Engineered biochar for simultaneous removal of heavy metals and organic pollutants from wastewater: mechanisms, efficiency, and applications

Nana Wang; Bing Wang; Hailong Wang; Pan Wu; Masud Hassan; Shengsen Wang; Xueyang Zhang; Nana Wang; Bing Wang; Hailong Wang; Pan Wu; Masud Hassan; Shengsen Wang; Xueyang Zhang

doi:10.48130/bchax-0025-0008

Figures (6) Tables (2)

Figure 1.
The number of literature on the application of biochar in water from 2015 to 2024 (Data come from Web of Science).
Figure 2.
Different engineered biochars for the co-removal of heavy metals and organic pollutants.
Figure 3.
Multiple mechanisms of engineered biochar for co-removing heavy metals and organic pollutants.
Figure 4.
The proportion of influencing factors on the removal performance of engineered biochar in co-removing heavy metals and organic pollutants.
Figure 5.
Applications of engineered biochar in wastewater environment remediation.
Figure 6.
System boundary of engineered biochar production process.

Engineered biochars	Pollutants	Removal performance (mg/g)	pH	Dosage (g)	Initial concentrations (mg/L)	Reaction time (min)	Reaction temperature (°C)	Ref.
Hydroxyapatite-modified cod bone biochar	Diclofenac	43.29	8.0	0.01	100	300	−	[172]
	Fluoxetine	12.53			100
	Pb²⁺	714.24			2,100
Silicon dioxide/biochar (corn cob) nanocomposite	U⁶⁺	255.10	5.0	0.6	10–100	−	25	[173]
	Cr⁶⁺	90.01	2.0	0.2
	MB	1,614.04	7.0	0.4
Potassium ferrate-activated wheat straw biochar	Cu²⁺	48.75	−	0.2	10	720	25	[127]
Potassium ferrate-activated wheat straw biochar	SMZ	51.72	−	0.2	10	720	25	[127]
Magnesium oxide/rice husk biochar composite	BPA	18.10	5.0	0.1	20–160	240	25	[174]
Magnesium oxide/rice husk biochar composite	Cu²⁺	64.90	5.0	0.1	20–160	240	25	[174]
Mixed silicate/hydrocarbon (pine sawdust) composites	Cu²⁺	214.70	−	0.5	10–300	−	−	[175]
	Zn²⁺	227.30
	TC	361.70
Iron/nitrogen co-doped rapeseed straw biochar	CIP	46.45	2.0−6.0	0.2	50	−	25	[176]
Iron/nitrogen co-doped rapeseed straw biochar	Cu²⁺	30.77	2.0−6.0	0.2	50	−	25	[176]
EDTA/chitosan bifunctionalized magnetic biochar	MO	305.4	5.0	0.5	200	−	25–45	[116]
	Cd²⁺	63.20			100
	Zn²⁺	50.80			100
Eagnetically-modified Enteromorpha prolifera−based biochar hydrogels	MO	47.65%	3.0	0.01	80		−	[177]
	Cr⁶⁺	42.50%	3.0	0.01	80	80	−	[177]
Polymethyl methacrylate/(rice husk ash)/polypyrrole composite film	Cr⁶⁺	360.50	2.0	0.006	0−80	150	25	[178]
	Tartrazine (E102)	165.70	2.0	0.006	0−80	60	25	[178]
Polyacrylic acid modified tobacco stem biochar	Quinclorac	80.74%	−	0.008	10	240	25	[179]
Polyacrylic acid modified tobacco stem biochar	Pb²⁺	73.20%	−	0.008	10	240	25	[179]
Iron/zinc activated rice straw biochar	17β-estradiol	123.00	−	0.006	6	−	25	[180]
Iron/zinc activated rice straw biochar	Cu²⁺	76.00	−	0.006	140	−	25	[180]
Nano zero valent iron loaded biochar	Cr⁶⁺	30.87	3.0	0.3	50	2,880	25	[181]
Nano zero valent iron loaded biochar	TCE	32.32	3.0	0.3	10	2,880	25	[181]

Table 1.

Performance and optimal conditions of engineered biochar for simultaneous removal of organic pollutants and heavy metals

Engineered biochars	Pollutants	Regeneration methods	Regeneration performance	Cycle number	Ref.
NaOH-modified cactus biochar	Peacock stone green	0.1 M NaOH	The removal rate of peacock stone green decreased by 15%, and the removal rates of Cu²⁺ and Ni²⁺ both decreased by 16%.	6	[109]
	Cu²⁺
	Ni²⁺
Iron/Zinc modified wood chip biochar	TC	0.1 M NaOH	The removal rates of TC and Cu²⁺ both exceed 89%.	3	[98]
Iron/Zinc modified wood chip biochar	Cu²⁺	0.1 M NaOH	The removal rates of TC and Cu²⁺ both exceed 89%.	3	[98]
Polyacrylic acid-modified tobacco stem biochar	Quinclorac	−	The removal rate of quinclorac was 53.8%, and the removal rate of Pb²⁺ was 45.5%.	5	[179]
Polyacrylic acid-modified tobacco stem biochar	Pb²⁺	−		5	[179]
Hydroxyapatite-modified cod bone biochar	Diclofenac	Deionized water	The adsorption capacity of diclofenac decreased by 11%−13%, the adsorption capacity of fluoxetine decreased by 15%−16%, and the adsorption capacity of Pb²⁺ decreased by 1.99%.	1	[172]
	Fluoxetine
	Pb²⁺
EDTA/Chitosan bifunctionalized magnetic biochar	MO	1 M NaOH	The removal rate of MO decreased by 16.8%, the removal rate of Cd²⁺ decreased by 1.5%, and the removal rate of Zn²⁺ decreased by 8.9%.	8	[116]
	Cd²⁺	0.01 M EDTA-2Na
	Zn²⁺	0.01 M EDTA-2Na
Potassium ferrate-activated wheat straw biochar	Cu²⁺	0.01 M NaOH	−	3	[127]
Potassium ferrate-activated wheat straw biochar	SMZ	0.01 M NaOH	−	3	[127]
Ball-milled magnetic nano biochar	TC	0.2 M NaOH	The adsorption capacities of TC and Hg²⁺ were approximately 90.55 and 87.36 mg/g.	5	[182]
Ball-milled magnetic nano biochar	Hg²⁺	0.5 M Na₂S		5	[182]
Iron/zinc-activated rice straw biochar	17β-estradiol	Ethanol	The removal rate of 17β-estradiol and Cu²⁺ decreased by 13.79% and 12.16%.	5	[180]
Iron/zinc-activated rice straw biochar	Cu²⁺	Deionized water		5	[180]
Iron/nitrogen co-doped rapeseed straw biochar	CIP	−	The adsorption capacities of CIP and Cu²⁺ were approximately 3.67 and 3.89 mg/g.	5	[176]
Iron/nitrogen co-doped rapeseed straw biochar	Cu²⁺	−		5	[176]

Table 2.

Regeneration performance of engineered biochar