Turbidity is removed by adding a chemical coagulant, which produces a secondary toxic of alumina residues in the water. Therefore, the aim of study was to evaluate the coagulation activity of NaCl extract from Leucaena leucocephala and Sesbania grandiflora seeds on the removal of turbidity for water purification. The proximate composition of the seeds was determined. Fourier transform infrared spectroscopy was used to identify the functional groups of protein, and the surface morphology was observed by SEM-EDS. To obtain the optimized condition, all experiments were evaluated by artificial turbid water before being applied on the natural water (i.e., Selokan Mataram). The coagulation process was evaluated by concentration (M), dosage (mL/L), and pH in terms of turbidity, total dissolved solids, and transmittance of light. The results showed that both coagulant seeds contained 25.32 and 30.81% of protein. These coagulants could remove the turbidity by 99.7% for L. leucocephala and 94.24% for S. grandiflora from artificial turbid water at the optimized concentration of 1.0 M, and dosage of 5 and 10 mL/L, respectively. At pH 5 the removal of turbidity from Selokan Mataram was 99.4% for L. leucocephala and 97.23% for S. grandiflora.
Water has a very important role in the survival of living things. About 97% of the water on Earth is salt water and less than 3% is fresh water. Most of Earth’s freshwater is frozen in glaciers, ice sheets, or deep underground in aquifers. This means that less than 1% of freshwater can be accessed to meet the needs . Although the amount of freshwater on Earth remains constant, there has been a scarcity of clean water in recent years, due to the differences in geography, climate, and regulations such as handling of industrial and household waste, especially in some developing countries. In Indonesia, clean water is still a problem. As a country with the fourth-largest population density in the world, the unequal availability of clean water is an important issue because it affects the aspects of life in terms of health and welfare. Based on statistical data, the achievement of access to safe clean water has only reached 72.55%, which means it is still below the target of sustainable development goals, which was determined to be 100%. Turbidity is one of the important parameters that could determine the freshwater quality. These properties are the transmittance of light in water. In cloudy water, pathogenic bacteria tend to survive because there is less or even no sunlight that can penetrate the water which results in disruption of photosynthesis in aquatic plants .
Coagulation process is extensively applied in water treatment as it is efficient and simple to operate. These processes are usually a surface phenomenon, which can be significantly influenced by the surface charge due to the mass of the coagulant . Thus, the optimization of required concentration or dosage of coagulant for scale-up equipment is economically necessary. This process can be determined from the temperature, speed of mixture and timing, among others . Many coagulants are widely used in conventional water treatment processes for tap water production. Usually, the coagulants can be either inorganic coagulants (e.g., aluminum sulfate (Al2(SO4)3), ferric chloride (FeCl3), and poly aluminum chloride), synthetic organic polymers (e.g., polyacrylamide derivatives and polyethylene imine), or naturally occurring coagulants (e.g., chitosan and microbial coagulants). These coagulants could neutralize colloid charges and bind these particles resulting in the formation of floc [4,5]. Although chemical coagulants have good performance in water treatment, they produce large quantities of secondary solid waste such as sludge which is not biodegradable and is toxic . Also, high trace of aluminum concentration in water can cause neurological disorders like Alzheimer’s . Additionally, chemical coagulants have high price and cause acidic pH in freshwater [8,9]. In this regard, natural coagulant is needed to replace the chemical coagulant for safe alternative usage on the freshwater treatment.
Several potential natural coagulants have been used in the treatment of turbid water, such as moringa seeds (Moringa oleifera), grape seeds (genus Vitis), orange peel (genus Citrus), sago flour (Cycas revoluta), corn flour (Zea mays), rice flour (Oryza sativa), banana peels (genus Musa), peanuts (Arachis hypogaea), etc. . These ingredients are in great abundance in Indonesia which contain several macromolecular compounds such as protein, tannins, and pectin . Proteins can be used as active compounds in coagulation process because they act as charged polymers or polyelectrolytes . Moringa seed (M. oleifera) is the most popular natural coagulant that is frequently applied in water purification because of its high protein content [13–15]. The application of M. oleifera in the treatment of domestic waste could decrease the turbidity from 278 to 4.2 NTU (98.5%), increase the pH from 4.8 to 7.1, and keep the total dissolved solids (TDS) according to WHO standard . Additionally, M. oleifera was able to decrease the total suspended solids, turbidity, color, ammonium (NH3-N), oil, and grease on the treatment of effluent from palm oil mill, respectively, for 95.42, 88.30, 90.15, 89, 81, and 87.05% at a dose of 2,000 mg/L .
