Synthetic Turbid Water Research Articles

Green bean seed coagulant for turbidity removal: parameter optimization and modelling

ABSTRACT This study investigates the effectiveness of a natural coagulant derived from green bean (GB) seeds for treating synthetic turbid water. The properties of GB and green bean coagulant (GB-Co) were analysed using FTIR, SEM, and EDX. The study focuses on the interaction between extraction parameters, such as mixing time (MT), mix concentration (MC), and solvent concentration (SC), on turbidity removal and protein concentration. The optimal parameters were determined using response surface methodology (RSM) and desirability functions. The analysis of variance (ANOVA) showed good agreement between experimental data and the proposed model. The quadratic model showed that factors SC and MC significantly influence both responses. The optimum extraction conditions were MT, SC, and MC at 48 min, 1.38 M, and 10 g/L, respectively. The coagulant achieved a turbidity removal of 95.57% and a protein concentration of 1092.11 mg/L. The results suggest that GB-based coagulants can effectively remove turbidity from wastewater.

Improving household water treatment: using zeolite to remove lead, fluoride and arsenic following optimized turbidity reduction in slow sand filtration

Despite the United Nations 2030 agenda, large number of both urban and rural dwellers in low-income countries continue to lack access to improved water. Thus, increased effort is required towards enhancing low-cost drinking water treatment technologies especially for developing countries. Slow sand filter (SSF) is one of the most commonly used low-cost and efficient technologies for treating household drinking water. However, effectiveness of SSF is substantially affected by very high turbidity and relatively large amounts of dissolved heavy metals. To enhance removal of both turbidity and heavy metals, this study optimized sand bed depth (SBD) of SSF and investigated the potential of natural zeolite from Uganda for removal of lead, arsenite (As(III)) and fluoride ions from water. To remove lead ions, the zeolite was used in its natural form. However, to remove As(III) and fluoride, the natural zeolite was modified using hexadecyltrimethylammonium bromide solution. Removal of high turbidity was found to require a large optimal SBD. Furthermore, efficiency of treating synthetic turbid water increased with increasing initial turbidity. Variation of final turbidity with SBD was found to be best described by an exponential function. Optimal SBDs on top of an underdrain gravel layer of 0.2 m were 453, 522, 561, and 580 mm for turbidity of 60, 80, 100, and 120 NTU, respectively. Optimized SBD used achieve at least 95% efficiency in removing suspended particles from water with turbidity 120 NTU was found to save up to 35% of the total cost for acquiring sand volume required by a conventional SSF. For a particular zeolite mass, removal efficiencies of lead, As(III) and fluoride generally increased with increasing contact time. Removal efficiencies of lead, As(III), and fluorides were also shown to increase with increasing zeolite mass. Lead removal efficiencies using natural zeolite were 75 and 98% under 20 and 40 min, respectively. Removal of As(III) using modified zeolite mass was 91% within contact time of 10 min. Adsorption of fluoride on modified zeolite was 80% within 5 min. Adsorption of lead, As(III), and fluorides indicated promising potential of natural zeolites from Uganda for treating polluted water.

Assessing the Efficacy of Bio-Coagulants in Water Treatment

The study was designed to investigate the efficacy of Bio-Coagulants in water treatment settling tanks using alum (the commercially available coagulant) as a control for comparison. The study employed the preparation of synthetic turbid water using clay as a source of turbidity, jar tests and settling columns to construct settling curves for evaluating removal efficiencies of the biocoagulants, using standard procedures. The findings of the study revealed significant linear correlation (R2 = 0.9967) between clay suspension dosage (x) and turbidity (y), which enabled the replication of synthetic turbid water of the desired turbidity using clay. The equation representing the relationship was found to be y = 1.0705x - 9.7131. From the jar tests, the optimum dosages of the coagulants were 3mg/l, and 8mg/l for M. Oleifera seed extract and watermelon seed extract respectively as coagulants. These dosages resulted in 97 and 91.6% turbidity removal for the respective coagulants. Also, the optimum removal efficiencies observed from the settling column tests were 97%, 84.5% and 70.8% using alum, Moringa oleifera and watermelon seeds, respectively. The study concluded that the plant dimensions designed using alum as coagulant were the most economical followed closely by the one designed using M. Oleifera seed extract (3m width by 37.2m length by 2.5m depth; and 3m wide by 37.8m length by 2.5m depth, respectively). The researcher therefore, recommends that M. Oleifera seed extract could be a viable alternative to alum as a coagulant for use in water treatment settling tanks.

