Next Article in Journal
A Comparison between Variable Deficit Irrigation and Farmers’ Irrigation Practices under Three Fertilization Levels in Cotton Yield (Gossypium hirsutum L.) Using Precision Agriculture, Remote Sensing, Soil Analyses, and Crop Growth Modeling
Next Article in Special Issue
Variation in Spectral Characteristics of Dissolved Organic Matter and Its Relationship with Phytoplankton of Eutrophic Shallow Lakes in Spring and Summer
Previous Article in Journal
Changes in Soil Moisture, Temperature, and Salt in Rainfed Haloxylon ammodendron Forests of Different Ages across a Typical Desert–Oasis Ecotone
Previous Article in Special Issue
Treatment of Wastewater Effluent with Heavy Metal Pollution Using a Nano Ecological Recycled Concrete
 
 
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Simultaneous Removal of CODMn and Ammonium from Water by Potassium Ferrate-Enhanced Iron-Manganese Co-Oxide Film

1
School of Urban Planning and Municipal Engineering, Xi’an Polytechnic University, Xi’an 710048, China
2
Shaanxi LangMingRun Environmental Protection Technology Co., Xi’an 710061, China
*
Author to whom correspondence should be addressed.
Water 2022, 14(17), 2651; https://doi.org/10.3390/w14172651
Received: 30 May 2022 / Revised: 25 August 2022 / Accepted: 25 August 2022 / Published: 28 August 2022
(This article belongs to the Special Issue Water Environment Pollution and Control)

Abstract

:
Iron-manganese co-oxide film (MeOx) has a high removal efficiency for ammonium (NH4+) and manganese (Mn2+) in our previous studies, but it cannot effectively remove CODMn from water. In this study, the catalytic oxidation ability of MeOx was enhanced by dosage with potassium ferrate (K2FeO4) to achieve the simultaneous removal of CODMn and NH4+ from water in a pilot-scale experimental system. By adding 1.0 mg/L K2FeO4 to enhance the activity of MeOx, the removal efficiencies of CODMn (20.0 mg/L) and NH4+ (1.1 mg/L) were 92.5 ± 1.5% and 60.9 ± 1.4%, respectively, and the pollutants were consistently and efficiently removed for more than 90 days. The effects of the filtration rate, temperature and pH on the removal of CODMn were also explored, and excessive filtration rate (over 11 m/h), lower temperature (below 9.2 °C) and pH (below 6.20) caused a significant decrease in the removal efficiency of CODMn. The removal of CODMn was analyzed at different temperatures, which proved that the kinetics of CODMn oxidation was pseudo-first order. The mature sands (MeOx) from column IV were taken at different times for microscopic characterization. Scanning electron microscope (SEM) showed that some substances were formed on the surface of MeOx and the ratio of C and O elements increased significantly, and the ratio of Mn and Fe elements decreased significantly on the surface of MeOx by electron energy dispersive spectrometer (EDS). However, the elemental composition of MeOx would gradually recover to the initial state after the dosage of Mn2+. According to X-ray photoelectron spectroscopy (XPS) analysis, the substance attached to the surface of MeOx was [(-(CH2)4O-)n], which fell off the surface of MeOx after adding Mn2+. Finally, the mechanism of K2FeO4-enhanced MeOx for CODMn removal was proposed by the analysis of the oxidation process.

