Optimum Coagulation Conditions Research Articles

Mitigation of reverse osmosis membrane fouling by coagulation pretreatment to remove silica and transparent exopolymer particles

The dissolution of silica and transparent exopolymer particles (TEP) can deposit on the membrane surface and cause serious membrane fouling in reverse osmosis (RO) technology. Coagulation, as a common pretreatment process for RO, can effectively intercept pollutants and alleviate membrane fouling. In this study, FeCl3 and AlCl3 coagulants and polyacrylamide (PAM) flocculants were used to explore the optimal coagulation conditions to reduce the concentration of silica and TEP in the RO process. The results showed that the two coagulants had the best removal effect on pollutants when the pH was 7 and the dosage was 50 mg/L. Considering the proportion of reversible fouling after coagulation, the removal rate of pollutants, and the residual amount of coagulation metal ions, the best PAM dosage was 5 mg/L for FeCl3 and 1 mg/L for AlCl3. After coagulation pretreatment, the Zeta potential decreased, and the particle size distribution increased, making pollutants tend to aggregate, thus effectively removing foulants. The removal mechanisms of pollutants by coagulation pretreatment were determined to be adsorption, electric neutralization and co-precipitation. This study determined the best removal conditions of silica and TEP by coagulation and explored the removal mechanism.

High-throughput screening to evaluate optimum coagulation conditions via colloidal stability analysis

Current methods of optimizing the coagulant dosage in wastewater treatment processes typically rely on the use of labor- and material-intensive jar testers, which are inadequate when coagulation processes require frequent adjustments due to variations in properties of the incoming feed. Analytical centrifuges (ACs) employ an integrated optics system that simultaneously monitors the position of the boundary between two separating phases in multiple samples of fairly low volumes (∼2 mL) – thus it was expected that ACs would be ideally suited to study the stability and settling kinetics of coagulation treatment processes. In this study, wastewater samples from a biogas generation facility (known as centrate) were collected in February 2022 (Batch A) and July 2022 (Batch B). A comprehensive screening of the treatment performance for Batch B was conducted at three pHs (5, 6, and 7) and nine concentrations of ferric chloride (0–500 mg-Fe3+/L) – it was found that the front-tracking profiles measured by the integrated optics system could be used to identify the minimal coagulation conditions needed to transition from slow to rapid settling. While the settling velocity was found to be well correlated with the instability index, a dimensionless number between 0 and 1 (where values closer to 1 indicate better separation), it was determined that the percentage of COD removal from the centrate samples increased up to an instability index of approximately 0.5 and then plateaued. Finally, it was found that the front-tracking profiles could be used to estimate the volume of sludge produced at various coagulation conditions. Thus, the results from this study establish ACs as an important screening tool for rapid evaluation of treatment performance while consuming minimal material and time – in this study, a total of 132 screening experiments were conducted using approximately ∼11 L of centrate and ∼6 hours of operator time.

Advanced Treatment of Coking Wastewater by Polyaluminum Silicate Sulfate for Organic Compounds Removal.

Coking wastewater is a typical high-strength organic wastewater, for which it is difficult to meet discharging standards with a single biological treatment. In this study, effective advanced treatment of coking wastewater was achieved by coagulation with freshly prepared polyaluminum silicate sulfate (PASS). The performance advantage was determined through comparison with commercial coagulants including ferric chloride, polyferric sulfate, aluminum sulfate and polyaluminum chloride. Both single-factor and Taguchi experiments were conducted to determine the optimal conditions for coagulation with CODCr and UV254 as indicators. A dosage of 7 mmol/L PASS, flocculation velocity of 75 r/min, flocculation time of 30 min, pH of 7, and temperature of 20 °C could decrease the CODCr concentration from 196.67 mg/L to 59.94 mg/L. Enhanced coagulation could further help to remove the organic compounds, including pre-oxidation with ozonation, adsorption with activated carbon, assistant coagulation with polyacrylamide and secondary coagulation. UV spectrum scanning and gas chromatography-mass spectrometry revealed that the coagulation process effectively removed the majority of organic compounds, especially the high molecular weight alkanes and heterocyclic compounds. Coagulation with PASS provides an effective alternative for the advanced treatment of coking wastewater.

