Biochar seeding properties affect struvite crystallization for soil application

Nageshwari Krishnamoorthy; Christopher Nzediegwu; Xiaohui Mao; Hongbo Zeng; Balasubramanian Paramasivan; Scott X. Chang

doi:10.1016/j.seh.2023.100015

Biochar seeding properties affect struvite crystallization for soil application

Nageshwari Krishnamoorthy, Christopher Nzediegwu, Xiaohui Mao, Hongbo Zeng, Balasubramanian Paramasivan, Scott X. Chang

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Struvite crystallization is a viable approach for recovering phosphorus from phosphorus-rich solutions such as urine and wastewater. However, designing seed materials to promote crystal growth and enhance the efficiency of struvite crystallization remains an area of active research. In this study, we investigated the seeding characteristics of biochars on struvite crystallization and the impact of biochar feedstock type and production temperature on the process. Microwave-pyrolyzed biochars produced from different feedstocks and under different temperatures were examined as seeding materials for struvite crystallization from urine and the influence of biochar properties on the overall struvite yield, nutrient recovery and struvite crystal size. Sawdust biochar (lignocellulosic biomass) produced at 500 °C had the highest struvite yield (7.91 g L⁻¹), phosphate (97.9%) and ammonium recovery (87.1%), and relative crystal size (85.2%) compared to the non-seeded treatment due to its higher surface area, pore volume, and hydrophobicity of the biochar. Manure pellet biochar (non-lignocellulosic biomass) produced at 500 °C also exhibited performance comparable to sawdust biochar produced at 500 °C. Increasing pyrolysis temperature increased biochar's hydrophobicity, zeta potential, electrophoretic mobility and bulk density, irrespective of the feedstock type, thereby improving the seeding process. The ash content of biochar was negatively correlated with its surface area, pore volume, and particle size, but positively correlated with biochar's bulk density and suspension stability. In conclusion, feedstock type and pyrolysis temperature significantly affected biochar properties, which interactively influenced struvite crystallization. Therefore, biochars should be carefully selected to improve their efficiency for phosphorus recovery from phosphorus-containing solutions such as urine and wastewater, with the recovered phosphorus being used for soil applications.

Original language	English
Article number	100015
Journal	Soil and Environmental Health
Volume	1
Issue number	2
DOIs	https://doi.org/10.1016/j.seh.2023.100015
State	Published - 1 Jun 2023
Externally published	Yes

Keywords

Biochar
Microwave-assisted pyrolysis
Nucleation
Phosphorus recovery
Pyrolysis temperature
Seeding materials
Struvite

ASJC Scopus subject areas

Soil Science
Environmental Science (miscellaneous)

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.seh.2023.100015

Cite this

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title = "Biochar seeding properties affect struvite crystallization for soil application",

abstract = "Struvite crystallization is a viable approach for recovering phosphorus from phosphorus-rich solutions such as urine and wastewater. However, designing seed materials to promote crystal growth and enhance the efficiency of struvite crystallization remains an area of active research. In this study, we investigated the seeding characteristics of biochars on struvite crystallization and the impact of biochar feedstock type and production temperature on the process. Microwave-pyrolyzed biochars produced from different feedstocks and under different temperatures were examined as seeding materials for struvite crystallization from urine and the influence of biochar properties on the overall struvite yield, nutrient recovery and struvite crystal size. Sawdust biochar (lignocellulosic biomass) produced at 500 °C had the highest struvite yield (7.91 g L−1), phosphate (97.9%) and ammonium recovery (87.1%), and relative crystal size (85.2%) compared to the non-seeded treatment due to its higher surface area, pore volume, and hydrophobicity of the biochar. Manure pellet biochar (non-lignocellulosic biomass) produced at 500 °C also exhibited performance comparable to sawdust biochar produced at 500 °C. Increasing pyrolysis temperature increased biochar's hydrophobicity, zeta potential, electrophoretic mobility and bulk density, irrespective of the feedstock type, thereby improving the seeding process. The ash content of biochar was negatively correlated with its surface area, pore volume, and particle size, but positively correlated with biochar's bulk density and suspension stability. In conclusion, feedstock type and pyrolysis temperature significantly affected biochar properties, which interactively influenced struvite crystallization. Therefore, biochars should be carefully selected to improve their efficiency for phosphorus recovery from phosphorus-containing solutions such as urine and wastewater, with the recovered phosphorus being used for soil applications.",

keywords = "Biochar, Microwave-assisted pyrolysis, Nucleation, Phosphorus recovery, Pyrolysis temperature, Seeding materials, Struvite",

author = "Nageshwari Krishnamoorthy and Christopher Nzediegwu and Xiaohui Mao and Hongbo Zeng and Balasubramanian Paramasivan and Chang, {Scott X.}",

note = "Publisher Copyright: {\textcopyright} 2023 The Author(s)",

year = "2023",

month = jun,

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doi = "10.1016/j.seh.2023.100015",

language = "English",

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T1 - Biochar seeding properties affect struvite crystallization for soil application

AU - Krishnamoorthy, Nageshwari

AU - Nzediegwu, Christopher

AU - Mao, Xiaohui

AU - Zeng, Hongbo

AU - Paramasivan, Balasubramanian

AU - Chang, Scott X.

