Algae Removal Research Articles

Removal of atrazine in catalytic degradation solutions by microalgae Chlorella sp. and evaluation of toxicity of degradation products via algal growth and photosynthetic activity

Degradation solutions containing atrazine need to be further purified before they are discharged into the aquatic environment. With the objectives of evaluating removal capacity of the microalga Chlorella sp. toward atrazine in degradation solutions and toxicity of the degradation products, we investigated the removal efficiency (RE) and bioaccumulation of atrazine in the microalgae after an 8 d exposure to diluted degraded solutions containing 40 μg/L and 80 μg/L of atrazine as well as degradation products in the present study. Moreover, pure atrazine solutions with similar concentrations were simultaneously inoculated with the microalgae in order to distinguish the influence of the products. The photocatalytic degradation results showed that 31.4% of atrazine was degraded after 60 min, and three degradation products, desisopropyl-atrazine (DIA), desethyl-atrazine (DEA), and desethyl-desisopropyl-atrazine (DEIA) were detected. After an 8-d exposure, 83.0% and 64.3% of atrazine were removed from the degraded solutions containing 40 μg/L and 80 μg/L of atrazine, respectively. In comparison with the control, i.e., pure atrazine solution with equal concentration, Chlorella sp. in the degraded atrazine solution showed lower RE and growth rate. The photosynthetic parameters, especially performance index (PIABS), clearly displayed the differences between treatments. The values of PIABS of Chlorella sp. cultured in degradation atrazine for 8 days were significantly lower (P < 0.01) than that in the corresponding pure atrazine, suggesting potential inhibitory effect of degradation products on the microalgae. Atrazine and the degradation products inhibited algal photosynthesis via depressed light absorption and electron transport, and reduced utilization of light energy via energy dissipation. Our results demonstrated that microalgae Chlorella sp. had an encouraging atrazine removal potential and the degradation products of atrazine may inhibit algal growth and removal capability. This study may be useful for the application of microalgae in herbicide wastewater treatment and understanding algal removal of atrazine in natural aquatic environment.

Addressing algal blooms by bio-pumps to reduce greenhouse gas production and emissions with multi-path

The collapse of dense algal blooms is identified as a significant source of methane (CH4) emissions. When flocculation is used for algae removal, algal carbon is often turned into CH4 and carbon dioxide (CO2). Here, we established a “bio-pump” to control algal blooms and reduce greenhouse gas (GHG) emissions by the introduction of submerged macrophytes to the aquatic ecosystem and combination of flocculation and capping. The results suggested that this strategy contributed to an approximately 98% algae removal and sustainably improved dissolved oxygen (DO) in the water and sediment after the 40-day incubation. The aerobic condition at the sediment-water interface and deeper oxygen penetration in the sediment inhibited the abundance of microorganisms related to anaerobic CH4 production, then changed the metabolic pathway and fate of algal carbon. After the 40-day incubation, compared with flocculation-capping treatments, the bio-pump reduced 69.07% CH4 and 77.57% CO2 emissions, which was jointly contributed by the inhibition of anaerobic CH4 production, aerobic oxidation of CH4 and carbon sequestration of submerged macrophytes. This was also demonstrated from the finding of a decrease in methyl coenzyme M reductase (mcrA) gene, an increase in particulate methane monooxygenase (pmoA) gene and the absorption of 13C-labeled from algae biomass by submerged macrophytes at the end of incubation. Therefore, the bio-pump established in the present study can improve DO in algal blooms water and turn algal-derived organic matter into the plant biomass, which supplied a sustainable method for algae removal and GHG reduction.

Fabrication of heterostructured Ag/AgCl@g-C3N4@UIO-66(NH2) nanocomposite for efficient photocatalytic inactivation of Microcystis aeruginosa under visible light

In this work, a novel Ag/AgCl@g-C3N4@UIO-66(NH2) heterojunction was constructed for photocatalytic inactivation of Microcystis aeruginosa (M. aeruginosa) under visible light. The photocatalyst was synthesized by a facile method and characterized by XRD, SEM, TEM, BET, XPS, FT−IR, UV–vis DRS, PL and EIS. The nanocomposite can not only provide lots of active sites, but also improve capacities to utilize visible-light energy and effectively transfer charge carriers, thus enhancing removal efficiencies of cyanobacteria (99.9% chlorophyll a was degraded within 180 min). Various factors in photodegradation of chlorophyll a were studied. Besides, changes on cellular morphologies, membrane permeability, physiological activities of M. aeruginosa during photocatalysis were investigated. Moreover, the cycle test indicated that Ag/AgCl@g-C3N4@UIO-66(NH2) exhibits excellent reusability and photocatalytic stability. Finally, a possible mechanism of M. aeruginosa inactivation was proposed. In a word, Ag/AgCl@g-C3N4@UIO-66(NH2) can efficiently inactivate cyanobacteria under visible light, thus providing useful references for further removal of harmful algae in real water bodies.

