Separation Technique

Advantages

Disadvantages

Physiochemical

Adsorption

Ion exchange

Membrane filtration

Electrokinetic coagulation

Chemical

Fenton reagent

Ozonation

Photocatalyst

Biological

Aerobic degradation

Anaerobic degradation

High adsorption capacity for all dyes.

No loss of sorbents.

Effective for all dyes with high quality effluent.

Economically feasible.

Effective process and cheap reagent.
No production of sludge.

Economically feasible and low operational cost.

Efficient in the removal of azo dyes and low operational cost.

By-products can be used as energy sources

High cost of adsorbents. Need to dispose of adsorbents. Low surface area for some adsorbents.
Not effective for disperse dyes.

Suitable for treating low volume and production of sludge.

Need further treatments by flocculation and filtration and production of sludge.

Sludge production and disposal problems.
Half-life is very short (20 min) and high operational cost.
Degrade of some photocatalyst into toxic by-products.

Very slow process and provide suitable environment for growth of microorganisms.

Need further treatment under aerobic conditions and yield of methane and hydrogen sulfide.

The advantages and disadvantages of various dye removal techniques [9, 11]

Adsorbents	Dyes	Adsorption capacity qmax (mg/g)	Reference
Peroxide treated rice husk	Malachite Green	26.0	[106]
Raw coffee residue	Basic blue 3G	251	[32]
Coffee waste	Toluidine Blue	142.5	[33]
Raw coffee residue	Remazol Blue	232	[32]
Pine cone	Congo red	19.18	[27]
Acid treated pine cone	Congo red	40.19	[27]
Eucalyptus wood	Congo red	66.7	[107]
Date Stones	Methylene blue	43.5	[108]
Palm-Trees	Methylene blue	39.5	[108]
Palm shell	Reactive red 141	14.0	[61]
Palm shell	Reactive blue 21	24.7	[61]
Acid treated papaya seed	Methylene blue	250	[109]
Papaya seed	Methylene blue	200	[109]
Papaya seed	Congo red	71	[109]
Acid treated papaya seed	Congo red	59	[109]
Peanut hull	Reactive black 5	55.6	[110]
Pine cone Pine tree leave	Methylene blue Methylene Blue	109.9 126.6	[4] [3]
Neem bark	Malachite green	0.36	[111]
Mango bark	Malachite green	0.5	[111]
Pine cone	Acid Black 26	62.9	[31]
Pine cone	Acid Green 25	43.3	[31]
Pine cone	Acid Blue 7	37.4	[31]
Pine tree leaves	Basic red 46	71.9	[26]
palm kernel fiber	Crystal violet	78.9	[112]
palm kernel fibre	Methylene blue	95.4	[112]
Organo-attapulgite	Congo red	189.4	[65]
Garlic peel	Methylene blue	142.9	[113]
Rice husk	Indigo Carmine	65.9	[62]
Yellow Passion fruit	Methylene blue	44.7	[114]
Soy meal hull	Direct red 81	120.5	[115]
Soy meal hull	Acid blue 92	114.9	[115]
Soy meal hull	Acid red 14	109.9	[115]
Rice husk	Methylene blue	40.6	[15]
Sugar cane bagasse	Congo red	38	[116]

Compilation results on the removal of various dyes by various raw and treated agricultural by-product waste adsorbent

Material	Dye	Adsorption capacity qmax(mg/g)	Reference
Commercial activated carbon	Reactive Violet 5	517.1	[36]
Commercial activated carbon	Acid Red 97	52	[1]
Commercial activated carbon	Acid Orange 61	169	[1]
Commercial activated carbon	Acid Brown 425	222	[1]
Commercial activated carbon	Congo red	300	[22]
Commercial activated carbon	Remazol red B	145	[117]
Pine cone based AC	Congo red	500	[30]
Cocoa shell AC	Reactive Violet 5	603.3	[36]
Bael shell based AC	Congo red	98	[42]
Waste tea based AC	Acid blue 29	596	[28]
Bamboo based AC	Methylene blue	454	[118]
Cattail based AC	Neutral red	192	[119]
Cattail based AC	Malachite green	196	[119]
Pomelo skin based AC	Acid blue 15	444	[59]
Pomelo skin based AC	Methylene blue	501	[59]
Date stone based AC	Methylene blue	316	[40]
Olive stone based AC	Remazol red B	9	[117]
Rice husk based AC	Methylene blue	442	[120]
Rambutan peel based AC	Malachite green	329	[121]
Rubber seed coat based AC	Malachite green	227	[122]
Myrtus communisbased AC	Congo red	19	[123]
Pomegranate based AC	Congo red	10	[123]

Removal of dyes by Commercial activated carbon (CAC) and biomass based activated carbon (AC).

Culture	Dye	Dye removal (%)	References
P. chrysosporium fungi	Coracryl violet	100	[101]
P. chrysosporium fungi	Coracryl pink	100	[101]
D. squalens fungi	Coracryl pink	100	[101]
T.versicolor ATCC 20869	Remozol blue	98	[124]
P. chrysosporium ATCC 24725	Remozol red	97	[124]
P. chrysosporium ATCC 24725	Remozol blue	95	[124]
Aspergillus niger fungi	Direct violet	92	[125]
Bacteria consortium SKB-II	Congo red	90	[126]
C. polyzonaMUCL 38443	Acid blue 62	90	[127]
Trametes species CNPR 4783	Remazol blue	89	[124]
T.Versicolor ATCC 20869	Remozol red	85	[124]
Bacteria consortium SKB-I	Blue BCC	74	[126]
P. sanguineus fungi	Coracryl black	67	[101]
Lyophilised bacterial consortium	Blue Bezaktiv 150	62	[98]
Trametes species CNPR 4801	Remazol blue	58	[124]
D. flavida fungi	Coracryl pink	53	[101]
T. versicolour DSM 11269	Disperse red 1	50	[113]
Myrioconium sp. UHH 1-6-18-4	Disperse blue 1	43	[113]
S.rugosoannulataDSM 11372	Reactive red 4	31	[113]

Table 6: Bacteria and Fungi strains commonly used in dye biodegradation