Leucaena leucocephala and Sesbania grandiflora seeds are legumes of the Fabaceae family. Some studies reported that the legumes can be used as a coagulant because of its high protein content [18–20]. According to proximate analysis the L. leucocephala and S. grandiflora seeds contain 31 and 35% of crude protein. Apart from crude protein, S. grandiflora seeds also contain carbohydrates, fat, and ash [21,22]. Additionally, L. leucocephala seed provided a comparable performance with M. oleifera on the treatment of turbid water . Regarding the application of L. leucocephala, this coagulant could reduce the turbidity of river water by 76% from initial turbidity of 319 NTU at a dose of 50 mg/L . Most reported study related to S. grandiflora is used in medicinal treatment, food, fodder, wood, and soil improvement [24–26]. Limited usage of S. grandiflora seeds has been reported on the treatment of contaminated water . Therefore, it is necessarily to explore the potential of S. grandiflora as natural coagulant in water treatment process.
A study suggested that the effectiveness of coagulation is increased when using the protein extract of coagulant . Salt-treated extraction is most widely used in the extraction of protein from natural coagulant seeds. Several chemicals have been applied on the extraction process, and the best coagulant extract has been prepared in the presence of KCl, NaNO3, and NaCl [14,15,28,29]. Moringa stenopetala extract could remove the dye as much as 98.5% from textile effluent . Common oak (Quercus robur) acorn was extracted with 0.5 M NaCl and removed the turbidity up to 41% . Therefore, in this study, the NaCl concentration on the extraction of L. leucocephala and S. grandiflora and its effect on the coagulation activity has been evaluated on the removal of turbidity from natural water. In this study, the effect of coagulant doses on the removal of turbidity, TDS, pH, and transmittance of light was also evaluated.
2.1 Chemicals and equipment
L. leucocephala and S. grandiflora seeds were collected from natural environment at Pemalang, Central Java province, Indonesia. Artificial turbid water was prepared by dissolving 1.0 g kaolinite clay (Wako Chemical, Japan) in 1.0 L tap water. The suspension was stirred for 1 h to achieve the uniform dispersion of clay particle. Meanwhile, the natural turbid water was obtained from Selokan Mataram water way, Yogyakarta province, Indonesia (i.e., GPS point 7°45′08.3″S 110°20′36.8″E). All raw and treated water was measured for the following parameters: TDS and pH using multi checker (Hanna HI 9813-5, Romania) and the turbidity using turbidimeter (Waterproof Portable TN100 Eutech, Netherland). Sodium chloride (NaCl) was purchased from E-Merck, Germany.
2.2 Preparation and characterization of coagulant
L. leucocephala and S. grandiflora seeds were separated from the peel and dried under the sunlight for about 7 days and then continued to dry in an oven at 60°C for 24 h. The dried seeds were ground to a fine powder and sieved to get particle size of 250 mesh. The samples were kept in sterile plastic box under laboratory ambient temperature before characterized by Fourier transform infrared (FT-IR) spectroscopy (Spectrum Two, PerkinElmer, USA), SEM (Phenom ProX, Phenom World, Nederland), and proximate analysis.
Protein content in natural coagulant was extracted by dissolving of 1 g powder in 1.5 M NaCl solution to a volume of 100 mL. The solution was stirred for 15 min, and then filtered to get the coagulant extract. The same preparation was carried out for the concentrations of 1.0 and 0.5 M NaCl solutions.
2.3 Coagulation process
Coagulant extract in 5 mL of NaCl molar concentrations (i.e., 0.5, 1.0, and 1.5 M) was added into 250 mL turbid water. The solution was then mixed in rapid mixing for 5 min and then continued by slow mixing for 30 min. After the agitation being stopped, the solution was settled for 60 min. Finally, the clarified water was measured for turbidity, TDS, pH, and transmittance of light. Another test aimed to evaluate the effect of coagulant dose that was prepared with the same preparation using various coagulant doses (i.e., 1.0, 2.0, 3.0, 5.0, and 10.0 mL) of 1.0 M NaCl solution into 500 mL turbid water. The percentage of turbidity removal was calculated by the following equation:
3 Results and discussion
3.1 Characterization of coagulant
Table 1 shows the proximate composition of L. leucocephala and S. grandiflora seeds. High protein content of 25.32 and 30.81%, respectively, for L. leucocephala and S. grandiflora indicated that these coagulants have the potential as a precursor in the treatment of turbid water. Oppositely charged protein is essential for neutralization of colloidal particles in the water. These ingredients induced the bridging process of coagulation, which stimulated the flocs development . Also, polysaccharide as an active compound in the natural coagulant has been promoted as coagulating agent .
