Maximum Flocculation Efficiency Research Articles

Study on the flocculation mechanism of a bioflocculant from Acinetobacter sp. TH40 combined with graphene oxide for the removal of metal ions from water.

In order to realize the simultaneous removal of nine metal ions from water, in this study, an excellent flocculant suitable for the simultaneous removal of multiple metal ions in water was developed by using the excellent flocculation properties of graphene oxide (GO) combined with biological flocculants. First, this study investigated the concentrations and pollution levels of nine metal pollutants in surface water and groundwater of a typical city in central China. The maximum concentrations of these nine metal ions were Al 0.29, Ni 0.0325, Ba 0.948, Fe 1.12, As 0.05, Cd 0.01, Zn 1.45, Mn 1.24, and Hg 0.16 (in mg/L). Second, the three-dimensional structure diagram of GO was established. Gaussian16W software and the pm6D3 semi-empirical method were used to analysis the structure and the vibration of GO. The B3LYP function and basis set DEF2SVP was used to calculate the single point energy. Third, with varying the flocculation time, it was found that the maximum flocculation efficiency could reach more than 80.00% under the optimal conditions, that is, with a metal ion mixture of 20mg/L. The optimal dosage of GO was 15mg/L. The optimal time for bioflocculation efficiency was 2.5h, and the optimal concentration of bioflocculant was 3mg/L. The optimal flocculation efficiency was 82.01% under the optimal conditions.

Growth of Dunaliella viridis in multiple cycles of reclaimed media after repeated high pH-induced flocculation and harvesting

Minimizing the use of water for growing microalgae is crucial for lowering the energy and costs of animal feed, food, and biofuel production from microalgae. Dunaliella spp., a haloterant species that can accumulate high intracellular levels of lipids, carotenoids, or glycerol can be harvested effectively using low-cost and scalable high pH-induced flocculation. However, the growth of Dunaliella spp. in reclaimed media after flocculation and the impact of recycling on the flocculation efficiency have not been explored. In this study, repeated cycles of growth of Dunaliella viridis in repeatedly reclaimed media from high pH-induced flocculation were studied by evaluating cell concentrations, cellular components, dissolved organic matter (DOM), and bacterial community shifts in the reclaimed media. In reclaimed media, D. viridis grew to the same concentrations of cells and intracellular components as fresh media—107 cells/mL with cellular composition of 3 % lipids, 40 % proteins, and 15 % carbohydrates—even though DOM accumulated and the dominant bacterial populations changed. There was a decrease in the maximum specific growth rate and flocculation efficiency from 0.72 d−1 to 0.45 d−1 and from 60 % to 48 %, respectively. This study shows the potential of repeated (at least five times) flocculation and reuse of media as a possible way of reducing the costs of water and nutrients with some tradeoffs in growth rate and flocculation efficiency.

A Chitosan-Based Flocculation Method for Efficient Recovery of High-Purity B-Phycoerythrin from a Low Concentration of Phycobilin in Wastewater.

Increasing the yield and purity of B-phycoerythrin (B-PE) can improve the economic state of microalgae industrial processing. One method of cost reduction involves the recovery of remaining B-PE from wastewater. In this study, we developed a chitosan (CS)-based flocculation technique for the efficient recovery of B-PE from a low concentration of phycobilin in wastewater. We investigated the effects of the molecular weight of chitosan, B-PE/CS mass ratio, and solution pH on the flocculation efficiency of CS and the effects of phosphate buffer concentration and pH on the recovery rate of B-PE. The maximum flocculation efficiency of CS, recovery rate, and purity index of B-PE were 97.19% ± 0.59%, 72.07% ± 1.37%, and 3.20 ± 0.025 (drug grade), respectively. The structural stability and activity of B-PE were maintained during the recovery process. Economic evaluation revealed that our CS-based flocculation method is more economical than the ammonium sulfate precipitation method is. Furthermore, the bridging effect and electrostatic interaction play important roles in B-PE/CS complex flocculation process. Hence, our study provides an efficient and economical method to recover high-purity B-PE from a low concentration of phycobilin in wastewater, which promoted the application of B-PE as a natural pigment protein in food and chemical applications.

