Alum Coagulation Research Articles

THE EFFECTIVENESS OF COAGULANTS FOR TURBIDITY AND COLOR REMOVAL FROM NATURAL WATER

In this work, the effectiveness of the use of coagulants Al2(SO4)3·18H2O and RM-1 in reducing the level of turbidity and colour (reduction in colour) of natural water was investigated. The object of the study is natural water, namely water from the Dnipro River. The results showed that the optimal dose of coagulant Al2(SO 4)3‧ 18H2O was 10.0 mg dm-3. The optimal dose of coagulant RM-1 was also 10.0 mg dm-3. Residual turbidity and colour are reduced to 0.0 mg dm-3, 12.50, 190, when using Al2(SO4)3·18H2O and RM-1, respectively. Since the residual concentration of aluminium in purified water in all samples after purification with coagulants was less than 0.05 mg dm-3, it is reasonable to use these coagulants, as they do not have a negative effect on the health of consumers. The efficiency of using the RM-1 coagulant to remove turbidity and reduce the colour of the natural water of the Dnipro is high, so this coagulant has the potential to be chosen as a new coagulant.

Comparative treatment of textile dye wastewater with chemical coagulants and bacterial exopolysaccharides

Traces of chemical coagulants, such as alum, commonly used in wastewater treatment, remain in the water effluent and also result in secondary sludge that is difficult to treat. On the other hand, Extracellular Polymeric Substances (EPS) are safer and can be used as alternative bio flocculants. A study was hence done to compare the effectiveness of the treatment of Reactive Black 5 (RB5) textile wastewater with chemical coagulants and bacterial EPS. The jar test method was used to treat the wastewater with Alum and Polyferrous Sulphate (PFS) at varied pH (2–10) and respective dose concentrations. EPS was produced by bacteria isolated from cotton gin trash soil collected from Kitui ginnery in Kenya. EPS treatment was done at 30 °C for 72 h. EPS-producing bacteria isolates were identified by molecular analysis. The chemically and EPS-treated wastewater was analyzed for color, Total Dissolved Solids (TDS), and Chemical Oxygen Demand (COD). Respective color and TDS removal capacity by PFS and alum were (86.1% and 42.18%) and (85.1% and 69%) at their optimal conditions of (pH 7 and 100 mg/L) and (pH 7 and 140 mg/L). Similarly, PFS and alum reduced COD by 27.25% and 26.65%. Respective dye removal by YEAK2 −5 and YEPD K2 −2 EPS was 69.1% and 85.7%. However, YEPD K2 −2 and YEAK2 −5 EPS caused a respective rise of TDS by 40.14% and 67.17%. The respective reduction of COD by YEPD K2 −2 and YEAK2 −5 EPS was 56.25% and 54.24%. The chemically and EPS-treated wastewater met the National Environment Management Authority (NEMA) limits. The YEPD K2 −2 and YEAK2 −5 isolates were both identified as Bacillus sp. GC–MS and FTIR analysis results indicated that the two EPS were heteropolysaccharides composed of different sugar derivatives and hydroxyl as the main functional group. The results for treatment of the dye wastewater by Alum, PFS, and EPS were therefore comparable. The bacterial EPS bio flocculants can therefore serve as effective and cleaner substitutes to the alum and PFS chemical coagulants.

Purification of a reactive dyes mixture solution by means of pre-hydrolysed coagulants in the standard tests and coagulating flow system

Reactive dyes, widely used in textiles, often leach into sewage due to incomplete bonding with fibers. Coagulation offers an effective solution, yet standard lab tests for coagulation efficiency lack realism and are significantly labour and time-consuming. To address this, a novel approach is proposed: optimizing coagulation through a prototype lab flow. This system automates solution flow, reagent dosing, coagulation, and sludge separation via sedimentation and filtration. Tests reveal effective coagulation of various reactive dyes with pre-polymerized Al coagulants, but limited efficacy with Fe(III) coagulant. The flow system demonstrates mostly better purification results than jar tests, achieving around 95% colour removal with Al coagulants. This study highlights the efficacy of coagulation and filtration in jar tests, offering a simplified yet efficient method for assessing coagulation performance.