|Proximate composition||Natural coagulants|
|L. leucocephala||S. grandiflora|
|N-total (%)||25.32 (158.25%)||30.81 (192.56%)|
The purpose of FT-IR characterization is to obtain the information related to the presence of functional groups in a molecule that has a certain vibrational area. The functional groups in the coagulant were measured to identify the presence of –OH, −COOH, and –NH groups, which concluded the possibility of intramolecular interactions between the proteinous polymer in the coagulant and colloidal particles in the solution . Figure 1 shows the IR spectra of the coagulants. L. leucocephala and S. grandiflora seed had almost the same spectral results. In the L. leucocephala seed there was the vibration of absorption bands at the peak of 3267.4 cm−1, which indicated the presence of an O–H group and C–H alkane at the peak of 2923.4 cm−1. A carbonyl group (C═O) was shown in the absorption band at the peak of 1634.4 cm−1, while NH group was shown at the peak of 1538.5 cm−1, and the C–O group at the peak of 1047.4 cm−1 absorption band. However, for S. grandiflora seed there was an absorption band at the peak of 3327.7 cm−1, which indicated the presence of O–H group, C–H alkane at the peak of 2921.5 cm−1. The absorption at the peak of 1633.8 cm−1 was due to the C═O group, and the C−O group at the peak of 1046.4 cm−1 absorption. The N–H group with low intensity was observed at wave number of 1539.0 cm−1. These peaks’ absorption confirmed the presence of hydroxyl (O−H) and carboxylic acid groups (C═O, C−O), while the N−H absorption representing the amine group in the amino acid of protein molecule causes the coagulation ability to be more effective.
Figure 2 shows the SEM micrographs and EDS spectra of L. leucocephala seed. The coagulant seed was hard and sturdy with bread crumb-like structure, which contributes to the sweep flocculation mechanism for the removal of colloidal particles. Among various elements found in the seed, carbon was a dominant element in the seed with 58.16%. Generally, the seed containment of polysaccharide, protein, and fatty acids which are formulated respectively by [C n (H2O) m ], [RCH(NH2)COOH], and [CH3-(CH2) n -COOH]. The presence of high O (22.84%) and N (18.60%) element has confirmed that the coagulant seed composition was either polysaccharide or protein, but nor fatty acid. Polysaccharide contains high amount of oxygen compared to proteins and fatty acids. Additionally, amino acids contain N element, thus the ingredient of coagulant might also contain protein extract. However, low percentage of P (0.29%) element is contributed by phospholipid acids in the coagulant seed. Mg and K element naturally occur in plant seeds. Thus, it can be concluded that the coagulant seed extract is majority protein and polysaccharide. The same conclusion was also reported in elsewhere publication .
3.2 Effect of natural coagulant concentration and dosage on the removal of turbidity
Figure 3 shows the effect of natural coagulant concentration on the removal of turbidity from water. Water extraction of natural coagulant performed low removal of turbidity, where L. leucocephala extract could remove the turbidity as much as 84.09%, while S. grandiflora extract was able to remove the turbidity as much as 74.9%. Contrary results showed that high removal of turbidity was achieved by 1.0 M NaCl extraction of coagulant for L. leucocephala as much as 97.63% and S. grandiflora as much as 91.55%. Further increase of the NaCl extraction of natural coagulants (i.e., 1.5 M) was not reflected by the increase in the removal of turbidity. In this regard, the proteinous coagulant can be more extracted by the NaCl solution for water treatment .