Evaluating the performance of bridging-assembly chelating flocculant for heavy metals removal: Role of branched architectures

A novel chelating flocculant with branched architectures, polyacrylamide grafted maleoyl chitosan-mercaptoacetic acid (PAM-g-M(CS-MA)), was successfully fabricated using maleic anhydride as the “bridge” between chitosan and polyacrylamide. The functional groups and structural characteristic information of copolymers were obtained via characterization analysis. Flocculation performance was systematically investigated via purifying a series of simulated wastewater containing Cu or Cd. The properties of the flocs were studied to give in-depth evidences for the role of chelation groups and branched architectures in flocculation. Results indicated that PAM-g-M(CS-MA) showed excellent flocculation capacity for heavy metals in high concentrations and was superior to other chelating flocculants. The maximum flocculation efficiency of Cu (93.90%) and Cd (92.47%) was achieved by PAM-g-M(CS-MA) at pH 7, dosage of 100 mg L−1 and stirring speed of 90 rpm. The flocculation mechanisms of PAM-g-M(CS-MA) were deeply explored through the analyses of floc properties. The strong synergistic chelation of mercapto, carboxyl, amide and hydroxyl groups predominated for the capturing of heavy metals; and the branched architectures facilitated the formation of large and stable flocs via adsorption and bridging-furl effect. This study provided a solid foundation for the fabrication of flocculants for heavy metal wastewater treatment.

Response surface methodology to optimize self-flocculation harvesting of microalgae Desmodesmus sp.CHX1

ABSTRACT This study aims to optimize the self-flocculation ability of microalgae Desmodesmus sp. CHX1 by the response surface methodology (RSM). Key parameters (i.e. pH, temperature and flocculation time) that significantly affected the Desmodesmus sp.CHX1 flocculation were determined. Results show that the flocculation efficiency of Desmodesmus sp.CHX1 increased in response to the prolonged settling time, particularly within the first 6 h, given the secretion of extracellular polymers. The RSM result suggested that both temperature and time exerted more significant effects on flocculation efficiency than solution pH. In specific, the maximum flocculation efficiency could reach 94.0% under the optimal conditions with the temperature, time and pH of 12.37°C, 6.96 h and 7.98, respectively. Validation experiments further indicated the reliability of the optimal parameter conditions.

Flocculation characteristics of anaerobic sludge driven-extracellular polymeric substance (EPS) extracted by different methods on microalgae harvesting for lipid utilization

Microalgae harvesting is the crucial step in algal biofuel production, which accounts 20–30% of the total production cost. The present study investigates the potentiality of anaerobic sludge-driven extracellular polymeric substance (EPS) as a bioflocculant. Five different methods, including physical and chemical, have been employed for EPS extraction from anaerobic sludge. Chemically extracted EPS showed better performance in microalgae harvesting as compared to physical ones. Maximum flocculation efficiency of 91.8 % was obtained using 30 mL L−1 EPS (0.40 g EPS g−1 biomass) extracted by formaldehyde-NaOH. However, microalgal lipid content was drastically decreased using chemically extracted EPS. In contrast, EPS extracted by thermal method had no significant effect on lipid recovery. Combining the bioflocculation performance and the lipid recovery suggests that the thermally extracted EPS was the most suitable for microalgae dewatering. Kinetic analysis revealed that pseudo-second-order kinetics (R2 = 0.979 – 0.999) and intra-particle diffusion (R2 = 0.974 – 0.986) are the most qualified for modeling of microalgal flocculation. Cost analysis showed that the cost of microalgae harvesting using EPS extracted by the thermal method was USD 1.95 and USD 4.9 for the recovery of 1 kg biomass and that of 1 kg lipid, respectively. The study was an attempt to develop a suitable microalgae harvesting technique using bio-based flocculant derived from a renewable resource.

Flocculation performance and mechanism of fungal pellets on harvesting of microalgal biomass

In this study, a bioflocculation method assisted by fungal pellets was developed for highly efficient microalgae harvesting. Effects of critical parameters, including flocculation type, temperature, rotation speed and initial pH, on the bioflocculation of fungal Aspergillus niger for microalgae Scenedesmus sp. were investigated. Results showed that the maximum flocculation efficiency of 99.4% was obtained when the fungal pellets were inoculated in the algal solution at the initial pH of 8.0, temperature of 30 °C and rotation speed of 160 rpm for 48 h in BG-11 medium. Furthermore, microscopy examination, scanning electron microscopy, Fourier transform infrared spectroscopy, Zeta potential measurement and three-dimensional excitation emission matrix fluorescence spectroscopy were used to explore the mechanism of bioflocculation process. It was found that the interaction of fungi and microalgae was related to the surface functional groups of fungal pellets. This study provides a interpretation of conceivable mechanism for microalgal bioflocculation by fungal pellets.