Graphical Abstract

1. Introduction

CODMn and ammonium (NH4+) are the main indicators for water quality evaluation of drinking water sources in China [1]. CODMn is a comprehensive index for determining the relative content of organic matter, and it is a key water pollutant index controlled by China. The excessive intake of organic matter into the human body may cause chronic poisoning and reproductive and genetic issues [2,3,4,5]. NH4+ is the main component of essential nutrients for aquatic plants and animals, but a high concentration of NH4+ can lead to eutrophication in surface water [6,7] and produce toxic disinfection byproducts in water plants [8,9]. In China, the maximum levels of CODMn and NH4+ in drinking water cannot exceed 3.0 and 0.5 mg/L, respectively.
The general methods for removing CODMn and NH4+ in the drinking water treatment process include an adsorption method, membrane separation technology and a biofiltration process. Activated alumina was used to adsorb CODMn in water, and the removal efficiency of 4.3 mg/L CODMn could reach 79.07% by reducing the hardness and chloride ions in water [10]. Green iron oxide nanoparticles synthesized on zeolite were used to remove 10 mg/L NH4+ and PO43−, and the removal efficiency of NH4+ was about 56.57% [11]. The adsorption method has a high removal efficiency and simple operation, but it is difficult to guarantee the quality of the effluent after adsorption saturation, and the adsorption material needs to be replaced and regenerated regularly. The removal efficiency of 3.73 mg/L CODMn could be 46.38% by an ultrafiltration-nanofiltration (UF-NF) double-membrane separation technology [12]. Guo et al. [13] combined continuous sand filtration (CSF) and ultrafiltration (UF) to treat raw water; the removal efficiencies of NH4+ and CODMn exceeded 70% and 30%, respectively. Although the membrane separation technology has a good removal effect for NH4+ and CODMn, its operation and maintenance costs are expensive, and the membrane is easily fouled. The simultaneous removal of NH4+ and CODMn could be achieved using an aerated bioactive filter with suspended filter media, and the removal efficiencies of NH4+ and CODMn were 88.11% and 57.49%, respectively [14]. The influence of the filter material thickness on the zeolite-ceramic aerated biological filter was studied, and the removal efficiencies of CODMn and NH4+ reached 38.62% and 93.02%, respectively [15]. The biological treatment process is less expensive to operate, but it has a long start-up period and is easily affected by low temperature [16].
In a previous study, the iron-manganese co-oxide film (MeOx) with catalytic oxidation activity could be formed on the surface of the quartz sand filter material in a pilot-scale filtration system. MeOx could be used to efficiently remove NH4+, iron (Fe2+) and manganese (Mn2+) from groundwater and surface water sources [17,18]. However, the removal effect of CODMn was very poor by MeOx. As an emerging green water treatment agent, potassium ferrate (K2FeO4) has the advantages of strong oxidation and no secondary pollution, but a high dosage concentration of K2FeO4 was required when it was used to remove CODMn from water [19]. Khoi et al. [20] explored the application of ferrate as the oxidant in river water purification, and the removal efficiency of CODMn could reach 86.2% by adding 20 mg/L of ferrate.
In this study, the mature quartz sands with MeOx were used as the filter material in a pilot-scale filtration experimental system, and a small dose of K2FeO4 was used to enhance the catalytic oxidation activity of MeOx so that NH4+ and CODMn could be removed simultaneously. The strengthening effect of K2FeO4 on MeOx, the optimal dosage of K2FeO4 and the effects of different filtration rates, pH and water temperature (T) on the CODMn removal process was mainly studied. Finally, some microscopic characterization techniques were used to explore the changes in the MeOx in these experiments, and the mechanism of the CODMn removal process was determined.

2. Materials and Methods

2.1. Raw Water Quality and the Pilot-Scale System

The raw water was a drinking water source in Xi’an, China. As shown in Table 1, the CODMn concentration and NH4+ concentration were significantly lower than the surface water quality standards, so they cannot be directly used for the experimental research. The CODMn concentration and NH4+ concentration in the influent could be increased by adding glucose and ammonium chloride, respectively.
As can be seen in Figure 1, the pilot-scale filter system includes four identical filter columns (inner diameter = 0.1 m, height = 3.0 m), the dosing system, the water distribution system and the backwashing system. Using potassium permanganate to continuously oxidize manganese and ferrous ions from raw water have been used to form the MeOx on the surface of virgin quartz sand quickly [17,18]. There was a 30 cm support layer (70–150 mm pebbles) at the bottom of the filter column. There are seven sampling ports on one side of the filter column. Eight dosing pumps were used for dosing different chemicals, and the filtration rate was controlled by the valve. The backwashing system includes air washing and water washing, and a flow meter was set to adjust the washing intensity. When the water level reached about 2.5 m above the bed layer, or the effluent water quality deteriorated, the pilot-scale column was backwashed, and the operation method of backwashing the filter column was as in a previous study [18]. The same batch of filter media was replaced after each experiment was completed.

2.2. Pollutant Removal Experiments

2.2.1. K2FeO4-Enhanced Filtration to Remove CODMn

Columns I, II and III were used for this experiment. The filter material was virgin quartz sands in column I, and in columns II and III, the filter material was mature sands with MeOx. The K2FeO4 solution (0.1 mg/L, prepared from potassium ferrate) and glucose solution (20.0 mg/L CODMn) were dosed into the static mixer by the dosing pump. K2FeO4 and a glucose solution were added to columns I and II, and only the glucose solution was added to column III, as shown in Table 2. The filtration rate was 7 m/h in this experiment, and all columns were run continuously for 10 days.

