Coagulant For Water Treatment Research Articles

New Trends in Composite Coagulants for Water and Wastewater Treatment

New Trends in Composite Coagulants for Water and Wastewater Treatment

Sunflower (Helianthus annuus) seeds as a natural coagulant for water turbidity treatment: assessment of efficacy and dosage

The quality of river and borehole water fluctuates because of both agricultural and industrial pollutants. Surface runoff during the rainy seasons is high which promote increased turbidity levels in water sources, and this exerts pressure on the quality and usability of the water for domestic use. Unfortunately, most municipalities in developing countries are poor to afford conventional water treatment methods. This study assessed the use of natural coagulants extracted from sunflower seeds for turbidity treatment. Water samples were collected during summer, winter, and autumn from 10 randomly selected groundwater sources and three segments of the Mwerahari River in Buhera District, Zimbabwe. Results captured seasonal turbidity variations across the river segments and the boreholes. Summer season recorded the maximum average levels of turbidity (76 NTU) while autumn and winter recorded 38.7 NTU 36.7 NTU, respectively. Water turbidity levels were above the acceptable 5 NTU Standard Association of Zimbabwe and WHO. The maximum removal efficiency of turbidity was achieved at 80 min at the dose of 4 g/l. These results revealed that the removal efficiency of 95% with 4.6 NTU turbidity is a function of dose; removal efficiency increases as dose of coagulant increases. These results demonstrated that sunflower seed is an effective low-cost natural coagulant for turbidity water treatment.

Green hybrid coagulants for water treatment: An innovative approach using alum and bentonite clay combined with eco-friendly plant materials for batch and column adsorption

Textile industries contribute to water pollution through synthetic dye discharge. This study explores the use of natural bio-coagulants to remove acid dyes from wastewater, investigating factors like pH, coagulant dose, dye concentration, contact time, and temperature for optimal results. The optimum pH and coagulants capabilities of (CAAPP, CAAPH, CBAGL, CBAPP and CBAPH) were 3 (49.6 mg/g), 3 (42.5 mg/g), 3 (38.9 mg/g), 4 (35.7 mg/g), 4 (34.1 mg/g), and 4 (29.4 mg/g) respectively, while treating of selected BRF-221 dyes from water solution. The acidic range (3–4) was found to have the best pH for the maximal coagulation, and the optimal dose were found to be 0.05 g/50 mL. The equilibrium was attained within 45–60 min for all coagulants. After 60 min of shaking, the maximum coagulation capacities (21.9, 21.02, 16.5, 27.9, 25.3, and 23.4 mg/g) of several coagulant composites (CAAGL, CAAPP, CAAPH, CBAGL, CBAPP, CBAPH) were determined. The initial BRF-221 dye concentration in the range of 10–200 mg/L was considered as optimum for gaiting maximum elimination of dye using different coagulants. At a dye value of 100 mg/L of BRF-221, maximal coagulation capacities CAAGL (179.19 mg/g), CAAPP (166.06 mg/g), CAAPH (141.60 mg/g), and CBAGL (126.49 mg/g), CBAPP (113.9 mg/g), CBAPH (93.08 mg/g) were attained. The study found 35 °C to be the optimal temperature for maximum acid dye removal using bio-coagulants. Increasing temperature reduced coagulation capacity, indicating an exothermic process. Freundlich and Langmuir isotherms showed suitability for pseudo-first-order and pseudo-second-order kinetics in biosorption. Thermodynamic parameters were assessed for process feasibility. Effective coagulants demonstrated sensitivity to electrolyte variations. In column studies, adjusting parameters achieved maximum coagulation efficiency for removing BRF-221 dyes. The study successfully applied optimal parameters to remove real textile effluents at a practical scale. SEM, FT-IR, BET and XRD characterized coagulants, providing insights into stability and morphology.

