Chemical digestion method to promote activated sludge cell wall breaking and optimize the polyhydroxyalkanoate (PHA)
Bowen Xiong1, Qian Fang1, Tong Wei2
1College of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China.
International Journal of Biological Macromolecules
|April 9, 2023
Summary
This study introduces a new method for recovering polyhydroxyalkanoates (PHA) from activated sludge using a two-stage chemical digestion process. The optimized method achieved 72.14% PHA recovery and 54.47% purity.
Area of Science:
- Biotechnology
- Environmental Science
- Polymer Science
Background:
- Polyhydroxyalkanoates (PHA) are biodegradable polymers with significant potential.
- Efficient recovery of PHA from microbial biomass is crucial for economic viability.
- Activated sludge is a common source for PHA production but requires effective extraction methods.
Purpose of the Study:
- To develop and optimize a novel protocol for PHA recovery from activated sludge.
- To investigate a two-stage chemical digestion method for enhanced PHA yield.
- To determine optimal conditions for PHA extraction using sodium hypochlorite and sodium dodecyl sulfate.
Main Methods:
- Activated sludge was subjected to a two-stage chemical digestion process.
- Sodium hypochlorite (NaClO) and sodium dodecyl sulfate (SDS) were used for PHA extraction.
- Optimization of NaClO concentration, sludge-to-SDS ratio, and reaction time was performed.
- Methanol was used for purification of the extracted PHA.
Main Results:
- The highest PHA recovery (72.14%) and purity (54.47%) were achieved using a combination of 25% (v/v) NaClO and a 1:2 dry weight ratio of activated sludge to SDS.
- The optimal reaction time for NaClO digestion was determined to be 30 minutes.
- Purification with methanol further improved the purity of the extracted PHA.
Conclusions:
- A novel and effective two-stage chemical digestion protocol for PHA recovery from activated sludge was successfully developed.
- The optimized extraction conditions significantly enhance PHA recovery and purity.
- This method offers a promising approach for the efficient and scalable production of PHA.
Related Concept Videos
01:26Microbial Bioremediation of Hydrocarbons
Bioremediation is an environmentally sustainable process that employs living organisms—primarily microorganisms—to degrade or neutralize pollutants from contaminated environments. In oil spills and hydrocarbon pollution, bioremediation involves the use of hydrocarbon-degrading bacteria to transform toxic compounds into less harmful substances. This approach leverages natural microbial metabolic processes and is considered both cost-effective and ecologically favorable compared to physical or...
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:27Bioplastics
Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrates (PHBs), have emerged as prominent candidates due to their biodegradability and biocompatibility. These polymers are synthesized by a variety of bacteria, such as Cupriavidus necator and Pseudomonas putida, which naturally accumulate PHAs as intracellular carbon and energy reserves, especially under...
01:30Biological Treatment of Effluent and Waste Water
Biological wastewater treatment relies on the metabolic activity of microorganisms to remove pollutants from sewage. In modern treatment systems, this process is organized into sequential stages that progressively reduce solid material, dissolved organic matter, and microbial contamination. Each stage plays a distinct role in improving water quality and preparing the effluent for safe discharge or reuse.Primary and Secondary TreatmentPrimary treatment is a physical process that removes large...
01:28Microbial Bioremediation of Plastics
Polyethylene terephthalate (PET) is a synthetic polymer widely utilized in the packaging industry, particularly for bottles and containers. Due to its chemical stability and durability, PET accumulates in the environment, contributing significantly to plastic pollution. It comprises repeating units of terephthalic acid and ethylene glycol, resulting in a semi-crystalline structure that is resistant to natural degradation processes.A notable breakthrough in plastic biodegradation came with the...