Isolation and Identification of Two Algae-Lysing Bacteria against Microcystis aeruginosa

Algae blooms present an environmental problem worldwide. In response to the outbreak of harmful algal blooms in cyanobacteria, the role of biological control has drawn wide attention, particularly for algicidal bacteria. The mechanism underlying algicidal activity was determined in our study. Algae-lysing bacteria used were separated from water and sediment collected from the Fenhe scenic spot of Taiyuan. Genetic and molecular identification was conducted by polymerase chain reaction amplification based on 16S rDNA gene. These bacterial strains were identified as Raoultella planticola and Aeromonas sp. The algae-lysing characteristics were evaluated on Microcystis aeruginosa. For the two algicidal bacteria, the high inoculation ratio (&gt;8%) of bacteria strains contributed to the lytic effect. M. aeruginosa could be completely removed by these strains at different cell ages. However, the time used decreased with an increase in cell age. The removal rate was increased while M. aeruginosa was in the lag and logarithmic phases. The earlier bacteria strains could be inoculated, the sooner all algae could be removed. Both algicidal substances were protein, which could destroy the photosynthetic systems and break the cell of M. aeruginosa. The algicidal bacteria strain has important theoretical and practical significance for economic and feasible algae removal and provides good germplasm resources and technical support for the control of cyanobacterial bloom.

Improved Cyanobacteria Removal from Harmful Algae Blooms by Two-Cycle, Low-Frequency, Low-Density, and Short-Duration Ultrasonic Radiation

Harmful algae blooms (HAB) in eutrophic lakes and rivers have become serious water quality problems that are difficult to eliminate using common methods. Previous research has demonstrated that powerful ultrasound can somewhat control cyanobacteria in HABs; however, effective and energy-efficient settings for ultrasonic parameters have not yet been rigorously determined. The results of this study showed that the effect of cyanobacteria removal was enhanced with ultrasonic frequencies, densities, and radiation durations of 20–90 kHz, 0.0005–0.1 W/mL and 0.5–10 min, respectively. Our analyses further demonstrated that the effective distance of ultrasound decreased with increasing frequency, and that damaged algae cells were able to repair themselves at low ultrasonic densities. To address the high energy consumption and small effective distance of conventional ultrasonic radiation treatments, we proposed a new cyanobacteria removal method based on two applications of low-frequency, low-density and short-duration ultrasonic radiation. We defined the energy effectiveness factors of ultrasonic radiation for algae removal as the algae removal rate divided by ultrasonic dosage. This method yielded an 87.6% cyanobacteria removal and the highest energy effectiveness factor, suggesting that two cycles of treatment provide a low-energy method for enhancing existing algae-removing technologies used in large bodies of water.

Remediation of Polluted River Water by Biological, Chemical, Ecological and Engineering Processes

Selection of appropriate river water treatment methods is important for the restoration of river ecosystems. An in-depth review of different river water treatment technologies has been carried out in this study. Among the physical-engineering processes, aeration is an effective, sustainable and popular technique which increases microbial activity and degrades organic pollutants. Other engineering techniques (water diversion, mechanical algae removal, hydraulic structures and dredging) are effective as well, but they are cost intensive and detrimental to river ecosystems. Riverbank filtration is a natural, slow and self-sustainable process which does not pose any adverse effects. Chemical treatments are criticised for their short-term solution, high cost and potential for secondary pollution. Ecological engineering-based techniques are preferable due to their high economic, environmental and ecological benefits, their ease of maintenance and the fact that they are free from secondary pollution. Constructed wetlands, microbial dosing, ecological floating beds and biofilms technologies are the most widely applicable ecological techniques, although some variabilities are observed in their performances. Constructed wetlands perform well under low hydraulic and pollutant loads. Sequential constructed wetland floating bed systems can overcome this limitation. Ecological floating beds are highly recommended for their low cost, high effectiveness and optimum plant growth facilities.