2.2.2. Simultaneous Removal of CODMn and NH4+

The CODMn concentration and NH4+ concentration in the influent were 20.0 ± 0.6 and 1.1 ± 0.1 mg/L, respectively, and different initial concentrations of K2FeO4 (about 0.1, 0.5, 1.0 and 2.0 mg/L) were added into the influent, which was used to determine the optimal dosage of K2FeO4. Each experimental condition was examined in triplicate. After the optimal dosage of K2FeO4 was determined, the experiment for the simultaneous removal of CODMn and NH4+ was performed in column IV, and the experiment was run for 90 days with daily sampling. The K2FeO4 (0.1 mg/L) was added for the entire 90 days, and 1.0 ± 0.1 mg/L Mn2+ was continuously added into the influent after day 47.

2.3. Influential Factors on the Removal of CODMn

Columns I, II and III were used to explore the experiment for influential factors on the removal of CODMn, and the CODMn concentration and K2FeO4 concentration in the influent were 20.0 ± 0.6 and 0.10 ± 0.03 mg/L, respectively. Each condition was run for 48 h, and all samples were taken and measured the change in the CODMn concentration along the filter column. The effect of K2FeO4 on the enhancement of MeOx to remove CODMn was explored under different filtration rates, pH and T.
The filtration rate (6–11 m/h) was controlled by the flow meters in the filter column. During the experiment, the water temperature was 20.0 ± 0.5 °C, and the pH was 8.0 ± 0.2 in the influent.
Hydrochloric acid (36% (w/w)) was used to adjust the pH value (in the range of 6.20–8.04) of the influent. The water temperature was 20.0 ± 0.5 °C, and the filtration rate was 7 m/h during the experiment.
The different initial temperatures (6.0–22.0 °C) of the influent were controlled by adding some ice cubes to the original water bucket. The filtration rate was maintained at 7 m/h, and the pH was 8.0 ± 0.2 in the influent.

2.4. Analytic Methods and Characterization Methods

The experimental reagents are glucose, potassium ferrate, sodium oxalate, potassium permanganate, ammonium chloride, mercury iodide, potassium sodium tartrate, potassium iodide, potassium periodate, potassium pyrophosphate, sodium acetate, sodium hydroxide and hydrochloric acid (36% (w/w)). All the above chemicals are of analytical grade. The hydrochloric acid (36% (w/w)) was purchased from Merck Ltd. (Beijing, China), and the rest of the chemicals were purchased from Shanghai Macklin Biochemical Co., Ltd (Shanghai, China).
The concentration of NH4+ was determined using Nessler reagent spectrophotometry, Mn2+ concentration was monitored by potassium periodate oxidation spectrophotometry, and the CODMn concentration was measured by the acid method according to the water and wastewater detection and analysis method [21]. The temperature, pH and DO were detected using a portable instrument (HACH, HQ30d, Loveland, CO, USA).
The microtopography of MeOx was characterized by scanning electron microscope (SEM) (FEI Quanta 600F, Portland, OR, USA), and the elemental composition was determined by energy-dispersive X-ray spectroscopy (EDS) (INCA Energy 350, Oxford, UK). The binding energy of C, O and Mn were analyzed using X-ray photoelectron spectroscopy (XPS) (Thermo Scientific K-Alpha, Waltham, MA, USA), and the XPS spectra were analyzed and peak fitted by bundled software (Avantage 5.9921, Thermo Scientific, Waltham, MA, USA).

3. Results

3.1. The Removal of CODMn and NH4+

3.1.1. K2FeO4-Enhanced Filtration to Remove CODMn

The process of K2FeO4-enhanced MeOx for the removal of CODMn was explored. From Figure 2 and Table 2, when 0.1 mg/L K2FeO4 was added to columns I and III, the removal efficiency of CODMn in water was only 5.0 ± 0.3% by the virgin quartz sands, while the removal efficiency of CODMn could reach 92.5 ± 1.5% by the mature sands (MeOx). When the filter media was the same batch of mature sand in columns II and III, the removal efficiency of CODMn was only 10.0 ± 0.3% without adding K2FeO4. To sum up, the presence of K2FeO4 enhanced the catalytic oxidation activity of MeOx, so the removal efficiency of CODMn was significantly improved.

