Method for the preparation of biopolymers

A method of preparing and separating biopolymers from sewage sludge;

• and subsequently using said biopolymers to remove phosphorus from wastewater in a method comprising adding biopolymers to said wastewater, and allowing said biopolymers to remove said phosphorus from the wastewater;
• wherein the biopolymers are prepared and separated by the following steps:
• i) removing extracellular polymeric substances (EPS) from bacterial cells in sewage sludge to provide an EPS-removed sewage sludge;
• ii) disrupting the bacterial cell walls of bacteria present in the EPS-removed sewage sludge by at least 75% to release the intracellular contents of the bacterial cells;
• and
• iii) separating the biopolymers from any contaminants present, wherein step i) is performed before step ii), and wherein step (ii) is performed before step iii).

A method of removing phosphorus from wastewater comprising:

• i) removing extracellular polymeric substances (EPS) from bacterial cells in sewage sludge by anaerobic digestion to provide an EPS-removed sewage sludge;
• iia) disrupting bacterial cell walls of the bacterial cells present in the EPS-removed sewage sludge by at least 75% to release intracellular contents of the bacterial cells so as to form a cell lysate and solubilising nucleic acids and contaminants present in the cell lysate;
• iib) precipitating the nucleic acids onto peptidoglycan debris present in the cell lysate to provide a precipitate comprising a blend of the nucleic acids and the peptidoglycan debris;
• iii) separating the biopolymers or biopolymer fractions from any contaminants present, wherein the biopolymers or biopolymer fractions comprise a blend of nucleic acids and peptidoglycan and wherein step i) is performed before steps iia), iib) and iii);
• iv) removing the precipitate from the cell lysate using a solid liquid separation technique;
• v) adding the removed precipitate to said wastewater;
• and
• vi) allowing the removed precipitate to remove said phosphorus from the wastewater.

A method of removing phosphorus from wastewater comprising:

• i) removing extracellular polymeric substances (EPS) from bacterial cells in sewage sludge to provide an EPS-removed sewage sludge;
• ii) disrupting bacterial cell walls of the bacterial cells present in the EPS-removed sewage sludge by at least 75% to release intracellular contents of the bacterial cells so as to form a cell lysate and solubilising nucleic acids and contaminants present in the cell lysate;
• iii) removing the nucleic acids, any EPS present, and the contaminants present in the cell lysate by anaerobic digestion;
• before removing peptidoglycan debris present in the digestate formed by the anaerobic digestion using a solid liquid separation technique to provide biopolymer fractions, wherein step i) is performed before steps ii) and iii);
• iv) adding the biopolymer fractions to said wastewater;
• and
• v) allowing the biopolymer fractions to remove said phosphorus from the wastewater.