Enhanced distribution of humic acid-modified nanoscale magnesia for in situ reactive zone removal of Cd from simulated groundwater

2019 ◽  
Vol 245 ◽  
pp. 9-19 ◽  
Author(s):  
Neel Kamal Koju ◽  
Xin Song ◽  
Na Lin ◽  
Keke Xu ◽  
Heng Fu
Keyword(s):  
Humic Acid ◽  
Reactive Zone ◽  
Simulated Groundwater

Enhanced coagulation with in situ manganese dioxide on removal of humic acid in micro-polluted water

2015 ◽  
Vol 72 (3) ◽  
pp. 406-414
Author(s):  
Yubin Zeng ◽  
Ziyang Zeng ◽  
Junlin Wang
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Ph Value ◽  
Orthogonal Experiment ◽  
Surface Characteristics ◽  
Polluted Water ◽  
Enhanced Coagulation ◽  
Total Solids ◽  
Solids Content

The morphology and surface characteristics of manganese dioxide (MnO2) formed in situ, which was prepared through the oxidation of MnSO4 using KMnO4, were studied. The effects of factors including the form of MnO2, dosage, pH, dosing sequence of in situ MnO2 on the enhanced coagulation were systematically evaluated. The results of analysis by the UV254 and permanganate index CODMn methods indicated that humic acid removal increased from 9.2 and 2.5% to 55.0 and 38.9%, when 10 mg/L of the in situ MnO2 was added in the presence of 2 mg/L of polyaluminum sulfate. The studies of orthogonal experiment revealed that coagulation was most affected by the pH, whereas the dosage of in situ MnO2 and slow stirring duration exhibited a weaker effect. At a pH value of 4.0, in situ MnO2 dosage of 10 mg/L, slow stir over 40 min, and the total solids content was 20 mg/L, the humic acid removal by UV254 and CODMn methods reached 71.2 and 61.2%. These results indicated that the presence of in situ MnO2 enhanced the coagulation and removal of humic acid from water.

scholarly journals An Electrochemical Process Comparison of As(III) in Simulated Groundwater at Low Voltage in Mixed and Divided Electrolytic Cells

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1126 ◽  
Author(s):  
Yanyan Qin ◽  
Yanping Cui ◽  
Lidan Lei ◽  
Ya Gao ◽  
Zhengwei Zhou ◽  
...  
Keyword(s):  
Low Voltage ◽  
Electrochemical Process ◽  
First Order ◽  
Electrolytic Cells ◽  
Process Comparison ◽  
First Order Kinetics ◽  
Simulated Groundwater ◽  
High Arsenic ◽  
High Arsenic Groundwater

A relatively low voltage can be favor of e- transfer and peroxide generation from dominant 2e--reduction of O2 on carbon materials as cathode, with low energy loss. In this study the conversion of As(III) in simulated high arsenic groundwater at low voltage was compared in a mixed and a anode–cathode separated electrolytic system. With applied voltages (the potential difference between cathode and anode) from 0.1 V to 0.8 V, As(III) was found to be efficiently converted to As(V) in the mixed electrolytic cells and in separated anodic cells. The complete oxidation of As(III) to As(V) at 0.1–0.8 V was also achieved on graphite in divided cathodic cells which could be long-running. The As(III) conversion process in mixed electrolytic cells, anodic cells and cathodic cells all conformed to the pseudo first-order kinetics equation. The energy consumed by As(III) conversion was decreased as the applied voltage declined. Low voltage electrolysis is of great significance for saving energy consumption and improving the current efficiency and can be applied to in-situ electrochemical pre-oxidation for As(III) in high arsenic groundwater.

scholarly journals British Museum Natural Radiocarbon Measurements XXII

Radiocarbon ◽  
1991 ◽  
Vol 33 (1) ◽  
pp. 51-68 ◽  
Author(s):  
Janet Ambers ◽  
Keith Matthews ◽  
Sheridan Bowman
Keyword(s):  
Humic Acid ◽  
Humic Acids ◽  
Chlorine Dioxide ◽  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
British Museum ◽  
Scintillation Counting ◽  
Dilute Acid ◽  
Organic Fraction

The following list consists of dates, obtained by liquid scintillation counting of benzene, for archaeologic samples mostly measured between June 1987 and October 1989.Charcoal and grain samples were pretreated with 1M HCl followed by washing in water and, where considered necessary, with dilute alkali for the removal of humic acids. Wood samples were treated either in the same way, or, where large enough, were reduced to cellulose by the action of chlorine dioxide produced in situ. All antler and bone samples were treated with cold dilute acid. The term ‘collagen’ is used throughout to mean the acid insoluble organic fraction produced by this treatment. Peat samples were treated with dilute acid and alkali to separate the humin and humic acid fractions, which were dated individually.

Humic acid removal by gas–liquid interface discharge plasma: performance, mechanism and comparison to ozonation

2019 ◽  
Vol 5 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Yanyan Cui ◽  
Jianwei Yu ◽  
Ming Su ◽  
Zeyu Jia ◽  
Tingting Liu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Advanced Oxidation Process ◽  
Discharge Plasma ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Liquid Interface ◽  
Oh Radicals ◽  
Discharge Process

A novel advanced oxidation process (AOP) based on plasma in gas–liquid interface discharge was evaluated for humic acid removal. Much better performance was obtained compared to ozonation. The OH˙ radicals generated by reaction of in situ produced ozone and H2O2 during discharge process were mainly responsible for the removal.

scholarly journals Formation and remediation simulation of an in-situ reactive zone with nanoiron for a nitrobenzene-contaminated aquifer

2018 ◽  
Vol 18 (6) ◽  
pp. 2071-2080
Author(s):  
Li Hui ◽  
Zhang Xue-qing
Keyword(s):  
Fine Sand ◽  
Coarse Sand ◽  
Water Yield ◽  
Permeability Change ◽  
Contaminated Aquifer ◽  
Permeability Constant ◽  
Sand Box ◽  
Reactive Zone ◽  
The Media

Abstract A two-dimensional simulated sand box was built to investigate the formation and remediation of an in-situ reactive zone (IRZ) of nanoscale zero-valent iron (NZVI) for a nitrobenzene-contaminated aquifer, and the permeability change of the zone was calculated through the loss of waterhead. The experimental results demonstrated that the remediation area in coarse sand was obviously larger than that in fine sand. The nitrobenzene concentration reached a stable level of 87.24 and 170.24 mg/L in coarse and fine sand by 50 d and 40 d, respectively; after 60 d, the concentration of aniline as the reduction end-product of nitrobenzene was 97.02 and 49.40 mg/L, corresponding to a mean production rate of 40.1% and 20.8%, respectively. This indicated that a wider zone will be formed in the media with a larger size, which is beneficial for pollution remediation. The water yield of the aquifer declined by 13.8% and 11.9% in coarse and fine sand after 60 d, and the final permeability constant was 22.94 and 1.82 m/d (declining by 60.9% and 70.6%), respectively. The reactive zone remained stable and the injection of NZVI slurry could not cause any dramatic changes in the aquifer permeability.

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