ANIONIC POLYELECTROLYTE = ANIONIC POLYACRYLAMIDE
Water-soluble polymers are found in a very broad range of industrial applications.
An important class of these is acrylamide-based polymers which bear negative charges along the polymer chain and are called anionic polyelectrolytes.
Anionic polyelectrolytes are widely used as flocculants, rheology control agents, and adhesives.
Anionic polyelectrolytes are employed especially in oil field operations as viscosity control agents for enhanced oil recovery and to a lesser degree in engineering fluids used for lubrication, for effluent reclaiming, and for opening oil passage channels in oil-bearing rock.
Paper manufacture, mining, and water treatment processes also benefit from the use of acrylamide-based polymers to flocculate solids in aqueous dispersions.
Polyacrylamides (Polyacrylamides) used for construction site erosion and sediment control (ESC) applications are a group of high molecular weight, water soluble molecules formed by polymerization of the monomer acrylamide.
Anionic polyelectrolyte is produced when acrylamide is polymerized with an anionic comonomer.
Water soluble Polyacrylamides have been used for decades to facilitate solid liquid separations in wastewater and drinking water treatment, the pulp and paper industry, aquaculture, and many other industrial processes.
Although polymer-based water clarification is a technique that is well established in industrial applications, treatment of construction runoff is a newer and less established use of this technology.
Today there are several anionic Polyacrylamide-based products marketed for use in construction site sediment management.
These products can be applied for erosion control, clarification of sediment laden runoff, and de-mucking of wet sediment during pond cleanouts.
They are designed to be used in conjunction with other best management practices, as part of a multi-barrier approach, to minimize soil loss and improve settling of suspended sediments.
Applications of Anionic Polyelectrolyte:
As a flocculating agent, mainly used in industrial solid-liquid separation process, including settlement, to clarify, concentrate and sludge dewatering processes.
Applications for all the major sectors are: Urban Sewage Treatment, Paper, Food Processing, Petrochemical, Metallurgical Processing, Dyeing and the Sugar and all kinds of industrial wastewater treatment.
In the paper industry, Anionic Polyelectrolyte can be used as dry strength agents, retention agent, filter aid.
Anionic Polyelectrolyte can be greatly improved as paper quality, enhance the physical strength of paper and reduce the loss of fiber, can also be used in the treatment of white water at the same time, in the deinking process can play a significant flocculation.
Anionic Polyelectrolyte can be used in coal washing as waste water clarifier in the mining industry.
Oil field profile controlling and water- plugging agent, matched with CMC and a certain amount of chemical adhesive added.
Anionic Polyelectrolyte can be used as oil field profile controlling and water-plugging agent.
Anionic Polyelectrolyte can also be used mud additive for EOR (Enhanced Oil Recovery) process to improve production of oil gas drilling chemical.
In oil field, Anionic Polyelectrolyte is a kind of mud additive.
Anionic Polyelectrolyte is used to increase the viscosity of water and improve the effectiveness of the water flooding process.
Anionic Polyelectrolyte is a kind of polyacrylamide (PAM) and shows electronegative which contains functional groups of sulfonic acid, phosphoric acid or carboxylic acid.
Due to more charge, the molecular chain of polymer can be more stretching in the water which will increase the capacity of adsorption and bridge for suspended particles removal.
The mainly interaction between APAM and suspended particles is static electricity, hydrogen bonding or covalent bond.
Anionic polyacrylamide with high molecular weight and good solubility property can be an important kind of flocculants.
And Anionic polyelectrolyte has been widely used in water treatment because of good flocculation performance.
Generally, molecular weight of polysaccharide polymer is determined by intrinsic viscosity.
Accordingly, how to improve the intrinsic viscosity and solubility property of APAM is the most critical point in the polymerization.
Based on comprehensive literature survey to the preparation technology and application progress of Anionic polyelectrolyte, Anionic polyelectrolyte can be found that a detailed analysis and review of past academic research progress could be valuable with the rapid development of synthesis technology.
Homopolymerization posthydrolysis process, homopolymerization cohydrolysis process, copolymerization approach, inverse emulsion polymerization, precipitation polymerization and radiation polymerization are the main six kinds of synthesis technologies of APAM.
Treatment of service water.
Clarification and filtration of river water and industrial water.
Condensation and dehydration of sludge from industrial water treatment.