Assessment of groundnut (Arachis hypogaea) as a natural coagulant for water treatment

Abstract Natural coagulants can be an alternative solution to minimise the environmental pollution and health risks caused by the use of chemical coagulants. The main objective of this research was to evaluate the performance of groundnut extract for turbidity removal from water. For this, the active coagulant agents were extracted from the deshelled nuts and used in a series of water treatment tests performed at low, medium, and high turbidity levels using synthetic turbid water. The groundnut extract showed good coagulative abilities, close to those of Al2(SO4)3. The best performance was obtained at medium turbidity (150 NTU), where the extract removed 89% of the turbidity using a 500 mg/L dosage. However, it was not as efficient as Al2(SO4)3, whose coagulation was better at every turbidity level. The use of the groundnut extract does not modify the water's pH significantly and the floc size decreases as turbidity increases, although they are bigger than those produced by Al2(SO4)3. Its flocculation and sedimentation processes are also quick (each less than 10 min) and quicker than those with Al2(SO4)3. Hence, the groundnut extract is a viable alternative to chemical coagulants.

Use of Bacteria to Recover Coagulant from Water Treatment Residue and Reuse for Turbidity Removal from Water

Aluminum is present in significant concentrations in water treatment residue (WTR), a waste product obtained during turbidity removal in drinking water treatment. This study aimed at exploring the potential for recovery of coagulant from WTR using Acidithiobacillus ferroxidans (ATF) and reusing the recovered coagulant (RC) for turbidity removal from water. The activity of ATF was measured by monitoring the pH and Al recovery (in %, AlR%). The effects of two factors (WTR and sulfur dose) on the activity of ATF were studied using central composite design (CCD) and response surface methodology (RSM). The results indicated that the bacteria activity decreased with an increase in WTR dose. The results also revealed that the sulfur dose does not have a significant effect on the ultimate AlR%; however, it significantly reduced the time required for achieving AlR%. ANOVA analysis indicated that the obtained model and factors were significant. The maximum AlR% around 70.9% was obtained with 10 g/L of WTR dose and 8 g/L of sulfur dose. The RC was reused for the turbidity removal from lake water and synthetic turbid water (STW) and compared with the turbidity removal achieved with 1% (w/v) aluminum sulfate. The doses of RC to bring the turbidity <5 NTU in lake water and STW were found to be 0.75 and 1 mL/L respectively. To obtain similar turbidity level, the dose required with aluminum sulfate was 2.5 and 1.5 mL/L for lake water and STW, respectively. There was no significant change in the pH and sulfate and metal concentrations in the effluent treated with RC. The results obtained indicate that the RC is efficient in turbidity removal. The RC, therefore, has potential to reduce the demand for fresh alum for water treatment purposes and provide an alternative use of a waste material.

A Comparison of the Effect of Cellulose Nanocrystals (CNCs) and Polyethylene Glycol (PEG) as Additives in Ultrafiltration Membranes (PES-UF): Characterization and Performance.

This work demonstrated the potential of CNC as a substitute for PEG as an additive in ultrafiltration membrane fabrication. Two sets of modified membranes were fabricated using the phase inversion technique, with polyethersulfone (PES) as the base polymer and 1-N-methyl-2 pyrrolidone (NMP) as the solvent. The first set was fabricated with 0.075 wt% CNC, while the second set was fabricated with 2 wt% PEG. All membranes were characterized using SEM, EDX, FTIR, and contact angle measurements. The SEM images were analyzed for surface characteristics using WSxM 5.0 Develop 9.1 software. The membranes were tested, characterized, and compared for their performance in treating both synthetic and real restaurant wastewater. Both membranes exhibited improved hydrophilicity, morphology, pore structure, and roughness. Both membranes also exhibited similar water flux for real and synthetic polluted water. However, the membrane prepared with CNC gave higher turbidity removal and COD removal when raw restaurant water was treated. The membrane compared well with the UF membrane containing 2 wt% PEG in terms of morphology and performance when synthetic turbid water and raw restaurant water were treated.

