TY - JOUR
T1 - Effect of ion water washing of neutralized sludge contaminated by high concentrations of chloride
AU - Tokoro, Chiharu
AU - Oda, Yuji
AU - Owada, Shuji
AU - Hayashi, Hiroshi
PY - 2013
Y1 - 2013
N2 - The effects of NO3- and SO42- ions on chloride ion removal from neutralized sludge were investigated to determine if removal of chloride ions enabled the use of sludge for cement production. An artificial sludge prepared from iron, calcium and chloride that primarily consisted of two-line ferrihydrite was prepared. Chloride ions in the sludge were easily washed out by distilled water, NO3- water or SO42- water to levels below those specified in the standard for Eco-cement production (1,000mg/kg), but the washed sludges did not meet the standard for ordinary Portland cement (350mg/kg). Conversely, artificial sludge prepared from aluminum, calcium and chloride mainly consisted of low crystalline boehmite with other minor components. Chloride ions in this sludge were only reduced to below those specified in the standard for the ordinary cement production if SO42- water was used to wash the sludge. The filtration rate during washing using SO4 2- water was faster than when distilled water or NO3 - water was used because SO42- ions were adsorbed onto the sludge particles and the absolute value of the zeta potential of the sludge particles decreased. Overall, sludge washing using SO 42- water was the best process for chloride ion removal and efficient filtration.
AB - The effects of NO3- and SO42- ions on chloride ion removal from neutralized sludge were investigated to determine if removal of chloride ions enabled the use of sludge for cement production. An artificial sludge prepared from iron, calcium and chloride that primarily consisted of two-line ferrihydrite was prepared. Chloride ions in the sludge were easily washed out by distilled water, NO3- water or SO42- water to levels below those specified in the standard for Eco-cement production (1,000mg/kg), but the washed sludges did not meet the standard for ordinary Portland cement (350mg/kg). Conversely, artificial sludge prepared from aluminum, calcium and chloride mainly consisted of low crystalline boehmite with other minor components. Chloride ions in this sludge were only reduced to below those specified in the standard for the ordinary cement production if SO42- water was used to wash the sludge. The filtration rate during washing using SO4 2- water was faster than when distilled water or NO3 - water was used because SO42- ions were adsorbed onto the sludge particles and the absolute value of the zeta potential of the sludge particles decreased. Overall, sludge washing using SO 42- water was the best process for chloride ion removal and efficient filtration.
KW - Chloride removal
KW - Filtration rate
KW - Low crystalline boehmite
KW - Sludge recycling
KW - Two-line ferrihydrite
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UR - http://www.scopus.com/inward/citedby.url?scp=84880633147&partnerID=8YFLogxK
U2 - 10.2320/matertrans.M2013001
DO - 10.2320/matertrans.M2013001
M3 - Article
AN - SCOPUS:84880633147
VL - 54
SP - 1176
EP - 1181
JO - Materials Transactions
JF - Materials Transactions
SN - 1345-9678
IS - 7
ER -