Harvesting of marine microalgae using cationic cellulose nanocrystals

Flocculation of marine microalgae is challenging because of the high ionic strength of the culture medium. We investigated cationic cellulose nanocrystals (CNCs) as biobased flocculants for the marine microalgae Nannochloropsis oculata, and compared its performance to chitosan. Cationic CNCs induced flocculation at a low dose of 11 mg L-1, while chitosan required a dose of 35 mg L-1. Our cationic CNCs possess a permanent positive charge, allowing flocculation over a wide pH-range (4 to 10). The CNC maximum flocculation efficiency was 90 %, while chitosan achieved > 95 %, attributed to small flocs remaining in suspension for CNCs. However, centrifugation for 1 min at 180 g or gravity filtration using a 30 μm nylon filter after CNC flocculation resulted in the removal of these small, stable flocs (∼150 μm diam) and > 95% harvesting efficiency. Cationic CNCs can thus serve as a sustainable alternative natural flocculant for harvesting both freshwater and marine microalgae.

Evaluation of flocculation characteristics and biodegradation studies of reduced gum rosin and psyllium‐based hydrogel

AbstractPresent study explored the swelling behavior, biodegradability and flocculation efficiency of hydrogel polymer based on renewable backbones‐psyllium and gum rosin. Swelling studies revealed that the polymer sample exhibit pH and temperature‐dependent swelling behavior. The polymer sample was assessed for its flocculation efficiency by optimizing the process parameters such as polymer dose, pH, and temperature. The polymer sample illustrated the maximum flocculation efficiency of 96% in 500 mg/L kaolin suspension under optimized experimental conditions. Investigation of biodegradation behavior was carried out using the soil burial and composting method. The percentage degradation of the polymer sample was observed to be 86.8% and 90.4% in 63 days using soil burial and composting method, respectively. The progress of biodegradation was analyzed through Fourier transform infrared and scanning electron microscopy techniques. Thus, the polymer sample was found to be cost effective, eco‐friendly, biodegradable material that has significant flocculation characteristics, and hence can be utilized for treatment of kaolinated wastewater.

Click chemistry to synthesize exfoliated xylan-g-quaternized chitosan/montmorillonite nanocomposites for retention and drainage-aid

In order to obtain new retention and drainage-aid agent, exfoliated xylan-g-QCS/MMT nanocomposites were prepared. Briefly, quaternized chitosan azide (QCS-N3) was intercalated into the layer of montmorillonite (MMT) to enlarge the interplanar gallery; subsequently, QCS-N3/MMT was grafted with xylan by click chemistry, during this process, the interlayer space of MMT was further increased till exfoliated. Subsequently, the exfoliated xylan-g-QCS/MMT was evaluated to act as retention and drainage-aid agent. The initial critical concentration of xylan-g-QCS/MMT was 0.01 mg/g in the adsorption behavior on cellulosic substrate. The maximum flocculation efficiency for CaCO3 was 37.41%. When dosages were about 0.01 mg/g, oSR values were the lowest. All these results show that retention and drainage-aid performance of xylan-g-QCS/MMT was better than only xylan, QCS or MMT. The study combined three kinds of natural resources to prepare organic/inorganic nanocomposites, providing a new method to develop papermaking additive and achieve high-value utilization of natural resources.

Characterization and flocculation evaluation of a novel carboxylated chitosan modified flocculant by UV initiated polymerization

