National Chi Nan University

Meng-Shan Lu

Chih-Chi Yang

Yung-Pin Tsai

Jan-Wei Lin

Hao Shiu

Shou-Te Chen

Yu-Wei Liou

The present invention relates to a method for increasing polyhydroxyalkanoates (PHAs) content of waste sludge, by taking the fermentation liquid fermented from waste sludge as a carbon source, and performing ADF domestication process, thereby quickly raising PHAs contentin the waste sludge, in accordance with the method of the present invention, the conventional complicated domestication steps is simplified and a higher content PHAs can be produced, additionally the added carbon source of the present invention is the VFA fermented by the waste sludge, so it's unnecessary to add extra material, therefore including more industrial utilization.

Method for increasing PHAs content of waste sludge by fermenting the waste sludge to produce volatile fatty acid

The present invention provides a method for extracting polyhydroxyalkanoates (PHAs), which comprises a pre-process step and an extraction step: removing water from waste sludge containing microorganisms in the pre-process step so that the waste sludge containing microorganisms has a water content of less than 40%; and applying a high-voltage pulsed electric field to the waste sludge during the extraction step to destroy the microorganisms and release the PHAs, wherein the high-voltage pulsed electric field is between 50 volts and 400 volts, an application time of the high-voltage pulsed electric field is between 5 seconds and 90 seconds, and an application frequency of the high-voltage pulsed electric field is between 500 Hz and 1000 Hz, thereby extracting the PHAs in the case of few chemicals.

Method for extracting polyhydroxyalkanoates (PHAs)

A method of recovering polyhydroxyalkanoates (PHAs) from municipal waste sludge includes: (a) removing coarse particles in the municipal waste sludge and measuring a solid content in the municipal waste sludge in terms of a volatile suspended solid in the municipal waste sludge; (b) removing a supernatant from the municipal waste sludge; (c) freezing the municipal waste sludge; (d) adding a controlled amount of sodium hypochlorite solution to the municipal waste sludge that has been frozen, a ratio of the solid content of the municipal waste sludge to a volume of the sodium hypochlorite solution added in step (d) ranging from 0.67 mg/ml to 4 mg/ml and being defined as a liquid-solid ratio; and (e) separating PHAs from non-PHAs substances in the municipal waste sludge obtained in the step (d).

Method of recovering polyhydroxyalkanoates (PHAs) from municipal waste sludge

A method of recovering polyhydroxyalkanoates (PHAs) from municipal waste sludge includes: (a) measuring a solid content in the municipal waste sludge in terms of a volatile suspended solid in the municipal waste sludge; (b) removing supernatant from the municipal waste sludge; (c) freezing the municipal waste sludge; (d) conducting a pretreatment of the municipal waste sludge that has been frozen; (e) adding a surfactant into the pretreated sludge to obtain a slurry; (f) adding a controlled amount of sodium hypochlorite solution to the municipal waste sludge obtained in step (e), a ratio of a volume of the sodium hypochlorite solution to the solid content of the municipal waste sludge ranging from 0.67 mg/ml to 1.25 mg/ml and being defined as a liquid-solid ratio; and (g) separating PHAs from non-PHAs substances in the municipal waste sludge obtained in the step (f).

Growing community of inventors

Nantou County, Taiwan

Meng-Shan Lu