Clean Water, Happy Customers: Managing Iron and Manganese through Chemical Analysis

Iron and manganese typically fall into the category of secondary contaminants, but they can still cause problems for municipal and private drinking water treatment systems. Iron and manganese are best known for creating unpleasant color, taste and odor in drinking water at high concentrations. While complaints from customers are never enjoyable, ongoing research is raising questions about iron and manganese's designation as secondary contaminants. Recent studies suggest that exposure to manganese above 0.1 mg/L in infancy and early childhood can impact development and lead to learning and behavioral problems later in life. 

And that’s not all. When left to form deposits, iron and manganese can build up in pipes, pressure tanks and other equipment. These deposits lead to more frequent equipment repairs and require more energy to pump water through constricted pipes. And if corroded pipes begin to leak or break altogether, the loss of water can create hazards and damage surrounding infrastructure. All of these consequences increase costs for plants and municipalities.

So, while not typically regulated, filtration of iron and manganese ultimately results in cost savings, protects and extends the life of pipes and other infrastructure, and contributes to higher overall customer satisfaction.

In a typical drinking water filtration process, a chemical is added to convert any dissolved iron and manganese into solid, oxidized forms that can then be easily filtered from the water. Chlorine is most commonly used as the oxidant, although potassium permanganate and hydrogen peroxide can also be used.

But how do you ensure proper chemical dosage?

Including too much chemical in the filtration process does little to solve the problem. For example, too high a dose of potassium permanganate can turn drinking water pink. While not as disturbing as the red or black tints caused by iron and manganese, customers would probably be hesitant to consume water that appeared to contain any chemical.

The key to fine-tuning your chemical dosage is accurate, continuous measurement of influent and effluent iron and manganese. Installing an analyzer before the filtration point allows for feed-forward control of the oxidizer, while an analyzer after the filtration point helps ensure minimal contaminate breakthrough. With continuous measurement of effluent, operators will know right away if there’s an increase in contaminate breakthrough and can divert flow to other tanks to backwash the filters.

Reliable measurements of influent and effluent iron and manganese ensure the filtration process meets recommended secondary contaminate levels as efficiently as possible. When selecting equipment for the job, it’s important to prioritize accuracy without signing up for frequent, intensive maintenance.

In-Situ’s ChemScan analyzers have a very low detection limit, so they can trace precise levels of contaminates. Large sample lines and self-cleaning features prevent clogging, minimize maintenance and downtime, and keep the treatment process running smoothly. Sample blanks in each reading eliminate electrical or optical drift for prolonged accuracy. And all analyzers are designed with easy-to-follow menus and instructions, to simplify what little maintenance, calibration and cleaning they require.

Built to last, their rugged design stands up to demanding environments. And to make installation simple, the mini Outdoor Enclosure provides a complete solution for mounting a ChemScan mini Analyzer and accessories on a rail, with options for freeze-resistant sample lines and other customizations to fit a variety of environments.

In-Situ’s ChemScan mini Analyzers for iron and manganese ensure secondary contaminate levels are within regulated limits and improve the efficiency of the filtration process with minimal labor from operators. Rugged design and self-cleaning features deliver accurate and reliable measurements with minimal maintenance, while simple installation and user-friendly navigation make these analyzers easy to work with.

Filtration of iron and manganese sustains the public’s trust in their drinking water systems, prolongs the health of infrastructure and can reduce energy and repair costs by protecting pipes from clogs and leaks and preventing water loss. Given these benefits, it’s important to trust measurement of iron and manganese to equipment fit for the job. In-Situ mini Analyzers provide accurate measurements for a low cost of ownership and support a more efficient treatment process.

Ansac Technology (S) Pte Ltd is the official authorised distributor in Singapore .