The coagulation behavior and removal efficiency of microplastics in drinking water treatment

As a kind of emerging contaminants, microplastics (MPs) have got great attention due to its worldwide distribution, ecotoxicology and difficult to remove. MPs have already been found in the drinking water because of its low removal efficiency during drinking water treatment. As an important process to remove the particles in water, the coagulation behavior of MPs with different characteristics is still not clear. Besides that, research about the removal of MPs by coagulation is on the initial stage and the results are not consistent. This article studied on the MPs which were hard to be removed during the coagulation by conventional coagulation methods during the drinking water treatment, aimed to found the influence of MPs characteristics on the coagulation behavior, explore the removal efficiency of MPs under optimal coagulation conditions and infer the coagulation mechanisms of MPs. According to the results of this article, size and concentration of MPs both had significant effect on the coagulation, but the size of MPs was the main impact factor, and the category of MPs had no significant effect on the coagulation. After operating condition optimization, the removal efficiency of MPs with size ≥13 μm could reach >70 % by PAC and PAM. During coagulation process, electrical neutralization of PAC played the most important role, the adsorption bridging and net sweeping of PAM could assistant the coagulation.

Improving the Dewaterability of a Filter Press through Optimization of the Coagulation Conditions of Sewage Sludge

This study applied a filter press for dewatering that uses pressure to reduce the water content of sludge generated in sewage treatment plants and evaluated the improvement of dewaterability under various coagulation conditions according to the type of coagulants, amounts, and pH conditions. The improvement of dewaterability was evaluated by measurement of time to filter (TTF), change in zeta potential, and sludge cake generated after filter press dewatering. It was found that under the applied coagulation conditions, inorganic coagulants were suitable for filter press dewatering. The optimum conditions were PAC with a dose of 70 mg/gTS, pH 10 for mixed sludge, and PAC with a dose of 100 mg/gTS, pH 6 for anaerobically digested sludge. Under optimal coagulation conditions, the water content of the sludge cake was 57% and 65%, respectively, marking a reduction by 19-27% compared to conventional centrifuge dewatering.

Experimental studies on the effects of coagulation and adsorption as a pretreatment process on the microfiltration of oily wastewater

Abstract To improve the performance of the membrane process in the treatment of oily wastewater, the combined effects of pretreatment, membrane modification, and optimization of operating parameters on the microfiltration membrane system were investigated. First, coagulation and adsorption were used as pretreatment steps. Polyaluminium chloride and ferric chloride were employed as coagulants, and granular activated carbon was used as an adsorbent. In the optimal coagulation condition (1 g/L polyaluminium chloride, pH 7.5), chemical oxygen demand (COD) was reduced by 96%, while in the optimal adsorption condition, in which large amounts of activated carbon were utilized, 48% of COD was eliminated. A membrane of polyethersulfone containing SiO2-g-polymethacrylic acid (PMAA) nanoparticles was then prepared by the non-solvent-induced phase separation method. To reduce fouling and increase the flux of the membrane, the SiO2 nanoparticles were first activated with amine groups and then PMAA was grafted onto the surface of the particles. Subsequently, the operating parameters were studied to optimize the performance of the polyethersulfone (PES)/SiO2-g-PMAA membrane using the response surface methodology (RSM) method. The results indicated that the flux of the modified membrane for pretreated wastewater was 72.2% higher than that of the PES membrane and non-pretreated wastewater at an optimum pressure of 2 bar and a flow rate of 3.5 L/min.

Camel Milk Curd Properties: Application of a Kiwi Juice as a Coagulant

Background: The transformation of camel milk into cheese is an operation considered very delicate because of several difficulties encountered in achieving coagulation. The present study aims to improve coagulation abilities of camel milk using enzyme extracts from kiwi juice. Methods: The optimum characteristics of extract were determined (pH, temperature and CaCl2 concentration), a fresh cheese was manufactured and the physicochemical and organoleptic qualities were determined. Result: Our results concerning the characterization of the enzymatic extract showed an extraction yield as 63.97%±5.22. The optimum coagulation conditions were: pH=6.6, temperature= 40°C and a volume of used enzymatic extract as 1.5 ml. A fresh cheese was made from camel milk with a particular nutritional quality and consistency. The kiwi proteases displayed chymosin-like properties and thus hold the best potential for use as a milk coagulant in cheese production.