Turbidity removal through the application of powdered azadirachta indica (neem) seeds

Various natural products used for water treatment are becoming more popular due to their general safety, eco-friendly sludge production, ease of degradation, cost-effectiveness, and local availability. This research assessed the efficiency of powdered neem (Azadirachta indica) seeds in removing turbidity from the water. Batch experiments determined the optimum coagulant dose, pH level, mixing time, and mixing speed to reduce turbidity from kaolin-based synthetic turbid water. Powdered neem seeds with a pore size of about 0.45 mm were prepared and used in water treatment under optimum conditions. Results showed that a coagulant dose of 3 g of neem seeds/L, 13.2 pH level, 60 mins mixing time at 80 rpm mixing speed could reduce turbidity levels to 35 NTU from 250 NTU (86% removal). Findings suggest that powdered neem seeds can be a potential substitute for conventional chemical coagulants for drinking water treatment.

Evaluation of Turbidity and Color Removal in Water Treatment: A Comparative Study between Opuntia ficus-indica Fruit Peel Mucilage and FeCl3.

Natural coagulants derived from by-products have gained popularity as sustainable alternatives to inorganic coagulants in water/wastewater treatment due to their abundant availability, biodegradability, low cost, easy disposal and low sludge volumes. In this study, the mucilage obtained from the peel of Opuntia ficus-indica fruit was evaluated as a biocoagulant for treating synthetic turbid water and compared with a traditional chemical coagulant (FeCl3). The effects of coagulant dosage and pH on the turbidity and color-removal efficiency of synthetic turbid water were analyzed. To estimate the coagulation mechanism, the flocs produced under optimal values were characterized structurally (FTIR and zeta potential) and morphologically (SEM). The optimal condition for the removal of turbidity and color was a coagulant dose of 12 mg/L at pH 13. For the optimal values, the biocoagulant and the FeCl3 presented a maximum removal of 82.7 ± 3.28% and 94.63 ± 0.98% for turbidity and 71.82 ± 2.72% and 79.94 ± 1.77% for color, respectively. The structure and morphology of the flocs revealed that the coagulation mechanism of the mucilage was adsorption and bridging, whereas that of FeCl3 was charge neutralization. The results obtained showed that the mucilage could be used as an alternative coagulant to replace FeCl3.

Optimization of Moringa oleifera cationic protein/zeolite adsorbent blend for synthetic turbid water treatment

Optimization of Moringa oleifera cationic protein/zeolite adsorbent blend for synthetic turbid water treatment

An investigation into the use of acid treated sugar cane bagasse ash-based coagulants for water treatment

Abstract The aim of the study was to investigate the possibility to use acid treated sugarcane bagasse ash (SCBA) as a coagulant. The effect of type of acid, coagulant dose, time and pH on the coagulation characteristic were investigated. Synthetic turbid water was used for the tests. The coagulants were treated with H2SO4 (SSCBA) and HCl (HSCBA). A 6% m/v solid loading (S/L) of HSCBA reduced turbidity by 97.7% whilst an 8% m/v S/L of SSCBA reduced turbidity by 90.9%. Both coagulants exhibited hindered, transition and compression settling characteristics, however HSCBA had faster settling pattern. Turbidity reduction was best in the 6–10 pH range where there was over 90% turbidity reduction from an initial synthetic turbid water of 110 nephelometric turbidity units (NTU). Both coagulants were tested against natural highly turbid river water, and it was shown that only the HSCBA could reduce turbidity from 1,644 NTU to 2 NTU over 100 min. It was also shown that an overflow rate allowance of 0.01 cm/s could achieve 90% turbidity reduction using HSCBA when type 1 settling used for empirical calculations. The use of HSCBA was also shown to result in an insignificant amount of residual pH, Fe, Cu and Zn in the treated water. This therefore makes the use of HSCBA favorable in that it does not change the chemistry of the treated water.

Evaluation of water consumption in rapid sand filters backwashed under varied physical conditions

Egypt suffers from water scarcity. In water treatment plants using sand filters, a significant amount of treated water is consumed, estimated at 10%–15% of the filtered water during backwashing. The objective of this study is to determine the most effective way to reduce the amount of treated water used for backwashing. The methodology of this study was to evaluate the effects of air and water rates, treated water turbidity of 1.6 NTU or slightly higher synthetic turbidity of 4.0 NTU, and media type with single or dual media on reducing treated water consumption during rapid sand filter backwashing procedures. The experimental set up was a bench-scale filter operated at a filtration rate of 189 m3/m2/day. Backwashing with the right water and air rates reduce water usage by 18%, enhanced process performance, and reduced the ripening period. Backwashing using synthetic turbid water recovered 100% of the treated water and improved the ripening duration without affecting backwashing efficiency. This study concluded that backwashing the dual media filter with silica sand and activated carbon achieved the highest treated backwash water consumption by approximately 60%. While anthracite coal was utilized as a dual-media filter, the least reduction in treated water consumption was discovered.