Assessment of chemically modified vegetable tannins as coagulants for water treatment

This research assessed the efficiency of chemically modified tannins as coagulants for water treatment. Tannins from Anacardium occidentale (cashew tree) and Mimosa caesalpiniifolia (‘sabiá’) barks and seedless fruits of Anadenanthera colubrina (‘angico’) and Pityrocarpa moniliformis (‘angico de bezerro’) were evaluated after cationization to remove turbidity from water. After extraction, the total solids content (TSC), Stiasny index (SI), and total condensed tannins content (TCC) of the tannins extracts were determined. Extracted tannins were converted into powders and cationized. Then, the cationized tannins' effectiveness on water turbidity removal, sedimentation time, and effect on pH were assessed. Three concentrations of each type of tannin were used to evaluate flocculant efficiency: 50, 100, and 150 mg L-1. Although the P. moniliformis extract had a higher TSC value (56.06%), it presented the lowest SI (0.42%) and TTC (0.23%) values. M. caesalpiniifolia had the lowest TSC (9.18%) and the highest SI (91.27%), while Ac occidentale stood out with the highest TCC (19.83%). All species have shown potential for tannin production and efficiently removed turbidity at all concentrations. However, only A. occidentale, at a concentration of 100 mg L-1, presented a nephelometric turbidity unit of 2.4, reaching the potability standards required by international specifications and, therefore, being indicated for water treatment. Keywords: condensed tannins, forest species, natural flocculants, turbidity removal.

Synergistic coagulation of hybrid polyaluminum ferric chloride coagulant for water treatment

Synergistic coagulation of hybrid polyaluminum ferric chloride coagulant for water treatment

Synergistic coagulation of hybrid polyaluminum ferric chloride coagulant for water treatment

Synergistic coagulation of hybrid polyaluminum ferric chloride coagulant for water treatment

Recycling of sludge residue as a coagulant for phosphorus removal from aqueous solutions.

Phosphorus pollution poses a significant challenge in addressing water contamination. The coagulant is one of the effective methods to remove phosphorus from wastewater. Abundant Al and Fe oxides in sludge residue make it have great potential to synthesize water treatment coagulants. However, the utilization of sludge residue for preparation of coagulant was seldom investigated. In this study, we fabricated a novel coagulant, polyaluminum ferric chloride (SM-PAC), using sludge residue as a raw material through acid leaching and polymerization processes. Characterization results confirm that the parameters of SM-PAC meet the specifications outlined in the national standard (GB/T 22627-2022). We investigated the effects of pH, dosage, initial phosphorus concentration, and contact time on the removal efficiency of SM-PAC. As anticipated, the prepared SM-PAC exhibited a significant efficacy in removing phosphorus, meeting the discharge standards set for municipal sewage. Furthermore, the adsorption kinetics analysis suggests that the predominant mode of phosphorus adsorption on SM-PAC is chemical adsorption. Furthermore, the SM-PAC was employed in the actual wastewater treatment plant and exhibited excellent efficiency in phosphorus removal. The utilization of SM-PAC can not only effectively address the issue of sludge disposal but also achieve the goal of "treating waste with waste." It is expected that the proposed method of reusing sludge residue as a resource can provide a sustainable way to synthesize a coagulant for phosphorus removal.

Evaluation of Plant-Based Natural Extracts as Coagulants for Surface Water Treatment

Evaluation of Plant-Based Natural Extracts as Coagulants for Surface Water Treatment

Comparative Analysis of Natural and Artificial Coagulants

Abstract: Turbidity is the measure of relative clarity of a liquid. It is an optical characteristic of water and is a measurement of the amount of light that is scattered by material in the water when a lightis shined through the water sample. The higher the intensity of scattered light, the higher the turbidity Turbidity in the water creates both aesthetic and health issues. Surface water treatment plants remove particles because they can cause objectionable appearances, tastes, and odour and can interfere with disinfection. A wide range of natural coagulants, such as moringa seeds, banana peel, jatropha curcas, cassava peel starch, watermelon, pawpaw, beans, nirmali seeds, papaya seeds, organic dry hibiscus and okra have been studied previously. Natural coagulants in powder forms are usually added directly to wastewater. The most commonly used inorganic chemical coagulants in water treatment. Aluminium sulfate Al2(SO4)3 is the most commonly used chemical for coagulation in wastewater treatment. Additional commonly used coagulants include sodium aluminate NaAIO₂, ferric sulphate Fe2(SO4)3 and ferric chloride FeCl3.