Enhanced Microcystis Aeruginosa removal and novel flocculation mechanisms using a novel continuous co-coagulation flotation (CCF)

Co-coagulation flotation (CCF) is a novel flotation technology that renders more efficient algal removal compared to traditional mechanical coagulation flotation (MCF) due to a short residence time (< 30 s) and fast rising behavior of algal flocs (> 250 m·h−1). This study compared the algal removal performance using continuous CCF and MCF using water samples taken from Lake Dianchi with severe Microcystis aeruginosa blooms. Removal efficiency, dosage of coagulant/flocculant, rising velocity and structural characteristics of the resulting flocs in the two processes were systematically compared. The results show that CCF could save >50 % polyaluminum chloride (PAC) and polyacrylamide (PAM) compared with MCF when the removal efficiency was both over 95 %. The average rising velocity of flocs in CCF could reach 254.3 m·h−1, much higher than that in MCF (154.5 m·h−1). In the respective optimal coagulation conditions, the flocs formed in CCF (G = 164.8 s−1) were larger (1843 ± 128 μm) and more spherical with a higher fractal dimension (Df = 1.85 ± 0.01) than those generated in MCF (G = 34.1 s−1). The Stokes's Law was found to correctly predict the rising velocity of spherical flocs with large fractal dimensions (Df > 1.7). In contrast, the Haarhoff and Edzwald's extended equation was more suitable for calculating the rising velocity of irregular flocs with small fractal dimension. This study provides new insights into the mechanisms of the enhanced algal removal by CCF and lays foundation for developing cost-efficient algal mitigation processes.

Application of Dragon Fruit Peel’s Mucilage in Coagulation – Flocculation Process to Remove Turbidity from Water

The study determined flocculation activity of mucilage extracted from dragon fruit peel (Hylocereus undatus) and its ability in reducing synthetic coagulant polyaluminium chloride (PAC) used in coagulation – flocculation process to remove turbidity of different types of water. Investigated waters were turbid waters made from kaolin suspension (KS), suspension of river water with hill soil (FW), and To Lich river water (TL). Turbidity removal was assessed in a sequent coagulation and flocculation model using PAC and mucilage extracted from dragon fruit peel in Jar-tests. Optimal coagulation conditions of PAC with PAC dosage of 20-50 mg/L and pH range of 6-8 regardless of water types and resulted in maximum turbidity removal of about 98%. In order to obtain a comparable turbidity removal, 50%-68% of the required PAC was reduced if mucilage was used. The presence of mucilage enhanced turbidity removal of PAC by 13-22% total efficiency. Mucilage extracted from dragon fruit peel has shown its flocculation ability and its potential as a green material in water treatment.&#x0D; &#x0D; &#x0D;

Optimizing coagulation–flocculation processes with aluminium coagulation using response surface methods

A data-based multivariate method such as response surface methods and desirability function is considered advantageous for analysing coagulation treatment optimization. Thus, this study investigated the optimization of coagulation–flocculation using response surface methodology. The parameters investigated were pH, alum dose and alkalinity. The optimum coagulation conditions for the individual responses: turbidity, colour, residual aluminium and phenanthrene were pH 7.0, alum dose 80.0 mg/L and alkalinity 80.0 mg/L; pH, 6.5, alum dose 70.0 mg/L and alkalinity 90.0 mg/L; pH, 7.0, alum dose 63.2 mg/L and alkalinity 80.0 mg/L and pH 6.2, alum dose 80.0 mg/L and alkalinity of 80.0 mg/L, respectively. The model equation derived from the optimization study was adequate for predicting the response values. The quadratic model was significant (p < 0.0001), and it had a high correlation (R2, 0.746–0.975) and an insignificant (LOF, p > 0.05) lack of fit.