Figure 4 shows the effect of coagulant dosage on the removal of turbidity from water. Generally, the higher the natural coagulant dosage, the higher the removal of turbidity from water. Each application of coagulant dosage showed a different impact. For example, L. leucocephala can remove the turbidity by 95.9–99.7% at an optimum dose of 2–10 mL from the initial turbidity of 326 NTU, while S. grandiflora can remove the turbidity by 92.7–94.3% from the initial turbidity of 307 NTU at an optimum dose of 5–10 mL. Similar results have been reported on the removal of turbidity from water by extracted protein in NaCl solution from M. oleifera seed, Plantago ovata seeds, Phaseolus vulgaris, and Acorn leaves [13,27,36–40].
Figure 5 shows the effect of coagulant dosage on the light transmittance from water. In this regard, the transmittance of light was measured by the light intensity while passing through the solution cell using a light meter. Generally, the higher the coagulant dose, the greater the transmittance of light. At the optimum dose of coagulant, it was 5 mL/L for L. leucocephala and 10 mL/L for S. grandiflora. The highest transmittance of light was proportion to the lowest turbidity content in the deionized water. In this regard, the transmittance of light after coagulation with S. grandiflora extract was higher than L. leucocephala extract, respectively, by 1142.33 and 993.33 Lux on the removal of turbidity from water.
3.3 Effect of natural coagulant concentration and dosage on the removal of TDS
Figure 6 shows the removal of TDS with the increase of coagulant concentration and dosage. TDS of the water increased with the increase of dissolved mineral elements, charged macromolecules, and another ionic compound . Additionally, dissolved NaCl on coagulant extract affects the increase of TDS. However, dissolved M. oleifera on the water treatment does not affect the increase of TDS . In accordance with the regulation of the Minister of Health of the Republic of Indonesia No. 32/2017 concerning to environmental health quality standards and water health requirements for sanitation hygiene, swimming pools, solus per aqua, and public baths as well as regulations from WHO regarding the maximum limit concentration of TDS was 1,000 mg/L [42,43]. Therefore, the optimized concentration and dosage on the removal of TDS of both L. leucocephala and S. grandiflora was 1.0 M and 10 mL/L, respectively.
3.4 Effect of pH levels on the removal of turbidity
Measuring the pH value aims to determine the effectiveness of the coagulant in terms of its ability to reduce the turbidity level. Table 2 shows that both the coagulants can remove the turbidity at pH 5. The surface of coagulant was positively charged as the functional groups bonded with hydrogen ions (H+) by a Coulombic attraction to the coagulant when the pH of solution was less than the pH points zero charge (pHpzc) of coagulant. In this study, the pHpzc of L. leucocephala and S. grandiflora was 6.3–6.5 and 8.2–8.4, respectively [20,44,45]. Therefore, optimum decrease of turbidity occurred at pH 5 by 3.28 ± 0.45 and 12.14 ± 0.26 NTU, respectively, for L. leucocephala and S. grandiflora. However, contrary results showed when the pH of the solution was higher than the pHpzc. In this regard, the surface of the coagulant was negatively charged. When the coagulant dose increased, the surface of coagulant was positively charged which bonded with the negatively charged colloidal particles by charge neutralization mechanism and resulted in a better coagulation process in the water as shown in Figure 4 [46,47]. Therefore, the final pH of the solution increased to neutral pH as can be inferred from Table 2.
|Coagulant||Initial pH||Control pH||Final turbidity (NTU)||Final pH|
|L. leucocephala||8.7||5||3.28 ± 0.45||6.8|
|8.6||7||16.19 ± 1.15||8.3|
|8.7||9||27.7 ± 0.35||8.9|
|S. grandiflora||8.7||5||12.14 ± 0.26||6.7|
|8.8||7||50.16 ± 1.48||8.2|
|8.8||9||62.73 ± 1.47||8.8|
Initial turbidity in artificial turbid water was 371.67 NTU. Optimum doses were 5 mL/L for L. leucocephala and 10 mL/L for S. grandiflora.
