alexa Adsorption of heavy metals by EPS of activated sludge.
Agri and Aquaculture

Agri and Aquaculture


Author(s): Liu Y, Lam MC, Fang HH

Abstract Share this page

Abstract Extracellular polymeric substances (EPSs) were extracted by high-speed centrifugation at 20,000 G for 30 min from an activated sludge treating municipal wastewater. Each gram of sludge, as measured in volatile suspended solids (VSS), contained 7.3 mg of EPS, including 6.5 mg of protein (EPSp) and 0.8 mg of carbohydrate (EPSc). The EPSp had a mean MW of 2.0 x 105; about 18\% of EPSp had MW over 5 x 104 and 16\% below 5 x 103. For heavy metal concentrations ranging 10-100 mg/l, EPS on average removed 99\% of Zn2+, 98\% of Cu2+, 97\% of Cr3+, 85\% of Cd2+, 69\% of Co2+, 37\% of Ni2+, and 26\% of CrO4(2-). The relative degrees of metal removals were inconsistent with those reported for the activated sludge process. Each mg of ESP had the capacity to remove up to 1.48 mg of Zn2+, 1.12 mg of Cu2+, 0.83 mg of Cr3+, 0.90 mg of Cd2+, 1.10 mg of Co2+, 0.25 mg each of Ni2+ and CrO4(2-). Results suggest the feasibility of recovering ESP from waste sludge for use as adsorbent. Freundlich isotherm correlated satisfactorily with the adsorption data of Ni2+, Cu2+, Cd2+, and CrO4(2-) (R2 ranging 0.89-0.97), whereas Langmuir isotherm correlated satisfactorily with those of Zn2+, Cr3+ and Ni2+ (R2 ranging 0.93-0.96). Both correlated poorly for those of Co2+.
This article was published in Water Sci Technol and referenced in Agrotechnology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version