Aluminum Sulfate

Basic Introduction

　　Aluminum sulfate is a widely used industrial reagent,often confused with alum.It is commonly used as a flocculant in drinking water purification and wastewater treatment equipment,and also in the paper industry.Under natural conditions,aluminum sulfate almost never exists in its anhydrous salt form.It forms a series of hydrates,with aluminum sulfate hexadechydrate being the most common.Aluminum sulfate is also a very effective molluscicide,effective against Spanish slugs,and widely used in various water purification processes.

Applications

　　In wastewater treatment,it is used as a coagulant with excellent decolorizing capabilities.It also removes heavy metal ions,removes oil and phosphorus,and has bactericidal functions.It is particularly effective for decolorizing and removing COD from dyeing and printing wastewater,and for ferrite co-precipitation in electroplating wastewater.
　　As a precipitant,it can react with sulfides and phosphates to form precipitates,thereby removing sulfides and phosphates.
　　It is readily soluble in water,and its aqueous solution is slightly acidic.It is widely used in the purification of drinking water and industrial water,suitable for treating wastewater with low alkalinity,and as a precipitant to remove sulfide ions and phosphate ions.
　　In the paper industry,it is used as a precipitant for rosin,wax emulsions,and other adhesives.It can also be used as an internal agent in foam fire extinguishers,a raw material for manufacturing alum and aluminum dioxide,a decolorizing and deodorizing agent for petroleum,and a raw material for certain pharmaceuticals.It can also be used to manufacture artificial gemstones and ammonium alum.

Quality indicators

Index items		Indicators
		Category I		Category II
		solid	liquid	solid	liquid
Alumina mass fraction (%)	≥	15.60	7.80	15.60	6.50
Iron (Fe) mass fraction (%)	≤	0.20	0.05	1.00	0.50
Water-insoluble matter mass fraction (%)	≤	0.10	0.05	0.20	0.10
pH(1% aqueous solution)	≥	3.0

　　Class I solid products are white to pale yellow flakes,blocks,and powders;liquid products are colorless to pale yellow transparent liquids.Class II solid products are pale green or pale yellow flakes,blocks,and powders;liquid products are pale green or pale yellow liquids.

Instructions for Use

　　Before use,a small-scale test should be conducted based on the water quality to determine the optimal point for good water purification effect and small dosage.The solution should be prepared and used immediately.
　　For non-drinking water,the dosage should be determined according to the actual situation.
　　When using solids,first dissolve them in water to prepare a 10-25%solution.When dissolving,add water slowly while continuously stirring.

Packaging,Transportation,and Storage

　　Solid products are packaged in woven plastic bags or composite woven plastic bags lined with polyethylene plastic bags.Liquid products are packaged in polyethylene plastic drums or transported in acid-resistant storage tanks.
　　During transportation,protect from rain and moisture,and avoid contamination by toxic substances.
　　Store in a cool,dry place,protected from rain and moisture.Solid products have a shelf life of one year,and liquid products have a shelf life of six months.

　　Aluminum Sulfate:A Versatile Workhorse in Water Treatment and Beyond

　　In the realm of industrial and municipal chemistry,few compounds demonstrate the versatility and consistent performance of Aluminum Sulfate.For decades,this simple inorganic salt has been a cornerstone in processes that define modern civilization,from delivering clear,safe drinking water to strengthening the paper we write on.Its efficacy stems not from complexity,but from a reliable and well-understood chemical behavior that makes it a preferred choice across numerous sectors.This document explores the inherent advantages,diverse applications,and problem-solving capabilities of Aluminum Sulfate,highlighting its role as a fundamental building block in various industries.

　　The widespread use of Aluminum Sulfate is anchored in several compelling benefits that it offers:

　　Effective Coagulation and Flocculation:In water treatment,Aluminum Sulfate hydrolyzes to form aluminum hydroxide,a gelatinous precipitate.This precipitate entraps suspended particles,colloidal matter,and even some dissolved contaminants,forming larger,heavier aggregates called"floc"that can be easily removed through sedimentation and filtration.This process is crucial for clarifying turbid water.