3.1.2. Simultaneous Removal of CODMn and NH4+

The optimal dosage of K2FeO4 was determined, and the results are shown in Figure 3a,b. As shown in Figure 3a,b, the CODMn concentration and NH4+ concentration in the effluent gradually increased with the gradual decrease in the dosage of K2FeO4. However, only 1.0 mg/L K2FeO4 was added to the influent, and the concentration of pollutants in the effluent could meet the standard, so the optimal dosage of K2FeO4 was determined to be 1.0 mg/L.
Column IV was continuously operated for more than 90 days, and the concentrations of CODMn and NH4+ in the influent and effluent are shown in Figure 3c. During the initial 30 days, the removal efficiency of CODMn and NH4+ remained stable. The concentration of the pollutants in the effluent began to gradually increase when the pilot-scale system was run for 37 days. There was no Mn2+ in the influent for a long time, and the MeOx on the surface of the filter media could not be renewed, so the activity of the MeOx gradually decreased [22]. Mn2+ was continuously added into the influent on the 47th day, and the concentration of pollutants in the effluent gradually decreased and returned to the same level after 5 days. The recovery of the oxide film activity could be achieved by the continuous addition of Mn2+ in the influent.

3.2. Influential Factors on the Removal of CODMn

3.2.1. Effect of Filtration Rate

The effect of the filtration rate on the removal of CODMn is shown in Figure 4. When the filtration rate was 6.0 m/h, the CODMn concentration reached the effluent standard at the 20-cm-deep filter layer. When the filtration rate increased from 6.0 to 11.0 m/h, the CODMn concentration in the effluent also increased gradually. However, the removal efficiency of CODMn was more than 80% even if the filtration rate reached 11.0 m/h, so the effect of the filtration rate on the removal of CODMn was not obvious when the filtration rate was 6.0–11.0 m/h.

3.2.2. Effect of pH

The effect of pH on the removal of CODMn is shown in Figure 5. From Figure 5, when the pH value of the influent was 6.2, the removal efficiency of CODMn was only 64.0 ± 3.2%. The removal efficiency of CODMn increased with the increase in pH value. Considering the different reduction products of K2FeO4 at different pH [23], Fe3+ exists in the dissolved state under acidic conditions.
FeO42− + 8H+ + 3e → Fe3+ + 4 H2O
Under neutral and alkaline conditions, Fe3+ exists in the form of Fe(OH)3 precipitation.
Neutral condition:
FeO42− + 4H+ + 3e → Fe(OH)3 + OH
Alkaline condition:
FeO42− + 4H2O + 3e → Fe(OH)3 + 5OH
The Fe(OH)3 colloid had an adsorption effect on CODMn in water under alkaline conditions, which could further improve the removal efficiency of CODMn, so the removal efficiency of CODMn was lower under acidic conditions than under alkaline conditions.

3.2.3. Effect of Temperature

The water temperature had a significant influence on the removal of CODMn, and the removal efficiency of CODMn decreased with the decrease in temperature, as shown in Figure 6a. The removal efficiency of CODMn was only 53.92 ± 0.82% when the temperature was reduced to 6.0 °C. Since the activity of MeOx was affected by the low temperature [18], the removal efficiency of CODMn was significantly reduced.
The oxidation kinetics of CODMn at different temperatures are shown in Figure 6b. By maintaining the concentration of DO and pH in the influent constant, the CODMn consumption rate was assumed to be pseudo-first order: −d[CODMn]/dt = k [CODMn], where k is the rate constant (min−1) [24]. The plot of log{[CODMn]t/[CODMn]0} versus empty bed contact time (EBCT) were linear at all temperatures (6.0–22.0 °C), confirming that the kinetics of CODMn oxidation was pseudo-first order.

3.3. Surface Property Variation of MeOx

3.3.1. The Morphology of the MeOx

The filter media at different stages (the 1st, 47th and 90th day) were taken in column IV for the microscopic characterization analysis. As shown in Figure 7a,b, MeOx on the surface of quartz sand was smooth and dense, and the pore structure was relatively developed on the 1st day. From Figure 7c,d, the experimental system was continuously operated until the 47th day, part of the structure of the MeOx was broken, and the pore structure was blocked by some substances. It was due to the oxidation of organic matter by K2FeO4 to form the substances, which were attached to the surface of MeOx. After adding Mn2+ into the influent (Figure 7e,f), the surface structure and pore structure of MeOx were gradually recovered to smooth and dense, and the dosage of Mn2+ was oxidized to form the manganese oxides, which could be used to restore the activity of the MeOx.

