Decrease of dissolved sulfide in sewage by powdered natural magnetite and hematite.
Natural magnetite and hematite were explored to decrease sulfide in sewage, compared with iron salts (FeCl3and FeSO4). A particle size of magnetite and hematite ranging from 45 to 60μm was used. The results showed that 40mgL-1of powdered magnetite and hematite addition decreased the sulfide in sewage by 79%and 70%, respectively. The achieved decrease of sulfide production capacities were 197.3, 210.6, 317.6 and 283.3mgSg-1Fe for magnetite, hematite, FeCl3and FeSO4at the optimal dosage of 40mgL-1, respectively. Magnetite and hematite provided a higher decrease of sulfide production since more iron ions are capable of being released from the solid phase, not because of adsorption capacity of per gram iron. Besides, the impact on pH and oxidation-reduction potential (ORP) of hematite addition was negligible; while magnetite addition resulted in slight increase of 0.3-0.5 on pH and 10-40mV on ORP. Powdered magnetite and hematite thus appear to be suitable for sulfide decrease in sewage, for their sparing solubility, sustained-release, long reactive time in sewage as well as cost-effectiveness, compared with iron salts. Further investigation over long time periods under practical conditions are needed to evaluate the possible settlement in sewers and unwanted (toxic) metal elements presenting as impurities.
Powdered magnetite and hematite were more cost-effective at only 30% costs of iron salts, such as FeCl3and FeSO4for decreasing sulfide production in sewage.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China; Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium. Electronic address: lezhanghua@ecust.edu.cn.
Lehua
L
Zhang
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium. Electronic address: Willy.Verstraete@UGent.be.
Willy
W
Verstraete
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Department of Chemical and Environmental Sciences, Superior Polytechnic School of the Coast (ESPOL), Guayaquil 090112, Ecuador.
María
M
de Lourdes Mendoza
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China.
Zhihao
Z
Lu
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China.
Yongdi
Y
Liu
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China.
Guangtuan
G
Huang
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China. Electronic address: lkcai@ecust.edu.cn.
Lankun
L
Cai
D057919:Biological Oxygen Demand Analysis; D005290:Ferric Compounds / Q000737:chemistry*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D008962:Models, Theoretical; D010316:Particle Size; D011208:Powders; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D013440:Sulfides / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D005290:Ferric Compounds; D011208:Powders; D012722:Sewage; D013440:Sulfides; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D052203:Ferrosoferric Oxide
Concrete pipe corrosion; Hematite; Magnetite; Municipal sewage; Sulfide decrease