Treatment of Ni-EDTA containing wastewater by electrocoagulation using iron scraps packed-bed anode.
The unique electrocoagulator proposed in this study is highly efficient at removing Ni-EDTA, providing a potential remediation option for wastewater containing lower concentrations of Ni-EDTA (Ni ≤ 10 mg L-1). In the electrocoagulation (EC) system, cylindrical graphite was used as a cathode, and a packed-bed formed from iron scraps was used as an anode. The results showed that the removal of Ni-EDTA increased with the application of current and favoured acidic conditions. We also found that the iron scrap packed-bed anode was superior in its treatment ability and specific energy consumption (SECS) compared with the iron rod anode. In addition, the packed density and temperature had a large influence on the energy consumption (ECS). Over 94.3% of Ni and 95.8% of TOC were removed when conducting the EC treatment at an applied current of 0.5 A, initial pH of 3, air-purged rate 0.2 L min-1, anode packed density of 400 kg m-3temperature of 313 K and time of 30 min. SEM analysis of the iron scraps indicated that the specific area of the anode increased after the EC. The XRD analysis of flocs produced during EC revealed that hematite (α-Fe2O3) and magnetite (Fe3O4) were the main by-products under aerobic and anoxic conditions, respectively. A kinetic study demonstrated that the removal of Ni-EDTA followed a first-order model with the current parameters. Moreover, the removal efficiency of real wastewater was essentially consistent with that of synthetic wastewater.
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China. Electronic address: xiaokye@hotmail.com.
Xiaokun
X
Ye
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Junya
J
Zhang
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Yan
Y
Zhang
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Yuancai
Y
Lv
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Rongni
R
Dou
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Shulong
S
Wen
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Lianghao
L
Li
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China. Electronic address: chenyc@scut.edu.cn.
Yuancai
Y
Chen
State Key Laboratory of Pulp and Paper Engineering, Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
YongYou
Y
Hu
D056831:Coordination Complexes / Q000032:analysis; D004492:Edetic Acid / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D005290:Ferric Compounds / Q000032:analysis; D052203:Ferrosoferric Oxide / Q000032:analysis; D007220:Industrial Waste / Q000032:analysis; D007501:Iron / Q000737:chemistry*; D009532:Nickel / Q000032:analysis*; D013696:Temperature; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D056831:Coordination Complexes; D004492:Edetic Acid; D005290:Ferric Compounds; D052203:Ferrosoferric Oxide; D007220:Industrial Waste; D007501:Iron; D009532:Nickel; D062065:Wastewater; D014874:Water Pollutants, Chemical; C000499:ferric oxide
Aeration; Initial pH; Iron scrap anode; Packed density; Specific energy consumption