3.3.2. Characterization of EDS

The EDS analysis results are shown in Figure S1. At the beginning of the experiment (the 1st day), the content of Mn was significantly higher than other elements on the MeOx surface. Due to the continuous dosage of CODMn into the influent, the content of Mn reduced, and the proportion of C and O increased significantly on the surface of MeOx. The main reason was that the organic matter was oxidized and covered on the surface of MeOx. After the addition of Mn2+, the proportions of C, Mn and O on the surface of MeOx were restored to the original state.

3.3.3. XPS of the Oxide Film

The XPS analysis was performed on the binding energies of C1s, O1s and Mn 3/2p, and the results are shown in Figure 8. By analyzing the binding energy of C1s, the organic matter was oxidized by K2FeO4 to form [(-(CH2)4O-)n] [25] on the surface of MeOx; this substance is more likely caused by the addition of glucose. In addition, the Si-C content increased due to MeOx exfoliation on the oxide film surface. From Figure 8b, the Mn (2p3/2) mainly exists in the form of manganese oxides, mainly including Mn2O3 [26], MnO [27] and Mn3O4 [28]. From the binding energy of O1s, the compound form of O was gradually changed from manganese oxide to [(-(CH2)4O-)n] and a small amount of MnO [29] with the dosage of CODMn. The activity of MeOx was recovered after adding Mn2+, and the compound form of O on the surface of MeOx is mainly C=O and part of Mn2O3, which was the intermediate product of CODMn after oxidation.

3.4. Proposed Mechanism for CODMn Removal

In previous studies, the removal mechanism of NH4+ and Mn2+ was inferred. NH4+ could be catalytically oxidized by MeOx to NO3 and H+ [19]. Mn2+ could be adsorbed by the surface of MeOx, and a new active oxide film and some loose oxides would be generated after a series of reactions [30].
As shown in Figure 9, a schematic presentation of the removal mechanism of CODMn by K2FeO4 enhanced filtration was proposed. The enhanced filtration process of K2FeO4 could be presented as three main steps: (1) Adsorption of FeO42− onto the surface of MeOx; (2) organic matter (glucose molecules) were adsorbed to the surface of [MeOx]·FeO42−, and the reaction occurs to generate [(-(CH2)4O-)n] and [MeOx]·FeO42−, and [MeOx]·FeO42− was reduced to [MeOx]·Fe3+; (3) [MeOx]·Fe3+ was still oxidized and finally reduced to [MeOx]·Fe(OH)3, and Fe(OH)3 was released from MeOx after backwashing.

4. Conclusions

By adding 0.1 mg/L K2FeO4 into the influent, the removal efficiency of 20.0 mg/L CODMn reached 92.5 ± 1.5% by MeOx. The filtration rate of the influent was lower than 11 m/h, which had little effect on the removal of CODMn. The removal efficiency of CODMn increased as the pH value increased from 6.20 to 8.04. Too low of a temperature (about 6.0 °C) would affect the activity of MeOx, and the removal efficiency of CODMn would drop to 53.92 ± 0.82%. The kinetics of CODMn oxidation was pseudo-first order. The optimal dosage of K2FeO4 for the simultaneous removal of 20.0 mg/L CODMn and 1.1 mg/L NH4+ was determined to be 1.0 mg/L. After the simultaneous removal of CODMn and NH4+ after about 30 days, the removal efficiency of the pollutants gradually decreased. From SEM characterization, the surface of MeOx was blocked by some substances. EDS analysis found that the proportion of C and O on the surface of MeOx increased significantly, while the proportion of Mn decreased by 45.93 ± 0.64%. The surface of MeOx was found to be covered with [(-(CH2)4O-)n] using XPS analysis. After Mn2+ was continuously added to the influent, the catalytic activity of MeOx was recovered after 5 days, and the efficient removal of CODMn remained stable until the 90th day of continuous operation.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/w14172651/s1, Figure S1: The elemental composition of the filter film at different experimental stages.

