Abstract

Polyacrylamide (PAM) and sodium polyacrylate (PAAS) are widely used in the oil industry, and their treatment processes each serve various yet complementary functions. PAM has a high molecular weight polymer employed primarily as a flocculant to increase the aggregation, dewatering of sludge, and sedimentation of particles. While PAAS acts as a de-flocculant, dispersing particles to regulate fouling and scale formation in industrial systems and pipelines. This study also presents a comparative analysis of these polymers, emphasizing their effectiveness, roles, cost implications, and dosage requirements in various treatment applications. A detailed examination of their mechanism highlights how PAM facilitates solid and liquid separation in wastewater treatment, increased oil recovery, and mining.

In contrast, PAAS is instrumental in preventing scale deposition in boilers, cooling towers, and petroleum extraction processes. The analyses of comparative dosage in different industrial settings, along with optimal concentrations for achieving maximum efficiency. Cost-effectiveness is evaluated by comparing PAM and PAAS treatment expenses versus conventional inorganic treatment methods, with and without polymer applications. The findings indicate that PAM significantly improves coagulation-flocculation efficiency, decreasing sludge volume and operational costs, whereas PAAS increases system longevity by mitigating scale-related maintenance issues. Understanding the balance between dispersion and flocculation is essential for selecting the appropriate treatment strategy. This study provides valuable insights into optimizing polymer applications for sustainable environmental and industrial management.

Keywords

Polyacrylamide; Sodium polyacrylate; Flocculant; De-flocculant; Water treatment; Oil industry; Cost analysis; Dosage comparison

Introduction

Water-soluble polymers such as polyacrylamide (PAM) and sodium polyacrylate (PAAS) are used in diverse industries due to their unique physicochemical properties [1]. Polyacrylamide (PAM), a high-molecular-weight polymer that is available in non-ionic, cationic, and anionic forms, is prepared from acrylamide monomers [2]. It is used extensively for soil conditioning, water treatment, and oil recovery. Primarily because of its excellent flocculating and gel-forming properties. These characteristics make PAM effective in solid-liquid separation processes, particularly in municipal and industrial wastewater treatment [3].

Conversely, sodium polyacrylate (PAAS), an acrylate-based superabsorbent polymer, is prized for its remarkable liquid retention ability taking up several hundred times more weight in water [4]. PAAS is used in coatings, drug delivery systems, water retention in agriculture, and personal hygiene products like diapers and sanitary napkins [5]. Although PAM and PAAS are both hydrophilic, their uses are different: PAM is primarily employed as a flocculant/thickener, while PAAS performs as an absorber and dispersion agent [6].

These polymers are versatile as they find applications in fields like food processing, pharma, environmental engineering, and manufacturing [7]. Their corrosion resistance, durability, and lightweight nature make them suitable for automotive, aerospace, and package usage [8]. Polymers also have a major application in drug delivery, biomedical devices, and membranes in fuel cells as well as in water purification systems because of their biocompatibility and their ability to be customized with degradation properties [9].

Aside from industrial applications, polymers such as PAM and PAAS play a large role in making the environment more sustainable through efficient removal of pollutants, water treatment, and biodegradable potential [10]. Polymer science has also stimulated the creation of smart materials such as conductive, shape-memory, and nanocomposite polymers that is the basis of advance robotics and electronics [11].

In water and oil treatment applications, PAM and PAAS are used as flocculants and dispersants. Flocculants help bring suspended particles together to increase sedimentation and filtration, thus improving water quality and resource recovery in applications like mining, mineral processing, and wastewater treatment [12]. On the other hand, dispersants or de-flocculants preserve slurry stability and avoid pipeline clogging, thus increasing the efficiency of operations and saving maintenance costs [13].

The escalating international demand for clean water and green industrial processes has fueled the necessity for more advanced, costefficient, and eco-friendly treatment technologies. Classic wastewater treatment is usually marred by excessive energy requirements, high sludge generation, and poor contaminant removal efficiency. Hence, polymer-based treatments like PAM and PAAS provide favorable alternatives [14].

The research seeks to analyze and compare PAM and PAAS relative to industrial water treatment and oil recovery based on efficiency of performance, cost-effectiveness, environmental sustainability, and operational feasibility

Literature Review

Flocculation and deflocculation are opposing but critical processes in the aggregation and dispersion of particles, governed by fluid dynamics, electrostatic interactions, and colloidal chemistry. Flocculation occurs when electrostatic repulsion between suspended particles is neutralized or reduced, leading to aggregation into larger flocs [15]. Flocculants such as aluminum sulfate and polyacrylamide (PAM) accelerate this process through mechanisms including adsorption, charge neutralization, and polymer bridging [16]. In mining, oil, and water treatment operations, forces such as Van der Waals interactions, hydrogen bonding, and ionic interactions further facilitate particle aggregation.

