Coagulation Sedimentation Research Articles

Effect of coagulation-sedimentation pretreatment on methane production from Indonesian palm oil mill effluent and kinetics

The current study purposed to investigate the influence of coagulation-sedimentation (CS) pretreatment on methane production from Indonesian palm oil mill effluent (POME). In the CS pretreatment, the coagulation process was conducted for 2 h at various alum doses (2, 4, 6, and 8 g/L), followed by the sedimentation process for 24 h to separate sludges from supernatants. Then, supernatants were used as methane feedstocks. The CS pretreatment with an alum dose of 6 g/L generated the highest reduction in chemical oxygen demand (COD) of 70.02 %. The anaerobic digestion (AD) of supernatant resulting from CS pretreatment with an alum dose of 6 g/L generated 8-fold higher methane production than the AD of raw POME. In kinetic analyses, the modified Gompertz model had a higher accuracy (R2 of 0.9938) in predicting methane yield evolution than the first-order model and the Cone model (R2 of 0.9449 and 0.9923).

Ubiquitous occurrence of 1,4-dioxane in drinking water of China and its ecological and human health risk

The occurrence and distribution of 1,4-dioxane was investigated in 280 source and finished drinking water samples from 31 Chinese cities, based on which its ecological and health risks were systematically evaluated. The findings demonstrated that 1,4-dioxane was detected in about 80.0 % samples with values ranging from n.d. to 7757 ng/L in source water and n.d. to 2918 ng/L in drinking water. 1,4-Dioxane showed limited removal efficiency using conventional coagulation–sedimentation–filtration processes (14 % ± 48 %), and a removal efficiency of 35 % ± 44 % using ozonation-biological activated carbon advanced treatment processes. Relatively higher concentrations, detection frequency and environmental risk were observed in Taihu Lake, Yellow River, Yangtze River, Zhujiang River, and Huaihe River mainly in the eastern and southern regions, where there are considerable industrial activities and comparatively high population densities. The widespread presence as by-products during manufacturing consumer products e.g., ethoxylated surfactants, suggested municipal wastewater discharges were the dominant source for the ubiquitous occurrence of 1,4-dioxane, while industrial activities, e.g. resin manufacturing, also contribute considerably to the elevated concentrations of 1,4-dioxane. The estimated risk quotients were in the range of <1.5 × 10−4 for ecological risk, <5.0 × 10−3 by oral exposure and < 5.0 × 10−2 by inhalation exposure for health risk, illustrating limited ecological harm to water environment or chronic toxicity to human health. For carcinogenic risk, 1,4-Dioxane presented a mean risk of 1.8 × 10−6 by oral exposure, which slightly surpassed the recommended acceptable levels of U.S. EPA (<10−6), and risk from inhalation exposure could be negligible. The pervasiveness in drinking water, low removal efficiencies during water treatment processes, and suspected health impacts, highlighted the necessity to set related water quality standards of 1,4-dioxane in order to improve water environment in China.

Development of a Temporary Wastewater Treatment Unit Using Single–Tank MBR and High Performance Coagulation–Sedimentation

Development of a Temporary Wastewater Treatment Unit Using Single–Tank MBR and High Performance Coagulation–Sedimentation

The use of central composite design (CCD) to optimize and model the coagulation-flocculation process using a natural coagulant: Application in jar test and semi-industrial scale

Currently, the field of water treatment represents a very important area for researchers due to developing reliable processes for the recycling and reuse of water. Plant-based coagulants used in treatment processes are cost-effective and environmentally friendly. In this study, the use of bio-coagulants based on Aloe vera was proposed for the treatment of the wastewater. The response surface method based on the central composite design was applied to optimize the considered parameters in the coagulation flocculation process. All experiments were conducted in laboratory and semi-industrial scale using a raw water with an initial turbidity and total suspended solids (TSS) of 204NTU and 240 mg/L, respectively. This study was carried out in two parts: (1) optimization and modeling of the coagulation flocculation process. Two parameters were considered, which are the pH and the coagulant dosage. The results obtained show that the R2 were 97.93 % and 98.95 %, with removal percentage efficiency of 99.13 % and 94.0 % for turbidity and TSS, respectively. (2) The jar test optimization results were applied on a pilot of coagulation flocculation and sedimentation, with a flow rate of 150 L/h. The obtained result showed that the removal percentage efficiency were respectively 98.45 % and 92.29 % for turbidity and TSS.