Suitability of inorganic coagulants for algae-laden water treatment: Trade-off between algae removal and cell viability, aggregate properties and coagulant residue

Inorganic coagulants could effectively precipitate algae cells but might increase the potential risks of cell damage and coagulant residue. This study was conducted to critically investigate the suitability of polyaluminum (PAC), FeCl3 and TiCl4 for algae-laden water treatment in terms of the trade-off between algal substance removal, cell viability, and coagulant residue. The results showed that an appropriate increase in coagulant dosage contributed to better coagulation performance but severe cell damage and a higher risk of intracellular organic matter (IOM) release. TiCl4 was the most destructive, resulting in 60.85% of the algal cells presenting membrane damage after coagulation. Intense hydrolysis reaction of Ti salts was favorable for the formation of larger and more elongated, dendritic structured flocs than Al and Fe coagulants. TiCl4 exhibited the lowest residue level and remained in the effluents mainly in colloidal form. The study also identified charge neutralization, chemisorption, enmeshment, and complexation as the dominant mechanisms for algae water coagulation by metal coagulants. Overall, this study provides the trade-off analyses between maximizing algae substance removal and minimizing potential damage to cell integrity and is practically valuable to develop the most suitable and feasible technique for algae-laden water treatment.

Moringa oleifera Seed Extracts as a Natural Coagulant for Raw Water Treatment and Improving its Quality

Moringa oleifera Seed Extracts as a Natural Coagulant for Raw Water Treatment and Improving its Quality

Preparation and application of polymeric silicate coagulant: a short review

Coagulation, a fundamental and crucial operation in water treatment, has a long history of application in water/wastewater treatment processes. The efficiency of coagulation depends primarily on the quality, type, and quantity of coagulants used. Although aluminum or iron-based coagulants are the most commonly employed, polymeric silicate coagulants (PSCs) are less frequently utilized. However, the PSCs are promising candidates that deserve further exploration and examination of their potential applications. This review presents an examination of the advantages, synthesis theory, coagulation mechanism, and structure of PSCs. It also delves into the current limitations of these coagulants in research and the challenges that lie ahead for future studies. Finally, it offers some suggestions for future research directions. These discussions are intended to aid readers in comprehending the fundamental characteristics of these coagulants, enabling them to grasp their design methodologies and application area. This understanding can contribute to overcoming the limitations of this type of flocculants, further enhancing their effectiveness.

Coagulation as an effective method for cyanobacterial bloom control: A review.

Eutrophication, the over-enrichment with nutrients, for example, nitrogen and phosphorus, of ponds, reservoirs and lakes, is an urgent water quality issue. The most notorious symptom of eutrophication is a massive proliferation of cyanobacteria, which cause aquatic organism death, impair ecosystem and harm human health. The method considered to be most effective to counteract eutrophication is to reduce external nutrient inputs. However, merely controlling external nutrient load is insufficient to mitigate eutrophication. Consequently, a rapid diminishing of cyanobacterial blooms is relied on in-lake intervention, which may encompass a great variety of different approaches. Coagulation/flocculation is the most used and important water purification unit. Since cyanobacterial cells generally carry negative charges, coagulants are added to water to neutralize the negative charges on the surface of cyanobacteria, causing them to destabilize and precipitate. Most of cyanobacteria and their metabolites can be removed simultaneously. However, when cyanobacterial density is high, sticky secretions distribute outside cells because of the small size of cyanobacteria. The sticky secretions are easily to form complex colloids with coagulants, making it difficult for cyanobacteria to destabilize and resulting in unsatisfactory treatment effects of coagulation on cyanobacteria. Therefore, various coagulants and coagulation methods were developed. In this paper, the focus is on the coagulation of cyanobacteria as a promising tool to manage eutrophication. Basic principles, applications, pros and cons of chemical, physical and biological coagulation are reviewed. In addition, the application of coagulation in water treatment is discussed. It is the aim of this review article to provide a significant reference for large-scale governance of cyanobacterial blooms. PRACTITIONER POINTS: Flocculation was a promising tool for controlling cyanobacteria blooms. Basic principles of four kinds of flocculation methods were elucidated. Flocculant was important in the flocculation process.

Turbidity Removal Performance of Selected Natural Coagulants for Water Treatment in Colombian Rural Areas