Conversely, deflocculation (dispersion) aims to stabilize suspended particles by increasing electrostatic repulsion or providing steric hindrance, thereby preventing aggregation. Dispersants like sodium polyacrylate (PAAS) and phosphate-based additives impart negative charges or steric barriers on particle surfaces, maintaining stable suspensions [17]. This is particularly crucial in oil drilling and ceramics industries, where stable, low-viscosity suspensions are essential for operational efficiency. A precise balance between flocculation and deflocculation is vital for maximizing solid-liquid separation, managing fluid rheology, and ensuring optimal process performance [18].

PAM is a well-established polymer with strong flocculating, viscosity-retaining, and water-binding properties. It is extensively used in mining, wastewater treatment, and enhanced oil recovery (EOR) operations [19]. By aggregating fine particles, PAM improves the removal of suspended solids, organic matter, and heavy metals, facilitating sedimentation and sludge dewatering. Anionic and cationic PAM derivatives enhance turbidity removal and pollutant elimination from municipal and industrial effluents. In mining, PAM-based flocculants support better solid-liquid separation, reduce tailings handling issues, and improve water recycling while lowering chemical use [20]. In EOR, PAM increases the viscosity of injected water, enhancing oil mobility and reservoir sweep efficiency [21]. Recent advancements in hydrolyzed polyacrylamide (HPAM) formulations have enhanced performance in high-temperature and high-salinity environments [22].

PAAS, on the other hand, is a multifunctional polymer widely used for scale inhibition and dispersion in industries such as cooling systems, oil refining, and water treatment. It chelates with metal ions and disperses suspended solids, effectively preventing the aggregation and deposition of mineral scales like calcium carbonate and calcium sulfate [23]. In boiler and cooling water systems, PAAS inhibits crystal formation, reduces fouling, and lowers operational costs [24]. In the oil and gas sector, PAAS mitigates scale formation in high-salinity environments, maintaining fluid flow and extending equipment lifespan [25]. Its use as a dispersant also spans paints, ceramics, and detergents, owing to its ability to enhance suspension stability via electrostatic repulsion. Due to its thermal stability, biodegradability, and environmental compatibility, PAAS is gaining attention as a sustainable, non-traditional scale inhibitor [26].

Despite the wide adoption of PAM and PAAS, knowledge gaps remain regarding their long-term toxicity, biodegradability, and environmental impact in large-scale applications. Comparative studies assessing their performance under extreme conditions such as variable salinity, temperature, and pH, particularly in deep-sea reservoirs and acidic waste streams are limited. Furthermore, their interactions with co-treatment chemicals in multi-component systems require further exploration. Bridging these gaps is essential for developing greener, more responsive, and economically viable polymer-based solutions across industries.

Properties and Mechanisms of PAM and PAAS

Sodium polyacrylate (PAAS) and polyacrylamide (PAM) are two types of polymers derived from acrylic-based monomers that differ in their chemical structures and properties, which allows their industrial application. Polyacrylamide (PAM) is a non-ionic, high-molecularweight, water-soluble polymer that consists of acrylamide (C₃H₅NO) repeat units along its chains, which contain amide (-CONH₂) functional groups in its backbone [27]. It exists in non-ionic, anionic (negatively charged), and cationic (positively charged) depending on the chemical modification of the polymer backbone. Hydrolyzed polyacrylamide (HPAM) is produced by the partial hydrolysis of PAM and has carboxylate (-COO^⁻) groups that improve flocculation ability. On the other hand, sodium polyacrylate (PAAS) is an anionic polyelectrolyte that consists of acrylate (C₃H₃O₂Na) monomers that provide unique water absorption and dispersion properties owing to the presence of nonbonded anionic carboxylate groups neutralized with sodium ions (Na⁺) [28].

As a dispersant and scale inhibitor, PAAS works by repelling cations with the help of the similarly charged ions which prevents particle aggregation and the formation of mineral scales. On the other hand, PAM is a flocculant that promotes aggregation of solids due to electrostatic interaction and hydrogen bonding. Their specific chemical compositions and charge distributions determine their commercial functions. The applications of PAAS include numerous fields from scale inhibition, detergent formulations, to biomedical applications, while only PAM still focusing on wastewater treatment, mining, and oil recovery processes. Both polymers play a key role in material science and industrial fluid management processes due to their structural versatility and functional tunability [29].