Evaluasi Aspek Teknis Kualitas Air Membran Ultrafiltrasi dalam Pengolahan Air Minum (Studi Kasus: IPA Krian Perumda Air Minum Sidoarjo)

The Sidoarjo Regional Public Company (Perumda) is a regionally owned business entity that participates in managing and providing clean water which will be distributed to the people of Sidoarjo Regency. The Sidoarjo Drinking Water Company, especially the Krian IPA, uses the main channel to supply raw water from the Mangetan Canal which passes through seven sluice gates to irrigate 17,583 Ha of rice fields. The series of air treatment installations at Perumda Air Minum Sidoarjo are coagulation units, flocculation units, sedimentation units and ultrafiltration membranes. However, not all technology can be implemented optimally due to considerations of costs and Perumda personnel. The problem is that the ultrafiltration membrane unit at Perumda Air Minum Sidoarjo is not activated. Therefore, the aim of the research is to determine the ineffectiveness of ultrafiltration membranes at Perumda Air Minum Sidoarjo in terms of technical aspects, namely the quality of water resulting from membrane processing in 2016-2020. The results of the research on the technical aspect, namely data on water quality parameters for turbidity and color for 2016-2020, have complied with Minister of Health Regulation Number 2 of 2023 for drinking water quality standards, the rejection percentage for turbidity parameters was 69.39%. - 95.48%; the percentage of color parameter rejection was 43.60% - 61.6% with the resulting flux value decreasing.

Synergistic Effects of Ionizing Radiation Process in the Integrated Coagulation–Sedimentation, Fenton Oxidation, and Biological Process for Treatment of Leachate Wastewater

This study evaluated the feasibility of ionizing radiation combined with coagulation–sedimentation and Fenton oxidation as a treatment method for landfill leachate. The experiments revealed a positive correlation between pollutant removal efficiency and increased ionizing radiation intensity. Remarkable pollutant removal efficiencies were achieved under ionizing radiation at 50 kGy, with a maximum of 27% removal of total organic carbon (TOC), 61% removal of total nitrogen, 51% removal of total phosphorus, and an impressive 93% removal of NO3−-N. With the addition of coagulation–sedimentation and Fenton oxidation, the treatment efficiency further increased by 33% nitrogen, 18% SCOD, and 8% phosphate. The most significant observation from the study was that for all the different treatment methods, the results were always better for leachate samples treated with ionizing radiation than for the untreated samples. Subsequently, biological treatment was applied as a post-treatment method to remove residual organic carbon and nitrogen, which found that the best removal efficiencies were only for the low salt concentration (0.5%) and the removal decreased with increasing salt concentration. These experimental results conclusively demonstrated that when treating leachate wastewater, it was more appropriate to employ physicochemical methods rather than a biological treatment, primarily due to the high salt concentration present.

Optimum Conditions for Enhancing Chitosan-Assisted Coagulation in Drinking Water Treatment

Coagulant aids are useful chemicals that enhance the efficiency of coagulation sedimentation treatment. For this purpose, it is necessary to choose safe chemicals to avoid various risks to the health of those who use the treated water. The use of chitosan, an abundant natural polysaccharide, as a coagulant aid is significant not only for safe water treatment but also for the effective utilization of unused natural water resources, which are mostly wasted. We experimentally determined the optimal treatment conditions for using chitosan as a coagulant aid in water treatment. The most efficient use was identified as adding chitosan at the stage of rapid stirring after the addition of coagulant accelerated initial dispersion. When used with the main coagulant polyaluminum chloride (PACl), the optimal concentration of chitosan was 0.8 mg L−1, as estimated using the ζ potential showing isoelectricity at the optimal chitosan concentration. Determining the chitosan concentration using the minimum ζ potential was also valid for estimating the optimum concentration of chitosan, which is an extension of the method used at much higher turbidity, as seen in wastewater. Thus, the ζ potential-based prediction of the optimum chitosan concentration was effective even when the effect of sweep coagulation, which is normally induced at higher turbidity, was negligible. The superiority of using the coagulant PACl in combination with chitosan as the coagulant aid was demonstrated by comparing the in situ-observed coagulation process to cases with other coagulants and coagulant aids using direct time-series observation of the coagulation process. The use of chitosan with PACl was found to make the flocs easier to remove because it resulted in the largest mass fraction of the resultant floc sedimentation on the bottom of the vessel. In this study, using the PACl coagulant in combination with chitosan as the coagulant aid was found to be as viable as using the current popular combination of aluminum sulfate and polyacrylamide. Replacing polyacrylamide with chitosan contributed to reducing the potential risk to the health of those to use the treated water.