Despite the recognized efficiency of natural coagulants, their widespread adoption in the water treatment industry remains low. Our study evaluates the effectiveness of three natural coagulants—Moringa Oleifera, Yausa (Abutilon Insigne Planch), and Breadfruit (Artocarpus Altilis)—in reducing water turbidity levels of 40–50 NTU. Among these, two are native plant species potentially applicable in rural Colombian areas, where there are evident disparities in water infrastructure. This research contributes to the development of these coagulants, exploring their integration with existing water treatment methods, determining their optimal concentrations, and efficiencies in turbidity removal. Our findings reveal significant turbidity removal efficiencies: 88.9% for Moringa Oleifera, 83.3% for Yausa, and 67.2% for Breadfruit. These results indicate the feasibility of these agents as sustainable replacements for traditional chemical coagulants, exhibiting a level of effectiveness alike to that observed in Moringa Oleifera. However, challenges in practical implementation and sustainability, covering technical, environmental, economic, and social aspects, are notable obstacles. The aim of this study is to not only demonstrate the effectiveness of these natural coagulants but also to encourage their broader acceptance and integration into sustainable water treatment practices incorporating two unstudied plant species, such as Yausa and Breadfruit, furthering research to overcome existing challenges. Doi: 10.28991/CEJ-2024-010-02-020 Full Text: PDF

Evaluation of plant based natural coagulants for surface water treatment of Pratapgarh District Uttar Pradesh, India

The efficacy of three plant-based natural coagulants, namely papaya seed powder, banana peel powder, and lemon peel powder, was evaluated in this study for their ability to remove high electric conductivity turbidity, hardness, fluoride, and nitrate from surface water. The experiments were conducted at room temperature without any adjustment to the initial pH. The results indicated that banana peel powder exhibited the highest turbidity removal rate, achieving 55.6% removal when used at a dosage of 0.4 g/L. Furthermore, banana peel powder demonstrated excellent removal efficiency for fluoride and nitrate, with 85% removal observed at the same dosage. Lemon peel powder also exhibited significant effectiveness, achieving 60% removal. Papaya seed powder proved to be the most efficient coagulant for removing hardness, demonstrating a removal rate of 69.66%. The study further revealed a noteworthy linear relationship between the removal of turbidity and hardness, as evidenced by correlation coefficients (R2) ranging from 0.67 to 0.88. Similar linear relationships were observed for turbidity removals, with R2 values ranging from 0.68 to 0.8. An additional advantage of using these natural coagulants was that they did not cause any pH alteration in the treated surface water. Moreover, Fourier-transform infrared (FTIR) analysis of banana peels indicated the presence of functional groups such as carboxylic acid, hydroxyl, and aliphatic amines. These functional groups likely play a crucial role in facilitating coagulation and flocculation by neutralizing the charges of impurities in the water.
 This study suggests that inexpensive natural coagulants hold promise for surface water treatment, offering a viable alternative to conventional methods.

Characterization of crude extracts from willow barks and their performance as proanthocyanidin -based coagulants in water treatment

This work investigates the proanthocyanidin profile of willow bark crude extracts and these materials were cationized and preliminarily tested as biocoagulants for water treatment. The characteristics of crude extracts proanthocyanidin were investigated using size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). XPS analysis indicates that the crude extracts contain significant amounts of sugars. Furthermore, SEC and liquid-state NMR spectroscopy showed that crude extract contains roughly 3–4 flavan-3-ol units with procyanidin (PC)/ prodelphinidin (PD) ratio of roughly 3–5. Thus, the modified form of tannin (proanthocyanidin-enriched) coagulants obtained the higher cationic charge density. The coagulation experiments with kaolin-river water mixture suggested that all the selected willow hybrids’ tannin coagulants were effective in settling the particles down. This study indicates that the value of willow bark can be significantly improved by the usage of crude extracts for water treatment.

Remediation of waste water through natural coagulants such as lemon and banana peel

Water is not only necessary for survival, but it also adds significantly to the quality of our lives. The rapid increase in population, economic expansion, and industrialization in developing nations has led to an unexpected need for water in cities. The capacity for water uses and wastewater generation in residential sectors has significantly risen during the past few decades. Wastewater treatment is an essential procedure in the sanitation system. Reusing resources and adhering to environmental regulations require efficient treatment and pollution management of municipal wastewater resources. The most preferred method for treating wastewater among the many options currently available is the coagulation and flocculation processes. People widely use this treatment due to its low energy consumption, reliability, affordability, and ease of use. This study evaluated the use of banana and lemon peels as coagulants in water treatment using coagulation-flocculation procedures as a potential substitute for alum. We determined the pH and coagulant dose for both banana and lemon peel combinations. The results of this experiment show that lemon peel works well as a coagulant to absorb biological oxygen demand. It has been discovered that the dehydration procedure works better with peels from bananas and lemons. The ideal duration of contact between lemon and banana peels is 90 minutes. For peels of bananas and lemons, the optimal particle size is 300μm, and the ideal dosage of adsorbent is 0.3g.

