Removal of Pb2+ and Ni2+ by bio-sludge in sequencing batch reactor (SBR) and granular activated carbon-SBR (GAC-SBR) systems.
Living bio-sludge from domestic wastewater treatment plant was used as adsorbent of heavy metals (Pb(2+), Ni(2+)) and its adsorption capacity was about 10-30% reduced by autoclaving at 110 degrees C for 10 min. The living bio-sludge acclimatized in synthetic industrial estate wastewater (SIEWW) without heavy metals showed the highest Pb(2+) and Ni(2+) adsorption capacities at 840+/-20 and 720+/-10 mg/g bio-sludge, respectively. The adsorbed Pb(2+) and Ni(2+) were easily eluted (70-77%) from bio-sludge by washing with 0.1 mol/l HNO(3) solution. The heavy metals (Pb(2+), Ni(2+)) removal efficiency of both SBR and GAC-SBR systems were increased with the increase of hydraulic retention time (HRT), or the decrease of organic loading. The SBR system showed higher heavy metals removal efficiency than GAC-SBR system at the same organic loading or HRT. The Pb(2+), Ni(2+), BOD(5), COD and TKN removal efficiencies of GAC-SBR system were 88.6+/-0.9%, 94.6+/-0.1%, 91.3+/-1.0%, 81.9+/-1.0% and 62.9+/-0.5%, respectively with industrial estate wastewater (IEWW) with 410 mg/l glucose, 5 mg/l Pb(2+) and 5 mg/l Ni(2+) under organic loading of 1.25 kg BOD(5)/m(3) d (HRT of 3 days). The bio-sludge quality (sludge volume index: SVI) of the system was less than 80 ml/g. The excess sludge from both SBR and GAC-SBR systems with SIEWW under the organic loading of 1.25-2.50 kg BOD(5)/m(3) d contained Pb(2+) and Ni(2+) at concentrations of 240-250 mg Pb(2+)/g bio-sludge and 180-210 mg Ni(2+)/g bio-sludge, respectively.
Sirianuntapiboon
Suntud
S
Department of Environmental Technology, School of Energy and Materials, King Mongkut's University of Technology Thonburi, Bangmod, Thung-khru, Bangkok 10140, Thailand. suntud.sir@kmutt.ac.th
Ungkaprasatcha
Ongorn
O
D000327:Adsorption; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors; D002606:Charcoal / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis; D007854:Lead / Q000737:chemistry / Q000378:metabolism*; D009532:Nickel / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*
D007220:Industrial Waste; D012722:Sewage; D002606:Charcoal; D007854:Lead; D009532:Nickel