Size of floc formation was affected by the pH of the solution in the coagulation process with L. leucocephala as shown in Figure 7. Generally, the formation of floc with small size diameter (i.e., 1–4 × 105 µm2) was lower than the floc formation without pH control suggesting the effectiveness of coagulant attached to the colloidal particle. Additionally, total number of larger sizes of floc under 1–5 × 105 µm2 was higher than the total number of floc formation without pH control, which, in turn, determines the density of the flocculated slime and its tendency and rate of settling out. This observation was also reported by elsewhere publication . The size of the flocs was also affected by the coagulation mixing time and coagulant dosage . Among four types of coagulation mechanisms, polymer bridging and charge neutralization are the possible coagulation mechanisms for plant-based natural coagulant . At a lower coagulant dosage, polymer bridging is preceded by polymer adsorption where long chain polymers attach itself to the colloidal particle’s surface. Only some part of the polymers is attached to the particle while the unattached parts will form loops and tails . These loops and tails are the main structure of polymer bridging because it allows attachment to other colloidal particles and thus forming larger flocs. However, when the coagulant dosage increased to a certain value (i.e., 1.0 M, 5 and 10 mL/L), the ionizable polymer (i.e., polyelectrolyte) as coagulant toils to stabilize the negatively charged colloidal particle by charge neutralization mechanism. Charge density of the polyelectrolyte will determine the optimum dosage of polyelectrolyte (i.e., coagulant) needed because higher charge density corresponds to lower coagulant dosage . As the overall charges changed, the collisions of agglomerates became more difficult, and thus the particles became smaller in size.
3.5 Treatment of natural turbid water from Selokan Mataram
Figure 8 shows effect of transmittance of light and TDS on the removal of turbidity from natural water of Selokan Mataram. Coagulant doses were more effective than the coagulant concentration on the removal of turbidity from natural water as shown in Figure 8a. For example, high removal of turbidity performed at 5 and 10 mL/L of coagulant doses decreased the turbidity by as much as 97.42 and 95.52%, respectively, for L. leucocephala and S. grandiflora, while at 1.0 M coagulant concentration, the turbidity decreased by as much as 93.20 and 79.82%, respectively, for L. leucocephala and S. grandiflora. Additionally, high removal of turbidity was performed at pH 5 by these coagulants by as much as 99.4 and 97.23%, respectively, for L. leucocephala and S. grandiflora. However, high presence of dissolved coagulant in natural water implied high TDS content in the natural water as shown in Figure 8a. Therefore, high transmittance of light occurred when the turbidity decreased in the natural water as shown Figure 8b. In this regard, the highest light intensity occurred at pH 5 of natural water with 828.67 Lux for L. leucocephala and 774.33 Lux for S. grandiflora. This value corresponds to reduce the turbidity by 2.33 NTU (99.4%) and 10.72 NTU (97.2%), respectively, for L. leucocephala and S. grandiflora as coagulant from the initial turbidity of natural water of 387 NTU.
Water treatment facility will use a type of coagulant that usually depends on the availability and affordability. Mostly metal coagulants (i.e., aluminum sulfate and ferry chloride) are preferred choice for public water treatment around the world. However, synthetic coagulants and biopolymer coagulants including natural biopolymers sourced from fungus, plant sources, and animals are also available. These coagulants have the advantage of producing less sludge, and they pose fewer toxicity or safety issues. Coagulation is a necessary water treatment process, but it cannot work alone. Filtration, sedimentation, and disinfection are also required to ensure that water is free from harmful contaminants and is safe for drinking. Therefore, further study is needed to accomplish the process in water treatment practice using natural coagulants.
Coagulation process was performed by optimum concentration of coagulant as much as 1.0 M, while the optimum dosage was 5 mL/L for L. leucocephala extract and 10 mL/L for S. grandiflora extract. In this regard, the best performance to reduce the turbidity up to 99.7 and 94.24%, respectively, for L. leucocephala and S. grandiflora seeds. Application of these coagulants on the removal of turbidity from natural water of Selokan Mataram was achieved at pH 5 with the highest results, which could reduce the turbidity by 99.4 and 97.23%, respectively, for L. leucocephala and S. grandiflora. However, these processes also increase the TDS value when the coagulant dosage increases, but the value was not over the standard regulation by WHO and Minister of Health of the Republic of Indonesia No. 32/2017 concerning to environmental health quality standards and water health requirements for sanitation hygiene, swimming pools, solus per aqua, and public baths.
The authors thank Universitas Islam Indonesia for the APC support.
Funding information: The authors acknowledge grants from Universitas Islam Indonesia through Collaborative Research (contract no. 3686/Rek/10/DSDM/XI/2020).
Author contributions: Writing – original draft preparation: D.N. and R.S.P.; software: M.S.; data curation: D.N. and M.S.; visualization: D.N., M.S., and R.S.P.; conceptualization and methodology: D.N. and R.S.P.; investigation: D.N. and M.S.; formal analysis: D.N., M.S., and R.S.P.; writing – review and editing: R.S.P. All authors have read and agreed to the published version of the manuscript.