Facilitating harmful algae removal in fresh water via joint effects of multi-species algicidal bacteria

Harmful algae blooms posing serious threats to the ecological environment occur frequently across the world. Multi-species algicidal bacteria were enriched by utilizing immobilized carriers in a pilot scale experiment, which significantly promoted the effect of algal control in the reactors. Under the optimal condition, the algicidal ratio and chlorophyll a degradation rate reached 87.69% and 47.00 μg/(L·d), respectively. The growth of Cyanophyta, diatom, Dinoflagellate and Cryptophyta was inhibited significantly by the joint action of algicidal bacteria and light shading of fillers, accounting for 53.74% and 36.47%, respectively. The results of 16S rRNA high-throughput sequencing suggested algicidal bacteria (10.17%) belonging to 13 genera were enriched. Among the algicidal process, Bacillus and Pseudomonas played crucial roles. Fluorescence spectroscopy and UV254 were adopted to assess the release of dissolved organic matter (DOM) and the precursors of disinfection by-products (DBPs). Two efficient algicidal strains (C1, C4) were isolated which showed high homology with Enterobacter asburiae JCM6051(T) and Pseudomonas simiae oli(T), respectively. This study provided new insights into the in-situ bioremediation of eutrophication in fresh water.

Enhancement of superoxide evolution by nickel-doped for the removal of organic pollutants and cyanobacteria

Organic pollutants and cyanobacteria exist in water widely, which make significant impacts on human health so that appropriate methods are needed for their removal. In this work, Ni doped Bismuth oxychloride (BiOCl) photocatalysts were successfully synthesized by a simple hydrothermal method. The light absorption and charge carriers separation involved in superoxide (·O2−) generation can be optimized with the introduction of Ni element. And photocatalytic degradation experiments showed that the 9% Ni-BiOCl enhanced photodegradation activity of organic matter (Rh B and BPA) as well as M. aeruginosa. The degradation efficiency of Ni-BiOCl on the removal of Rh B and BPA were approximately 34.99% and 57% higher than that of pristine BiOCl. Furthermore, the algae inactivation was systematically studied by three-dimensional fluorescence spectrum. Results showed that ·O2− acted an irreplaceable role among the experiment of photocatalytic algae removal, and the details were described as ·O2− and h+ first destroyed the cell wall of M. aeruginosa, secondly inactivated the active fluorescent substances in the cell, and then catalyzed the oxidation of intracellular exudates such as chlorophyll and phycocyanin as inorganic substances. This study provides a multifunctional catalyst for controlling water pollution and environmental restoration.

An investigation of mechanisms for the enhanced coagulation removal of Microcystis aeruginosa by low-frequency ultrasound under different ultrasound energy densities

There is a lack of studies elaborating the differences in mechanisms of low-frequency ultrasound-enhanced coagulation for algae removal among different ultrasound energy densities, which are essential to optimizing the economy of the ultrasound technology for practical application. The performance and mechanisms of low-frequency ultrasound (29.4 kHz, horn type, maximum output amplitude = 10 μm) -coagulation process in removing a typical species of cyanobacteria, Microcystis aeruginosa, at different ultrasound energy densities were studied based on a set of comprehensive characterization approaches. The turbidity removal ratio of coagulation (with polymeric aluminum salt coagulant at a dosage of 4 mg Al/L) was considerably increased from 44.1% to 59.7%, 67.0%, and 74.9% with 30 s of ultrasonic pretreatment at energy densities of 0.6, 1.11, and 2.22 J/mL, respectively, indicating that low-frequency ultrasound-coagulation is a potential alternative to effectively control unexpected blooms of M. aeruginosa. However, the energy density of ultrasound should be deliberately considered because a high energy density (≥18 J/mL) results in a significant release of algal organic matter, which may threaten water quality security. The specific mechanisms for the enhanced coagulation removal by low-frequency ultrasonic pretreatment under different energy densities can be summarized as the reduction of cell activity (energy density ≥ 0.6 J/mL), the slight release of negatively charged algal organic matter from cells (energy density ≥ 1.11 J/mL), and the aggregation of M. aeruginosa cells (energy density ≥ 1.11 J/mL). This study provides new insights for the ongoing study of ultrasonic pretreatment for the removal of algae via coagulation.