In this work, carboxylated chitosan modified flocculant (CC-g-PCD) was prepared by graft copolymerization technique to enhance the charge-attracting and adhesion of bridges and net-sweeping capacity of flocculants. The dimethyldiallylammonium chloride (DMDAAC), carboxylated chitosan (CMCS), and 3-chloro-2-chloropropyltrimethylammonium chloride (CTA) were utilized for synthesis of CC-g-PCD via photopolymerization techniques. The synthesized CC-g-PCD was characterized by 1H NMR, SEM, XRD, and FTIR, and the characteristic groups on the main chain and surface morphological structure of CC-g-PCD were investigated. The obtained results indicated that CTA and DMDAAC were successfully grafted into the CPCTS. In ordered to evaluate the flocculation performance of CC-g-PCD at various dosages, stirring intensity (G value), and pH value by detecting Chl a, COD, and turbidity, the actual lake water that contains algae was used for flocculation assessment tests. The experimental results of the water sample with flocculation showed that the maximum flocculation efficiency of turbidity (91.1%), Chl a (97.2%), and COD (97.0%) can be achieved by CC-g-PCD at pH 7, G value 200 s−1, and 4.0 mg/L. The comparison results demonstrated that CC-g-PCD had better flocculation efficiency than commercial flocculants. Finally, based on the analysis of algae removal in combination with Zeta potential measurements, the flocculation mechanisms in actual lake water at various dosages and pH values were adsorption bridging and electrical neutralization.

Strategies to increase the potential use of oleaginous microalgae as biodiesel feedstocks: Nutrient starvations and cost-effective harvesting process

Abstract Two locally isolated oleaginous microalgae from Songkhla Lake in Thailand were identified as Micractinium reisseri SIT04 and Scenedesmus obliquus SIT06. The effects of nutrient starvations on the responses of these two strains were intensively investigated in order to increase their lipid contents and manipulate their fatty acid compositions for suitable use as biodiesel feedstocks. Starvation of either phosphorus or ferrous less affected cell growth but did stimulate lipid accumulation of both strains by 1.2 folds. While nitrogen starvation severely limited cell growth but most effectively increased lipid content of both strains by 1.54 folds for M. reisseri SIT04 (up to 36.6%) and by 1.6 folds for S. obliquus SIT06 (up to 56.8%). The lipid accumulated during nitrogen starvation contained higher saturated fatty acids which could make biodiesel with better fuel properties and higher oxidative stability. The harvesting process through bioflocculation was optimized by Response Surface Methodology. The maximum flocculation efficiency greater than 99.5% was achieved using minimum dosage of chitosan as bioflocculant. This study has revealed the strategies to increase the potential use of oleaginous microalgae as biodiesel feedstocks and the cost-effective process for the harvesting of microalgal biomass.

Improvement in electrically induced biomass harvesting of Chlorella sp. MJ 11/11 for bulk biomass production

Oleaginous microalgae could be a promising feedstock for biodiesel production, but their small size, negative surface charge, and diluted suspended biomass create a hindrance in harvesting. In addition, the low value of biofuel makes existing harvesting technologies uneconomical. The aim of the present study was to lower the energy input and investigate the suitability of electroflocculation-sedimentation for harvesting the oleaginous microalga Chlorella sp. MJ 11/11. The Taguchi design of experiments was used to understand the degree of influence of different process parameters (current density, initial pH, biomass concentration, electrode distance, surface/volume ratio, and time) and response surface methodology to determine the suitable conditions for maximization of flocculation efficiency for harvesting using sacrificial ferritic stainless steel (type 430) electrode. Harvested biomass was analyzed by FTIR and SEM to identify the chemical reactivity of functional groups and morphological changes at their surface, respectively. According to the Taguchi analysis, the most influential process parameter was found to be current density followed by initial pH and flocculation time. A multi-parameter interaction study for the maximization of biomass recovery was performed using the response surface methodology. Under the most suitable conditions (current density 11 A m−2, voltage 12 V, initial pH 6, electrode distance 4 cm, medium conductivity 2.52 mS cm−1, and time 30 min), the maximum flocculation efficiency of 98%, sludge volume index (SVI) value of 91, and lowest energy consumption of 1.85 kWh kg−1 or 1.81 kWh m−3 were observed. Thus, electro-harvesting with low energy consumption and high biomass removal can be applied as a promising method for efficient microalgal biomass harvesting.

Photosynthetic carbon uptake induces autoflocculation of the marine microalga Nannochloropsis oculata

