Aeration is a cheapest and simple method to removal of iron in water. It is successfully practicing in some places in Sri Lanka. However some limitations may occur such as temperature, pH, dissolved oxygen and iron content itself.

4Fe2+ + O2 + 8OH- + 2H2O = 4Fe (OH)3

(Ref.- Water Treatment Processes: Simple Options By S. Vigneswaran, C. Visvanathan)

Aeration is also an effective method of bacteria control, decarbonation and ammonia and hydrogen sulfide reduction.

Water-fall aerator may be used for the aeration of water. This is the most common industrial use of aeration techniques. Many variations of the water-fall principle can be used for this type of aeration. The simplest configuration employs a vertical riser that discharges water by free fall into a basin. The riser usually operates on the available head of water. The efficiency of aeration is improved as the fall distance is increased. Also, steps or shelves may be added to break up the fall and spread the water into thin sheets or films, which increases contact time and aeration efficiency.

Thank you Kumara. Aeration may not be possible on individual/private owned house. The three tier government requires that potable water should be made available for citizens. The State government is already applying aeration process to treat borehole water, but the process cannot meet the demand for the populace. Individuals make effort to provide borehole for themselves sinking private boreholes. In the circumstance, another method that may not require large surface area is being sought. Water-fall aerator for an individual may be expensive, and maintenance may be an issue.

Dr. Ujile, You can use oxidation filters based on a chemical oxidation process (react with KMnO4). This type of low cost commercially available filters can be found from the markets. These are handy and can be operate simply. But your case, Fe2+ are very high. so, the cartridge may be replace regularly within short time period.

Have you tried activated carbon filters? 

Activated carbon filters on a packed bed have been tried. The result is satisfactory, but it is expensive because with high concentration of iron loadings frequent regeneration of the filter bed is required.

Aeration with sand-charcoal filtration could be a cheap and easy method, affordable to the rural communities.

Application of multi-stage adsorption processes have been considered and cost effective to an extent.

IRON IS A NUTRIENT USEFUL FOR HUMAN HEALTH. IRON CAN BE FOUND IN FOODS SUCH AS PLANTAIN. INFACT, THIS IS THE REASON THAT NIGERIAN FEDERAL ENVIRONMENTAL PROTECTION AGENCY (FEPA) RECOMMENDED A DISCHARGE LIMIT FOR IRON IN TREATED WASTEWATER TO BE DISCHARGED INTO WATER BODIES AS HIGH AS 20 mg/L. IN WHAT WAYS IS IRON IN BOREHOLE WATER HAZARDOUS TO HUMAN HEALTH OR TO THE ENVIRONMENT? LET ME KNOW. HOWEVER, ADSORPTION METHOD USING ACTIVATED CARBON AS THE ADSORBENT HAS BEEN RECOMMENDED FOR REMOVAL OF HEAVY METALS FROM HAZARDOUS WASTES, BUT IRON IS ESSENTIAL NUTRIENT FOR HUMAN HEALTH. IF MAN DRINKS WATER CONTAINING TRACE OF IRON THE BETTER. THANK YOU AND GOD BLESS YOU,SIR.

Dear Sampson, the iron the body needs is not from drinking water. Iron in water is a pollution problem and should be removed to make it portable. Diabetes, hemochromatosis, nausea and vomiting have been linked to high iron levels in water. Please for your information,the federal ministry of water resources in their latest regulations now lists iron as one of the metals of concern (Heavy metals) to environmental Chemists in Nigeria. I have a copy of the regulation.

In my opinion, I will suggest the use of plant materials to serve as a biofilter. There is current research launched by Young Champions of the Earth on UN Environment Program where banana is used as a biofilter to clean off hydrocarbon from Amazon water. This serves as a means of purifying the water. This method may also filter out iron or some other plants may. If given a trial I think it could be a more simple way to remove iron from borehole water. BIOFILTER is the way.

Thanks

PLEASE, DR. JOSHUA LELESI KONNE, WHAT YOU ARE TRYING TO SAY IS THAT IRON EXISTS IN DIFFERENT FORMS. IS THE FORM OF IRON IN BOREHOLE WATER DIFFERENT FROM THE FORM OF IRON IN FOODS SUCH AS PLANTAIN? I WOULD BE VERY GRATEFUL IF YOU CAN EXPLAIN THE COMPONENTS OF THE IRON IN BOREHOLE WATER THAT MAKES IT DELETERIOUS TO HUMAN HEALTH AND THE COMPONENTS OF IRON IN FOODS SUCH AS PLANTAIN THAT MAKES IT NUTRITIONAL. THAT WILL MAKE YOUR READERS BELIEVE YOU THE MORE. HEAVY METALS CAN BE REMOVED BIOLOGICALLY USING MICRO-ORGANISMS. I HAVE NOT TRIED IT BEFORE, BUT I THINK MICRO-ORGANISMS ARE NOT SOLD, SO THIS SHOULD BE THE MOST COST EFFECTIVE. CHEMICAL PRECIPITATION AND ADSORPTION USING CHARCOAL OR ACTIVATED CARBON HAS BEEN RECOMMENDED FOR REMOVAL OF HEAVY METALS FROM INDUSTRIAL WASTES. AERATION HAS BEEN RECOMMENDED FOR FURTHER DESTRUCTON OF BIOCHEMICAL OXYGEN DEMAND AT THE DOWNSTREAM SECTION OF A WASTEWATER TREATMENT PLANT. AERATION HAS ALSO BEEN RECOMMENDED FOR REMOVAL OF VOLATILE ORGANIC COMPUONDS. IS THE FORM OF IRON PRESENT IN BOREHOLE WATER VOLATILE? I DONOT KNOW THE CHARACTERISTICS OF THIS FORM OF IRON. I WOULD BE MORE GRATEFUL IF SOMEONE CAN EXPLAIN THE CHARACTERISTICS OF THIS FORM OF IRON TO ME. THANK YOU AND GOD BLESS YOU,SIR.