AWWA Water Science Author Spotlight

Having published an article in AWWA Water Science, Amir Alansari answered questions from the publication's editor-in-chief, Kenneth L. Mercer, about the research. Critical Elements of Flocculation in Drinking Water Treatment Amir Alansari and James Amburgey I'm a water treatment specialist at Stantec at their office in Winston-Salem, N.C. My research focus is primarily on coagulation chemistry and process optimization. Lately I've been working on developing new digital tools for predicting optimal coagulation conditions using artificial intelligence. It was a $5,000 stipend to participate in the Research Experiences for Undergraduates (REU) program over the summer at the University of North Carolina at Charlotte. I was in the civil and environmental engineering program and stumbled into the world of water treatment by chance. Amir won first place in the ACE19 student poster contest. Dr. Amburgey had the biggest influence on my career and on everything I have accomplished so far. I completed all three civil engineering degrees (bachelor's, master's, doctorate) working with him at the same university. In total, I spent 12 years under his mentorship, during which time I was able to freely follow my curiosity and work on whatever I wanted. The best advice I got from him was to use the time I had in graduate school to grow my skill sets as a researcher and an engineer as much as possible. My coauthor and I read a paper that was published in 1992 in Journal AWWA by Han and Lawler, where they mathematically showed that mechanical mixing played an insignificant role in the flocculation process. We recognized the implications of their work on the recommended design guidelines for flocculation; however, an extensive literature review did not yield any conclusive evidence that supported or challenged their theory. Our article presents results from a series of experiments we performed to measure the effects of various flocculation parameters (e.g., mixing duration) on settled and filtered water-turbidity removal efficiency and determine whether Han and Lawler were correct. I try my best to have a positive impact on the lives of people around me. I'd like to think that my work is contributing to the body of knowledge, even if it is a tiny contribution. Many of our current design guidelines are based on work done about four to six decades ago. There have been a lot of scientific and technological advancements since then. I believe water treatment design could benefit from a 21st-century overhaul, which would require a renewed research interest and collective effort from the research community, regulators, consulting engineers, and industry. The current funding model does not favor this type of research. It considers topics such as coagulation as matured topics, with nothing left to discover. Our research highlighted the benefits of optimizing coagulation conditions (via jar tests) using filtered turbidity as the performance metric instead of settled water turbidity. We found that jar-test mixing conditions had a significant effect on settled turbidity removals. This means that operators no longer have to “calibrate” their jar test procedures to get their results to match the full-scale process. It simplifies the optimization process by reducing the number of variables to just two—coagulant dose and coagulation pH—which ultimately means they can achieve better treatment performance while minimizing chemical usage. To learn more about Amir's research, visit his AWWA Water Science article, available online at https://doi.org/10.1002/aws2.1213.

Simultaneous reduction and coagulation removal of perrhenate with titanium (III) trichloride: Performance and mechanism

Abstract 99 Tc is a common radioactive element in nuclear waste. Due to its long half-life and high mobility, it easily leads to environmental pollution. This study firstly reported the use of titanium trichloride (TiCl 3 ) as reductant and coagulant to remove perrhenate (ReO 4 − ), which is a non-radioactive chemical substitute for 99 TcO 4 − . The results showed that ReO 4 − could be completely removed (removal efficiency of Re reach 99.6%) under the optimal coagulation conditions and achieved rapid separation of pollutants from water. When competing ions (such as ClO 4 − ) coexist at a concentration of 1850 times, the removal efficiency of Re can still reach 93.9%. The standing experiment of flocs in aerobic condition exhibited the existence of high affinity between flocs and Re oxides, guaranteeing the fixation of Re. Based on the experimental results and various characterizations of the flocs, it is proposed that the mechanism is the reduction-electrostatic interaction-coagulation process. Firstly, the added Ti(III) hydrolyzed to generate the Ti(III) hydrates and reacted with ReO 4 − . And then, the titanium hydrates and ReO 2 aggregated with each other through electrostatic interaction to form flocs, which settled down quickly to achieve the removal of Re. The results indicated TiCl 3 may be used as a candidate reagent to eliminate 99 Tc pollution in water efficiently. • TiCl 3 was firstly applied as reducing agent and coagulant for perrhenate treatment. • The in-situ formed Ti(OH) 3 were essential for the perrhenate reduction. • The high affinity between flocs and Re oxides guaranteed the fixation of Re.

Synthesis and Performance of PAFS Coagulant Derived from Aluminium Dross

Polymerised aluminium ferric sulphate (PAFS) was prepared from aluminium dross as a coagulant in wastewater treatment. The effects of leaching time, leaching temperature, and sulfuric acid concentrations on the turbidity removal of the wastewater were investigated, and the optimum conditions were determined using response surface methodology. The results showed that the optimum PAFS preparation conditions were at a leaching time of 60 minutes, a leaching temperature of 65°C, and a sulfuric acid concentration of 1 mol/L. Furthermore, experiments were performed to investigate the effect of coagulant dosages using the PAFS prepared under the optimum leaching conditions, settling time and initial pH of the wastewater on the turbidity removal efficiency. As a result, it was found that the optimum coagulation conditions for PAFS coagulants were at a settling time of 15 minutes, coagulant dosage of 0.5g, and raw water pH 8. Under these optimum conditions, the turbidity removal efficiency of the wastewater was 91.45%. The purpose of this study was to investigate the possibility of aluminium dross utilisation as a coagulant agent for wastewater treatment. Therefore, it can be concluded that PAFS prepared by leaching metal oxides from aluminium dross is an effective wastewater coagulant.