Microalgal biomass has been used to produce biofuels, aquaculture feed, high-value chemicals such as pigments and antioxidants, and even human food. This study addresses one of the key bottlenecks to the commercialisation of microalgal bioproducts: the high energy and environmental cost of harvesting microalgal cells out of suspension. An innovative and sustainable autoflocculation procedure was developed to pre-concentrate microalgal biomass for easier harvesting. Microalgal cell agglomeration by autoflocculation at high pH was induced for the first time, without the addition of a chemical flocculant, in the commercially-relevant microalga Nannochloropsis oculata. Photosynthetic inorganic carbon uptake, in the absence of carbon dioxide supply by mass transfer, was used to raise the culture pH. Autoflocculation started at pH9.5 and reached a maximum flocculation efficiency of 90% at pH10.4. Microalgal surface charge-neutralisation by calcium cations, and sweep flocculation by calcium carbonate and calcium phosphate precipitates were identified as the dominant flocculation mechanisms. This was also the first study to measure changes in bacterial community composition under autoflocculation. There was a clear shift from free-living bacteria in suspension to attached bacteria during autoflocculation, with Flavobacteriales becoming the dominant order of bacteria. This highlights the influential role of attached bacteria and bacteria-produced extracellular polymeric substances in microalgal flocculation. This study shows that regulating carbon dioxide supply is a promising green alternative to traditional microalgal flocculation processes as it alleviates the requirement for costly and harmful chemical flocculants and brings us closer to sustainable microalgal bioproducts.

Efficient harvesting of marine Chlorella vulgaris microalgae utilizing cationic starch nanoparticles by response surface methodology

Harvesting involves nearly thirty percent of total production cost of microalgae that needs to be done efficiently. Utilizing inexpensive and highly available biopolymer-based flocculants can be a solution for reducing the harvest costs. Herein, flocculation process of Chlorella vulgaris microalgae using cationic starch nanoparticles (CSNPs) was evaluated and optimized through the response surface methodology (RSM). pH, microalgae and CSNPs concentrations were considered as the main independent variables. Under the optimum conditions of microalgae concentration 0.75gdry weight/L, CSNPs concentration 7.1mgdry weight/L and pH 11.8, the maximum flocculation efficiency (90%) achieved. Twenty percent increase in flocculation efficiency observed with the use of CSNPs instead of the non-particulate starch which can be due to the more electrostatic interactions between the cationic nanoparticles and the microalgae. Therefore, the synthesized CSNPs can be employed as a convenient and economical flocculants for efficient harvest of Chlorella vulgaris microalgae at large scale.

Central Composite Design Model to Study Swelling of GrA-cl-poly(AAm) hydrogel and Kinetic Investigation of Colloidal Suspension

In the present study, the flocculation behavior of crosslinked copolymer GrA-cl-poly(AAm) hydrogel has been studied for the removal of turbidity from waste water. Sodium borohydride has been used for the reduction of the Gum rosin acids by which it gets converted into rosin alcohols. The reduced Gum rosin alcohol was crosslinked by the use of MBA and copolymerized with acrylamide using KPS as a redox initiator. Synthesized sample was then optimized for reaction conditions like reaction time, reaction temperature and the amount of solvent, monomer concentration, initiator concentration and pH of the reaction medium in order to get maximum percentage swelling. Synthesized samples were characterized using Fourier transform infrared spectroscopy, scanning electron of microscopy and X-ray diffraction techniques. Response surface methodology (RSM) based central composite design was used to study the effect of pH of swelling medium and temperature to maximize the percentage swelling. A statistical model (ANOVA) predicted pH 7.0 and temperature 40 °C as optimum operating conditions in order to get maximu swelling. GrA-cl-poly(AAm) hydrogel was found to be pH and temperature sensitive. Kaolin has been employed as a coagulant. The flocculation efficiency of the synthesized polymer was studied as a function of polymer dose, temperature and pH of the solution. GrA-cl-poly(AAm) observed to show maximum flocculation efficiency (95%) with 70mgL−1 polymer dose in pH 5.0 at 30 °C. The adsorption capacity of malachite green dye removal (95%) was also studied with this synthesized polymer. The results validate that GrA-cl-poly(AAm) hydrogel has significant flocculation and dye removal properties and can be employed as an effective and low-cost material for removal of impurities from waste water.

Biodiesel Production from Scenedesmus obliquus Cultivated in Outdoor Conditions at Large Scale

Scenedesmus obliquus was discussed by phycologists as a promising microalga for biodieselproduction based on its biomass and fatty acid productivity. In the present study, S. obliquuswas pilot cultivated for large scale production in a semi continuous culture for three months usingbubbled glass boxes photo- bioreactor. Cultivation of S. obliquus resulted in a maximum biomassproductivity of 0. 59 g L−1 d−1 and maximum esterified fatty acid productivity of 20.37 mg l−1 d−1in (March, April and May), different flocculants for biomass harvest showed maximumflocculation efficiency of 82% using 250 mg l−1 of NaOH for 2 h. Solar drying of the harvestedbiomass showed significant increase of esterified fatty acid content by 50% with respect to control.In addition, fatty acid profile and iodine number of S. obliquus oil meet biodiesel standardspecifications which make the fatty acid of S. obliquus eligible for further research to be used as afeed stock for biodiesel production.