Evaluation of the relative deviation for coagulation and gravitational sedimentation model from experimental results of submicron aerosol in water vapor environments

This paper evaluates the relative bias of submicron aerosol coagulation and gravity deposition experiments and model prediction results under water vapor conditions, and discusses the model prediction bias results at high steam fraction. When submicron aerosols are at room temperature and lower vapor molar ratios, the model predictions and experimental results are in good agreement. When the molar fraction of steam is high, the prediction results of the model are poor. Through analyzing thermal data and conducting gas superheating experiments, it was found that under saturated steam conditions in the experimental vessel, the number of suspended small droplets also increases with the increase of steam molar fraction. The presence of these droplets alters the coagulation and sedimentation results of submicron aerosols. Based on experimental data, this paper adds correction coefficients of coalescence and sedimentation to the original model, making it suitable for predicting submicron aerosol coagulation and sedimentation under high steam molar fraction.

The Effect of Cone Area Variations on the Continuous Discharges Flow (CDF) Method Sedimentation Unit as a New Method for Raw Water Turbidity Removal

The Sedimentation Unit Continuous Discharges Flow (CDF) method is a modification by adding a continuous and controlled discharge flow as a net force acting on the particles to increase the efficiency of turbidity removal by applying the principle of a leaky tank at the bottom of the settling zone. The production capacity of the sedimentation unit using the CDF method is reduced due to the CDF flow of 6% of the flow rate so it needs to be recirculated. This study aims to maintain the production flow rate of the system and increase the efficiency of turbidity removal by recirculating the CDF flow. The research reactor consisted of a coagulation unit, flocculation unit, and sedimentation method using 6% CDF with a flow rate of 240 L/hour and 360 L/hour, and variations in the recirculation flow of 6% CDF to the flocculation unit were 0%, 25%, 50%, 75%, and 100 %. The sedimentation detention time at a flow rate of 240 L/hour and 360 L/hour was 90 minutes and 60 minutes, respectively. Research on a laboratory scale with raw water turbidity of 25,536 NTU. The results showed that the greater the CDF flow recirculation value, the higher the turbidity removal efficiency. Rank Spearman analysis, the correlation value of the CDF flow recirculation value to the efficiency of removal of turbidity is 0.980 and the significance value is 0.00 which means strong and significant. The highest turbidity removal efficiency was achieved at the 100% CDF flow recirculation value, ie at 240 L/hour flow rate was 87.21% with final turbidity 3.267 NTU, while at 360 L/hour flow rate was 82.50% with final turbidity 4,528 NTU. Uprating the flow rate in the experiment was able to produce a final turbidity value that met the drinking water quality standard, which was 5 NTU

Performance of gravity-driven membrane filtration for treatment of low-temperature and low-turbidity water: Effect of coagulation pretreatment

As a promising technology for decentralized drinking water treatment, performance of gravity-driven membrane (GDM) filtration for low-temperature and low-turbidity water purification and effects of coagulation pretreatment were investigated in this study. Flux development and permeate water quality of three GDM systems, i.e., control GDM without pretreatment, GDM with in-line coagulation (IC) pretreatment (IC-GDM), GDM with coagulation-sedimentation (CS) pretreatment (CS-GDM), were compared. Moreover, composition and morphology of bio-cake layer were characterized to explain underlying mechanisms for performance improvement by coagulation pretreatment. Results suggested that permeate flux of control GDM stabilized at ∼4.0 L/(m2·h) for raw water with relatively low temperature (8.1– 10.8 °C) and turbidity (1.15– 2.47 NTU). IC pretreatment increased stable flux by 65 %, although the bio-cake layer thickness in IC-GDM was increased by 71.7 %, probably due to a significant reduction (57.1 %) in extracellular polymeric substances (EPS) in the bio-cake layer. Meanwhile, CS pretreatment increased stable flux by 87.5 %, which can be attributed to 63.3 % reduction in EPS and 47.0 % decrease in bio-cake layer thickness. As for permeate water quality, dissolved organic matter (DOM) was significantly reduced by both IC and CS pretreatments, mainly due to transformation from dissolved state to particulates. Compared with control GDM, both IC and CS pretreatments resulted in decrease in microbial abundance and activity and changes in microbial community, probably due to decrease in bioavailable phosphate and DOM. This study suggested that both IC and CS pretreatments can be integrated with GDM filtration for efficient purification of low-temperature and low-turbidity water.

