Polyhydroxyalkanoates extraction system

A polyhydroxyalkanoates (PHAs) extraction system comprising:

• a pretreatment subsystem including:
• a fermentation device, including a fermentation tank, a first sludge placed in the fermentation device and fermented in the fermentation tank to form a fermentation broth;
• and
• an activation device, including a thermostatic water tank and an oxygen supply device, a second sludge placed in the activation device and diluted by water in the thermostatic water tank, the oxygen supply device supplying oxygen to the second sludge in the thermostatic water tank to activate the second sludge and form an activated sludge, and the activation device receiving the fermentation broth and performing a microorganism acclimation process with the activated sludge in the thermostatic water tank and to form a third sludge;
• an extraction subsystem including:
• a freezing device, receiving the third sludge and performing a freezing process with the third sludge in the freezing device to form a fourth sludge;
• a pretreatment device, receiving the fourth sludge and performing a pretreatment process to disrupt cells of microorganism in the fourth sludge;
• and
• an extraction device, including an extraction tank and a precipitation tank, the extraction device receiving the fourth sludge and performing an extraction process and a purification process in the extraction tank to form a polyhydroxyalkanoates mixture and a first waste, wherein the extraction process is adding an aqueous solution of sodium hypochlorite (NaClO) into the fourth sludge to lyse cell walls of microorganism and release polyhydroxyalkanoates, and wherein the purification process is removing substances other than polyhydroxyalkanoates, the precipitation tank receiving the polyhydroxyalkanoates mixture and performing a precipitation process to produce a polyhydroxyalkanoates precipitate and a second waste;
• and
• a recycling subsystem including:
• an aerobic sludge digestion device, receiving part of the first waste and/or part of the second waste and performing an aerobic sludge digestion process;
• and
• a sequencing batch reactor activated sludge treatment device, receiving part of the first waste and/or part of the second waste and performing a sequencing batch reactor activated sludge process.