Table 3.

Compared advantages and disadvantages of three main degradations.

Degradation Type	Commonly Used Reagent	Advantages	Disadvantages	Ref.
Chemical degradation	HCl; acetylsalicylic acid; Calcium Thiocyanate; 1-butyl-3-methyl imidazole chloride and WCl6;	Degradation rate can reach more than 80%; The reaction is relatively stable; short reaction time and strict reaction conditions;	Serious pollution to the environment; strict reaction conditions;	[139,140,141,142]
Physical degradation	Thermal degradation; Photodegradation; Electron laser;	Less pollution to the environment; the reaction is controllable;	High experiment cost; Less degradation quantity;	[143,144]
Biological degradation	Cellulase; Pectinase; Hemicellulose; Rhizobium sp.; Aeromonas caviae; Serratia sp.; Lytic polysaccharide monooxygenases;	No pollution to the environment; suitable for the degradation of large amounts of cellulose;	The composting of bacterial flora takes a long time; the enzyme activity was unstable so the degradation yields are unstable; Cellulase from different sources varies greatly in structure and function;	[145,146]