Goto, & Fujie, ), reverse osmosis, electrodialysis (Ouardi, Qourzal, Alahiane, Assabbane, & Douch, ), and ion exchange (Bae, Jung, Han, & Shin, ). Among the mentioned methods, application of adsorbents in recent research has attracted more attention thanks to being an economical and effective alternative of nitrate removal from water.…”

Adsorption of Nitrate from Ground Water using Indian Bentonite: Fixed Bed Column Study

“…Several adsorbents are used for nitrate removal such as carbon based adsorbents, various types of clays, various inorganic materials. Of all the adsorbents that are generally used inorganic adsorbents are gaining importance in the recent years, many researchers [17] [18] have shown inorganic materials to be better than their organic counterpart.…”