Dear Idongesit Effiong Sampson, Iron in food occurs in complexated form (just as Mg in chlorophyll is), while iron in water occur as iron(II) or iron(III) ions... I hope I still very well remember biomolecules in Functional Biology and complexation reactions in Basic Analytical Chemistry. However, Joshua Lelesi Konne should have given some answers to the main question asked in addition to his reply to your comment.

Algae that can sequester metals into their cells, such as Chlorella sp. which sequester gold from dilute process stream (Prescott et al. 1999), can be used (in immobilized form) for water treatment in removing the iron. However, another problem can arise such as their metabolic products of which some are toxins. And then this problem can be taken care of by boiling the water before drinking; heat (100 degrees C and above) destroys toxins of biological origin.

Dear Lekia Peekate, thank you for your contributions to Idongesit Sampson's question. Metals in foods, drugs, etc exist as complexes and at concentrations that can be worked upon or metabolized by the body enzymes but that's not the case in aqueous solutions like water. It exists as ions. Just as you have clarified him using Mg as an illustration. Forinstance, Idongesit can get all the potassium he needs from banana and other fruits but not from drinking a 20 ppm potassium water. When do we say water is polluted if water with some levels of iron is said to be portable by him? Dissolved metal ions in water may be harmful to the body. The main issue here is that he is alleging that permissible discharge concentration of metals like iron implied its availability to humans that would drink such water, but that's not correct.

ILLINOIS DEPARTMENT OF PUBLIC HEALTH (2019) STATED THAT IRON IS NOT HAZARDOUS TO HEALTH, BUT IT IS CONSIDERED A SECONDARY OR AESTHETIC CONTAMINANT. ESSENTIAL FOR GOOD HEALTH, IRON HELPS TRANSPORT OXYGEN IN THE BLOOD. MOST TAP WATER IN THE UNITED STATES SUPPLIES APPROXIMATELY 5 % OF THE DIETARY REQUIREMENT FOR IRON. MORESO, WATER GUIDE ENVIRONMENT (2019) STATED THAT IRON ASSOCIATED WITH DRINKING WATER IS NOT USUALLY ASSOCIATED WITH HEALTH RISKS. A SPECIAL HEALTH CONDITION KNOWN AS HEMOCHROMATIS, IS RESPONSIBLE FOR MOST HEALTH PROBLEMS ASSOCIATED WITH IRON. HEMOCHROMATIS IS A GENETIC DISEASE THAT CAUSES TOO MUCH IRON TO BE ABSORBED BY THE INTESTINES,WHICH INTURN CAUSE IRON TO ACCUMULATE IN THE BODY. BECAUSE IRON IN DRINKING WATER DOES NOT POSE A HEALTH RISK TO MOST PEOPLE, NO HEALTH BASED GUIDELINES FOR IRON IN DRINKING WATER HAVE BEEN PROPOSED BY THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (USEPA) OR THE WORLD HEALTH ORGANIZATION (WHO). INSTEAD THE USEPA HAS SET A SECONDARY MAXIMUM CONTAMINANT LEVEL ( SMCL) FOR IRON OF 0.3 (mg/L OR PARTS PER MILLION), WHICH IS THE CONCENTRATION OF IRON AT WHICH PROBLEMS WITH WATER COLOUR OR STAINING START TO APPEAR. WATER WITH IRON CONCENTRATIONS BELOW THE SMCL SHOULD NOT REQUIRE TREATMENT.

REFERENCES

1. ILLINOUS DEPARTMENT OF PUBLIC HEALTH. (2019). IRON IN DRINKING WATER. ENVIRONMENTAL HEALTH FACT SHEET.

2. WATER GUIDE ENVIRONMENT (2019). IRON IN DRINKING WATER HOW TO REMOVE. www.filterwater.com

What are the health standards by WHO and other International bodies? I think the water Fe content in both soil and bio-entity like plant is either biomagnified or bioaccumulation and even aggravated by pollutants in the Niger Delta. We a Scientist should tread cautiously and scientifically in order not confuse our readers and our knowledge dependent seekers.

The use of some newly developed oxidants are able to do this miracle

Aeration may be the best and cheapest option to remove iron from water. The iron remains in the dissolved ferric state in the absence of oxygen or when the water is in the groundwater table. As the water comes in contact with oxygen, the dissolved iron changed into a ferrous state and settled at the bottom of the container. After filtration, the water free of iron can be collected and used for domestic application.