Blended natural and synthetic coagulants for the COD and BOD removal from surface water; optimization by response surface methodology: The case of Gibe river

A novel wastewater treatment method is presented in this study. It combines natural coagulants derived from watermelon seeds with the commonly used synthetic coagulant alum. This research demonstrates a remarkable synergy between these two coagulants in removing nutrients from Gibe River wastewater. Combining natural and chemical coagulants often improves water treatment by enhancing particle destabilization, accelerating floc formation, and broadening the range of removable contaminants, resulting in lower chemical dosage requirements. The optimal mixing ratio, found to be 1 part watermelon seed coagulant to 3 parts alum, leads to improved treatment efficiency. At this ratio, the process achieves impressive removal rates: 98.26 % for total dissolved solids (TDS), 96.10 % for biochemical oxygen demand (BOD), and 95.26 % for chemical oxygen demand (COD). These findings not only validate the use of watermelon seeds as a coagulant but also highlight the combined approach's environmental and economic benefits. This integrated method offers a more sustainable and cost-effective solution for wastewater treatment.

Impacts of distinct residual aluminum on gypsum scaling in nanofiltration: Identification of key species

Membrane scaling severely hinders practical application of nanofiltration (NF) for brackish water treatment. However, the contributions of residual aluminum (Al), especially various species with differing polymerization degrees and sizes, to gypsum scaling remain unclear. Herein, the complex interactions between three Al species (AlCl3, Al13 and Al30) and gypsum scaling were investigated, including surface and bulk crystallization processes. Results demonstrated that Al species adhering to the membrane surface promoted surface crystallization and altered crystal morphology. Notably, the Al13 species induced the formation of dense, complete rosette crystals causing the most severe flux decline. For bulk crystallization, Al30 was the primary species to promote nucleation. This promotion resulted from two factors: a lower nucleation energy barrier and the promoted aggregation of small crystals. Furthermore, molecular dynamics (MD) simulations revealed that the inhibition of nucleation due to the competition between Al species and calcium ions at nucleation sites was negligible compared to the strong promotion effect. These findings demonstrated that PACl exhibit higher scaling potential during NF than monomeric Al coagulants. Ultimately, the competition between surface and bulk crystallization determined the final membrane flux decline. This study offers valuable insights into the mechanisms of NF scaling caused by residual Al and guides mitigation strategies.

Color, COD, and turbidity removal from surface water by using linseed and alum coagulants: optimization through response surface methodology

This study examined the treatment of surface water using a mixed natural (linseed) and chemical (alum)-based coagulant in terms of color, turbidity, and chemical oxygen demand (COD) (%) removal in a laboratory jar test. Experimental results showed that using a combined coagulant has shown higher removal of color (99.72%) and turbidity (97.76%) at pH values of 3.5 using a 1.5 g/L dosage and a stirring time of 38.58 min. Similarly, at the same pH value and 2.5 g/L dosage, the COD removal was 96%. To determine the optimum value with the highest percent removal efficiency of the coagulation–flocculation process, several experimental parameters including blended dosage, pH, COD concentration, and initial turbidity have been studied in terms of the percent of color, chemical oxygen demand, and turbidity removal. The optimum value was found for the highest removal of color-97.75%, turbidity-96.86%, and COD-90.33% with the pH values of 7.0, at a dosage of 2.5 g/L and a stirring time of 40 min, respectively. Statistical techniques of response surface methodology were used in experimental design and optimization, in order to calculate the confidence intervals to assess population parameter precision. An ANOVA-95% confidence interval ensures that the high reliability optimizes the result. The findings proved the excellent adsorption potential and high performance of the blended coagulant in the removal of contaminants from surface water.

Comparison of Alum and Poly Aluminum Chloride Coagulant Performance on Turbidity and pH of Lematang Enim PDAM Raw Water

Raw water is natural water found in lakes, rivers, streams, and underground sources before any treatment or purification processes. It typically contains various impurities, such as suspended solids, organic matter, pathogens, and dissolved minerals, which need to be removed to make it safe for consumption. Aluminum Sulfate and Poly Aluminum Chloride (PAC) are two commonly used chemicals in the treatment of raw water to remove impurities and make it suitable for drinking, industrial, or agricultural purposes. These chemicals play crucial roles in the purification process by aiding in the coagulation and flocculation of contaminants, which facilitates their removal through filtration. Study on raw water treatment using Aluminum Sulphate and Poly Aluminum Chloride (PAC) coagulants was carried out at Talang Jawa IPA PDAM Lematang Enim of Muara Enim District by taking raw water samples from Talang Jawa Intake and Pelita Sari Intake. This study aimed to find out the right type and dose of coagulant in the raw water treatment process. he test parameters were turbidity and pH values. The research was conducted using a jar test to determine the dose of coagulant. The results showed the use of solid PAC was more effective for both intakes. The optimum coagulant dose is 20 ppm PAC in the raw water of Talang Jawa intake and Pelita Sari intake with turbidity of 2.62 NTU and 4.15 NTU and pH of 7.8 and 7.6.

