Isolation of Extra Cellular Biopolymer producing Microorganisms from Wastewater Sludge for Sludge Settling and Dewatering
Sludge settling and dewatering are carried out by employing cationic synthetic polymer (CSP) in municipal and industrial wastewater treatment plant. CSP are expensive and further pollute the environment, hence to address these problems bioflocculation of sludge was examined in this study. Microorganisms were isolated from municipal and industrial wastewater sludges and six extracellular polymeric substances (ECP) producing bacterial strains and one pellet forming fungal strain were screened for bioflocculation of sludge. Microbial strains were grown in tryptic soy broth (TSB) to produce ECP from bacterial strains and fungal pellets. Slime ECP was harvested by centrifugation at 6000g for 15 min and capsular ECP obtained from the bacterial pellet. Combination of both slime and capsular ECP was obtained from the fermented bacterial broth without centrifugation. Zeta potential characterization of ECPs carried out, all produced biopolymers showed anionic in nature. Sludge settling efficiency was evaluated by Sludge Volume Index (SVI). Results showed that slime ECP showed better performance in sludge settling than the capsular ECP and bacterial broth with and without addition of Ca++ ions. Fungal pellets were also harvested from the TSB broth after 5 days of growth at 25°C at 200 rpm. Produced pellets were incubated with different concentration of sludge suspended solids (1, 2.5, 5, 10 & 15 g/l) of sterilized (S) and non-sterilized (NS) sludge. Microbiological staining results revealed that the mechanisms of sludge solids and fungal mycelium interactions were mainly through physical adsorption or entrapment. Zeta potential value of fungal biomass also showed (− 49.42 mV) anionic in nature. SVI results revealed that sterilized sludge showed better settling index than the non-sterilized sludge at higher concentrations of sludge solids. Based on SVI results bacterial strains B1 (Slime ECP), B3 & B6 (Capsular ECP) were selected and fungal strains were also considered for further study.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2006-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites