Modified Hazelnut Shells as a Novel Adsorbent for the Removal of Nitrate from Wastewater

Abstract

The aim of the study was to prepare a novel adsorbent by chemical modification of hazelnut shells and evaluate its potential for the nitrate removal from model solutions and real wastewater. The characterization of the novel adsorbent, i.e., modified hazelnut shell (MHS) was performed. The adsorbent characterization included the analysis of elemental composition and the surface characteristics analysis by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The adsorption experiments (batch technique) were performed to investigate the effects of adsorbent concentration, contact time, initial nitrate concentration, and solution pH. The nitrate removal efficiency increased with the increase in MHS concentration and decreased with the initial nitrate concentration. MHS was found to be effective in nitrate removal over a wide pH range (from 2 to 10), and the highest amount of nitrate adsorbed was 25.79 mg g−1 in a model nitrate solution. Depending on the aqueous medium (model solutions or real wastewater samples), it was shown that both Langmuir and Freundlich adsorption isotherm models can be used to interpret the adsorption process. It was found that the kinetics are well described by a pseudo-second order model and the nitrate adsorption process can be controlled by chemisorption. The intraparticle diffusion model has been used to identify an adsorption-controlled process by diffusion mechanisms. Adsorption/desorption experiments in column confirmed that MHS could be successfully used in multiple cycles (at least three), indicating the potential of MHS as an alternative to costly commercial adsorbents for the removal of nitrates from wastewater.

Preparation and application of a surfactant‐modified Halloysite nanotubes for the adsorption of nitrates from aqueous solutions: Kinetic and equilibrium studies

“…The effectiveness of the HNTs and HNTs-CTAB in the removal of nitrate has been examined using batch adsorption modes. 49,50 A determined quantity of each adsorbent (10 mg) in tubes containing 10 ml of a NO 3 solution (100 mg/L) was kept with a speed of 200 rpm at initial pH solution of about 5.4 at room temperature.…”

Amine-Grafted Pomegranate Peels for the Simultaneous Removal of Nitrate and Phosphate Anions from Wastewater

“…Several chemical activation agents have been used to chemically activate the surface of agricultural waste, such as dimethylamine/epichlorohydrin grafted onto the surface of several by-products (sugarcane bagasse, hazelnuts, and rice shells). This chemical activation improved the ability of these by-products to adsorb NO 3 − which expected q e of 55.6 mg/g in the case of rice peel [54][55][56]. Other chemicals with amino functions, such as cetyltrimethylammonium bromide [53], polyethyleneimine [57], N-(3-chloro-2hydroxypropyl) trimethylammonium chloride (CHMAC) [55], and 3-aminopropyltriethoxy silane (APTES) [58] have also been commonly used to improve the adsorption of NO 3 − anions.…”

“…In fact, in general, agro-resources are increasingly used in water treatment to reduce the environmental impact of many activities, such as fabric dyeing [41][42][43][44], molecular detection of chemical elements [45,46], and pollutant removal. In this regard, several studies have reported the use of ago-wastes (raw and modified) as adsorbents for several pollutants such as dyes [47,48], heavy metals [49][50][51], and NO 3 − /PO 4 3− anions [52][53][54][55][56]. The natural raw materials mentioned above adsorb pollutants but inefficiently with low adsorption capacity (qe).…”

“…The natural raw materials mentioned above adsorb pollutants but inefficiently with low adsorption capacity (qe). Therefore, chemical activation of the surface is needed to improve the adsorption efficiency of agricultural waste [53][54][55][56] in order to remove the pollutants concerned. Several chemical activation agents have been used to chemically activate the surface of agricultural waste, such as dimethylamine/epichlorohydrin grafted onto the surface of several by-products (sugarcane bagasse, hazelnuts, and rice shells).…”

Black Tea Waste as Green Adsorbent for Nitrate Removal from Aqueous Solutions

“…Recent research has shown that the low anion exchange capacity of soils frequently limits the removal performance of nitrate. As a result, carbon additions such as woodchips, sawdust, crop residues and biochar have been suggested for nitrate removal [ 18 , 19 ].…”