Author Contributions

Conceptualization, Y.G. and B.M.; methodology, S.Y. and Y.Z.; formal analysis, J.Y. and L.L.; writing—original draft preparation, B.M. and R.Z.; project administration, Y.G.; funding acquisition, J.Y. and Y.G. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the Scientific Research Program Funded by Shaanxi Provincial Education Department (21JK0650), the Natural Science Basic Research Program of Shaanxi (2021JQ-688), the Scientific Research Project of Shaanxi province of China (2021GY-147) and the Graduate Scientific Innovation Fund for Xi’an Polytechnic University, China (chx2022030).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. You, Q.; Fang, N.; Liu, L.; Yang, W.; Zhang, L.; Wang, Y. Effects of land use, topography, climate and socio-economic factors on geographical variation pattern of inland surface water quality in China. PLoS ONE 2019, 14, e0217840. [Google Scholar]
  2. Yu, Y.; Zhang, C.; Ding, W.; Zhang, Z.; Wang, G.G.X. Determining the performance for an integrated process of COD removal and CO2 capture. J. Clean. Prod. 2020, 275, 122845. [Google Scholar]
  3. Dos Santos, N.O.; Teixeira, L.A.; Zhou, Q.; Burke, G.; Campos, L.C. Fenton pre-oxidation of natural organic matter in drinking water treatment through the application of iron nails. Environ. Technol. 2021, 43, 2590–2603. [Google Scholar] [CrossRef] [PubMed]
  4. Sillanpää, M.; Ncibi, M.C.; Matilainen, A. Advanced oxidation processes for the removal of natural organic matter from drinking water sources: A comprehensive review. J. Environ. Manag. 2018, 208, 56–76. [Google Scholar] [CrossRef] [PubMed]
  5. Sillanpää, M.; Ncibi, M.C.; Matilainen, A.; Vepsäläinen, M. Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review. Chemosphere 2018, 190, 54–71. [Google Scholar]
  6. Yadu, A.; Sahariah, B.P.; Anandkumar, J. Influence of COD/ammonia ratio on simultaneous removal of NH4+-N and COD in surface water using moving bed batch reactor. J. Water Process Eng. 2018, 22, 66–72. [Google Scholar] [CrossRef]
  7. Zhang, R.; Qi, F.; Liu, C.; Zhang, Y.; Wang, Y.; Song, Z.; Kumirska, J.; Sun, D. Cyanobacteria derived taste and odor characteristics in various lakes in China: Songhua Lake, Chaohu Lake and Taihu Lake. Ecotoxicol. Environ. Saf. 2019, 181, 499–507. [Google Scholar] [CrossRef]
  8. Tabassum, S. A combined treatment method of novel Mass Bio System and ion exchange for the removal of ammonia nitrogen from micro-polluted water bodies. Chem. Eng. J. 2019, 378, 122217. [Google Scholar] [CrossRef]
  9. Dos Santos, P.R.; Daniel, L.A. A review: Organic matter and ammonia removal by biological activated carbon filtration for water and wastewater treatment. Int. J. Environ. Sci. Technol. 2020, 17, 591–606. [Google Scholar] [CrossRef]
  10. Szatyłowicz, E.; Skoczko, I. Studies on the efficiency of groundwater treatment process with adsorption on activated alumina. J. Ecol. Eng. 2018, 18, 211–218. [Google Scholar] [CrossRef]
  11. Xu, Q.; Li, W.; Ma, L.; Cao, D.; Owens, G.; Chen, Z. Simultaneous removal of ammonia and phosphate using green synthesized iron oxide nanoparticles dispersed onto zeolite. Sci. Total Environ. 2020, 703, 135002. [Google Scholar] [CrossRef] [PubMed]
  12. Yuan, C. Experimental Study on UF-NF filtration purification of pipe drinking water. J. Phys. Conf. Ser. 2019, 1176, 062021. [Google Scholar] [CrossRef]
  13. Guo, Y.; Bai, L.; Tang, X.; Huang, Q.; Xie, B.; Wang, T.; Wang, J.; Li, G.; Liang, H. Coupling continuous sand filtration to ultrafiltration for drinking water treatment: Improved performance and membrane fouling control. J. Membr. Sci. 2018, 567, 18–27. [Google Scholar] [CrossRef]