A combined evaluation of the characteristics and antibiotic resistance induction potential of antibiotic wastewater during the treatment process

Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance (AR) when released into the environment. Although these substances are mostly in concentrations lower than those known to induce AR individually, it is possible that antibiotic wastewater discharge might still promote the AR transmission risk via additive or synergistic effects. However, the comprehensive effect of antibiotic wastewater on AR development has rarely been evaluated, and its treatment efficiency remains unknown. Here, samples were collected from different stages of a cephalosporin production wastewater treatment plant, and the potential AR induction effect of their chemical mixtures was explored through the exposure of the antibiotic-sensitive Escherichia coli K12 strain. Incubation with raw cephalosporin production wastewater significantly promoted mutation rates (3.6 × 103–9.3 × 103-fold) and minimum inhibition concentrations (6.0–6.7-fold) of E. coli against ampicillin and chloramphenicol. This may be attributed to the inhibition effect and oxidative stress of cephalosporin wastewater on E. coli. The AR induction effect of cephalosporin wastewater decreased after the coagulation sedimentation treatment and was completely removed after the full treatment process. A Pearson correlation analysis revealed that the reduction in the AR induction effect had a strong positive correlation with the removal of organics and biological toxicity. This indicates that the antibiotic wastewater treatment had a collaborative processing effect of conventional pollutants, toxicity, and the AR induction effect. This study illustrates the potential AR transmission risk of antibiotic wastewater and highlights the need for its adequate treatment.

Ozonation and Granular Activated Carbon Adsorption for the Removal of Refractory Organic Matter and Decolorization During Wastewater Tertiary Treatment

This study investigated two different hybrid processes for the treatment of municipal secondary-treated biological effluents to meet the reuse of recycled water requirements for organic matter and color. The two hybrid treatment approaches were an oxidation-based treatment process (coagulation–sedimentation–deep-bed filtration [CSDF]–ozone oxidation) and an adsorption-based treatment process (CSDF-granular activated carbon [GAC] adsorption). The efficiencies of ozonation and GAC adsorption in removing chemical organic demand (COD), dissolved organic carbon (DOC), and color intensity were evaluated. The effect of CSDF as the pretreatment was also studied. Ozonation showed a much higher color removal efficiency (88%, 4.7 mg/L ozone dose) than GAC adsorption (23%). Organic matter with an apparent molecular weight of 2–3 kDa, being humus-like, might be the colored fraction in the secondary and CSDF effluents. Ozonation had a stronger ability to remove these substances than GAC adsorption, resulting in a visibly higher color removal efficiency. In addition, higher COD and DOC removal were achieved by ozonation when the average ozone dose was increased to 9.1 mg/L. Although both hybrid processes were reliable for reducing organic matter and color, the results show that ozonation is more suitable for simultaneously removing refractory organic matter and color.

Treatment of mixed domestic–industrial wastewater by combined coagulation–sedimentation, biological processes and advanced oxidation

Treatment of mixed domestic–industrial wastewater by combined coagulation–sedimentation, biological processes and advanced oxidation

Comparison Performances of Microfiltration and Rapid Sand Filter Operated in Water Treatment Plant

Water treatment of river water is generally carried out conventionally, a rapid sand filter consisting of a coagulation unit, flocculation, sedimentation, and sand filtration. One of the disadvantages of sand filters is that it requires a large volume of water for washing, inconsistent quality, and escape of microorganisms less than 0.01 mm in size. Membrane technology can solve this problem with the advantages of including a more compact unit with a larger surface area per volume. The immersed membrane has another advantage that it is possible to integrate with sedimentation units so that it can save the land. This paper will study a comparison of the performance of the microfiltration membrane with sand filters in two drinking water treatment plants. The comparison method is based on technical specification, capacity, and quality performance. The results show that the quality of the microfiltration membrane filtrate is better than the sand filter. Overall immersed membrane microfiltration with pore size 0.05 µm had removal efficiency of E. Coli was 100%, turbidity 93 %, TSS 100%. Organic permanganate value 37%, and Microplastics 81.5%, whereas pore size 0.07 µm removal E. Coli was 99.8%, turbidity 52.9 %, Organic permanganate value 17.6%, and Microplastics 37.1%. The productivity of microfiltration membranes is more significant than rapid sand filters. The removal efficiency of WWTP Ngagel was better than Siwalan Panji.