Conflict of interest: The authors declare no conflict of interest.
Data availability statement: All data generated or analyzed during this study are included in this published article.
Ethical approval: The conducted research is not related to either human or animal use.
 World Bank Group. Environment and Natural Resources; 2020. Earth’s Water. https://olc.worldbank.org/sites/default/files/sco/E7B1C4DE-C187-5EDB-3EF2-897802DEA3BF/Nasa/chapter1.html (Accessed 13 August 2020).Search in Google Scholar
 Nelson KL, Boehm AB, Davies-Colley RJ, Dodd MC, Kohn T, Linden KG, et al. Sunlight-mediated inactivation of health-relevant microorganisms in water: a review of mechanisms and modeling approaches. Environ Sci Process Impacts. 2018 Aug;20(8):1089–122.10.1039/C8EM00047FSearch in Google Scholar PubMed PubMed Central
 Bobadilla MC, Lorza RL, Garcia RE, Gomez FS, Gonzalez EP. Coagulation: determination of key operating parameters by multi-response surface methodology using desirability functions. Water. 2019;11(2):398.10.3390/w11020398Search in Google Scholar
 Ehteshami M, Maghsoodi S, Yaghoobnia E. Optimum turbidity removal by coagulation/flocculation methods from wastewaters of natural stone processing. Desalin Water Treat. 2015;57(44):1–9.10.1080/19443994.2015.1110725Search in Google Scholar
 Rahimah Z, Heldawati H, Syauqiah I. Pengolahan limbah deterjen dengan metode koagulasi-flokulasi menggunakan koagulan kapur dan PAC. J Konversi. 2016;5(2):13–9.10.20527/k.v5i2.4767Search in Google Scholar
 Sun Q, Aguila B, Song Y, Ma S. Tailored porous organic polymers for task-specific water purification. Acc Chem Res. 2020 Apr;53(4):812–21.10.1021/acs.accounts.0c00007Search in Google Scholar PubMed
 Wang W, Yang H, Wang X, Jiang J, Zhu W. Factors effecting aluminum speciation in drinking water by laboratory research. J Environ Sci (China). 2010;22(1):47–55.10.1016/S1001-0742(09)60073-5Search in Google Scholar
 Kristianto H, Prasetyo S, Sugih AK. Pemanfaatan ekstrak protein dari kacang-kacangan sebagai koagulan alami [Review]. J Rekayasa Proses. 2019;13(2):65–80.10.22146/jrekpros.46292Search in Google Scholar
 Kristianto H, Paulina S, Soetedjo JN. Exploration of various indonesian indigenous plants as natural coagulants for synthetic turbid water. Int J Technol. 2018;3(3):464–71.10.14716/ijtech.v9i3.279Search in Google Scholar
 Ramavandi B, Hashemi S, Kafaei R. A novel method for extraction of a proteinous coagulant from Plantago ovata seeds for water treatment purposes. MethodsX. 2015 May;2:278–82.10.1016/j.mex.2015.05.006Search in Google Scholar PubMed PubMed Central
 Magaji UF, Sahabi DM, Abubakar MK, Muhammad AB. Biocoagulation activity of Moringa oleifera seeds for water treatment. IJES. 2015;4:19–26.Search in Google Scholar
 Okuda T, Baes AU, Nishijima W, Okada M. Improvement of extraction method of coagulation active components from Moringa oleifera seed. Water Res. 1999;33(15):3373–8.10.1016/S0043-1354(99)00046-9Search in Google Scholar
 Okuda T, Baes AU, Nishijima W, Okada M. Coagulation mechanism of salt solution-extracted active component in Moringa oleifera seeds. Water Res. 2001 Mar;35(3):830–4.10.1016/S0043-1354(00)00296-7Search in Google Scholar
 Vunain E, Masoamphambe EF, Mpeketula PM, Monjerezi M, Etale A. Evaluation of coagulating efficiency and water borne pathogens reduction capacity of Moringa oleifera seed powder for treatment of domestic wastewater from Zomba, Malawi. J Environ Chem Eng. 2019;7(3):103118.10.1016/j.jece.2019.103118Search in Google Scholar