Enhanced removal strategy towards organic matter with low coagulability: Immediate entrapment and complexation of oxidized intermediates by the hybrid ozonation-coagulation process

The existence of dissolved organic matter (DOM) with low coagulability poses great challenges for conventional coagulation (CC) in water treatment. As a kind of typical organochlorine pesticide, 2,4-dichlorophenoxyacetic acid (2,4-D) cannot be efficiently removed by CC. To enhance the 2,4-D removal, ozonation was applied with coagulation. The hybrid ozonation-coagulation (HOC) achieved 60.61% DOC removal efficiency, which was obviously higher than pre-ozonation coagulation (POC) (45.83%). Synchronous fluorescence spectroscopy revealed stronger complexation between modified 2,4-D and coagulants during the HOC than that in subsequent coagulation of the POC process. During the HOC process, ozone promoted the formation of polymeric Al species, such as Alb. To investigate the 2,4-D removal mechanism, γ-Al2O3/O3 process with the same oxidation ability as the HOC was established. 2,4-D was oxidized step-by-step to 2,4-dichlorophenol, 4,6-dichlororesorcin, 3,5-dichlorocatechol, 2-chlorohydroquinone, 4-chlorocatechol, 1,2,4,5-tetrahydroxybenzene, pentahydroxybenzene and oxalic acid in γ-Al2O3/O3 process. However, during the HOC process, these oxidized intermediates were readily complexed by coagulants and accumulated in flocs. Especially 1,2,4,5-tetrahydroxybenzene and pentahydroxybenzene, completely complexed by AlCl3•6H2O hydrolysates as soon as being formed. Immediate entrapment and complexation between coagulant hydrolysates and 2,4-D oxidized intermediates inhibited the generation of small-molecular-weight organics such as oxalic acid, which enhanced the removal of organics with low coagulability.

An XAS study of Hg(II) sorption to Al-based drinking water treatment residuals

Drinking water treatment residuals (DWTRs) are produced from the coagulation and flocculation processes in conventional drinking water treatment. The abundant metal oxide content of these materials resulting from the use of coagulants, like alum and ferric chloride, has driven strong research interest into the reuse of DWTRs as sorptive materials. Using a suite of aluminum-based DWTRs, we provide new insights into Hg(II) sorption mechanisms. Experiments performed at circum-neutral pH show that sorption capacities are related to the amount of organic carbon/matter present in DWTRs. We found that carbon rich samples can scavenge about 9000 mg/kg of Hg, in contrast to 2000 mg/kg for lime based DWTRs. X-ray absorption spectroscopy (XAS) at the Hg L3 edge further characterizes mercury coordination. X-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) results point to a partial association of mercury with sulfur at low mass loadings, transitioning to a full association with oxygen/carbon at higher concentrations of sorbed Hg(II) and in DWTRs with limited sulfur content. These results suggest that sorption of Hg(II) is primarily controlled by the carbon/organic matter fraction of DWTRs, but not by the coagulants.

New method of producing a more efficient coagulant for the treatment of water from seeds of moringa oleifera

The coagulation is essential in raw water treatment. The most used coagulants are often of chemical origin and expensive and their use generates non-biodegradable residues. This is why innovative studies on the synthesis of natural coagulants based on plant extracts are very important. This study presents a new method of producing a coagulant for the treatment of water from seeds of moringa oleifera. The application of the new method is done in several steps: Harvesting moringa oleifera seeds, shelling, crushing the seeds, extracting oil from moringa oleifera powder, extracting salts from powder from moringa seeds oleifera, microfiltration with a 0.2 µm filter and lyophilization which gives the final product in dry form. We used the resulting product for coagulation of lake water with an initial turbidity of 40 NTU. This treatment reduced the turbidity of the water by almost 95 % when we used 0.7 mg of this coagulant per liter of water. Moringa has previously been used to produce coagulant but the peculiarity of this study is that it takes a very small amount of the synthesized product to effectively treat water.­The results of this research work have shown that the coagulant produced rom the seeds of Moringa oleifera can be used effectively for the treatment of surface water.­The residual turbidity obtained after the treatment of lake water with the coagulant produced was in accordance with the drinking water standard according to the World Health Organization (WHO) (less than 5 NTU).­The coagulant produced by this new method from moringa oleifera seed is an alternative to aluminum sulfate coagulant for water treatment.