Sodium polyacrylate (PAAS) and polyacrylamide (PAM) both possess substantial molecular differences, as presented in terms of functional groups, charges, and structures in the aqueous environment, making them suitable for industrial use. PAM is built of linear or slightly cross-linked chains of acrylamide units (C₃H₅NO) having amide groups (-CONH₂) that confer hydrophilicity to the polymer, while retaining electrical neutrality in its non-ionic form [30]. This results in hydrolyzed polyacrylamide (HPAM), a negatively charged polymer which upon partial hydrolysis, some of the amide groups convert to carboxylate (-COO^⁻) groups. This structural diversity affects their ionic dynamics and performance functionalities. PAAS is completely anionic and creates an electrostatic repulsion between the particles, thus preventing scale that occurs, whereas the PAM aggregates via hydrogen bonding, van der Waals force and charge bridging mechanism [31].

Furthermore, PAAS is more rigid and distinctly water-absorbent, which makes it particularly useful in superabsorbent and dispersion applications. At the same time, PAM is more flexible and has a higher molecular weight, enabling it to shape big polymeric networks. These molecular variations highlight their adaptability in industrial methods and define their numerous roles in mining, oil restoration, wastewater treatment, detergents, and biological packages [32].

Polyacrylamide (PAM) is a powerful flocculant that aggregates fine suspended particles by the mechanisms of charge neutralization, bridging, and adsorption. Depending on its molecular structure, PAM can exist in non-ionic, anionic, or cationic, which each type interacting differently with pollutants making it useful in industries such as water treatment, mining, and oil recovery operations. The negative electric charge of anionic PAM is due to the presence of carboxylate (-COO^⁻) groups [33]. First, the negatively charged PAM can compete with negatively charged groups on the surface of the oil and form metal ions and organic contaminant aggregation, leading to destabilization. Conversely, the reaction of cationic PAM with anions of negatively charged colloids (e.g. clay, organic matter and microbial cells) would favor sedimentation. This bridging mechanism [34] relies on long PAM polymer chains that physically link particles leading to the creation of large, compact flocs capable of rapidly settling under gravity. Moreover, the high molecular weight and flexibility of PAM chain increase surface adsorption capacity, floc strength and sludge dewatering efficiency.

The above-mentioned properties render PAM as an important polymer in mineral processing, waste-water treatment, and enhanced oil recovery where solid-liquid separation is important for environmental impulse and economic efficiency [35].

An effective de-flocculant (dispersant), the sodium polyacrylate (PAAS) helps with controlled aggregation of suspended particles by increasing electrostatic repulsion which will provide stable dispersions in a variety of industrial systems. As for PAAS, the carboxylate groups (–COO−) are interpreted to be neutralized by sodium ions (Na+) forming a strong anionic polyelectrolyte that maintains particle separation compared to the flocculating behavior of PAM. PAAS binds onto the surface of individual particles increasing electrostatic repulsion resulting in hindering the sedimentation due to the high negative charge released by PAAS. This property is particularly significant in the industries of drilling fluids, ceramics, detergent formulations, and scale inhibition from cooling systems - all of which require stable suspensions [36].

PAAS are used to stabilize slurry during mining and wastewater processes to prevent premature and unwanted flocculation that disrupts stability and compromises fluid dynamics. Furthermore, PAAS also works by inhibiting nucleation and crystal growth, and thus prevents deposition of scale in pipelines and industrial equipment by minimizing the formation of mineral scales. PAAS is therefore widely applied in chemical processes, industrial water, and scale prevention applications when stability and biodegradability ability is required to enhance operational efficiency and longevity of the process by controlling particle behavior [37].

PAM vs PaaS Overview

Feature	PAM	PAAS
Polymer Unit	Acrylamide (C3H5NO)	Sodium acrylate (C3H3O2Na)
Charge Type	Non-ionic, Anionic, or Cationic	Strongly Anionic
Key Function	Flocculant (particle aggregation)	Dispersant & Scale inhibitor
Main Mechanism	Charge neutralization and bridging	Electrostatic repulsion
Typical Applications	Wastewater, mining, EOR, soil	Cooling systems, oil pipelines, detergents
Environmental Profile	Acrylamide toxicity concerns	Biodegradable, low toxicity
Mechanical Behavior	Flexible, large network formation	Rigid, superabsorbent, stable suspensions

Industrial Applications

PAM and PAAS have become essential in many industries due to their excellent flocculating, dispersing, water-retaining, and scale inhibition properties.