PY - 2023/6/1

Y1 - 2023/6/1

N2 - Struvite crystallization is a viable approach for recovering phosphorus from phosphorus-rich solutions such as urine and wastewater. However, designing seed materials to promote crystal growth and enhance the efficiency of struvite crystallization remains an area of active research. In this study, we investigated the seeding characteristics of biochars on struvite crystallization and the impact of biochar feedstock type and production temperature on the process. Microwave-pyrolyzed biochars produced from different feedstocks and under different temperatures were examined as seeding materials for struvite crystallization from urine and the influence of biochar properties on the overall struvite yield, nutrient recovery and struvite crystal size. Sawdust biochar (lignocellulosic biomass) produced at 500 °C had the highest struvite yield (7.91 g L−1), phosphate (97.9%) and ammonium recovery (87.1%), and relative crystal size (85.2%) compared to the non-seeded treatment due to its higher surface area, pore volume, and hydrophobicity of the biochar. Manure pellet biochar (non-lignocellulosic biomass) produced at 500 °C also exhibited performance comparable to sawdust biochar produced at 500 °C. Increasing pyrolysis temperature increased biochar's hydrophobicity, zeta potential, electrophoretic mobility and bulk density, irrespective of the feedstock type, thereby improving the seeding process. The ash content of biochar was negatively correlated with its surface area, pore volume, and particle size, but positively correlated with biochar's bulk density and suspension stability. In conclusion, feedstock type and pyrolysis temperature significantly affected biochar properties, which interactively influenced struvite crystallization. Therefore, biochars should be carefully selected to improve their efficiency for phosphorus recovery from phosphorus-containing solutions such as urine and wastewater, with the recovered phosphorus being used for soil applications.

AB - Struvite crystallization is a viable approach for recovering phosphorus from phosphorus-rich solutions such as urine and wastewater. However, designing seed materials to promote crystal growth and enhance the efficiency of struvite crystallization remains an area of active research. In this study, we investigated the seeding characteristics of biochars on struvite crystallization and the impact of biochar feedstock type and production temperature on the process. Microwave-pyrolyzed biochars produced from different feedstocks and under different temperatures were examined as seeding materials for struvite crystallization from urine and the influence of biochar properties on the overall struvite yield, nutrient recovery and struvite crystal size. Sawdust biochar (lignocellulosic biomass) produced at 500 °C had the highest struvite yield (7.91 g L−1), phosphate (97.9%) and ammonium recovery (87.1%), and relative crystal size (85.2%) compared to the non-seeded treatment due to its higher surface area, pore volume, and hydrophobicity of the biochar. Manure pellet biochar (non-lignocellulosic biomass) produced at 500 °C also exhibited performance comparable to sawdust biochar produced at 500 °C. Increasing pyrolysis temperature increased biochar's hydrophobicity, zeta potential, electrophoretic mobility and bulk density, irrespective of the feedstock type, thereby improving the seeding process. The ash content of biochar was negatively correlated with its surface area, pore volume, and particle size, but positively correlated with biochar's bulk density and suspension stability. In conclusion, feedstock type and pyrolysis temperature significantly affected biochar properties, which interactively influenced struvite crystallization. Therefore, biochars should be carefully selected to improve their efficiency for phosphorus recovery from phosphorus-containing solutions such as urine and wastewater, with the recovered phosphorus being used for soil applications.

KW - Biochar

KW - Microwave-assisted pyrolysis

KW - Nucleation

KW - Phosphorus recovery

KW - Pyrolysis temperature

KW - Seeding materials

KW - Struvite

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U2 - 10.1016/j.seh.2023.100015

DO - 10.1016/j.seh.2023.100015

M3 - Article

AN - SCOPUS:85181911778

SN - 2949-9194

VL - 1

JO - Soil and Environmental Health

JF - Soil and Environmental Health

IS - 2

M1 - 100015

ER -

Biochar seeding properties affect struvite crystallization for soil application

Abstract

Keywords

ASJC Scopus subject areas

UN SDGs

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