 Jagaba AH, Kutty SR, Hayder G, Latiff AA, Aziz NA, Umaru I, et al. Sustainable use of natural and chemical coagulants for contaminants removal from palm oil mill effluent: a comparative analysis. Ain Shams Eng J. 2020;11(4):951–60.10.1016/j.asej.2020.01.018Search in Google Scholar
 Bodlund I. Coagulant protein from plant materials: potential water treatment agent. M.Sc. Thesis. Stockholm, Sweden: Royal Institute of Technology; 2013.10.1007/s13762-013-0282-4Search in Google Scholar
 Devi VN, Ariharan VN, Prasad PN. Nutritive value and potential uses of Leucaena Leucocephala as biofuel – a mini review. RJPBCS. 2013;4(1):515–21.Search in Google Scholar
 Cimá-Mukul CA, Olguín MT, Abatal M, Vargas J, Barrón-Zambrano JA, Ávila-Ortega A, et al. Assessment of Leucaena leucocephala as bio-based adsorbent for the removal of Pb2+, Cd2+ and Ni2+ from water. Desalin Water Treat. 2020;173:331–42.10.5004/dwt.2020.24736Search in Google Scholar
 Shareef H, Rizwani GH, Ziaulhaq M, Ahmad S, Zahid H. Tocopherol and phytosterol profile of Sesbania grandiflora (Linn.) seed oil. J Med Plants Res. 2012;6(18):3478–81.10.5897/JMPR12.117Search in Google Scholar
 Argadyasto Y, Retnani, Diapari D. Pengolahan daun lamtoro secara fisik dengan bentuk mash, pellet dan wafer terhadap performa domba. Bul Makanan Ternak. 2015;102(1):19–26.Search in Google Scholar
 Al-Mamun A, Basir AT. White popinac as potential phyto-coagulant to reduce turbidity of river water. ARPN J Eng Appl Sci. 2017;11:7180–3.Search in Google Scholar
 Evans DO. Sesbania grandiflora: NFT for beauty, food, fodder and soil improvement, NFTA 94-05; 1994. https://winrock.org/factnet-a-lasting-impact/fact-sheets/sesbania-grandiflora-nft-for-beauty-food-fodder-and-soil-improvement/. Accessed on 28 August 2022.Search in Google Scholar
 Putra RS, Sinta D, Female NZ. Effectiveness of turi seed (Sesbania grandiflora) as biocoagulant on the treatment of batik effluent. AIP Conf Proc. 2022;2638:100001.10.1063/5.0105357Search in Google Scholar
 Trefalt G, Szilagyi I, Borkovec M. Poisson–Boltzmann description of interaction forces and aggregation rates involving charged colloidal particles in asymmetric electrolytes. J Colloid Interface Sci. 2013 Sep;406:111–20.10.1016/j.jcis.2013.05.071Search in Google Scholar PubMed
 Sánchez-Martín J, Ghebremichael K, Beltrán-Heredia J. Comparison of single-step and two-step purified coagulants from Moringa oleifera seed for turbidity and DOC removal. Bioresour Technol. 2010 Aug;101(15):6259–61.10.1016/j.biortech.2010.02.072Search in Google Scholar PubMed
 Dalvand A, Gholibegloo E, Ganjali MR, Golchinpoor N, Khazaei M, Kamani H, et al. Comparison of Moringa stenopetala seed extract as a clean coagulant with Alum and Moringa stenopetala–Alum hybrid coagulant to remove direct dye from textile wastewater. Environ Sci Pollut Res Int. 2016 Aug;23(16):16396–405.10.1007/s11356-016-6708-zSearch in Google Scholar PubMed
 Antov MG, Šćiban MB, Prodanović JM, Kukić DV, Vasić VM, Đorđević TR, et al. Common oak (Quercus robur) acorn as a source of natural coagulants for water turbidity removal. Ind Crop Prod. 2018;117:340–6.10.1016/j.indcrop.2018.03.022Search in Google Scholar
 Igwegbe CA, Onukwuli OD. Removal of total dissolved solids (TDS) from aquaculture wastewater by coagulationflocculation process using Sesamum indicum extract: effect of operating parameters and coagulation-flocculation kinetics. Pharm Chem J. 2019;6(4):32–45.Search in Google Scholar
 Torres LG, Carpinteyro-Urban S, Corzo-Rios LJ. Use of Annona diversifolia and A. muricata seeds as source of natural coagulant-flocculant aids for the treatment of wastewater. Eur J Biotechnol Biosci. 2013;1(2):16–22.Search in Google Scholar