This functional versatility leads to performance enhancement in municipal, industrial, energy, mining, chemical, and agricultural market sectors [38-48].

Overview of industrial applications

Industry Sector	Application Area	Role of PAM	Role of PAAS
Municipal Water & Wastewater Treatment	Sedimentation & Sludge Dewatering	Flocculates solids, improves sedimentation and sludge dewatering	Prevents scaling in membranes and pipelines
	Drinking Water Treatment	Aids coagulation, improves filterability	—
	Effluent Treatment	—	Scale inhibition during water recycling
Industrial Wastewater Management	Effluent Purification	Removes dyes, oils, heavy metals	Scale control in effluent systems
	Filtration	Enhances filtration throughput	—
Mining & Mineral Processing	Tailings Management	Accelerates settling of mineral slurries	Stabilizes slurry viscosity during transport
	Ore Beneficiation	Improves solid-liquid separation	—
Oil & Gas Industry	Enhanced Oil Recovery (EOR)	Improves sweep efficiency in polymer flooding	—
	Drilling Fluids	—	Stabilizes fluids, maintains wellbore stability
	Produced Water Treatment	Aids oil-water emulsion separation	—
Power Generation & Cooling	Scale Inhibition	—	Prevents scale deposits in cooling towers, boilers
	Boiler Feed water Treatment	—	Binds calcium/ magnesium to prevent precipitation
	Condensate Polishing	—	—
Pulp & Paper Industry	Retention Aid	Improves retention of fillers and fibers	—
	Wastewater Clarification	Removes fine fibers and solids	—
	Sludge Treatment	Enhances sludge dewatering	—
Textile & Dye Industry	Effluent Treatment	Flocculates dyes and pigments	—
	Color Fixation	Enhances dye uptake and color fastness	—
	Water Recycling	Supports water reuse by flocculation	—
Chemical Processing Industry	Suspension Stabilization	—	Prevents settling in slurry mixtures
	Effluent Polishing	Removes fine chemical particulates	—
	Scale Inhibition in Reactors	—	Minimizes insoluble salt formation

Here are the few areas where they are used very effectively:

i. Municipal water and wastewater treatment

• Secondary and primary sedimentation augmentation: PAM is known to flocculate suspended solids, which can increase sedimentation efficiency and decrease turbidity.

• Sludge dewatering: By improving the performance of mechanical device dewatering (belt presses, centrifuges), cationic PAM reduces both the volume and cost of sludge handling.

• Drinking water treatment: Low-dose polyacrylamide (PAM) aids in the coagulation of fine particles and improves filterability without degrading the water quality.

• Effluent treatment: During advanced recycling of water, PAAS is used to prevent membranes and pipelines from scaling.

ii. Industrial wastewater management

• Effluent refinement: PAM purifies waste streams such as dyes, oils, and heavy metals from wastewater in textile, paper, biofuel food processing, and chemical industries.

• Enhanced filtration: PAM-treated effluents demonstrate higher throughput and lower chemical oxygen demand (COD).

• Scale control in effluent systems: PAAS inhibits calcium carbonate and sulfate scales, increasing the efficiency of equipment in the effluent plants.

iii. Mining and mineral processing

• Tailings management: PAM accelerates the settling of fine mineral slurries, improving water recovery and reducing tailings pond volumes.

• Ore beneficiation: PAM assists in solid-liquid separation processes like flotation, enhancing mineral yield and reducing processing time.

• Slurry stabilization: Consistent slurry viscosity, preventing sedimentation in maintained by PAAS during ore transport and processing.

iv. Oil and gas industry

• Enhanced Oil Recovery (EOR): Partially hydrolyzed PAM (HPAM) is used in polymer flooding to improve the mobility ratio, which results in an increase in sweep efficiency, and enhance oil extraction.

• Drilling fluids: PAAS used to stabilize drilling fluids and keeps solids dispersed and maintains wellbores stable even under high salinity.

• Produced Water Treatment: PAM helps in oil-water emulsion separation which can improve the discharge water quality or can also help in water reuse.

v. Power generation and cooling systems

• Scale inhibition in cooling towers: PAAS is widely used in water treatment as a scale inhibitor that prevents the formation of scale deposits in pipes and equipment.

• Treatment of boiler feed water: PAAS binds with calcium and magnesium salts to prevent their precipitation, thereby extending boiler life and preventing the need for chemical cleaning cycles.

• Condensate Polishing Systems

vi. Pulp and paper industry

• Retention Aid: The addition of cationic PAM as a retention aid helps in improving the retention of fillers and fibers in paper, thereby enhancing paper strength and increasing production yield.