Mechanistically harvesting of Chlorella vulgaris and Rhodotorula glutinis via modified montmorillonoid

In this study, the flocculation process of Chlorella vulgaris and Rhodotorula glutinis induced by inorganic salts modified montmorillonoid was conducted. The maximum flocculation efficiency (FE) of 98.50% for C. vulgaris and 11.83% for R. glutinis were obtained with 4g/L and 5g/L flocculant within the dosage scope of 1–5g/L. The difference of FE was then thermodynamically explained by the extended DLVO theory and the FE of R. glutinis was mechanically enhanced to 90.66% with 0.06g/L cationic polyacrylamide (CPAM) at an optimum pH of 9. After that, aimed to utilize the remainder flocculant capacity, C. vulgaris culture was added to the aggregation of R. glutinis. Fortunately, the coagulation of R. glutinis and C. Vulgaris was achieved with 0.05g/L CPAM and 5g/L flocculant at pH 9 and the FE reached 90.15% and 91.24%, respectively.

Study of ionic charge dependent salt resistant swelling behavior and removal of colloidal particles using reduced gum rosin-poly(acrylamide)-based green flocculant

Present work reports the under pressure preparation of reduced gum rosin and acrylamide-based GrA-cl-poly(AAm) green flocculant. Characterization of the synthesized product was carried out by different techniques such as Fourier transform infrared spectroscopy, X-ray diffraction method and scanning electron microscopy. In addition, several variables such as time, physiological pH, solvent, pressure, monomer, cross-linking agent and initiator were examined to obtain maximum flocculation efficiency and explore the salt resistant swelling of the system. The maximum percentage swelling (P s) at pH 7.0 and pressure 8.0 psi was found to be 578 %. Thermal behavior of the flocculant was investigated and the synthesized sample showed higher thermal stability than the gum rosin. The effect of ionic strength and charges of various cations (Na+, Ba+2, Fe+3, Sn+4) on salt resistant swelling of GrA-cl-poly(AAm) flocculant, in different salt solutions such as sodium chloride, barium chloride, ferric chloride and stannic chloride (NaCl, BaCl2, FeCl3 and SnCl4), was also studied. The synthesized sample was found to show ionic charge and salt concentration related behavior. Further, the removal of colloidal particles from wastewater through flocculation showed that GrA-cl-poly(AAm) exhibited significant flocculation efficiency (95.18 %) at a dose rate of 55 mg at 30 °C and pH 5.0. Flocculant capacity in saline medium was found to be maximum (99 %) at 1 % concentration. Further, increase in saline concentration resulted in decreased flocculant capacity. The kinetics of the aggregation of particles, deflocculation and reflocculation was analyzed through the Smoluchowski classical model based on first-order and second-order kinetics.

Maximum microalgae biomass harvesting via flocculation in large scale photobioreactor cultivation

AbstractThis study evaluated the ability of Tanfloc SG flocculation to recover microalgae biomass cultivated in a tubular photobioreactor using swine wastewater effluent as the culture media in a pilot‐scale microalgae production plant. The objective function was the flocculation efficiency (ηf), which was evaluated by central composite design (CCD) experiments which varied the Tanfloc concentration (TC) and pH. Subsequently, the biomass recoveries of highly efficient flocculants recommended by the literature and the CCD conditions of Tanfloc were compared. The maximum flocculation efficiency (96.7 ± 1.0 %) was obtained for the following optimal conditions: 210 mg/L Tanfloc concentration, pH 7.8. After jar test experiments, the scale‐up of the process was performed by using the best obtained results and applying Tanfloc in a 1 m3 flocculator where the complementary analyses demonstrated efficient nitrogen, carbon, and biomass removal. The flocculation efficiency obtained with Tanfloc was equivalent to that of most conventional flocculants currently used. However, Tanfloc presented the following economic advantages with respect to other flocculants: i) its nontoxic nature allows for low‐cost disposal; and ii) its low market price makes it a promising alternative for harvesting microalgae biomass.