Removal of Microcystis aeruginosa and control of algal organic matter by Fe(II)/peroxymonosulfate pre-oxidation enhanced coagulation

Fe(II)/Peroxymonosulfate (PMS) pre-oxidation enhanced coagulation was investigated to remove Microcystis aeruginosa (M. aeruginosa) in this study. When the initial algae cell concentration was 1.0 × 106 cells/mL, the highest removal efficiency of algae cells (94.3%) was achieved with lower chemical dosage (e.g. 20 mg/L PMS and 4.5 mg/L Fe(II)). During the pre-oxidation, the release of K+ and death rate of algae cells were lower, meanwhile, relative intact cellular structure was remained. Sulfate radical (SO4•−) was the predominant radical species to facilitate algae removal by decreasing zeta potential in the Fe(II)/PMS system. The majority of algal organic matter (more than 83% of proteins and 76% of polysaccharides) was eliminated after coagulation and sedimentation, indicating that the potential of disinfection by products (DBPs) formation was decreased. Furthermore, Fe(II)/PMS process was optimized by response surface methodology (RSM) according to central composite design (CCD), the higher removal efficiency of M. aeruginosa with lower reagent cost under optimal conditions were obtained. This study provides a promising method of eliminating M. aeruginosa and controlling algal organic matter effectively in eutrophic water.

Algae removal performance of UV-radiation-enhanced coagulation for two representative algal species

Algal blooms severely impact the ecological environment and human health, as well as drinking water supplies and treatment systems. This study investigated UV-radiation-enhanced aluminum (Al)-based coagulation for the removal of two representative algal species (Microcystis aeruginosa and Cyclotella sp.) which are responsible for most fresh water algal bloom in different seasons. The results demonstrated that the UV-Al process can enhance algae removal, and simultaneously control algal organic matter (AOM) release. Comparing with Microcystis aeruginosa, Cyclotella sp. was more sensitive to UV irradiation and its activity was severely inhibited by 240 s of UV irradiation; intracellular reactive oxygen species (ROS) increased sharply then decreased rapidly, and SEM images showed cell walls exhibited substantial compression. UV irradiation decreased the zeta potential, which might have contributed to algae removal. Approximately 93.5% of Microcystis aeruginosa cells and 91.4% of Cyclotella sp. cells were removed after 240 s of UV irradiation with 0.4 mmol/L Al. The MCs concentrations after Al coagulation were low (<100 ng/L). The DOC of Microcystis aeruginosa and Cyclotella sp. was also lower (1.2 and 1.6 mg/L, respectively) than the national standard level after UV-Al process. This study highlights the practical application of UV irradiation for enhancing algae removal and simultaneously controlling AOM release in water treatment plants, which is a simple and promising technology. This result also indicates that the water treatment parameters should be adjusted according to the algae species present in different seasons, especially for diatom which needs low UV irradiation and Al dosage.

Interfacial catalytic oxidation for membrane fouling mitigation during algae-laden water filtration: Higher efficiency without algae integrity loss

Membrane fouling remains a significant issue in algae removal during membrane filtration. We constructed an interfacial catalytic oxidation membrane to mitigate membrane fouling caused by microalgae. Specifically, zero-valent iron (ZVI) nanoparticles (NPs) were immobilized on polycarbonate (PC) membrane to activate peroxymonosulfate (PMS). The activated PMS can oxidize extracellular organic matter (EOM) near the membrane surface and result in better filtration performance. The optimal ZVI NPs coated PC membrane with 0.1 mM PMS exhibited excellent anti-fouling property during the filtration of Chlorella v. suspension. The membrane performance can stay stable at least in five algae-laden water filtration cycles by regenerating ZVI NPs. Moreover, the interfacial oxidation only happened on the membrane surface, thereby minimizing algae cell breakage and associated disinfection by-products formation potential (DBPFP) in comparison with traditional in situ pre-oxidation. Indeed, no severe cell breakage was observed with the PMS dosages of less than 0.2 mM. The new interfacial catalytic oxidation strategy proposed here paves a sustainable way to the treatment of algae-laden water.

Inactivation of harmful Anabaena flos-aquae by ultrasound irradiation: Cell disruption mechanism and enhanced coagulation

Harmful algal blooms pose a potential threat to the safety of drinking water sources. Ultrasound is an effective method for algae removal. However, this method can lead to the release of algal organic matter and the effects and toxic mechanisms of ultrasound on Anabaena are still poorly understood. The destruction mechanism of Anabaena flos-aquae cells under different ultrasonic conditions, the safety of intracellular organic matter (IOM) release to water and the enhanced coagulation efficiency of ultrasound were studied. Results showed that high-frequency ultrasound was effective in breaking down algae cells. After 10 min ultrasonication at 20 kHz, 5 min at 740 kHz and 1 min at 1120 kHz, the algae cells were inactivated and algae growth was halted. Ultrasound radiation can lead to the release of IOM, primarily chlorophyll a and phycocyanin, followed by some tryptophan and humic substances, polysaccharides, and proteins. The sonicated ribosomes were considerably reduced, and the antioxidant system of cells was also damaged to some extent. The coagulation effect of algae cells was substantially improved after ultrasonication. Thus, the safety of algae cell removal could be improved by controlling the changes in physiological structure and IOM release of algae cells by adjusting the ultrasound parameters.