• Wastewater clarification: PAM facilitates process water fine fiber and suspended solids action.

• Sludge treatment: PAM enhances paper mill sludge dewatering, minimizing landfill disposal requirements.

vii. Textile and dye industry

• Effluent treatment: PAM flocculates the dye and pigment particles, allowing their removal before discharge.

• Color fixation: During dyeing, cationic PAM is used to enhance the uptake of dyes and promote color fastness.

• Water recycling: The flocculated water will be recycled back into dyeing operations, which reduces freshwater intake.

viii. Chemical processing industry

• Suspension stabilization: The effect of PAAS in the prevention of settling in chemical slurry mixtures.

• Effluent polishing: PAM guarantees the removal of fine chemical particulates, thereby enhancing the quality of treated water.

• Scale inhibition in reactors: By adding PAAS to the reactor, this minimizes the formation of insoluble salts in continuous processing units thereby promoting reaction efficiency and uptime.

PAM-primarily based EOR techniques have been implemented in heavy oil recuperation, fractured reservoirs, and offshore oil fields, enhancing oil restoration charges by using up to 20-30% beyond conventional water flooding strategies. PAM contributes to oilfield operations through financial viability and sustainability via growing oil extraction performance, reducing water usage, and extending reservoir life. In cooling towers, boilers, and heat exchangers, sodium polyacrylate (PAAS) is a potent scale inhibitor to prevent the formation of mineral deposits that can reduce heat transfer efficiency and cause operational.

Experimental Analysis and Dosage Comparison

Due to variations between suspended solids characteristics, treatment objectives and operational conditions, the dosage requirements of polyacrylamide (PAM) vary widely across industrial applications. The PAM required for municipal water treatment is typically in the range of 0.5-5 mg/L due to the simple nature of contaminants as shown in table 1. On the other hand, slightly higher chemical doses of 1-10 mg/L are required for industrial wastewater treatment to achieve optimal flocculation due to more complex and diverse effluents. For such applications as sludge dewatering, much higher concentrations are required, in the vicinity of 10 to 50 mg/L, to encourage and aid the release of the water and further enhance mechanical dewatering devices like centrifuges and filter presses. PAM is used at 5 to 20 mg/L in mineral processing operations depending on the composition of the ore and the content of slurry, which promotes the solid-liquid separation and the water recovery. Polymer flooding for enhanced oil recovery (EOR) results in considerable PAM dosage [500-2000 mg/L], with the goal of increasing the viscosity of the injected water to maximize oil displacement and injectivity by modifying the fluid (invaded zone) mobility in high-temperature and /or high salinity reservoirs. Such variations in dosage reinforce the importance of polymer optimization based on application, via delineation of operational efficiency and cost savings within each category (Table 2).

Application	Optimal dosage (mg/L)	Key Factors Influencing Efficiency
Municipal Water Treatment	0.5-5	pH, turbidity, suspended solids concentration
Industrial Wastewater	1-10	Type of pollutants, charge of suspended particles
Sludge Dewatering	10-50	Sludge type, dewatering equipment, solid content
Mining (Tailings)	5-20	Ore type, particle size, slurry composition
Enhanced Oil Recovery	500-2,000	Reservoir temperature, salinity, permeability

Table 1: Optimal Dosage of Polyacrylamide (PAM) in Various Industrial Applications [35-40].

Application	Optimal dosage (mg/L)	Key Factors Influencing Efficiency
Cooling Towers	2-15	Water hardness, pH, scaling ion concentration
Boiler Water Treatment	5-30	Temperature, pressure, mineral content
Industrial Detergents	0.1-5	Water hardness, detergent formulation
Pulp and Paper Processing	5-25	pH, ionic strength, process water composition
Textile and Dye Industry	5-20	Dye chemistry, fiber type, processing conditions

Table 2: Optimal Dosage of Sodium Polyacrylate (PAAS) for Scale Inhibition and Dispersion [27-42].

The correct concentration of sodium polyacrylate (PAAS) necessary to effectively inhibit scale and disperse scales is generally from 5 to 20 mg/L, based on the water chemistry, operating temperature, and kind of scaling cations present (e.g., calcium, magnesium, or barium). Through effective chelation of multivalent cations and dispersion of deposited scale crystals, PAAS prevents surface adhesion at this concentration. Although dosages greater than 20 mg/L could lead to declining performance and potential environmental problems, dosages less than 5 mg/L could be insufficient to provide adequate protection. Thus, to guarantee peak efficiency and cost-effectiveness, determining the optimal PAAS dosage requires careful study of system-specific factors and can be improved with pilot testing.

