Techno-economic and environmental approaches of Cd²⁺ adsorption by olive leaves (Olea europaea L.) waste

Synthesis of sludge-derived biochar modified with eggshell waste for monoethylene glycol removal from aqueous solutions

“…Figure 1d displays the FTIR spectra of the adsorbent material before and after MEG adsorption. It was demonstrated that the main functional groups of raw biochar were: N-H stretching at 3700 1/cm; bonded hydroxyl groups (OH) at 3250-3600 1/cm; -C-H or CH 3 at 2100-2360 1/cm; -CH 2 or aromatic C=C stretching at 1417 1/cm; alcohol C-O stretching at 1029 1/cm; C-H at 939 1/cm; Si-O at 468 1/cm [8,12]. These surface OH groups would serve as reactive sites for adsorbed species [26].…”

“…CC was expressed as a cost per cubic meter of treated water (US$/m 3 ). The construction cost was calculated from the capacity of the adsorption unit, as reported by Fawzy et al [8] (Eq. 8).…”

“…The summation of capital costs for the treatment of 1 m 3 wastewater containing MEG was 4.80 US$ for the BC option and 6.50 US$ for the EMBC option. The equipment used for biochar preparation included an oven, standard sieves, muffle furnace (i.e., (8)…”

“…These studies have revealed that adsorption would be a promising and cost-effective approach for the treatment of wastewater containing MEG. Adsorption is a simple and environmentally friendly technology that has found relevant results, regarding energy utilization, sludge disposal issues, and operation and maintenance costs [8,9].…”

“…In comparison, the biological systems used for the treatment of industrial wastewater containing ethylene glycol entail a retention time over 12 h [10]. The long hydraulic residence time leads to large reactor volumes and initial investment costs [8]. Moreover, the chemical treatment of petroleum wastewater requires advanced reactions and processes, and it utilizes large amounts of reagent and raw material [3].…”