Table 2.

Summary of some currently available herbicide removal technologies.

Physico-chemical/Biological/Chemical Treatments		Herbicides	Optimum conditions	q (mg/g or mmol/g) or R%	Reference
Type of adsorbents	Foxtail palm fruit activated carbon	Metamifop	10 ppm metamifop	86.65%	[60]
	H3PO4-activated spent coffee ground (SCG) biochar	2,4-D	pH 2 with adsorbent dosage of 0.75 gL−1.	323.76 mgg−1	[61]
	Bifunctional porous polyethyleneimine-grafted lignin microspheres	2,4-D	pH 4–10 removal efficiency decreased by 8% after 5 cycles)	909.09 mgg−1 at 45°C	[64]
	Thiol modified the magnetic mesoporous silica (magMCM-41) nanoparticles using extracted silica from rice husk ash	2,4-D glyphosate	herbicides concentration 20 mgL−1 adsorbent dose 0.2 gL−1 contact time 30 min (2,4-D) and 60 min for glyphosate. pH 6 for 2,4-D pH 5 for glyphosate	2,4-D − 83.44% Glyphosate − 79.38%	[72]
Type of microbes	Consortium activity of Pseudomonas stutzeri, Comamonas odontotermitis, and Sinomonas atrocyanea	Glyphosate	Glyphosate concentration: 5 to 50 mgL−1 No aminomethylphosphonic acid formation (AMPA).	53% to 79%	[80]
	Chryseobacterium sp. Y16C	Glyphosate	96 hours contact time 400 mgL−1 glyphosate concentration	Complete degradation	[81]
	Randomly methylated cyclodextrin + A. aurescens CTFL7	Trifluralin	19 days contact time 10 mgL−1 trifluralin concentration	88%	[86]
Type of Advanced Oxidation Processes (AOPs)	UV/H2O2 UV/S2O82- UV/HSO5−	Alachlor	UVC lamp, [S2O82-]0 = [H2O2] = 0.3mM, pH = 5.0 UVC lamp, [HSO5−]0 = 0.3mM, pH = 9.5	Above 95.0%	[101]
	Fe0@Fe3O4/UV	2,4-D	[2,4-D]0 = 5.0 mgL−1, [Fe0@Fe3O4]0 = 0.5 gL−1, H2O2 = 1 mM, pH = 5.0 ± 0.2, T = 30°C	Completely removed in 90 min; nearly 66% of them could be mineralized.	[107]
	TiO2/Al2O3/carbon nanotube	Metamifop	20 mg of TiO2/Al2O3/CNT photocatalyst, [metamifop] = 10 mgL−1, air flow rate = 2 Lmin−1, 3 hours UV irradiation	95.0%	[111]
	P, K-doped g-C3N4 with cyano group and nitrogen vacancies (PKCN)	Atrazine	40 mg PKCN, [atrazine]0 = 10 mgL−1, Xe lamp of 300 W visible light (420 nm filter) for 60 minutes, pH = 5.0,	95.0%	[113]