In many industrial applications, sodium polyacrylate (PAAS) is used as a potent scale inhibitor and dispersant, the optimal dosage depends on the water quality, the concentration of scaling ions, and the system’s conditions. PAAS is introduced at low concentrations of 0.1 to 5 mg/L in commercial detergents, especially to melt water and improve cleansing efficiency by stopping mineral deposition on fabrics and surfaces. In cooling towers, PAAS is used at concentrations between 2 and 15 mg/L to prevent calcium carbonate and calcium sulfate scaling, retaining efficient heat alternate surfaces. For boiler water treatment, wherein excessive temperatures and pressures accelerate scale deposition, 5 to 30 mg/L is needed to disperse mineral deposits and prevent technique damage efficiently. The fabric and dye industry makes use of a dosage variety of 5 to 20 mg/L to ensure proper dye dispersion, prevent particle aggregation, and improve fabric satisfaction at some point of processing, whilst the pulp and paper industry makes use of 5 to 25 mg/L of PAAS to prevent scaling in processing device and enhance operational performance in paper manufacturing. These dosage variations demonstrate the versatility of PAAS in maintaining system performance, prolonging device lifespan, and lowering maintenance costs across multiple industries.

PAM vs. PAAS performance metrics in water and oil treatment

Performance aspects of PAM and PAAS are also unique for water and oil treatment operations depending mostly on their functional mechanism, environmental resilience, and operational efficiency (Figure 1).

Figure 1: Performance comparison of PAM vs. PAAS in water and oil treatment.

The efficiency of polyacrylamide (PAM) and sodium polyacrylate (PAAS) in water and oil treatment is compared in the bar chart based on five crucial parameters. The effectiveness of PAM in aggregating particles and extracting hydrocarbons is shown by its superior flocculation efficiency and rising oil recovery. Conversely, PAAS is superior to PAM in environmental impact and inhibition of scale, indicating the former’s higher ability to inhibit mineral scale production and its lower environmental impact. In water holding capacity, the two polymers are equal, with PAAS having a slight advantage. This comparison indicates that PAAS is more suitable for sustainable applications requiring scale management and lower environmental impact, while PAM is better for enhanced oil recovery and flocculation.

Flocculation and solid-liquid separation efficiency

PAM enables flocculation in wastewater systems (industrial and municipal), with optimized conditions yielding up to 90-95% removal of suspended solids. High molecular weight and ability to form larger, interconnected flocs, resulting in rapid settling, improved sludge dewater ability, and reduced turbidity levels in treated water. At large scale, this flexibility impacts PAM performance, which remains effective over a broad pH range (4-10) and at different ionic strengths, placing it well for complex effluents, including mine slurries and chemical effluent.

On the other hand, PAAS acts as a dispersant instead of a flocculant. It plays a crucial role in stabilizing suspensions rather than avoiding particles aggregation, thus limiting its application in direct sedimentation processes. PAAS itself does not directly treat water but provides indirect benefits by stabilization of fine particulates in pretreatment phases and prevention of fouling and clogging in membrane and filtration systems.

Oil recovery and water management

Polyacrylamide (PAM) particularly in its partially hydrolyzed form (HPAM) finds extensive utility in enhanced oil recovery (EOR), significantly increasing oil displacement efficiency. PAM increases the viscosity of injected water and improves the sweep efficiency in heterogeneous areas of the reservoir, resulting in 10-30% incremental oil recovery over conventional water flooding techniques. PAM-based polymer flooding has been particularly effective in moderate to high salinity environments, but stability is known to decrease at elevated temperatures (>90°C) without specific chemical modification.

PAAS while not directly used in polymer flooding but provides scale inhibition and produces water treatment that assist oilfield operations. The use of PAAS aids in preventing mineral scaling built-up in the well pipes and production equipment, thus helps maintain flow rates of fluids and reduces downtime. It has been applied as non-toxic, biostable based dispersants to stabilize residual oil droplets and fines in produced water treatment systems, resulting in improved separation efficiencies in downstream separation processes without adding to sludge volumes.

Dosage and chemical consumption: PAM shows excellent flocculation efficiency at low dosages (0.5-10mg/L), which implies lower cost of chemicals and sludge generation compared with inorganic coagulants such as alum or ferric chloride. This bridging and adsorption mechanisms make it more sustainable for treatment residual management by minimizing the volume. As a scale inhibitor or dispersant, PAAS acts at doses (5-50 mg/L) based on water hardness, temperature, and flow conditions. Its use also leads to slightly elevated chemical loading than PAM, but it significantly reduces periodic descaling operations, which could help achieve indirect operational savings in the long run, throughout the system operational life.

