Synthesis optimisation and characterisation of chitosan-calcite adsorbent from fishery-food waste for phosphorus removal

Abstract

Here, Box-Behnken design (BBD) approaches were utilised to optimise synthesis methodology for the chitosan-calcite rich adsorbent (CCM) made from fishery-food waste material (crab carapace), using low-temperature activation and potassium hydroxide (KOH). The effect of activation temperature, activation time and impregnation ratio was studied. The final adsorbent material was evaluated for its phosphorus (P) removal efficiency from liquid phase. Results showed that impregnation ratio was the most significant individual factor as this acted to increase surface deacetylation of the chitin (to chitosan) and increased the number of amine groups (-NH 2 ) in the chitosan chain. P removal efficiency approached 75.89% (at initial P concentration of 20 mg/L) under optimised experimental conditions, i.e. where the impregnation ratio for KOH:carapace (g/g) was 1:1, the activation temperature was 105°C and the activation time was 150 min. Predicted responses were in good agreement with the experimental data. Additionally, the pristine and CCM material were further analysed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), Brunauer-Emmett-Teller technique (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). Characterisation showed enhancements in surface chemistry (introducing positively charged amine groups), textural properties and thermal stability of the CCM.

Substrate-Driven Phosphorus Bioavailability Dynamics of Novel Inorganic and Organic Fertilizing Products Recovered from Municipal Wastewater—Tests with Ryegrass

“…The wastewater from the primary settling tank of a WWTP was used as a P source for MA production [50,51]. The production of crab carapace material (CCM) from ERI-Veolia employed thermochemical modification using potassium hydroxide (KOH) to deacetylate the chitin chain of crab carapace (Cancer pagurus) and dry it at 105 • C to create a chitosan-calcite adsorbent [52,53]. The absorbent was then applied in Veolia's pilot reactor FILTRAFLO TM -P that uses gravitational wastewater filtration through an adsorption media with continuous self-backwashing.…”

Evaluation of microwave-dried black soldier fly (Hermetia illucens) larvae meal as a dietary protein source in broiler chicken diets

“…It has been reported that chitosan, which is a deacetylated form of chitin, reduced serum phosphorus in rats (Baxter et al, 2000). According to Pap et al (2020), chitosan can bind to phosphorus via its amine group (-NH 2 ), and the similar structure of chitin with chitosan may explain the observed decrease in serum phosphorus. The CPK level decreased in the 50HILM group, which may be ascribed to the low muscle mass caused by the lower final body weight of HILM-fed broilers (Garcia and Creatine, 1974;Yen et al, 2017).…”

New developments in biological phosphorus accessibility and recovery approaches from soil and waste streams

“…Pap et al. (2020) [70] found an adsorbent capacity for P of 76.9% of the initially provided 0.02 g P L –1 on lab‐scale. This capacity was even higher for modified mussel shell powder used for microalgae immobilization with P removal rates of 88% from initial 0.1025 g L –1 on lab‐scale [71].…”