Turbidity removal from synthetic turbid water using coagulant recovered from water treatment sludge: A potential method to recycle and conserve aluminium

The water treatment sludge (WTS), a byproduct of coagulation-flocculation-sedimentation process in drinking water treatment contains significant concentration of aluminium (Al). The WTS is mostly disposed on land or in sewers without treatment. This practice not only poses a serious threat to environment but also results in permanent loss of metals like Al. In order to prevent the adverse effects, studies are being conducted to find alternative use of WTS, and one of the focus areas is to recover coagulant (a solution containing Al) from the WTS by leaching with high strength acid and reuse it as coagulant for treating industrial wastewater. However, the use of the recovered coagulant (RC) for treatment of drinking water is not yet reported. The main concern being the presence of other metals in the RC along with Al. The RC if added to remove turbidity from drinking water may result in elevated concentration of metals in treated water which is objectionable.In order to address this issue, the present study proposes a method to recover coagulant from WTS, and reuse it safely as a coagulant in drinking water treatment without hampering the treated water quality. Specifically, the study used low strength nitric acid to leach Al from WTS. The leaching studies were performed using a Box-Behnken Design (BBD) with three factors: acid strength (M), reaction time and sludge dose. Each factor was set at three levels: acid strength (0.025 M, 0.1625 M and 0.3 M), reaction time (30 min, 75 min and 120 min) and sludge dose (10 g/l, 12.5 g/l and 15 g/l). As Al is the main element responsible for coagulation, leaching efficiency of Al (AlLE) was fixed as the response variable. Performance of the RC in removing turbidity was evaluated on synthetic turbid water and was compared with turbidity removal obtained with 1% (w/v) solution of commercial alum.The results indicate that a maximum concentration of 432 mg/l of Al could be achieved in the RC with optimum factor settings (obtained from statistical analysis) of 0.25 M acid strength, 11.17 g/l sludge dose and 120 min reaction time. The addition of 1 ml/l of the RC in synthetic turbid water resulted in 74% removal of turbidity (with effluent turbidity concentration < 20 NTU) which was similar to removal efficiency obtained with addition of 0.6 ml/l of 1% (w/v) commercial alum solution.The environmental significance of the study is that, it shows that the RC has potential to be used as a coagulant in drinking water treatment. This will not only prevent the permanent loss of Al due to disposing the WTS in landfills but also minimize the requirement of fresh Al salts for coagulation thus resulting in conservation of a natural resource.

Predictive modelling of a rapid stratified bed filter for turbidity removal from surface water

The objective of the present work was to evaluate the hydrodynamic behaviour of a stratified bed filtration column consisting of 4 cm of sand and 2 cm of limestone to remove turbidity and measuring the head loss through the filter in several runs. In this study, two types of sand were used as filtering bed material, one fine and one medium. Crushed limestone was also available. These materials were characterized to determine the average particle diameter, porosity, and permeability coefficient. These were respectively 1.7∙10 –4 m, 336.96 and 0.68 m∙day –1 for fine sand, 3.3∙10 –4 m, 654.24 and 2.59 m∙day –1 for the medium sand and 1.26∙10–3 m, 388.8 and 8.64 m∙day–1 for crushed limestone. Using these materials, hydrodynamic analyses were carried out using clean water under rapid filtration conditions. In these analyses, different filtration rates were determined to be used in each experiment. Once the filtration rates were determined, the filtration analysis was performed with synthetic turbid water prepared at 8 NTU using tap water and bentonite. From the results obtained, a predictive model was developed based on total head losses for the evaluated filter, maintaining the rapid filtration condition. As a result, a turbidity removal efficiency of 97.7% was obtained with a total head loss of 17.8 cm at a filtration rate of 153 m·day –1. The developed model predicted head loss as a function of operating time, filtration rate, and filter depth to maximise turbidity removal. The model showed excellent prediction accuracy with R2 of 0.9999, which indicates that the model predictions are not biased. It was concluded that, due to the porosity of these materials, a stratified bed of sedimentary rocks has a great potential to be used in surface water filtration processes, which implies that it could be used at the rural community level as a form of water treatment, since the

Impact of Moringa oleifera Seed-Derived Coagulants Processing Steps on Physicochemical, Residual Organic, and Cytotoxicity Properties of Treated Water