Environmental impact and regulatory compliance: The environmental considerations for PAM are primarily driven by the residuals from acrylamide monomer, which is toxic and controlled under strict safety limits (i.e., <0.05% residual content in drinking water applications). Particularly in potable water treatment and environmentally sensitive EOR projects, careful manufacturing and operational control are needed to minimize risk.

In contrast, PAAS is non-toxic, biodegradable, and safer for longterm environmental exposure. PAAS’s favorable regulatory profile makes it the preferred choice for applications where direct discharge to natural bodies of water are anticipated, including industrial cooling water and desalination brine management.

Thermal and salinity tolerance: Recent advancements in PAM formulation, such as HPAM or nanocomposite PAM, have currently widened the temperature up to 120°C, the salinity range up to 100,000 ppm. However, degradation at extreme hydrogen concentrations remains a performance ceiling, which requires careful chemical selection for harsh environments. PAAS possesses inherent thermal stability and retains its dispersant activity at elevated temperatures, even in the presence of high salinity, an important consideration for oilfield brine disposal and seawater-based cooling systems.

Cost-Benefit Analysis

Economic viability and operational sustainability are critical factors influencing the selection of treatment polymers in industrial applications. Cost-benefit studies of PAM and sodium polyacrylate (PAAS) show considerable trade-offs in terms of material and dosage costs versus system functionality and maintenance cost savings (Figure 2).

Figure 2: Economic and environmental trade-offs of PAM, PAAS, and inorganic alternatives.

Material costs and dosage efficiency

PAM typically carries a higher unit price ($2–$5/kg) relative to inorganic coagulants, such as alum or ferric chloride. However, PAM’s high molecular weight and superior flocculation efficiency enable effective performance at extremely low dosages (typically 0.5–10 mg/L), reducing overall chemical consumption. Thus, despite the higher cost per kilogram, the cost of treatment per cubic meter of water is often competitive or even lower as compared to conventional alternatives.

PAAS, with a typical market price of $1.50-$4 per kilogram, is economical in direct material terms. Yet its dosages for scale inhibition or dispersion in operation (5-50 mg/L) are higher than PAM’s flocculation dosages. However, because PAAS inhibits mineral scale formation and keeps the system clean, it has a proven history of reducing maintenance costs and downtime, as well as equipment replacement over the lifetime of cooling, boiler, and pipeline systems.

The graph compares PAM, PAAS, and inorganic alternatives’ environmental and economic trade-offs using five criteria that are most important. With regards to sludge production, long-term cost-effectiveness, environmental acceptability, and government compliance. Except for the up-front cost, PAAS excels in all categories and is therefore the best overall and most sustainable option. PAM excels dramatically in sludge generation and compliance but has average performance in most other categories. Although involving a greater initial investment, this analysis demonstrates that PAAS is a more sustainable choice compared to inorganic counterparts that are initially less expensive but lack environmental and compliance considerations.

Operational savings and system performance

The PAM delivers substantial savings in sludge handling and disposal by enhancing the efficiency of dewatering and lowering sludge volumes. Improved solid-liquid separation performance leads to reduced energy demands of centrifuges, belt presses and filtration units. PAM polymer flooding for oil recovery applications demonstrate better oil production rates which will enhance the economic return on investments towards enhanced oil recovery.

PAAS results mostly in long-term savings on operations scale prevention. The use of PAAS on a consistent basis decreases chemical cleaning, mechanical de-scale and unscheduled plant shutdowns. These improvements prolong the service life of industrial equipment by maintaining the best possible heat transfer rates in cooling towers, boilers, and all industrial processes, PAAS helps achieve cumulative cost benefits over multi-year operating cycles.

Environmental compliance and sustainability costs

The environmental management costs associated with PAM usage stem from the need to control acrylamide monomer residuals. This is vital in drinking water and environmentally sensitive operations. Regulatory compliance adherence (e.g., when required, acrylamide compliance < 0.05%) may increase additional monitoring, purification steps, and certification cost.

Conversely, PAAS’s biodegradability and low toxicity reduce the need for specialized handling or post-treatment remediation, providing a corresponding decrease in compliance costs. In the domains with a focus on green operations, or for ESG certification, PAAS is significantly lower in environmental footprint with cost benefits.

