REMOVAL OF HEAVY METALS IN ACTIVATED SLUDGE TREATMENT SYSTEMS

1987 ◽  
Vol 60 (1-6) ◽  
pp. 79-99 ◽  
Author(s):  
DONALD B. AULENBACH ◽  
MICHAEL A. MEYER ◽  
EILEEN BECKWITH ◽  
SHRIKANT JOSHI ◽  
CHITTIBABU VASUDEVAN ◽  
...  
2021 ◽  
Vol 25 ◽  
Author(s):  
Alejandro Jorge Mariñelarena ◽  
Hugo Di Giorgi ◽  
Jorge Donadelli

Objective: This research aimed to assay the dehydration and stabilization of surplus biosolids from a wastewater activated sludge treatment plant, with sludge-treatment wetlands, at the Iguazú National Park (Misiones, Argentina). Materials and Methods: A 12-cell sludge-treatment reed beds (STRB) system was built and operated for four years. Afterwards, the accumulated sediments were analyzed for total solids (TS) concentration, volatile solids (VS) reduction, specific oxygen-uptake rate (SOUR), and heavy metals and pathogens concentrations. Results and Discussion: TS concentration increased from 0.55 % to 14.3 %, VS were reduced by 33.3 %, and SOUR lowered to 1.09 mg O2gTS-1 h-1. These figures and the final concentrations of heavy metals and pathogenic microorganisms (102 MPN E.coli.gTS-1) indicated a degree of stabilization and sanitation that allowed classifying these biosolids as Class A, according to the Argentine guidelines, National Resolution 410/18, and enabled their reuse for soil amendment in landscapes and other agronomic purposes. Conclusion: The technology tested showed good results applied under a tropical climate, with annual temperatures between 17 and 27 °C, rainfall of 1870 mm y-1, and planted with autochthonous vegetation. Furthermore, it allowed the reuse of 221 t (144 m3) of a harmless product in an environmentally sustainable way.


1988 ◽  
Vol 20 (4-5) ◽  
pp. 285-292 ◽  
Author(s):  
István Licskó

The removal of five different heavy metals (Zn2+, Cu2+, Cr 3+,Cd 2+ and Ni 2+) was studied under laboratory conditions using close to neutral mixed municipal wastewater. 90 to 95 % of the Zn2+, Cu2+ and Cr3+ was found to precipitate within 5 min and to become removable by simple phase separation. The Cd2+ and Ni2+, however, refused to precipitate, unless a “reagent” (sulphide ion, primary and activated sludge) was added. In the presence of these, cadmium was normally more readily removed than nickel. Both heavy metals were removed most efficiently, when primary sludge (1.4 g.dm−3) and sulphide ions (5-15 mg.dm−3) were added in combination. As demonstrated by plant trials, this treatment would cause the heavy metals to precipitate and settle out in the primary settling tank, so that traces only would enter the aeration tank.The excess sludge would thus contain trace quantities of heavy metals only, removing an obstacle to land disposal. The introduction of this unit operation has been estimated to increase the overall construction and costs of sewage and sludge treatment by 2.3 %, the unit costs of treatment by 6 %.


2012 ◽  
Vol 65 (10) ◽  
pp. 1765-1773 ◽  
Author(s):  
Maria Fuerhacker ◽  
Tadele Measho Haile ◽  
Daniel Kogelnig ◽  
Anja Stojanovic ◽  
Bernhard Keppler

This paper presents the results of adsorption studies on the removal of heavy metals (Cr, Cu, Cd, Ni, Pb and Zn) from standard solutions, real wastewater samples and activated sewage sludge using a new technique of liquid–liquid extraction using quaternary ammonium and phosphonium ionic liquids (ILs). Batch sorption experiments were conducted using the ILs [PR4][TS], [PR4][MTBA], [A336][TS] and [A336][MTBA]. Removal of these heavy metals from standard solutions were not effective, however removal of heavy metals from the industrial effluents/wastewater treatment plants were satisfactory, indicating that the removal depends mainly on the composition of the wastewater and cannot be predicted with standard solutions. Removal of heavy metals from activated sludge proved to be more successful than conventional methods such as incineration, acid extraction, thermal treatment, etc. For the heavy metals Cu, Ni and Zn, ≥90% removal was achieved.


2011 ◽  
Vol 2 (3) ◽  
pp. 1-8 ◽  
Author(s):  
Sasmita Sabat ◽  
◽  
R V Kavitha R V Kavitha ◽  
Shantha S L Shantha S L ◽  
Gopika Nair ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document