Dynamic evolution of ultrafiltration membrane fouling affected by S(IV)–Fe(II)-activated permanganate pretreatment during a long-term operation

ABSTRACT The S(IV)–Fe(II)/PM pretreatment has demonstrated preliminary potential as an effective ultrafiltration (UF) pretreatment technology. However, a comprehensive understanding of its impact on UF membrane fouling control and the dynamic evolution of membrane fouling during prolonged operation is still lacking. In this study, a relatively prolonged fouling experiment was conducted. Results revealed that the S(IV)–Fe(II)/PM pretreatment exhibited superior performance over Al(III) coagulation pretreatment in mitigating the transmembrane pressure difference and addressing both reversible and irreversible membrane fouling. The application of a cluster analysis method to classify membrane fouling evolution stages further confirmed that S(IV)–Fe(II)/PM pretreatment effectively decelerated the rate of membrane fouling evolution. The surface cake layer of UF membranes pretreated with S(IV)–Fe(II)/PM exhibited greater looseness and smoothness. It also showed better results than Al(III) coagulation pretreatment in reducing the accumulation of organic foulants, controlling the Si content and reducing the total microorganisms and live microorganisms in the UF feed water. Variance Partitioning Analysis indicated that the combined contribution of organic, inorganic, and biological foulants was the most significant for UF membranes after S(IV)–Fe(II)/PM pretreatment (50.4%) and UF membranes after Al(III) coagulation pretreatment (70.2%). These findings underscore the efficacy of S(IV)–Fe(II)/PM pretreatment in controlling UF membrane fouling under prolonged operation.

Effectiveness of Reducing Turbidity Levels of Tofu Industry Wastewater with Alum Coagulant

Tofu industry liquid waste is one of the pollutants that can pollute the environment, especially can cause turbidity in rivers, lakes, and other waters. One of the countermeasures is to treat the liquid waste by giving alum coagulant. The purpose of this study was to measure the turbidity level of tofu industry wastewater before and after the application of alum coagulant and calculate the effectiveness or optimal dose/concentration of alum coagulant. This research is a type of quantitative research with a quasi-experimental research design. The research was conducted at the Public Health Laboratory of Universitas Muhammadiyah Surakarta in January 2024. The data analysis technique used was quantitative to determine the effectiveness of alum coagulant, the test used was anova test. The results of this study indicate that the level of turbidity in the liquid waste of the tofu industry after the coagulation process using alum is at a concentration of 2 ml which produces a decrease in turbidity levels of 22.93%, a concentration of 4 ml produces a decrease in turbidity levels of 26.24%, a concentration of 6 ml produces a decrease in turbidity levels of 29.08%, and a concentration of 8 ml produces a decrease in turbidity levels of 36.41%, so that the optimum dose / concentration of alum coagulant is 8 ml because it has the best effectiveness value in reducing turbidity levels in the liquid waste of the tofu industry.

Unraveling the characteristics of dissolved organic matter removed by aluminum species based on FT-ICR MS analysis

Given the complexity of dissolved organic matter (DOM) and its interactions with coagulant chemicals, the mechanisms of DOM removal by aluminum (Al) coagulants remains a significant unknown. In this study, six test waters containing DOM with molecular weight (MW, <1 kDa, 1–10 kDa and >10 kDa) and hydrophobicity (hydrophilic, transphilic and hydrophobic) were prepared and coagulated with Al0, Al13 and Al30. The molecular-level characteristics of DOM molecules that were removed or resistant to removal by Al species were analyzed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results showed that at the molecular level, saturated and reduced tannins and lignin-like compounds containing abundant carboxyl groups exhibited higher coagulation efficiency. Unsaturated and oxidized lipids, protein-like, and carbohydrates compounds were relatively resistant to Al coagulation due to their higher polarity and lower content of carboxyl groups. Al13 removed molecules across a wider range of molecular weights than Al0 and Al30, thus the DOC removal efficiency of Al13 was the highest. This study furthers the understanding of interactions between Al species and DOM, and provides scientific insights on the operation of water treatment plants to improve control of DOM.

