Differences and Uses of Cationic, Anionic, and Nonionic PAM

Polyacrylamide (PAM) is a linear water-soluble polymer and is the most commonly used water treatment agent in our wastewater treatment processes, bar none! In our practical applications, PAM is divided into three types: cationic, anionic, and nonionic. How to choose between these three types of PAM? Let's start by discussing their differences!

Differences in the Uses of Cationic, Anionic, and Nonionic Polyacrylamide

Uses of Nonionic Polyacrylamide

Wastewater Treatment Agent

When the suspended wastewater is acidic, nonionic Polyacrylamide serves as a more suitable flocculant. PAM functions via adsorption and bridging action, causing suspended particles to flocculate and settle, thus purifying the wastewater. It can also be used in the purification of drinking water, especially when used in conjunction with inorganic flocculants, yielding the best results in water treatment.

Textile Industry Additives

By adding some chemicals, it can be formulated into a chemical material for textile sizing.

Sand Prevention and Solidification

Dissolve nonionic polyacrylamide intoa 0.3% concentration, add a crosslinking agent, and spray it on the desert to achieve the effect of sand prevention and solidification.

Soil Moisture Retention Agent

Used as a soil moisture retention agent and as a basic raw material for various modified polyacrylamides.

Uses of Cationic Polyacrylamide

Sludge Dewatering

Depending on the properties of the sludge, an appropriate grade of this product can be selected. It can effectively perform gravity sludge dewatering before the sludge enters the filter press. During dewatering, large flocs are formed, the filter cloth is non-stick, dispersion is prevented during pressing, dosage is low, dewatering efficiency is high, and the moisture content of the sludge cake is below 80%.

Treatment of Sewage and Organic Wastewater

This product presents cationic properties in both acidic and alkaline media, making it extremely effective for flocculating and settling suspended particles with negative charges in wastewater, thus clarifying it. For instance, in wastewater from alcohol factories, breweries, monosodium glutamate factories, sugar factories, meat processing plants, beverage plants, and textile dyeing and printing plants, cationic polyacrylamide is significantly more effective than anionic polyacrylamide, nonionic polyacrylamide, or inorganic salts, often outperforming them by several times or even dozens of times, because such wastewater typically carries negative charges.

Uses of Anionic Polyacrylamide

Industrial Wastewater Treatment

It's most effective for the treatment of wastewater that contains suspended particles, has a high concentration, particles carry positive charges, and the water's pH value is neutral or alkaline. Such cases include wastewater from steel factories, electroplating factories, metallurgical wastewater, and coal washing wastewater.

Recovery of Starch and Distiller's Grains in Starch Factories and Alcohol Factories

Many starch factories' wastewater contains a large amount of starch. By adding anionic polyacrylamide, starch particles can be flocculated and settled. The sediment can then be pressed into cakes using a filter press to be used as feed. Similarly, alcohol can be recovered in alcohol factories using anionic polyacrylamide for dewatering and pressure filtration.

How to Distinguish Between Three Types of PAM

Using pH Value for Identification

First, prepare an appropriate proportion of a water solution of the polyacrylamide reagent that is currently being used and showing good results. Prepare pH test papers. Different ionic types of polyacrylamide reagents will have different pH levels, and the production process of polyacrylamide also affects the pH level. To understand this better, one can consult and inquire with reputable polyacrylamide manufacturers.

Using the Exclusion Method for Identification

Anyone with basic chemistry knowledge would know that anions and cations react chemically when put together. We can use this point to conduct a simple identification.

Judging Based on Laboratory Wastewater Treatment Results

First, we need to understand the water quality characteristics of the wastewater to be treated. Anionic polyacrylamide reagents are most effective for wastewater with high alkalinity or high inorganic content or wastewater with many negatively charged particles. Cationic polyacrylamide reagents are most effective for wastewater with high acidity or high organic content or wastewater with many positively charged particles. By observing the effects of the reagents, a simple identification can be made.