Copper oxide nanoparticles removal by coagulation and optimization by matter–element analysis model

Nanoparticles have been inspected in water environment and sewage treatment plants, but how to achieve efficient removal of them through existing treatment processes is a potential issue. In this study, the organic–inorganic composite coagulant (PAC-CA) was applied to remove copper oxide nanoparticles (CuO-NPs) and study their coagulation behavior and the characteristics of flocs produced by coagulation. Under the optimal coagulation conditions with a dosage of 25 mg/L, pH of 7, stirring intensity of 200 s−1, and settling time of 15 min, the removal rates of CuO-NPs and turbidity were 89.83% and 93.51%, respectively. Zeta potential studies show that the main action mechanism of PAC-CA under low dosage or alkaline conditions is charge neutralization, and under high dosage or acidic conditions, the main action mechanism is adsorption bridging. A matter–element analysis model was established based on the evaluation index of stirring intensity, kaolin concentration, humic acid concentration, initial CuO-NPs concentration, pH, PAC-CA dosage, turbidity removal rate, and CuO-NPs removal rate. Kaolin can promote the removal of CuO-NPs and turbidity by PAC-CA. The main action mechanisms of PAC-CA are charge neutralization and adsorption bridging. PAC-CA has good coagulation performance for CuO-NPs wastewater, and provides a theoretical basis for the practical engineering application of coagulation for removing nanoparticles in wastewater.

Camel Milk-Clotting Using Plant Extracts as a Substitute to Commercial Rennet

The transformation of camel milk into cheese is an operation considered very delicate because of several difficulties encountered in achieving coagulation. The present study aims to improve coagulation abilities of camel milk using enzyme extracts from pineapple, kiwi, and ginger. Our results concerning the characterization of the enzymatic extract showed an extraction yield that varies according to the type of extract (pineapple: 75.28% ± 4.59, kiwi: 63.97% ± 5.22, and ginger: 28.64% ± 1.47). The optimum coagulation conditions of the 3 types of extract were as follows: for pineapple: pH = 5 and temperature = 45°C; for kiwifruit: pH = 6.6 and temperature = 40°C; and for ginger: pH = 6.6 and temperature = 45°C. A fresh cheese was made from camel milk with a particular nutritional quality and consistency. The kiwi proteases displayed chymosin-like properties and thus hold the best potential for use as a milk coagulant in cheese production.

Magnetic flocculation of Cu(II) wastewater by chitosan-based magnetic composite flocculants with recyclable properties

In this study, three magnetic flocculants, namely, MC, MC-g-PAM, and MC-g-PAA, were prepared. The structure characteristics, flocculation performance, and floc characteristics of the three magnetic flocculants were systematically studied and compared. SEM, FT-IR, XPS, XRD, TG–DSC, and VSM characterization results show that MC, MC-g-PAM, and MC-g-PAA are successfully prepared and exhibit good magnetic induction. The removal rates of copper ions by MC, MC-g-PAM, and MC-g-PAA under the optimal coagulation conditions are 93.39 %, 88.64 %, and 61.41 %, respectively. Kinetic fitting shows that the flocculation reaction process of MC and MC-g-PAM conforms to pseudo first-order kinetics, while the flocculation reaction process of MC-g-PAA conforms to pseudo second-order kinetics. The flocs produced by MC-g-PAA have larger particle size and fractal dimension than those by MC and MC-g-PAM. At 80 mg/L dosage and pH 6, the floc size and floc fractal dimension obtained by MC-g-PAA reach the maximum values of 48.28 um and 1.468, respectively. Zeta potential studies show that the flocculation functions of the three flocculants are mainly adsorption bridging, adsorption electric neutralization, and chelating precipitation. Recycling experiments show that MC-g-PAA has good recyclability, and the recovery rate after the fifth use is 77.24 % with the Cu(II) removal rate of 67.53 %.