System longevity and lifecycle economics

The lifecycle impact of using PAM is primarily observed in wastewater systems. And better in sludge dewatering reduces landfill reliance and transportation costs. In oilfields, PAM-enhanced oil recovery prolongs the working life of mature reservoirs, postponing the need for costly secondary development programs. Investing in a PAAS leads to long-term ROI since it keeps system infrastructure intact (avoiding corrosion from scaling), promotes thermal system efficiency, and provides higher resilience. Overall water cycle economic benefits obtained from PAAS on the entire industrial operating life cycle can soon offset the materials and applications costs.

Across countries, advanced filtration and monitoring processes are mandated due to restriction on the amount of residual acrylamide in treated water. However, PAAS is non-toxic and biodegradable, which makes it more ecologically friendly and a better choice for companies with stringent eco-compliance requirements.

Conclusion

To Conclude, Polyacrylamide (PAM) and sodium polyacrylate (PAAS) have emerged as critical polymeric agents, in addressing the challenges of solid-liquid separation, scale inhibition, and system stabilization cutting across industries.

PAM can be used as a wastewater treatment agent for the petroleum industry due to its outstanding flocculation efficiency, low dosage and good oil displacement utility as well. However, the environmental risks posed by residual acrylamide monomers mean that its application needs to be carefully regulated.

On the other hand, PAAS provides a complementary suite of benefits, acting as a dispersant and scale inhibitor in aggressive thermal and saline environments. Biodegradable and low toxicity features align well with increasing requirements regarding eco-friendly industrial methods. PAAS offers lifecycle cost benefits, particularly in water and energy-intensive sectors where the ability to keep systems clean and operating over longer periods is an advantage.

The differential assessment of the performance approach metrics vs. cost v/s benefit factors suggests that the choice of PAM, as compared with a PAAS, should be based on process specific priorities, such as contaminant profile, system complexity, environmental regulations and economic limitations. Future innovations, such as the development of bio-based and Nanocomposite-type polymer variants are expected to enhance the functional properties of PAM and PAAS (e.g., addressing current environmental and durability limitations).

Concluding, integrating these advanced polymers into industrial treatment frameworks not only optimizes operational performance but also supports broader goals of sustainability, adherence to regulations, and the responsible resource management across modern industry.

To conclude, Sodium polyacrylate (PAAS) and polyacrylamide (PAM) have extraordinary benefits and disadvantages regarding industrial-scale management, oil restoration, and water treatment. PAM is regularly utilized in wastewater treatment, sludge dewatering, and more advantageous oil healing (EOR) and exhibits extraordinary flocculation effectiveness (up to 90%). However, because of residual acrylamide monomers it could pose environmental risks that need to be carefully regulated. On the other hand, PAAS is an outstanding scale inhibitor that effectively stops calcium carbonate (CaCO₃) and sulfate (CaSO₄) deposits, making it ideal for boilers and cooling towers. Study shows that although inorganic alternatives, including aluminum sulfate and ferric chloride, are less expensive, they produce large volumes of sludge and require more frequent pH adjustments, leading to higher long-term operational costs. While PAM remains a cost-effective alternative for good overall performance in flocculation applications, PAAS is considered the more environmentally friendly choice because of its higher biodegradability and better regulatory compliance. The choice of these polymers is contingent upon unique commercial requirements, balancing cost, effectiveness, environmental impact and regulatory constraints to obtain first-class viable treatment outcomes.

Industries should optimize PAM and PAAS dosages depending on water chemistry, temperature, and specific process requirements to minimize waste and costs and maximize performance and sustainability. Regular monitoring and regulatory compliance need to be maintained to avoid environmental hazards. Future studies need to concentrate on Nanotechnology-compatible polymers must be analyzed for flocculation and scale inhibition performance.

Further research is needed to determine the long-term environmental consequences and degrade mechanisms of PAAS and PAM in numerous ecosystems. Additionally, one of the top priorities is to improve hybrid polymer compositions for superior performance under harsh industrial circumstances.

I sincerely thank Harry J Moyle - President of Aurora Specialty Chemistries for permitting me to publish this article.

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Article Type: REVIEW ARTICLE

Citation: Ajjarapu VMK (2025) Comparative Analysis of Polyacrylamide (PAM) and Sodium Polyacrylate (PAAS) Applications in Water Treatment and Oil Industry Processes. Int J Water Wastewater Treat 10(2): dx.doi.org/10.16966/2381-5299.197

Copyright: ©2025 Ajjarapu VMK. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication history: 

Received date: 02 May, 2025

Accepted date: 22 May, 2025

Published date: 30 May, 2025