 Masyrotut T. Perbedaan Kandungan Karbohidrat Pada Biji Turi (Sesbania Grandiflora) Merah Dan Putih Sebagai Alternatif Pangan Potensial. Undergraduate Thesis. Universitas Brawijaya; 2016.Search in Google Scholar
 Kumar V, Othman N, Asharuddin S. Applications of natural coagulants to treat wastewater − a review. Conference Paper in MATEC Web of Conferences. vol. 103; 2017. p. 06016.10.1051/matecconf/201710306016Search in Google Scholar
 Dhivya S, Ramesh ST, Gandhimathi R, Nidheesh PV. Performance of natural coagulant extracted from Plantago ovata seed for the treatment of turbid water. Water Air Soil Pollut. 2017;228(11):423.10.1007/s11270-017-3592-1Search in Google Scholar
 Kukic D, Sciban M, Prodanovic J, Vasic V, Antov M, Nastic N. Application of natural coagulants extracted from common beans for wastewater treatment. Adv Civ Archit Eng. 2018;16:77–84.Search in Google Scholar
 Putra RS, Ayu M, Amri RY. Performance comparison between biocoagulant based on protein and tannin compared with chemical coagulant. Key Eng Mater. 2020;840:29–34.10.4028/www.scientific.net/KEM.840.29Search in Google Scholar
 Eman NA, Tan CS, Makky EA. Impact of Moringa oleifera cake residue application on waste water treatment: a case study. J Water Resour Prot. 2014;6(7):677–87.10.4236/jwarp.2014.67065Search in Google Scholar
 Menteri Kesehatan Republik Indonesia (Menkes RI). Peraturan menteri kesehatan Republik Indonesia No. 32/2017 tentang standar baku mutu kesehatan lingkungan dan persyaratan kesehatan air untuk keperluan hygiene sanitasi, kolam renang, solus per aqua, dan pemandian umum. Jakarta, Indonesia: 2017.Search in Google Scholar
 World Health Organization (WHO). Guidelines for Drinking-Water Quality. Vol. 2, Health Criteria and Other Supporting Information. 2nd edn. Geneva: World Health Organization (WHO); 1996. (Accessed 8 September 2020).Search in Google Scholar
 Elango KP, Arivoli S, Sundaravadivelu M. Kinetic and thermodynamic studies on the adsorption of dyes onto low cost activated carbon. ESAIJ. 2007;2(3):167–75.Search in Google Scholar
 Putra RS, Fitria F. Effect of mixing time on the coagulation-flocculation process of peat water using Sesbania grandiflora seed. In: Lalu Rudyat Tely Savalas, editors. NiTRIC’2022. Proceedings of 1st Nusa Tenggara International Conference on Chemistry. Indonesia (Submission): Lombok; 2022 July 28–29.Search in Google Scholar
 Okaiyeto K, Nwodo UU, Okoli SA, Mabinya LV, Okoh AI. Implications for public health demands alternatives to inorganic and synthetic flocculants: bioflocculants as important candidates. Microbiol Open. 2016 Apr;5(2):177–211.10.1002/mbo3.334Search in Google Scholar PubMed PubMed Central
 Oliyaei N, Moosavi-Nasab M, Ghorbani M. Effect of salt and alkaline on the physicochemical properties of the protein isolates extracted from lanternfish (Benthosema pterotum). Iran J Fish Sci. 2018;18(2):371–85.Search in Google Scholar
 Bouaouine O, Bourven I, Khalil F, Baudu M. Identification of functional groups of Opuntia ficus-indica involved in coagulation process after its active part extraction. Environ Sci Pollut Res Int. 2018 Apr;25(11):11111–9.10.1007/s11356-018-1394-7Search in Google Scholar PubMed
 Kristianto H, Reynaldi E, Prasetyo S, Sugih AK. Adsorbed Leucaena protein on citrate modified Fe3O4 nanoparticles: synthesis, characterization, and its application as magnetic coagulant. Sustain Environ Res. 2020;30(1):32.10.1186/s42834-020-00074-4Search in Google Scholar
 Tripathy T, De BR. Flocculation: a new way to treat the wastewater. J Physiol Sci. 2006;10:93–127.Search in Google Scholar
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