This study explored the application of whole and defatted Moringa oleifera seed-derived coagulants in powder (P-MOS and DP-MOS), aqueous extraction (AEP-MOS and AEDP-MOS), and saline extraction (SEP-MOS and SEDP-MOS) in the treatment of a synthetic turbid water by coagulation, flocculation, and sedimentation in a jar test apparatus. The performance of M. oleifera seed-derived coagulants was quantified and compared with alum in terms of the ability to neutralize and restabilize the suspension charge, turbidity removal, effect on pH and electrical conductivity, residual organic matter, as well as cytotoxicity in the treated water. All evaluated forms of M. oleifera seed-derived coagulants were able to neutralize and restabilize (in overdose) the particles charges in the suspension. Saline extractions obtained the best turbidity removal results (90%) between the M. oleifera seed-derived coagulants, while alum removed 98% of turbidity. Differently from alum, increased dosage of M. oleifera seed-derived coagulants did not change pH value. Saline extractions and, to a lesser extent, alum increased the electrical conductivity with increasing coagulant dosage. M. oleifera seed-derived coagulants increased residual organic matter (DOC), unlike alum, which did not change this property with increasing dosage. Saline extractions at high dosages enhanced the cytotoxicity to mammalian cells. On the other hand, defatted seeds reduced water cytotoxicity when compared to whole seeds. Despite not being able to reduce the residual organic matter, the previous oil extraction proved to be an important step in the processing of M. oleifera seed-derived coagulants, not changing the turbidity removal capacity and reducing the cytotoxicity of the treated water in addition to generating a significant by-product (Ben oil). Although saline extractions have shown the best turbidity removal results, they should be used with caution due to increased electrical conductivity and cytotoxicity of the treated water at high dosages.

Turbid Water Treatment Using Deshelled Carica papaya Seed: Analysis Via Factorial Design

Natural coagulants are proven to be a good alternative to conventional coagulants with the removal of various pollutants and are environmentally friendly. Despite its advantages, the least studies were carried out on local agro-wastes such as papaya seeds as natural coagulants concerning different operational factors. The study analyzes the main and interactions effect between the coagulant dosage, initial turbidity, and pH on deshelled Carica papaya seeds for turbid water treatment. A 2-level factorial design was used to investigate the main and interaction effects of the main operational factors, viz. coagulant dosage (50-200 mg/L), pH (3-7), and initial turbidity (100-500 NTU) on the turbidity removal of the synthetic turbid water. Based on individual performance, the results suggested that initial turbidity and pH are the most significant factors among the investigated operational factors. In combination, all interactions are significant, but the interaction between initial turbidity and pH is most significant, with 97.2% turbidity removal. Upon application of Carica papaya seed as a natural coagulant in water and wastewater treatment, these operating variables and their interactions are best to be considered.

Hydrodynamic evaluation of a filter bed of porous material from stratified sedimentary rocks for the removal of turbidity in surface waters

In this study, the behavior of a filter bed of stratified sedimentary rocks was evaluated through the analysis of turbidity removal efficiency and head losses. Two types of sands were used as materials, fine and medium, as well as crushed limestone. The materials were characterized to determine the average particle diameter, porosity, and permeability coefficient, obtaining respectively 0.17 mm, 0.39, and 1 × 10−3 cm/s for fine sand, 0.33 mm, 0.41, and 3 × 10−3 cm/s for medium sand, and 1.26 mm, 0.45, and 1 × 10−2 cm/s for crushed limestone. Hydrodynamic analyses of the clean filter under conditions of rapid filtration were carried out, by which the different rates of filtration to be used in each experiment were determined, establishing a direct correlation between the rate of filtration and the thickness of the bed; in this way, it was possible to determine the maximum bed thickness that could be used to maintain a rate of rapid filtration higher than 120 m/day. A hydrodynamic study with synthetic turbid water prepared at 8 NTU using tap water and bentonite was also carried out. Total head losses and turbidity removal were studied for each material at a rate of 153 m/day with removal efficiencies of 93.7% for medium sand with a loss of 23 cm and 67.8% for limestone with a loss of 4.5 cm and a rate of 389 m/day. It is recommended to use the medium sand and limestone type material for use in surface water filtration processes.

