143
concentrating the biomass to facilitate the recovery process. The pretreatment step
aims at simplifying the retrieval of polyhydroxyalkanoates in the next steps by
weakening the cell walls. Pretreatment methods are various and include lyophilization; mechanical, chemical, and biochemical treatments; thermal drying; and grinding (Kourmentza et al. 2017).
The next step of the process is retrieval and recovery of polyhydroxyalkanoates.
There are a few routes to recover the polyhydroxyalkanoates granules, including
polyhydroxyalkanoates solubilization and the non-polyhydroxyalkanoates material
dissolution (Visakh 2014), which are the main two routes employed. Nonpolyhydroxyalkanoates dissolution step starts with the modification of the cell wall
permeability, followed by the dissolution of the polyhydroxyalkanoates in a solvent,
and finally solvent extraction. The solvent extraction methods are the most developed and most employed for polyhydroxyalkanoates polymer recovery as they
result in a high purity of polyhydroxyalkanoates. Solvents such as chloroform,
methylene chloride, and 1,2-dichloroethane were employed for polyhydroxybutyrate extraction and recovery (Tan et al. 2014). However, the issue with the nonpolyhydroxyalkanoates material dissolution method is the high costs and solvent
disposal when employed at a large scale as the amount of solvent needed is high
(Chee et al. 2010; Visakh 2014). Subsequently, the solubilization method was
Fig. 5.6 Polyhydroxyalkanoates recovery system
5 Integration of Polyhydroxyalkanoates Production with Industrial Wastewater…
concentrating the biomass to facilitate the recovery process. The pretreatment step
aims at simplifying the retrieval of polyhydroxyalkanoates in the next steps by
weakening the cell walls. Pretreatment methods are various and include lyophilization; mechanical, chemical, and biochemical treatments; thermal drying; and grinding (Kourmentza et al. 2017).
The next step of the process is retrieval and recovery of polyhydroxyalkanoates.
There are a few routes to recover the polyhydroxyalkanoates granules, including
polyhydroxyalkanoates solubilization and the non-polyhydroxyalkanoates material
dissolution (Visakh 2014), which are the main two routes employed. Nonpolyhydroxyalkanoates dissolution step starts with the modification of the cell wall
permeability, followed by the dissolution of the polyhydroxyalkanoates in a solvent,
and finally solvent extraction. The solvent extraction methods are the most developed and most employed for polyhydroxyalkanoates polymer recovery as they
result in a high purity of polyhydroxyalkanoates. Solvents such as chloroform,
methylene chloride, and 1,2-dichloroethane were employed for polyhydroxybutyrate extraction and recovery (Tan et al. 2014). However, the issue with the nonpolyhydroxyalkanoates material dissolution method is the high costs and solvent
disposal when employed at a large scale as the amount of solvent needed is high
(Chee et al. 2010; Visakh 2014). Subsequently, the solubilization method was
Fig. 5.6 Polyhydroxyalkanoates recovery system
5 Integration of Polyhydroxyalkanoates Production with Industrial Wastewater…