A Study of the Effects of Alum and PAC on the Coagulation Process of Dug Well Water

The local population of Pal IX Village in West Kalimantan heavily depends on dug wells as their main source of obtaining clean water. The prolonged consumption of elevated concentrations of manganese (Mn) and iron (Fe) in water sourced from dug wells have neurotoxic effects on both adults and children. Therefore, it is imperative to employ alum and PAC coagulants for the treatment of dug well water in order to comply with the established national quality standard. However, the utilization of both coagulants resulted in elevation in the levels of iron (Fe), hence restricting the capacity to satisfy the quality standards. An augmentation in the mass of the coagulant is associated with a decline in the reduction efficiency. It is indicated that utilizing a mass of 0.5 grams of alum coagulant is the most favorable choice, resulting in a reduced of 50.14% for total dissolved solids (TDS), 86.25% for color, 97.70% for turbidity, and 94.48% for the concentration of Mn metal. By PAC coagulant, it has been determined that an ideal coagulant mass of 0.5 gram produces favorable outcomes with a TDS reduction of 45.08%, a color reduction of 97.71%, a turbidity reduction of 97.22%, and a Mn reduction of 95.04%.

Investigating the improvement of the quality of industrial effluents for reuse with added processes: coagulation, flocculation, multi-layer filter and UV

Reuse of wastewater is one of the ways to develop water resources. In addition to the need for drinking water, many industries also need high-quality water in the production line. Therefore, the purpose of the present study is to investigate the advanced treatment of the wastewater treatment plant of Morche Khort industrial town using the processes of coagulation, flocculation with aeration, multi-layer filter, and disinfection by ultraviolet radiation to increase the quality of wastewater and reuse it in industries. In this study, to investigate the effect of coagulation and flocculation units along with aeration, filtration, and disinfection by ultraviolet rays (UV), on the quality of the secondary effluent from the wastewater treatment plant of Morche Khort industrial town, they were operated on a pilot scale. Polyaluminum chloride (PAC) was used as a coagulant. Layering of three layers of sand filter, from bottom to top including granulated silica at a height of 10 cm, sand at a height of 20 cm, and activated carbon at a height of 70 cm was used. The input and output sampling points of each unit were considered. By repeating twice in five stages of flow rates of 1, 2, 4, 6, and 8 (L/min), the samples were collected to determine COD, TSS, TDS, turbidity, pH, hardness, total coliform, and fecal coliform. Jar test results showed that Alum coagulant works almost the same as PAC in removing turbidity, but the efficiency of removing organic substances by PAC coagulant is higher than that of Alum at lower doses. The results of this study showed that the efficiency of the coagulation and flocculation process in removing turbidity, COD, TSS, TDS, and fat was 56.88%, 46.66%, 38%, 23.19%, and 91.43% respectively. In the current study, the results of the wastewater entering the sand filter showed that the percentage of removal efficiency with a loading rate of 1 (L/min) was turbidity, TSS, COD, TDS, and fat was 16. 93%, 56.84%, 50%, 5.67%, 33.44% respectively. In the UV disinfection unit, the removal efficiency percentage with a loading rate of 1 (L/min) for COD, TSS, turbidity, hardness, total coliform, and fecal coliform is 16%, 3.45%, 3.58%, 5.21%, 99.88%, and 98.37% respectively. Coagulation and flocculation system—multi-layer filter and disinfection can remove chemical–physical and microbial parameters to an acceptable level for using water in advanced purification systems and also for irrigation.

Use of Paci and Alum to Reduce Tss Levels in People's Rubber Soaking Liquid Waste

The coagulants used are PACl and alum because, in addition to their low price, PACl and alum are also proven to reduce turbidity and TSS levels in wastewater. This study aimed to determine the effect of PACl and alum on reducing TSS levels in people's rubber bath waste. This type of research is classified as an actual experiment, utilizing a pretest and posttest design with a control group. Integrated sampling was the sampling technique used in this study. Statistical analysis is performed using the normality test, and if the data is normally distributed, it is continued with the one-way ANOVA test. The normality test results showed average distributed TSS level data. They continued the Anova test (p = 0.005 &lt; ɑ = 0.05), which found a difference between PACl and alum coagulant in reducing TSS levels in people's rubber immersion liquid waste. A PACl dose of 1200 mg/L lowered TSS levels by 46%. While the alum dose of 3000 mg/LL has not been able to reduce TSS levels, The variation in the dose of PACl and alum coagulants should be reduced again to be optimal for reducing TSS levels in liquid waste. To meet the quality standards of rubber immersion waste by reducing TSS levels, liquid waste with acidic or alkaline properties needs a neutralization process by adding lime.