Comparative study of acid mine drainage neutralization by calcium hydroxide and concrete sludge–derived material

A novel neutralizing agent (PAdeCS) was produced from concrete sludge generated during the production of secondary concrete products by centrifugal molding, and the effect on actual acid mine drainage (AMD) was evaluated. The effect was compared with a conventional neutralizing agent (i.e., calcium hydroxide). Nine reaction tanks were temporarily installed and operated, imitating the treatment of actual AMD. The amount of discharged water and sediment generated was evaluated. The amount of PAdeCS required to neutralize the actual mine wastewater was 1.5 times that of Ca(OH)2, and the amount of sludge generated was less with PAdeCS than with Ca(OH)2. The coagulation sedimentation performance of PAdeCS is greater than that of Ca(OH)2, determined by comparing the thickness of the sludge layer and the transparency of the supernatant. The reduction of CO2 emissions for the substitution of Ca(OH)2 and CaCO3 by PAdeCS was evaluated, and the neutralization performance of this novel neutralizing agent prepared from concrete sludge in AMD was determined.

Coagulation sedimentation performance and model optimization of ultra-fine tailings overflow from hydrocyclone

In order to study the sedimentation characteristics of ultra-fine tailings overflow from hydrocyclone in a coagulation environment, the sedimentation velocity of overflow ultra-fine tailings under different coagulant dosage, pulp pH and temperature conditions were analyzed experimentally in this study. The results indicate that with the increase in sedimentation time, the sedimentation velocity of the coagulant first increases, followed by a decline before becoming flat. When the ferric chloride coagulant dosage is 90 mg/L, the pH of the pulp is 9. The sedimentation velocity reaches the maximum value of 5.57 mm/s, when the temperature of the pulp is 60 °C. According to the sedimentation process of the coagula, the coagulation sedimentation model of total tailings was extended and modified. The average absolute error between the corrected settlement velocity and the actual velocity was found as 0.0034, with the root mean square error is as 0.0088, which is relatively small. The results obtained from the theoretical calculations are consistent with the experimental data. The modified and optimized coagulation sedimentation model is important in promoting the theoretical research on the coagulation and sedimentation of such ultra-fine mineral particles.

Control for chlorine resistant spore forming bacteria by the coupling of pre-oxidation and coagulation sedimentation, and UV-AOPs enhanced inactivation in drinking water treatment

Spore forming bacteria (SFB) are strongly chlorine resistant. Their presence in drinking water may cause diseases and pose threat to public health. Three SFB strains, i.e. Bacillus alvei, Bacillus cereus, and Lysinibacillus fusiformis, were isolated and identified from the finished water of a drinking water treatment plant where bacteria colonies occasionally reached the limit value. Due to their chlorine resistance, a SFB control strategy coupling pre-oxidation, coagulation sedimentation, and UV-AOPs inactivation in water treatment process was studied in lab scale. Five minutes pre-oxidation treatment by applying Cl2 and ClO2 induced remarkable spore transformation. Longer pre-oxidation exposure time didn't have apparent improvement. Cl2 and ClO2 dosages of 0.9 mg/L and 0.5 mg/L were suggested, respectively. The formed spores can be efficiently removed by the following coagulation sedimentation treatment. At a suggested dosage combination of 20 mg/L PAC and 0.08 mg/L PAM, spore removal efficiency reached about 3.15-lg. Comparing to applying sole UV irradiation, enhanced UV inactivation by adding 0.1 mM H2O2, or Cl2, or peroxymonosulfate (PMS) substantially improved the inactivation of the most chlorine resistant SFB strain, Lysinibacillus fusiformis. UV-AOPs stably achieved 2-lg inactivation rate at UV dosage of 40 mJ/cm2. UV/H2O2, UV/Cl2 and UV/PMS inactivation kinetically enhanced 1.20 times, 1.36 times and 1.91 times over sole UV irradiation. Intracellular DNA and ATP leakages were detected, and remarkable damages of Lysinibacillus fusiformis cells’ surface and ultrastructure were observed. These findings evidenced cell wall and cell membrane destructions, guaranteeing substantial SFB cells inactivation. This study was carried out based on three SFB strains isolated from a finished water, and common engineering practical operations. By providing engineeringly relevant references, the outcomes obtained would be helpful for dealing with SFB outbreak risk in drinking water treatment.

