Screening of Raw and Modified Biochars from Food Processing Wastes for the Removal of Phosphates, Nitrates, and Ammonia from Water

Abstract

The aim of this work was to compare the performance of biochar from various food processing wastes of different origin for the removal of different nutrients from water. Eggshells (EGS), rice husk (RH), and coffee biochars were pyrolyzed at 400 and 800 °C and were examined for the removal of phosphates, nitrates, and ammonia nitrogen. The raw materials were also modified with magnesium chloride in order to investigate their sorption behavior. The highest sorption capacity (qmax) for phosphates and ammonium was observed with EGS pyrolyzed at 800 °C and was 11.45 mg PO43−-P/g and 11.59 mg NH3-N/g, while the highest nitrates sorption capacity was observed with the magnesium-modified RH pyrolyzed at 800 °C (5.24 mg NO3−-N). The modified EGS biochars pyrolyzed at 800 °C had almost the half the sorption capacity for phosphates and nitrates compared to the unmodified materials. The modification of RH pyrolyzed at 800 °C resulted in higher sorption capacity by 34 and 158% for phosphates and ammonium, respectively. The coffee raw and modified biochars were less efficient in nutrient removal compared to the other materials. The specific surface area values of the biochars examined is not a decisive factor for nutrient sorption. The reaction between magnesium and calcium (for the eggshell samples) ions with phosphates is responsible for the higher sorption efficiency. On the other hand, the presence of magnesium and calcium ions has a detrimental effect on the sorption of NH3-N.

Efficient and selective separation of Re(VII), an analogue of Tc(VII), by a defective biochar with honeycomb‐like porous structure

“…It was clear that the intensity of (002) crystal plane peak decreased visibly after KOH activation, showing that the graphitic defects of BC‐PH increased. The diffraction peak at 42° corresponded to the (100) crystal plane of carbon species with sp 2 hybridization and was intensified after KOH activation 38,39 . The hydrophobicity of BC‐PH may be related to the C in sp 2 hybridization.…”

“…The diffraction peak at 42°corresponded to the (100) crystal plane of carbon species with sp 2 hybridization and was intensified after KOH activation. 38,39 The hydrophobicity of BC-PH may be related to the C in sp 2 hybridization. The Raman spectra, as depicted in Fig.…”

Chlorococcum sp. biofilm growth on biochar from olive kernels solid support

“…As far as closed reactors are concerned, they provide better control over pH and temperature, low contamination and evaporation rates and high cell densities; however, the harvesting mode remains a significant challenge 8 . The most usual harvesting techniques include flocculation, membrane filtration and centrifugation 8‐10 . In suspended cultures, water must be removed to obtain algal biomass.…”

“…8 The most usual harvesting techniques include flocculation, membrane filtration and centrifugation. [8][9][10] In suspended cultures, water must be removed to obtain algal biomass. However, the cost of biomass harvesting is estimated to be at least 20% to 30% of the total cost of biomass production, due to the energy consumption.…”

Synthesis, Characterization and Performance of Materials for a Sustainable Future

“…The reliability of competitive sustainable sorption processes for the treatment of wastewater was also assessed by comparing the performance of biochar obtained from different preparation conditions and raw biomass, such as eggshells, rice husks, and spent coffee grains for the removal of phosphates, nitrates, and ammonia from water [7]. The materials were pyrolyzed at 400 and 800 • C with and without magnesium modification.…”