　　Phosphorus Removal:In wastewater treatment,excess phosphorus can lead to eutrophication in natural water bodies,depleting oxygen and harming aquatic life.Aluminum Sulfate reacts with phosphate ions to form insoluble aluminum phosphate,which precipitates out of the water,thereby reducing nutrient pollution effectively.

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　　Cost-Effectiveness and Accessibility:As a widely manufactured chemical,Aluminum Sulfate is often considered a cost-efficient option for many applications,particularly in large-scale operations like municipal water treatment.Its availability in various forms(liquid,granular,lump)adds to its operational flexibility.

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　　Acidity Regulation:The hydrolysis reaction of Aluminum Sulfate tends to lower the pH of the solution.This property can be beneficial in certain contexts,such as in soil amendment for alkaline soils or in specific industrial processes where a slight pH adjustment is needed alongside coagulation.

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　　General Compatibility and Handling:With well-established safety guidelines and handling procedures,Aluminum Sulfate is a manageable chemical for trained personnel in industrial settings.

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　　Wide-Ranging Applications and Problem-Solving Capabilities

　　Aluminum Sulfate's utility extends far beyond a single function.Its ability to clarify,precipitate,and subtly alter chemical environments makes it a multi-talented solution for various challenges.

　　1.Water Purification and Treatment

　　Problem Solved:Raw water from rivers or lakes is often cloudy and contains harmful microorganisms,organic matter,and impurities.

　　Solution:As a primary coagulant,Aluminum Sulfate clarifies turbid water by removing suspended solids.The resulting floc also entraps bacteria and viruses,which are then filtered out,significantly improving water quality and safety for potable use.

　　2.Wastewater and Effluent Treatment

　　Problem Solved:Industrial and municipal wastewater carries suspended solids,color,and nutrients like phosphorus that can be damaging if discharged directly into the environment.

　　Solution:It is used to thicken sludge,remove phosphorus,and reduce the biological oxygen demand(BOD)and chemical oxygen demand(COD)of effluent,helping treatment plants meet environmental discharge regulations.

　　3.Pulp and Paper Manufacturing

　　Problem Solved:Paper sheets formed from pulp fibers lack strength and need to be sized to control ink absorption during printing.

　　Solution:In the paper industry,it acts as a sizing agent.It helps bind rosin size to the cellulose fibers,improving the paper's resistance to water and ink penetration.It also aids in the retention of fine particles and pigments,enhancing the paper's opacity,finish,and overall strength.

　　4.Soil Conditioning in Agriculture and Horticulture

　　Problem Solved:Some plants,like azaleas and blueberries,require acidic soil to thrive,but many gardens have neutral or alkaline soil conditions.

　　Solution:Aluminum Sulfate can be used to lower soil pH,making it more acidic.This amendment makes essential nutrients like iron more available to acid-loving plants,promoting healthier growth.

　　5.Other Specialized Applications

　　Its utility is also seen in other areas such as acting as a hardening agent in styptic pencils to stop minor bleeding from shaving cuts,a mordant in dyeing processes to fix colors to fabrics,and in some formulations of firefighting foam.

　　Application Areas at a Glance

　　The following table provides a concise overview of the primary application fields for Aluminum Sulfate:

Application Field	Primary Function	Problem It Helps Address
Drinking Water Treatment	Coagulation / Flocculation	Removes suspended particles, turbidity, and microorganisms to produce clearer, safer water.
Wastewater Treatment	Phosphorus Removal & Sludge Conditioning	Reduces nutrient pollution (eutrophication) and aids in dewatering sewage sludge.
Pulp & Paper Industry	Sizing Agent & Retention Aid	Improves paper strength, ink resistance, and fine-particle retention during sheet formation.
Agriculture & Horticulture	Soil Acidifier	Lowers soil pH to create favorable growing conditions for acid-loving plants.
Textile Industry	Mordant in Dyeing	Helps bind dyes to fabrics, improving color fastness and vibrancy.
Personal Care & Cosmetics	Astringent	Used in formulations like styptic pencils for its ability to constrict skin tissue and stop minor bleeding.