Enhanced treatment of oily ink wastewater using a modified degreaser by nano-Fe3O4/Na2S2O8: Efficient coagulation and sedimentation

Ink wastewater is hazardous because it contains oil and refractory pollutants, with high Chroma and turbidity. There are many aromatic compounds in the wastewater, such as benzene, toluene, xylene, and phthalocyanines, azos, and nitroso, which make high chemical oxygen demand (COD) and ammonia nitrogen content. The refractory pollutants are always encapsulated in diverse oil-water systems. Usually a massive degreaser has to be used to destroy the dispersant oil forms under preferred alkaline condition, and advanced oxidation is used for good removal of refractory pollutants under preferred acid condition, which commonly lead to a bad coagulation and sedimentation as a result. In this study, the nano-Fe3O4 (MNPs) activated sodium persulfate (SPS) has been testified to enhance degrease with efficient coagulation and sedimentation. The results showed that the removal of oil, COD, ammonia nitrogen, Chroma and turbidity reached respectively 96.40%, 98.35%, 88.00%, 99.70% and 98.22%, within 40–50 min. The mechanism shows that the catalytic oxidation significantly decreased the Zeta potential of the colloidal particles in the wastewater, which destroyed the steady-state of the colloid and enhanced the effect of coagulation sedimentation. Importantly, the combination of MNPs and colloidal particles successfully promoted the simultaneous production of SO4− and a large amount of HO under weakly alkaline (pH = 7.5–8.0) conditions, which made synergistic oxidation to remove micro-oil and organic pollution efficiently.

Treatment of Waterborne Coating Wastewater by Coagulation Sedimentation Fenton Oxidation Process

waterborne coatings have become the development trend of the coating industry because of their less use of organic solvents and good environmental protection performance. However, the wastewater produced in the production process of waterborne coatings has become a difficult pollution source. Based on this, this paper uses coagulation sedimentation method and Fenton oxidation method to treat waterborne coating wastewater. Taking the COD of treated wastewater as the research index, this paper studies various factors affecting the treatment effect of coagulation sedimentation and Fenton oxidation. Through single factor analysis, the results show that the best dosage of PFS and PAM is PFS: 8 g/L and PAM: 0.8 g/L; In Fenton oxidation, the dosage of H2O2 is 9.98mL/L, the dosage of FeSO4 · 7H2O is n (Fe2+): n (H2O2) = 1:6, pH is 2, and the dosage times are 2.

Chromium(VI) adsorption–reduction using a fibrous amidoxime-grafted adsorbent

To comply with regulations and mitigate environmental pollution, efficient technologies are required for treating chromium-contaminated industrial wastewater. To develop a safe and simple method for the reduction of toxic chromium(VI) to the less harmful chromium(III), we proposed using radiation-induced graft polymerization. This method allows for any functional group to be introduced into conventional polymeric materials, which enables the synthesis of solid adsorbents with good handling properties. Herein, we synthesized a fibrous adsorbent with amidoxime functional groups that have a high affinity for chromium, and investigated the changes in the chromium valence state over time in the amidoxime-grafted adsorbent. Fourier transform infrared analysis suggested that the amide groups were oxidized by chromium(VI) and converted to nitro groups. Furthermore, in situ X-ray absorption fine structure analysis revealed that most of the chromium(VI) was reduced to chromium(III) relatively early during the adsorption process, followed by gradual changes in the bonding structure of the amidoxime-chromium complex. Although more than one day was required to completely stabilize the structure of chromium(III), this approach provides a safe method for chromium(VI) removal. Furthermore, because wastewater can be treated via simple circulation with this method, it is easier to operate than coagulation sedimentation or electrochemical methods. Thus, it is expected to contribute to the development of practical technologies for wastewater treatment.