Treatment of Synthetic Turbid Water by using Natural Tamarind Seeds

This study is done to find the alternatives to solve the water pollution problem. The common ways to treat polluted water is by using alum. However, the usage of alum as conventional coagulant had caused the formation of sludge that can pollute the water and also cause illness. Tamarind seed was chosen as the alternative because it is naturals, non-toxic, and 100% biodegradable sources. In this study, the research was done in two parts, there are tamarind seed extraction by using different extraction solutions and the jar test. The extraction solution that was used were sodium chloride, potassium chloride and distilled water. In jar test, synthetic turbid water with turbidity range from 200 to 220 NTU was used to determine the effectiveness of tamarind seed as natural coagulant. Form the results obtained, sodium chloride extract achieved the highest percentage or turbidity removal with the percentage 91.32% with the dosage 25mg/L at pH 6, while the distilled water extract obtained the lowest percentage of turbidity removal with the percentage 56.60 % with the dosage 30mg/L at pH 3. As a conclusion, tamarind seed can be used as a natural coagulant in the treatment of polluted water.

Comparison of coagulation performance using natural coagulants against traditional ones

ABSTRACT Coagulation performance of different seeds’ extracts, namely, (Bean, Lima bean, Lentil, and Fenugreek) were evaluated using synthetic turbid water. The coagulation active agents were extracted from the crushed seeds using different types of solvents like sodium chloride and sodium hydroxide solutions with different molarities. Batch coagulation experiments were conducted to evaluate the activity of the extracted bio-coagulants for water decontamination. The coagulation effectiveness of the seeds’ extracts has been compared with that of alum. The highest % turbidity removal using Fenugreek was 98% while that of alum was 85%. Thus, using Fenugreek as plant-based natural coagulants is a promising alternative toward sustainable water clarification.

Citrus aurantiifolia and citrus microcarpa fruit peels waste as eco-friendly natural coagulants

Turbidity is one of the importance of physical water quality parameter in the water treatment process. Aluminum sulfate (alum) and ferric chloride are the most widely groups of chemical coagulant and have been extensively used to remove turbidity. However, there are several flaws relates to the environmental issue and impose health risk to the consumer. Fruit peel waste as a natural coagulant is one of the alternative techniques in minimizing the usage of chemical coagulant in water treatment. This research focused on a combination of ratio 60:40 and 80:20 of citrus microcarpa peels and citrus aurantiifolia peels to act as a natural coagulant for turbidity removal. Furthermore, the effect of mixing duration is determined to establish the optimum mixing duration for the highest turbidity removal. Standard practice using jar test were performed in synthetic turbid water using kaolin. The highest turbidity removal occurred at optimum ratio of 80:20 with 77.6% efficiency removal where the optimum mixing duration was found to be at 120 rpm of rapid mixing at 3 minutes, 50 rpm of slow mixing at 20 minutes and 60 minutes of settling time. The study demonstrated that combination of citrus aurantiifolia peels and citrus microcarpa peels have the potential to be used as natural coagulant for a future alternative in water treatment.

Mo-HLPs: New flocculating agents identified from Moringa oleifera seeds belong to the hevein-like peptide family

Cationic peptides found in Moringa oleifera seeds belong to different protein families and are described as the main flocculating agents of the species. In this study we report the identification and isolation of four new flocculant peptides, called Mo-HLPs 1–4, belonging to the family of hevein-like peptides, previously only known for their members' antimicrobial activity. Purification of the peptides followed two sequential membrane ultrafiltration steps and separation by reverse-phase liquid chromatography. Proteomic analyses showed that Mo-HLPs are extremely basic (pI >10) cysteine-rich molecules with molecular masses between 4.5 and 4.8 kDa and with a highly conserved chitin-binding domain. Searches in BLAST revealed high similarity of Mo-HLPs with hevein and other hevein-like peptides and 90% identity with morintides, which are members of the 8C-hevein-like subfamily found in M. oleifera leaves. Mo-HLPs microflocculation assays showed distinct coagulation/flocculation efficiencies, promoting turbidity reduction levels between 67 and 89% in synthetic turbid water. Activity variations were attributed to the substitution of some amino acids among the isoforms, which may have altered the final net charge of the molecules. The identification of Mo-HLPs represents the discovery of a new group of cationic peptides involved in the flocculation properties of M. oleifera seeds. SignificanceThe study reveals the presence of hevein-like peptides in Moringa oleifera seeds. It is reported for the first time that members of this family have properties to act as flocculating agents of importance for water treatment processes. The identification of these peptides as well as new functional assignment broadens the horizon for speculation on new species which could act as sources of green coagulants for sustainable water treatment, and contributes to the knowledge about occurrence, distribution, molecular and active diversity of peptides belonging to the hevein-like family.