Other Applications of Anionic Polyelectrolyte:
Sedimentation and condensation of magnesium hydroxide in manufacturing process of magnesium clinker (Mgo).
Clarification of phosphoric acid solution.
Treatment of sewage from red oxide manufacture.
Sedimentation of slimes of copper, zinc, sulfides ores.
Filtration of slimes and coal powder.
Treatment of sewage from mining process.
Treatment of coal washing.
Enhanced oil recovery.
Condensation, sedimentation of slurry in wet type cement manufacture.
In Waste water treatment:
Pulp and paper:
Recovery and clarification of white water, steel and metal
Treatment of sewage containing blast furnace dust.
Treatment of sewage from metal plating.
Treatment of sewage from acid cleaning of metals.
Treatment of sewage from wool washing.
Treatment of sewage from dyeing.
Usage Areas of Anionic Polyelectrolyte:
In chemical wastewater treatment plants, anionic polyelectrolyte is applied by making a solution with water depending on the type of waste.
Anionic Polyelectrolyte is a type of polymer used in dewatering sludge arising from biological treatment processes.
Anionic Polyelectrolyte is used in drinking water and wastewater treatment, Paper Industry, Petroleum Industry, Mining, Agriculture, Textile, Cosmetics industry.
Anionic Poly Electrolyte is specially designed for improvising filtration and purification processes in sugar processing.
This organic based copolymer coagulant is effective in complex systems that coagulate solids and immediately form flocs.
Anionic Polyelectrolyte is processed more carefully to make Anionic Polyelectrolyte compatible with any pH range.
Anionic Polyelectrolyte Powder is a medium anionic charged powder polyelectrolyte to be used as a thickener in the direct filtration process to precipitate inorganic suspended solids, waste water.
Anionic polyacrylamides are used, among other things, for water clarification and process water recycling.
Anionic polyacrylamides are easier to polymerize to very high molecular weights.
Anionic Polyelectrolyte presents high polymer electrolyte characteristics in neutral and alkaline mediums.
With good flocculation, Anionic polyelectrolyte can reduce the frictional resistance between the liquid and be widely used in mining industries and water treatment etc.
Other Uses of Anionic Polyelectrolyte:
Some of the main areas of a construction site that can benefit from stabilization with Anionic Polyelectrolyte include:
Low traffic sloped areas,
Stripped areas left inactive for extended periods of time,
Any other stripped areas of the site where dust control is needed.
The following guidelines should be applied for any use of Anionic Polyelectrolyte as an erosion control on construction sites.
Granular Anionic Polyelectrolyte applied to a soil surface for erosion control should be applied at least 15 metres away from any watercourse, wetland, well, etc. or other natural water feature.
Anionic polyelectrolyte should never be applied directly to natural features (e.g. woodlots, wetlands, streams).
When not used in combination with other ground covers, Anionic Polyelectrolyte should only be applied to protect against erosion in areas receiving nonconcentrated sheet flows.
Prior to Polyacrylamide application, rills and/or gullies should be filled in and/or the surface should be prepped according to the manufacturer’s specifications.
Application of Anionic Polyelectrolyte with seed (through hydroseeding or a similar method), or some sort of cover, is preferable to the use of the polymer alone on bare soil.
The roots will help to anchor the soil in place and the Polyacrylamide helps to stabilize soil early on before the seed has germinated.
Accepted application methods include (i) broadcast of granular Polyacrylamide, by hand or with a seed/fertilizer spreader, (ii) application of Polyacrylamide solution with a construction site watering vehicle, and (iii) addition to hydroseeding mixture, followed by normal hydroseed application.
Manufacturing of Anionic Polyelectrolyte:
Anionic Polyelectrolyte is made by the free-radical polymerization of acrylamide and Anionic polyelectrolyte derivatives via bulk, solution, precipitation, suspension, emulsion, and copolymerization techniques.
Among these, solution polymerization is a preferred technique because of difficulty with temperature and agitation control in bulk polymerization and the cost of surfactants and solvents for suspension, emulsion, and precipitation polymerization.
The anionic polymers may interact with particles in aqueous dispersions in several ways that result in the stability or instability of the dispersions.
The particles in solid-liquid phases can be destabilized through three main mechanisms which promote flocculation and cause destabilization.
These mechanisms are polymer bridging, charge neutralization, and polymer adsorption.
The particles in solid-liquid phases can be stabilized by the anionic polymers through both electrostatic and steric repulsive forces.