Al and Mn speciation changes during the pre-oxidation with potassium permanganate and coagulation removing natural organic matter and its membrane fouling behavior

In this study, we systematically explore coagulation behavior, ultrafiltration membrane fouling behavior and the mechanism involved in during the process of pre-oxidation of potassium permanganate and coagulation of aluminum chloride at different condition to treat model pollutants (humic acid, HA) and natural water. The KMnO4 pre-oxidation significantly enhances flocs formation, and for HA artificial water the flocs size increases from 82 to 122 μm at pH 5.5, from 63 to 185 μm at pH 7.0 and from 0 to 75 μm at pH 8.5, respectively, as for natural water it increases from 72 to 139 μm. The enhanced coagulation at pH 5.5 is attributed to the increased polymeric Al speciation after pre-oxidation along with the generated Mn2+ damaging the electric double layer structure. And for pH 8.5 it is mainly caused by the in-situ MnO2 as combination nuclei during pre-oxidation. Besides, for pH 7.0, the combined effect of in-situ MnO2 and the increased polymeric Al speciation both contribute to improvement of the coagulation. What's more, the enhanced Al coagulation by pre-oxidation of KMnO4 also helps alleviate the membrane fouling for both HA artificial water and natural water, and a much rougher surface with larger flocs forms after KMnO4-aided Al coagulation filtration. This study provides an alternative perspective on the mechanism of pre-oxidation coagulation process.

Enhanced coagulation coupled with cyclic IX adsorption-ARP regeneration for removal of PFOA in drinking water treatment.

Laboratory investigations were conducted to demonstrate a potentially transformative, cost-efficient per- and polyfluoroalkyl substances (PFAS) treatment approach, consisting of enhanced coagulation and repeated ion exchange (IX)-advanced reduction process (ARP) for concurrent PFAS removal and IX resin regeneration. Enhanced alum coagulation at the optimal conditions (pH6.0, 60 mg/L alum) could preferentially remove high molecular-weight, hydrophobic natural organic matter (NOM) from 5.0- to ~1.2-mg/L DOC in simulated natural water. This facilitated subsequent IX adsorption of perfluorooctanoic acid (PFOA, a model PFAS in this study) (20 μg/L) using IRA67 resin by minimizing the competition of NOM for functional sites on the resin. The PFOA/NOM-laden resin was then treated by ARP, generating hydrated electrons (eaq - ) that effectively degraded PFOA. The combined IX-ARP regeneration process was applied over six cycles to treat PFOA in pre-coagulated simulated natural water, nearly doubling the PFOA removal compared with the control group without ARP regeneration. This study underscores the potential of enhanced coagulation coupled with cyclic IX-ARP regeneration as a promising, cost-effective solution for addressing PFOA pollution in water. PRACTITIONER POINTS: Enhanced alum coagulation can substantially mitigate NOM to favor the following IX removal of PFOA in water. Cyclic IX adsorption-ARP regeneration offers an effective, potentially economical solution to the PFOA pollution in water. ARP can effectively degrade PFOA during the ARP regeneration of PFOA/NOM-laden resin.

Aluminium recovery from aluminium foil waste as coagulant for domestic wastewater treatment

The high use of aluminium foil in food and beverage packaging has caused solid waste to increase rapidly, so solid waste treatment is required. This study investigates the best concentration of reactant to aluminium recovery from aluminium foil waste as potash alum coagulant. Potassium hydroxide is used for dissolved aluminium, and sulphuric acid is added to form potash alum crystals. The experimental result got a maximum point for the synthesis of potash alum from aluminium foil: potassium hydroxide 3 M dan sulphuric acid 3 M which produced a potash alum yield’s 99,59% and contains 11,19% of aluminium oxide. The quality of potash alum products is compared to the technical requirements of SNI 0032:2011. Potash alum was applied to the domestic wastewater and compared with commercial alum. The turbidity, TSS, and TDS domestic wastewater treatment results showed that potash alum has better performance than commercial alum.