알칼리수를 활용한 연속식 조류제거에 관한 연구

알칼리수를 활용한 연속식 조류제거에 관한 연구

Simple, Cheap and Low Waste System for Drinking Water Treatment Using Fabricated Polymeric Spiral Wound Ultrafiltration Modules

Simple, cheap and low waste system for drinking water treatment was designed and installed as a pilot system. Ultrafiltration polymeric membranes were prepared using polyvinylchloride and polyvinylidene difluoride. The membranes were prepared by phase inversion process and were characterized by scan electron microscope, mechanical testing and membrane performance test. Spiral wound polymeric membranes modules were fabricated and used in fabricated pilot system. Continuous tap water stream was used in this experiment for six months. The results indicated that PVC spiral wound membrane module provides high productivity 9.36 m3/d, with organic removal (COD) 100%, blue green algae removal 100%, 95.7% for total algae removal and clear bacteria from water efficiently. The results of this study affirm that none of the water quality parameters (chemical or biological) that were monitored in this study exceeded the Standard Specification for Egyptian Drinking Water.

β-cyclodextrin improve the tolerant of freshwater algal Spiny Scenedesmus to chiral drugs venlafaxine and its metabolite

This study based on the freshwater algae Spiny scenedesmus (S. scenedesmus) with tolerance to venlafaxine aiming to investigate algae removal abilities. Here presented for the first time to evaluate the effect of β-cyclodextrin (β-CD) on reduce toxicity and enhance removal ability of venlafaxine and O-desmethylvenlafaxine to S. scenedesmus. Based on dose-response results, the toxicity of R-venlafaxine (EC50 = 6.81 mg·L −1) and R-O-desmethylvenlafaxine (EC50 = 3.36 mg·L −1) to algae were more than two times than those in the presence of β-CD treatment (10.64 mg L −1 for R-venlafaxine and 11.87 mg L −1 for R-O-desmethylvenlafaxine). The significant differences were observed between S-venlafaxine (11.07 mg L −1) and S-O-desmethylvenlafaxine (10.24 mg L −1), which were more toxic than R-forms. The half-lives of R- and S-venlafaxine were 0.8 d and 0.5 d in the presence of β-CD, which were obvious shorter than those in alone treatments. In addition, our experiments not only demonstrated that β-CD performed particularly well for removal of venlafaxine and O-desmethylvenlafaxine, it significantly reduces the toxicity of venlafaxine to alga. These results highlight advantages of β-CD relevant to chiral drugs removal and protection of aquatic organisms, which may have a better application for environmental and ecological safety in future.

Control of Nuisance Cyanobacteria in Drinking Water Resources Using Alternative Algae-Blocking Mats

The water intake facility of Paldangho Lake (PIF), constructed in 1988, supplies drinking water to the Seoul metropolitan area and satellite city (ca. 20 million inhabitants) in South Korea. A nuisance cyanobacterial bloom (CB) has been observed every year in the PIF. Thus, related governments have been funding the control of CBs and algal-originated materials (AOMs). In this study, an algae-blocking mat (ABM) was developed to protect against CBs and AOMs considering temperature and water depth. We evaluated the daily and monthly performance of the ABM on phytoplankton, pH, dissolved oxygen, chlorophyll-a, and light intensity between April and October 2015. Although the average cell abundance of cyanobacteria between July and September approached the warning level of the Korea alert system, the highest algal removal efficiency was recorded as 92% in August when the cyanobacterial cells were over 66,000 cells/mL. On average, the ABM showed a low removal efficiency of 26% on both geosmin and 2-methylisoborneol, whereas total phytoplankton was more than 30%. In conclusion, our results indicate that the ABM may be an economical blocking tool for nuisance cyanobacteria in drinking water resources, considering AOMs and total phytoplankton.