  14. Xu, K.; Wang, J.; Li, J.; Wang, Z.; Lin, Z. Attapulgite suspension filter material for biological aerated filter to remove CODMn and ammonia nitrogen in micro-polluted drinking water source. Environ. Prot. Eng. 2020, 46, 21–40. [Google Scholar]
  15. Liu, J.; Xie, S.; Cheng, C.; Lou, J.; Li, S. Effect on bed material heights to the performance of ZCBAF in the treatment of micro-polluted raw water. Appl. Mech. Mater. 2012, 209–211, 2053–2057. [Google Scholar] [CrossRef]
  16. Terry, L.G.; Summers, R.S. Biodegradable organic matter and rapid-rate biofilter performance: A review. Water Res. 2018, 128, 234–245. [Google Scholar] [CrossRef]
  17. Cheng, Y.; Zhang, S.; Huang, T.; Li, Y. Arsenite removal from groundwater by iron–manganese oxides filter media: Behavior and mechanism. Water Environ. Res. 2019, 91, 536–545. [Google Scholar] [CrossRef]
  18. Guo, Y.; Huang, T.; Wen, G.; Cao, X. The simultaneous removal of ammonium and manganese from groundwater by iron-manganese co-oxide filter film: The role of chemical catalytic oxidation for ammonium removal. Chem. Eng. J. 2017, 308, 322–329. [Google Scholar] [CrossRef]
  19. Sharma, V.K.; Zboril, R.; Varma, R.S. Ferrates: Greener oxidants with multimodal action in water treatment technologies. Acc. Chem. Res. 2015, 48, 182–191. [Google Scholar] [CrossRef]
  20. Tran, T.K.; Nguyen, D.H.C.; Hoang, G.P.; Nguyen, T.T.; Nguyen, N.H. Application of ferrate as coagulant and oxidant alternative for purifying Saigon river water. VNU J. Sci. Earth Environ. Sci. 2020, 36, 1–7. [Google Scholar]
  21. State Environmental Protection Administration. Water and Wastewater Monitoring and Analysis Methods, 4th ed.; China Environmental Science Press: Beijing, China, 2002; pp. 224–226. [Google Scholar]
  22. Guo, Y.; Ma, B.; Huang, J.; Yang, J.; Zhang, R. The simultaneous removal of bisphenol A, manganese and ammonium from groundwater by MeOx: The role of chemical catalytic oxidation for bisphenol A. Water Supply 2022, 22, 2106–2116. [Google Scholar] [CrossRef]
  23. Zhang, J.; Wang, D.; Zhang, H. Oxidative degradation of emerging organic contaminants in aqueous solution by high valent manganese and iron. Prog. Chem. 2021, 33, 1201–1211. [Google Scholar]
  24. Cheng, Y.; Zhang, S.; Huang, T.; Hu, F.; Gao, M.; Niu, X. Effect of alkalinity on catalytic activity of iron-manganese co-oxide in removing ammonium and manganese: Performance and mechanism. Int. J. Environ. Res. Public Health 2020, 17, 784. [Google Scholar] [CrossRef] [PubMed]
  25. López, G.P.; Castner, D.G.; Ratner, B.D. XPS O1s binding energies for polymers containing hydroxyl, ether, ketone and ester groups. Surf. Interface Anal. 1991, 17, 267–272. [Google Scholar] [CrossRef]
  26. Hercule, B.R. Surface spectroscopic characterization of Mn/AI2O3 catalysts. J. Chem. Phys. 1984, 88, 4922–4929. [Google Scholar]
  27. Oku, M.; Hirokawa, K. X-ray photoelectron spectroscopy of Co3O4, Fe3O4, Mn3O4, and related compounds. J. Electron Spectrosc. Relat. Phenom. 1976, 8, 475–481. [Google Scholar] [CrossRef]
  28. Audi, A.A.; Sherwood, P.M.A. Valence-band X-ray photoelectron spectroscopic studies of manganese and its oxides interpreted by cluster and band structure calculations. Surf. Interface Anal. 2002, 33, 274–282. [Google Scholar] [CrossRef]
  29. Oku, M.; Hirokawa, K.; Ikeda, S. X-ray photoelectron spectroscopy of manganese–oxygen systems. J. Electron Spectrosc. Relat. Phenom. 1975, 7, 465–473. [Google Scholar] [CrossRef]
  30. Guo, Y.; Zhang, J.; Chen, X.; Yang, J.; Huang, J.; Huang, T. Kinetics and mechanism of Mn2+ removal from groundwater using iron-manganese co-oxide filter film. Water Supply 2019, 19, 1711–1717. [Google Scholar] [CrossRef]