Revelation of the interaction between aluminum coagulants and natural organic matters in the dual-system during nanofiltration membrane scaling

Aluminum (Al) coagulants are widely and frequently applied to coagulation pretreatment before nanofiltration. However, the excess coagulants and residual natural organic matters (NOMs) might affect the gypsum scaling during nanofiltration process. This study investigated the nanofiltration membrane fouling process under Al coagulants and specific NOMs, including humic acids (HA), bovine serum protein (BSA), and sodium alginate (SA) in a dual-system. The flux and the particle size decreased significantly when both above were present. The gypsum crystallization on the membrane surface was enhanced, while the bulk crystallization was weakened. Zeta potential and the NICA-Donnan model showed that Al coagulants competed with Ca2+ to bind HA weakening the bulk crystallization of gypsum. Meanwhile, Al coagulants decreased the salt rejection rate. Interestingly, the BSA and SA alleviated the flux decrease. Furthermore, the characterization of the fouled membrane showed that the concentration of Ca2+ and SO42− on the membrane surface increased further in the presence of Al coagulants, the grain size reached 582.0 nm when both HA and Al were present, larger than the control group and when they were present in the feed solution alone. Finally, the modified Hermia model was introduced to analyze the mechanism of the interaction between Al coagulants and NOMs. It is suggested that the control of Al coagulants and HA is necessary for the coagulation pretreatment before nanofiltration.

Molecular Transformation of Dissolved Organic Matter during the Processes of Wildfire, Alum Coagulation, and Disinfection Using ESI(−) and ESI(+) FT-ICR MS

Molecular Transformation of Dissolved Organic Matter during the Processes of Wildfire, Alum Coagulation, and Disinfection Using ESI(−) and ESI(+) FT-ICR MS

Coagulation-flocculation process for greywater treatment using Chitosan and Hibiscus Sabdariffa

Abstract Greywater means faecal free wastewater from households and buildings. Recycled greywater can be used for daily activities where freshwater is not necessary. Coagulation and flocculation technique in water recycling mostly utilize chemical coagulant alum. However, alum residue in water causes neural diseases and the process produces toxic sludge. Hence, natural coagulant is a safer alternate. Previous studies had proved the efficiency of different types of natural coagulant used individually and as a combination. However, the combination of chitosan and H. Sabdariffa had not been tested. The objective of this research is to investigate the efficiency of chitosan and H. Sabdariffa used alone and combined in greywater treatment. Jar test experiment was conducted using 0.5 L greywater in beakers mixed with the coagulants. The pH and coagulant dosage in each beaker were manipulated to determine the optimum condition. The greywater was then mixed rapidly for 4 minutes at 140 rpm, then slowly for 20 minutes at 30 rpm. Before assessing the final turbidity and Chemical Oxygen Demand (COD), the beakers were allowed to settle for an hour. At pH 4, 0.8 mg/L of chitosan reduced turbidity by 51 % and COD by 60 %. With a dosage of 200 mg/L, H. Sabdariffa demonstrated its best effectiveness at pH 2, resulting in an 88 % reduction in turbidity and a 53 % reduction in COD. When chitosan and H. Sabdariffa were combined, the optimal composition was determined to be 40% chitosan and 60% H. Sabdariffa by weight at pH 4, resulting in a turbidity reduction of 94% and a COD reduction of 56%. The same experiment was carried out using alum at pH 6 and a coagulant dose of 200 mg/l, turbidity and COD were reduced by 96% and 62% respectively. respectively. As a result, the performance of chitosan and H. Sabdariffa have been shown to be comparable to alum in the treatment of greywater, separately and in combination.

The Utilization of Pectin as Natural Coagulant-Aid in Congo Red Dye Removal

Coagulation using inorganic compounds such as aluminum sulfate is commonly used in water-wastewater treatment. However, there are some drawbacks to its utilization, such as a significant decrease in the treated water’s pH, non-biodegradable sludge, and a potential negative impact on human mental health (dementia and Alzheimer's). The use of inorganic coagulants can be minimized with the addition of natural-based coagulant-aid such as pectin. In this study, Congo red solution, a model dye substance, was coagulated by varying the pH (3–7) using alum coagulant to determine the best pH for coagulation. At the best pH, pectin was introduced at various doses (0–30 mg/L), and subsequently various dye concentrations (50–100 mg/L). The effect of pectin as coagulant-aid was compared with aluminum sulfate and pectin only; with a response of %removal and sludge volume. It was found that the Congo red dye coagulation had the best %removal at pH 6 indicating a charge neutralization mechanism. The addition of 15 mg/L pectin at an aluminum sulfate dose of 30 mg/L resulted in 97.7% dye removal with a sludge volume of 14 mL/L at a Congo red concentration of 50 mg/L. This value is higher compared to those of aluminum sulfate and pectin only which gave 75.6 and 3.19% removals, respectively. Furthermore, the addition of pectin as a natural coagulant-aid could halve the sludge volume due to the formation of denser flocs. The results show a promising potential of pectin as a natural coagulant-aid in water-wastewater treatment.