Coagulation-flocculation of turbid water using graphene oxide: simulation through response surface methodology and process characterization

It was aimed to precisely investigate the coagulation properties of graphene oxide (GO) as a novel coagulant for turbidity removal from water. For this purpose, the process was simulated through response surface methodology (RSM) to determine the effect of the preselected independent factors (pH, GO dosage, and initial turbidity) and their interaction effects on the process. Based on the results, increased turbidity removal efficiencies were obtained as pH decreased from 10 to 3. Besides, increase of GO dosage within the test range (2.5-30 mg/L) was highly beneficial for enhancing the process performance. However, a slight overdosing of GO was observed for dosages of more than 20 mg/L under pH values of less than about 4. For initial turbidity with test range of 25-300 NTU, there was an optimum range (approximately 120-200 NTU) out of which the removal efficiency declined. According to the results of the analysis of variance (ANOVA), pH and GO dosage, orderly, had the strongest individual effect on the process performance. The most significant interaction effect was also observed between pH and GO dosage. The optimal coagulation conditions with GO dosage of 4.0 mg/L, pH of 3.0, and initial turbidity of 193.34 NTU led to a turbidity removal efficiency of about 98.3%, which was in good agreement with RSM results. Under basic pH levels, the sweeping effect was recognized as the main coagulation mechanism occurred between the negatively surface charged particles of GO and soil. However, according to zeta potential (ZP) analysis results, under acidic pH conditions in addition to the sweep coagulation, the electric double layer compression, and the subsequent ZP reduction also contributed significantly to the process. Scanning electron microscopy (SEM) images showed that the layered structure of GO particles provided an appropriate platform on which the flocs were formed.

Eco-friendly approach for elimination of olive mill wastewaters (OMW) toxicity using cactus prickly pears juice as a coagulant

Abstract Currently, research focuses on the application of newer biocoagulant products in wastewater treatment. In this study, the performance of cactus juice to clarify Olive Mill Wastewater (OMW) was investigated by using Jar-test experimentation and assessed by physicochemical analysis of the obtained supernatant: turbidity, total suspended solids (TSS), (λ465; λ395) absorbance, polyphenols (pp), chemical oxygen demand (COD) and Fourier-Transform-Infrared spectroscopy (FTIR) on lyophilized sludge. A series of experiments were conducted to estimate the influence of various experimental parameters, such as the amounts of biocoagulants used, time, stirring speed, and pH. The study showed the optimal coagulation conditions were as follows: sample pH10; cactus juice dose, 10% (v/v); rapid mixing time, 30 s at a speed of 150 rp/min. Under these conditions, the overall removals of 74% for COD, 93% for turbidity and 51% for polyphenols were achieved. As referring to the FTIR analysis, the cactus juice of Opuntia spp. operates predominantly through an adsorption interparticle bridging coagulation mechanism. These results are encouraging in the context of developing a low-cost technology and eco-friendly approach for the effective management of OMW.

Ultrafiltration as a simple purification method of a water extract of common bean seed as a natural coagulant

Natural coagulants from a crude water extract of common bean seed showed very good efficiency of turbidity removal from water of ~89 % under optimal coagulation conditions, which were determined using response surface methodology (RSM). However, they also increased the content of organic matter in treated model water by ~66 %, which is the main drawback of usage of natural coagulants, in general. Thus, ultrafiltration was applied for processing of the crude water extract in order to separate biomolecules, which exhibit the coagulation activity. Four fractions obtained by ultrafiltration were applied in coagulation tests under the same conditions as the crude extract, and the 4th fraction (molecules with molecular weights &gt;30 kDa) with the predominant content of proteins with molecular weights 50 - 60 kDa, achieved almost as high efficiency of turbidity removal (75 %) as the crude extract. At the same time, the content of organic matter in treated water increased just for 16 % in comparison to the blank (model water processed in the same way but without coagulant). After optimization of process parameters by RSM for usage of the 4th fraction, the coagulation activity increased further to 80 %.

Coagulation and disinfection by-products formation potential of extracellular and intracellular matter of algae and cyanobacteria.

Coagulation and flocculation can remove particulate algal cells effectively; however, they are not very effective for removing dissolved algal organic matter (AOM) in drinking water plants. In this work, optimum coagulation conditions using alum for both extracellular and intracellular organic matter of six different algal and cyanobacterial species were determined. Different coagulation conditions such as alum dosage, pH, and initial dissolved organic carbon (DOC) were tested. Hydrophobicity, hydrophilicty, and transphilicity of the cellular materials were determined using resin fractionation method. The removal of DOC by coagulation correlated well with the hydrophobicity of the AOM. The disinfection by-product formation potential (DBPFP) of various fractions of AOM was determined after coagulation. Although, higher removal occurred for hydrophobic AOM during coagulation, specific DBPFP, which varied from 10 to 147 μg/mg-C was higher for hydrophobic AOM. Of all the six species, highest DBPFP occurred for Phaeodactylum tricornutum, an abundant marine diatom species, but is increasingly found in surface water.