Figure 1. Schematic diagram of the pilot filter system.
Figure 1. Schematic diagram of the pilot filter system.
Water 14 02651 g001
Figure 2. K2FeO4 enhanced the MeOx for the removal process of CODMn.
Figure 2. K2FeO4 enhanced the MeOx for the removal process of CODMn.
Water 14 02651 g002
Figure 3. Effect of K2FeO4 concentration on the removal of (a) CODMn and (b) NH4+; (c) The removal of CODMn and NH4+ over the continuous operational period in the pilot-scale filter system.
Figure 3. Effect of K2FeO4 concentration on the removal of (a) CODMn and (b) NH4+; (c) The removal of CODMn and NH4+ over the continuous operational period in the pilot-scale filter system.
Water 14 02651 g003aWater 14 02651 g003b
Figure 4. The effect of the filtration rate on the removal of CODMn.
Figure 4. The effect of the filtration rate on the removal of CODMn.
Water 14 02651 g004
Figure 5. The effect of pH on the removal of CODMn.
Figure 5. The effect of pH on the removal of CODMn.
Water 14 02651 g005
Figure 6. (a) The concentration changes of CODMn along with the filter depth, (b) linear regression analysis of CODMn depletion with the EBCT at different temperatures.
Figure 6. (a) The concentration changes of CODMn along with the filter depth, (b) linear regression analysis of CODMn depletion with the EBCT at different temperatures.
Water 14 02651 g006
Figure 7. The morphology of the oxide film on the 1st, 47th and 90th day: (a) 1st day filter × 100, (b) 1st day filter × 10,000, (c) 47th day filter × 100, (d) 47th day filter × 10,000, (e) 90th day filter × 100, (f) 90th day filter × 10,000.
Figure 7. The morphology of the oxide film on the 1st, 47th and 90th day: (a) 1st day filter × 100, (b) 1st day filter × 10,000, (c) 47th day filter × 100, (d) 47th day filter × 10,000, (e) 90th day filter × 100, (f) 90th day filter × 10,000.
Water 14 02651 g007aWater 14 02651 g007b
Figure 8. XPS energy spectra of (a) C1s, (b) Mn2p3/2 and (c) O1s with different experimental stages.
Figure 8. XPS energy spectra of (a) C1s, (b) Mn2p3/2 and (c) O1s with different experimental stages.
Water 14 02651 g008
Figure 9. Mechanism of K2FeO4-enhanced MeOx removal of CODMn.
Figure 9. Mechanism of K2FeO4-enhanced MeOx removal of CODMn.
Water 14 02651 g009
Table 1. Raw water quality.
Table 1. Raw water quality.
IndexUnitValueSurface Water Quality Standard Class III (GBT3838-2002)
Ammoniummg·L−10–0.2≤1.0
CODMnmg·L−10.87–2.10≤6.0
Nitratemg·L−13.8–4.3≤10.0
Manganesemg·L−10–0.05≤0.1
pH-7.5–8.06.0~9.0
Ironmg·L−10.051–0.062≤0.3
Temperature°C14.9–26.5-
Dissolved oxygen (DO)mg·L−18.0–9.5≥5.0
Table 2. The operating conditions.
Table 2. The operating conditions.
ColumnFilter MaterialCODMnK2FeO4
Ivirgin quartz sands20.0 mg/L0.1 mg/L
IImature sands20.0 mg/L0.1 mg/L
IIImature sands20.0 mg/L0
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Guo, Y.; Ma, B.; Yuan, S.; Zhang, Y.; Yang, J.; Zhang, R.; Liu, L. Simultaneous Removal of CODMn and Ammonium from Water by Potassium Ferrate-Enhanced Iron-Manganese Co-Oxide Film. Water 2022, 14, 2651. https://doi.org/10.3390/w14172651

AMA Style

Guo Y, Ma B, Yuan S, Zhang Y, Yang J, Zhang R, Liu L. Simultaneous Removal of CODMn and Ammonium from Water by Potassium Ferrate-Enhanced Iron-Manganese Co-Oxide Film. Water. 2022; 14(17):2651. https://doi.org/10.3390/w14172651

Chicago/Turabian Style

Guo, Yingming, Ben Ma, Shengchen Yuan, Yuhong Zhang, Jing Yang, Ruifeng Zhang, and Longlong Liu. 2022. "Simultaneous Removal of CODMn and Ammonium from Water by Potassium Ferrate-Enhanced Iron-Manganese Co-Oxide Film" Water 14, no. 17: 2651. https://doi.org/10.3390/w14172651

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop