Hybrid Coagulant Research Articles

Application of Thymus Species as Natural Coagulant for Elimination of Turbidity of Water and Its Comparison with the Conventional Coagulant

Introduction: The most important pollutant in surface water sources is turbidity. The aim of the study is to determine the most effective thyme plant extract as a natural coagulant to remove water turbidity and compare it with alum as a chemical coagulant.. Materials and Methods: In this study, plant extracts obtained from Thymus vulgaris (Tv), Thymus kotschyanus (Tk), and Thymus eriocalyx (Te) were used as natural coagulants for elimination of water turbidity. Then, the best of plant extract was confirmed by ninhydrin and FTIR analyses and the effect of simultaneous use of plant extract with chemical coagulant of aluminum sulfate (alum) was investigated in the hybrid ratio of 1:1, 2:1, and 1:2. Then, the effect of parameters include of pH, coagulant dose, turbidity removal efficiency, and the most suitable solvent for coagulant extraction were studied. Results: The results of this study showed that among the natural coagulants, Tv had a higher efficiency in elimination of water turbidity, and the highest amounts of turbidity elimination for Tv, alum, and Tv/alum hybrid coagulants was 94, 90, and 96, respectively. According to the results of this study, the most effective solvent for preparing plant extracts was 1M KCl solvent. Conclusion: The natural coagulant removes more turbidity from water than the chemical coagulant, and the simultaneous use of natural and chemical coagulants with a 1:1 ratio was more effective.

Superior microplastic removal and gravity-driven membrane filtration optimization: The role of octadecyl-quaternium hybrid coagulant and molecular dynamics insights

Microplastics (MPs) contamination in surface water poses significant environmental and health threats, particularly in rural areas without centralized water treatment systems. Although pre-coagulated gravity-driven membrane (GDM) is a promising decentralized drinking water treatment technology, the impact of MPs on its performance has not been clearly understood yet. In this study, octadecyl-quaternium hybrid coagulant (OQHC) is proposed as an innovative solution for the efficient removal of MPs. Specifically, the effectiveness and mechanisms of OQHC in removing MPs are investigated, and the performance of a GDM pre-coagulated with OQHC is comprehensively evaluated. The findings reveal that OQHC achieves a superior MPs removal efficiency of 93.45 % in surface water, outperforming conventional coagulants such as PACl and AlCl3. Molecular dynamics simulations suggest that OQHC primarily removes MPs through hydrophobic interactions facilitated by its long octadecyl carbon (C18) chains, with humic acid (HA) enhancing the electrostatic interactions. Furthermore, the stability and permeability of GDM filtration pre-coagulated with OQHC are influenced by the cake layer’s zeta potential in the initial stage (0–90 h) and porosity in the late stage (90–120 h). Moreover, the presence of MPs increases the quantity of particles smaller than 6 µm, resulting in lower porosity of the cake layer and steeper flux decline rates during prolonged filtration. Overall, this study establishes OQHC pre-coagulated GDM filtration as a promising approach for addressing MPs contamination in surface water, offering an efficient solution for ensuring safe drinking water in rural areas.

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.

Navigating Heavy Metal Removal: Insights into Advanced Treatment Technologies for Wastewater: A review.

<p><span lang="EN-US" style="font-size:12.0pt"><span style="background:white"><span style="line-height:107%"><span style="font-family:"Times New Roman",serif"><span style="color:black">This paper provides an overview of heavy metal removal technologies for wastewater treatment, with a focus on adsorption, chemical oxidation, ion exchange, and various coagulation processes. The discussion revolves around wastewater characterization as an essential first step in creating efficient treatment systems. The study examines the uses of different treatment technologies, emphasizing both their benefits and drawbacks. Although flocculation is a rapid and economical procedure, it produces waste and needs further filtration and sedimentation. In addition, natural coagulants are found to be more environmentally friendly than synthetic ones, their effects on water quality may make disinfectants necessary. Despite their low toxicity, stability, and environmental advantages, hybrid coagulants have certain drawbacks that are related to operational variables. Despite its broad applicability and low cost, adsorption faces challenges with regeneration and sludge creation. Although it is acknowledged to have a high metal recovery rate, ion exchange is expensive and requires special maintenance. Chemical oxidation techniques, in particular advanced oxidation processes (AOPs), are useful for eliminating heavy metals and breaking down organic materials. The limitations and difficulties of each approach are discussed in the abstract's conclusion, which highlights the necessity of future study aimed at enhancing treatment efficacy for extremely low quantities of heavy metals. To allay worries about energy usage, the integration of electrochemical processes with renewable energy sources is recommended.</span></span></span></span></span></p>

Integration of Copperas and <i>Moringa oleifera</i> Seeds as Hybrid Coagulant for Turbidity and Ammonia Removal from Aquaculture Wastewater

The rapid development of the aquaculture industry has contributed to the high amount of nutrients in wastewater that subsequently led to eutrophication and deterioration of water quality. Aquaculture wastewater consists of uneaten fish feed, fecal and other excretion or residue of chemicals used. Thus, this study aimed to evaluate the performance of hybrid coagulants of Moringa oleifera (MO) and copperas for aquaculture wastewater treatment. In this present study, different formulations of MO and copperas were explored in the coagulation treatment of aquaculture wastewater using a jar test experiment. The FTIR and SEM analysis are used to determine the morphology and surface of MO. This study focuses on the effect of coagulant aids formulation, coagulant dosage, the effect of initial pH and coagulation time on turbidity and ammonia removal in the coagulation of aquaculture wastewater. The finding shows that the highest removal of turbidity and ammonia was obtained with the use of 80% MO and 20% copperas at the condition of initial pH of 6 at 20 min of coagulation time, with the highest percentage removal of 66% and 91%, respectively. The coagulation isotherm of hybrid coagulant 80:20 is well described with the Freundlich isotherm model which describes the surface heterogeneity.

Enhanced sludge dewaterability using a bifunctional hybrid coagulant

The combination of coagulation and addition of skeleton builder is a popular pretreatment method to improve the dewaterability of sludge. In this study, a novel bifunctional inorganic/organic hybrid coagulant (CS–Si@ATP) was designed and obtained by chemically coupling a cationic starch (CS) with a popular clay, that is, attapulgite (ATP), via a silane coupling agent (APTES) for one-step conditioning of sludge. CS-Si@ATP can evidently enhance the sludge dewatering performance compared with CS, ATP, and their simple combination due to the distinct dual functions of this hybrid coagulant. The tentacle-like cationic CS in CS-Si@ATP shows efficient charge neutralization effect to aggregate and precipitate the suspended solids for further formation of compact sludge cakes. Meanwhile, the internal ATP with a stable and rigid structure acts as the skeleton builder to notably improve the filterability and permeability of the sludge cakes. The synergistic effects of CS and ATP in CS-Si@ATP, i.e., the charge neutralization of CS and the skeleton construction of ATP, cause the evidently enhanced sludge dewaterability, with a filter cake moisture content approximately 78.30% after the mechanical dewatering at 0.05 MPa. In comparison with the traditional two-step combination process by separated addition of CS and ATP, the one-step addition of CS-Si@ATP can reduce the required ATP dose nearly an order of magnitude. Thus, CS-Si@ATP has the notable advantages of simple operation, efficient utilization of ATP and evident reduction of disposal cost. This study provides an environmentally friendly and cost-effective coagulant to further improve the dewaterability of sludge.

A versatile organic silicate aluminum hybrid coagulant for broad-spectrum removal of heavy metal ions

Complete removal of metals in wastewater remains challenging due to the co-existence of multiple types of free and complexed metal ions, which hold distinctive molecular properties. Current technologies face the problem of specificity in metal capture that simultaneous removal of various metal ions is highly inefficient. Herein, we report a versatile hybrid coagulant with the capability of indiscriminately removing multifarious metal ions through the synergistic effect of its organic and inorganic groups. Diverse customized organic groups collectively capture metal ions, meanwhile inorganic polynuclear aluminum aggregate into flocs for easy separation from water. The coagulant is the first to achieve nearly full removal toward a wide range of metal ions including free metal ions covering hard acids (La3+, Zr4+, Mn2+), soft acids (Hg2+, Cd2+, Pd2+) and borderline acids (Zn2+, Ni2+, Co2+), as well as a typical complexed metal ion, i.e., Cu-citrate. Free metal ions were captured through complexation with hard base –OH and soft base -SH, while complexed metal ion was removed via ion exchange by -N+(CH3)2RCl− and ligand exchange by Al-OH. The coagulant exhibited excellent stability and reusability in several recycling processes. The versatile coagulant provides a highly efficient way for heavy metal pollution control, which is applicable for the treatment of any wastewaters with unpredictable metal species.

Novel covalently bound organic silicon-ferrum hybrid coagulant with excellent coagulation performance and bacteriostatic ability

The complex composition of water bodies often complicates the water treatment process. Coagulation is an important part of water treatment, subsequent water treatment can be simplified by maximally removing suspended particles, natural organic matter, and pathogenic microorganisms during coagulation. Here, we developed a novel silicon-ferrum hybrid coagulant (SFHC). The morphology and structure were described by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and X-ray diffraction (XRD). The Fe-ferron reaction kinetics were used to evaluate the morphological distribution of Fe species in SFHC. It was finally determined that the SFHC with Si/Fe of 0.1 and B value of 1.0 showed the best coagulation efficiency. At the optimum dose, SFHC achieved 95.83% removal of 20 mg L−1 humic acid wastewater, and turbidity was almost completely removed in kaolin wastewater. SFHC maintained high coagulation efficiency over a wide range of pH values (pH 5–9), which was superior to conventional coagulants. Furthermore, SFHC has excellent coagulation performance to the soluble small-molecular pollutants as nitrate (NO3–), phosphate (PO43−) and diclofenac (DCF) in water, and has good bacteriostatic ability to pathogenic microorganisms (96.94% bacteriostatic rate at 40 × 10−5 mol L−1 dosage). Regarding actual water bodies, SFHC also showed excellent performance. Therefore, SFHC has great potential as a multifunctional and effective coagulant.

Investigation of the treatability of paint industry wastewater using hybrid coagulant poly-aluminum-chloride-sulfate

Investigation of the treatability of paint industry wastewater using hybrid coagulant poly-aluminum-chloride-sulfate

Molecular dynamics simulation study of covalently bound hybrid coagulants (CBHyC): Molecular structure and coagulation mechanisms

Covalently-bound organic silicate-aluminum hybrid coagulants (CBHyC) have been shown to efficiently remove low molecular weight organic contaminants from wastewater. However, the interaction dynamics and motivations during the coagulation of contaminant molecules by CBHyC are limited. In this study, a molecular dynamics (MD) simulation showed that CBHyC forms core-shell structure with the aliphatic carbon chains gather inside as a core and the hydrophilic quaternary ammonium-Si-Al complexes disperse outside as a shell. This wrapped structure allowed the coagulant to diffuse into solutions easily and capture target contaminants. The adsorption of anionic organic contaminants (e.g., diclofenac) onto the CBHyC aggregates was driven equally by van der Waals forces and electrostatic interactions. Cationic organic contaminants (e.g., tetracycline) were seldom bound to CBHyC because of substantial repulsive forces between cationic molecules and CBHyC. Neutrally-charged organic molecules were generally bound through hydrophobic interactions. For adenine and thymine deoxynucleotide, representatives of antibiotic resistance genes, van der Waals forces and electrostatic interaction became the dominant driving force with further movement for adenine and thymine, respectively. Driving forces between target contaminant and coagulant directly affect the size and stability of formed aggregate, following the coagulation efficiency of wastewater treatment. The findings of this study enrich the database of aggregation behavior between low molecular weight contaminants and CBHyC and contribute to further and efficient application of CBHyC in wastewater treatment.

Iron-based technology coupling moderate preoxidation with hybrid coagulation for highly effective removal and moderate growth inhibition of Oscillatoria in drinking water treatment plants

A novel technology coupling moderate preoxidation and hybrid coagulation was invented to solve the issues caused by Oscillatoria in drinking water treatment plants (DWTPs). In this technology K2FeO4 can reduce the electronic repulsion between Oscillatoria filaments without cells’ lysis and thereby make them tend to aggregate into flocs. After preoxidation in-situ Fe(III) reduced from Fe(VI) will form a highly efficient hybrid coagulant through addition of a low dose of chitosan quaternary ammonium salt (HTCC). This process can remove most of the algal cells and metabolites in Oscillatoria-laden water and alleviate filter blockages. After treatment, 93.0% of algal cells can be removed and the DOC, turbidity and CYN can be respectively decreased from 15.3 mg/L to 5.8 mg/L, from 5.76 NTU to 1.48 NTU, and from 22 mg/L to 4.55 mg/L. During sludge storage, the effects of the moderate oxidation of Fe(VI) and the anti-algal activity of HTCC can consistently control the proliferation of Oscillatoria and the increase of algal metabolites, thereby reducing the difficulty of sludge treatment and making the reuse of sludge water more feasible. In a nutshell, the new technology is suitable for DWTPs when Oscillatoria blooms break out in source water.

A novel technology using iron in a coupled process of moderate preoxidation–hybrid coagulation to remove cyanobacteria in drinking water treatment plants

Preoxidation–coagulation is adopted by many drinking water treatment plants to enhance the removal of cyanobacteria. However, conventional technologies — such as the combination of prechlorination with Al-salt coagulation — can easily induce secondary pollution caused by cell lysis and yield unsatisfactory performance both in removal of cyanobacterial cells and metabolites and in alleviation of filter unit fouling. To solve these issues, an iron-based coupled process of moderate preoxidation–hybrid coagulation was invented. In this technology Fe(VI) can moderately oxidize algal cells, resulting in the removal of electronegative organics coating the surfaces of the cells without destroying the algae. After preoxidation, in-situ Fe(III) produced from Fe(VI) will form a highly effective hybrid coagulant by adding a low dose of chitosan quaternary ammonium salt. Combining the reduction of electrostatic repulsion between algal cells obtained from K2FeO4 preoxidation with the enhancement of charge neutralization, polymer bridging and adsorption capability obtained from hybrid coagulation, 92.6% of Microcystis aeruginosa cells were removed and the DOC and microcystin concentrations respectively decreased from 23.54 to 7.63 mg/L and from 16.2 to 0.96 mg/L. Meanwhile the membrane fouling was markedly alleviated. Hence this new technology couples moderate preoxidation and hybrid coagulation through the Fe(VI)–Fe(III) pairing, which is safer and more effective and can thus be a better alternative for cyanobacterial removal in drinking water treatment plants.

Characteristics of the Waste Wood Biomass and Its Effect on the Properties of Wood Sanding Dust/Recycled PP Composite.

To decrease climate changes, more research focuses on decreasing waste wood biomass (WWB) burning and increasing its conversion into value-added products. The WWB was isolated from model wood processing wastewater with a new hybrid coagulant by the coagulation/flocculation method. This study is aimed to characterize the WWB and to investigate its effect in the composition of a hybrid lignocellulosic filler on the properties of recycled polypropylene (rPP)-based wood–plastic composites (WPCs). The waste biomass contained high-molecular lignin and hemicelluloses substances and represented a finely dispersed powder. It was hydrophobic and was characterized by enhanced thermal stability. To minimize the negative effect of polymer wastes on the environment, recycled polypropylene as a polymer matrix was used with the hybrid filler in fabricating WPC samples. The presence of the coagulated WWB in the hybrid filler composition positively affects the mechanical properties, water uptake and dimensional stability of the composite samples. Such a behavior of the waste biomass showed its function as a compatibilizer, which promoted the interfacial adhesion in the composite system.

Molecular Dynamics Simulation Study of Covalently Bound Hybrid Coagulants (Cbhyc): Molecular Structure and Coagulation Mechanisms

Molecular Dynamics Simulation Study of Covalently Bound Hybrid Coagulants (Cbhyc): Molecular Structure and Coagulation Mechanisms

Comparison of natural extract as a clean coagulant with alum and natural extract-alum hybrid coagulant for removal of water turbidity

Comparison of natural extract as a clean coagulant with alum and natural extract-alum hybrid coagulant for removal of water turbidity

Novel Covalently Bound Organic Silicon-Ferrum Hybrid Coagulant with Excellent Coagulation Performance and Bacteriostatic Ability

Novel Covalently Bound Organic Silicon-Ferrum Hybrid Coagulant with Excellent Coagulation Performance and Bacteriostatic Ability

Effects of different polymerisation conditions using hybrid polymer on high turbidity suspensions

PurposeIn this study, new hybrid polymers composed of Zinc chloride (ZnCl2), acrylamide and chitosan were prepared at different ratios and temperatures. The effects of pH and polymer dosage were examined for different polymers to observe their efficiency in the removal of turbid water. The polymers’ zeta potential, morphology, elemental composition and functional groups were also identified and studied.Design/methodology/approachThe free-radical polymerisation process was executed in the presence of N, N’-Methylene bis-acrylamide and potassium persulphate in one molar acrylamide solution. ZnCl2 and chitosan (CO) were later introduced into the suspension under nitrogen gas flow. Ratio and temperature were varied during polymerisation. The hybrid polymer produced, termed Polyacrylamide + chitosan oligosaccharide + zinc chloride (PAMCOZ), was analysed using Fourier transform infra-red spectroscopy attenuated total reflectance and scanning electron microscope with energy dispersive X-ray. The hybrid PAMCOZ was experimented with in high turbid kaolin suspension using jar testing analysis to see its ability as a coagulant.FindingsThe coagulation process using PAMCOZ with a ratio of 11 (3:2) at 70°C surrounding temperature showed a 100% reduction at pH 4 with 50 mg/L of the polymer. The functional groups present in ratio 11 polymer were hydroxyl, carbonyl, amide and methyl groups. In addition, several elements were spotted on the surface of PAMCOZ, such as zinc (Zn), carbon (C), chlorine (Cl), nitrogen (N) and oxygen (O). The effect of pH also demonstrated that PAMCOZ was unfavourable in an alkaline turbid water environment.Research limitations/implicationsDue to the research methodology approach, the research results may lack actual wastewater application. Therefore, researchers are encouraged to test the hybrid coagulant on raw wastewater, such as pulp and paper mill effluent with a high turbidity value similar to this study.Originality/valueThe polymerisation between zinc chloride, acrylamide and chitosan has not yet been applied. The different ratios and effects of temperature were analysed on PAMCOZ to see the turbidity removal. PAMCOZ showed better turbidity removal in acidic conditions.

Tire pyrolysis wastewater treatment by a combined process of coagulation detoxification and biodegradation

Recycling waste tires through pyrolysis technology generates refractory wastewater, which is harmful to the environment if not disposed properly. In this study, a combined process of coagulation detoxification and biodegradation was used to treat tire pyrolysis wastewater. Organics removal characteristics at the molecular level were investigated using electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results showed that nearly 90% of the organic matter from the wastewater was removed through the process. Preference of the two coagulants for different classes of organics in tire pyrolysis wastewater was observed. The covalently bound inorganic-organic hybrid coagulant (CBHyC) used in this work had a complementary relationship with biodegradation for the organics removal: this coagulant reduced toxicity and enhanced the biodegradation by preferentially removing refractory substances such as lignin with a high degree of oxidation (O/C > 0.3). This study provides molecular insight into the organics of tire pyrolysis wastewater removed by a combined treatment process, supporting the advancement and application of waste rubber recycling technology. It also contributes to the possible development of an effective treatment process for refractory wastewater.

Enhanced coagulation for mitigation of disinfection by-product precursors: A review

The unintended formation of disinfection by-products (DBPs) has received considerable attention as it may pose risks to human health. Coagulation is the most common process for removing particulates as well as dissolved organic matter (DOM) (i.e., DBP precursors) during drinking water and wastewater treatments. With the improvement of water quality standards and the increased fluctuation in source water quality, conventional coagulation becomes challenging. Thus, significant efforts have been made to enhance coagulation to promote the removal of DOM in source water and mitigate the formation of DBPs in drinking water. This review provides a brief summary of the properties of DBP precursors and summarizes the effectiveness of enhanced coagulation involving three types of coagulants (metal-based coagulants, organic polymers, and organic-inorganic hybrid coagulants) in controlling the formation of DBPs during chlor(am)ination disinfection. Metal-based coagulants can achieve a reduction in DBP formation potential of approximately 20%–60% in natural water under enhanced coagulation conditions. Both the organic polymers (used as coagulant aids) and novel hybrid coagulants increase the removal of DOM and exhibit high potential for mitigating DBP formation. In addition, integrated treatments combining coagulation with other treatment processes (e.g., oxidation, membrane filtration, ion exchange, and adsorption) to enhance DBP precursor removal are evaluated in terms of performance, mechanisms, and features. Advanced treatments, such as membrane filtration and activated carbon adsorption, are effective coagulation-assisted processes, and can further control chlorinated DBPs; however, the elevated formation of bromate or highly brominated DBPs is of particular concern.

Removal of disinfection by-product precursors by Al-based coagulants: A comparative study on coagulation performance

Coagulation is well-established for controlling regulated disinfection by-products (DBPs), but its effectiveness for controlling unregulated DBPs remains unclear. The efficiency of coagulation in controlling unregulated DBPs requires clarification owing to their relatively high toxicity. In this study, three Al-based coagulants, aluminum sulfate (Alum), polyaluminum chloride (PAC), and a novel type of covalently bond hybrid coagulant (CBC, synthesized using AlCl3) were selected, and the coagulation performance of these Al-based coagulants in controlling DBPs and DBP-associated toxicity was compared over 5 classes of DBPs, including trihalomethanes, haloacetic acids, haloacetaldehydes, haloacetonitriles, and halonitromethanes. The results showed that Alum was the least efficient in removing DBP precursors among the three coagulants. The effectiveness of CBC and PAC for DBP control varied with the characteristics of source waters. CBC had an advantage in water with a low content of humic acids, and reduced DBP concentration and DBP-associated toxicity by 47% and 25%, respectively. For water rich in aromatic organics, CBC might serve as DBP precursors at a high-required dosage, suggesting that a trade-off between enhanced DBP control and serving as DBP precursors should be considered for CBC coagulation; PAC achieved the most reduction in DBP concentration and DBP-associated toxicity by 50% and 34%, respectively.