Improving energy efficiency of pretreatment for seawater desalination during algal blooms using a novel meshed tube filtration process

A new meshed tube filtration (MTF) process was developed and assessed as a low energy-consuming pretreatment process that withstands algal blooms (i.e., red tide). This process can potentially replace the dissolved air flotation (DAF) process in typical seawater reverse osmosis (SWRO) desalination plants. Two marine microalgae species, namely C. polykrikoides and T. suecica, were first cultivated and then utilized to simulate algal bloom conditions in the lab-scale filtration experiments. The algal matter was coagulated and circulated by aeration in the MTF system that was filled with cylindrical polypropylene meshed tubes with ciliary ends and had the ability to capture coagulated algae in an effective manner. The efficiency of the MTF process to remove algal cells was significantly enhanced by optimizing the coagulant dose and the aeration rate. In order to further verify the MTF performance, DAF experiments were conducted, under similar conditions, for the comparison of algal removal effectiveness and energy consumption rates. The results showed high removal rates of algal cells as well as turbidity for MTF, although only a limited reduction of algal organic matter (AOM) was observed. When DAF was operated at energy consumption levels equivalent to MTF, its algae removal rate was lower than that of MTF. Furthermore, under optimal operating conditions, MTF consumed approximately one-third of the energy needed for DAF operation, mainly due to the fact that MTF requires less aeration. For future improvements in the AOM removal process, an energy-efficient pretreatment process could be realized for SWRO desalination facilities facing potential algal blooms.

Dynamics of algae blooming: effects of budget allocation and time delay

Algal blooms are increasing in coastal waters worldwide. The study on the features of algal pollution in water bodies and the ways to eliminate them is of vital importance. Preventing, treating, and monitoring algal blooms can be an unanticipated cost for a water system. To tame algal bloom in a lake, the government provides funds through budget allocation. In this paper, we propose a mathematical model to investigate the effect of budget allocation on the control of algal bloom in a lake. We assume that the growth of budget follows logistic law and also increases in proportion to the algal density in the lake. A part of the budget is utilized for the control of inflow of nutrients, while the remaining is used in the removal of algae from the lake. Our results show that algal bloom can be mitigated from the lake by reducing the inflow rate of nutrients to a very low value, which can be achieved for very high efficacy of budget allocation for the control of nutrients inflow from outside sources. Also, increasing the efficacy of budget allocation for the removal of algae helps to control the algal bloom. Further, more budget should be used on the control of nutrient’s inflow than on the removal of algae, as the presence of nutrients in high concentration will immediately proliferate the growth of algae. Moreover, the combined effects of controlling the inflow of nutrients and removing algae at high rates will result in nutrients and algae-free aquatic environment. Further, we modify the model by considering a discrete time delay involved in the increment of budget due to increased density of algae in the lake. We observe that chaotic oscillations may arise via equilibrium destabilization on increasing the values of time delay. We apply basic tools of nonlinear dynamics such as Poincare section and maximum Lyapunov exponent to confirm the chaotic behavior of the system.

Efficiency and mechanisms of simultaneous removal of Microcystis aeruginosa and microcystins by electrochemical technology using activated carbon fiber/nickel foam as cathode material

The significant removal efficiency of microcystis aeruginosa was presented using Pt/Ti anode and activated carbon fiber/nickel foam (ACF/Ni) cathode by addition of Fe2+ slightly in a wide range of initial pH (3–9). Results showed that about 93% of the Microcystis aeruginosa cells were removed within 15 min for Pt/Ti-ACF/Ni–Fe2+ system. Dosage of Fe2+, current density, and initial pH had remarkable effects on the removal efficiency of microcystis aeruginosa. The mechanism of algae removal in the Pt/Ti-ACF/Ni–Fe2+ electrochemical system was revealed by the comparison between Pt/Ti-ACF/Ni–Fe2+ process and classical Fenton process, the analysis on Microcystis aeruginosa and ACF/Ni by SEM, the specific surface area and pore size analysis of ACF, and the determination of UV254, OD620 and microcystin-LR (MC-LR). Results showed that the main mechanism of this system was the electro-Fenton process, which was accompanied by electro-adsorption, electro-floatation, and electro-coagulation process. And the cooperation mechanism on the electrochemical removal system was further speculated. With the breakdown of algal cells during the electrolysis, the MC-LR and other substances released from the cells were effectively degraded. Besides, the new cathode exhibited favorable and stable reusability. This study built up a high-efficiency algae removal system, which broke through the limits of narrow working pH range and large consumption of exogenous chemicals in electro-Fenton process.