Water Treatment Chemicals

Almost every disinfection failure described as “the chlorine does not work” is one of three things: the dose was calculated against the target residual without allowing for the water’s chlorine demand, the pH put most of the chlorine into an ineffective form, or the contact time was far shorter than the organism needed. This article

Disinfection and industrial microbial control use two quite different families of chemistry, and choosing between them is decided by the water or surface being treated rather than by potency tables. Oxidising biocides – the chlorine donors, peracetic acid, ozone, chlorine dioxide – kill fast, leave no residue that resists, and are consumed by organic load.

Sodium dichloroisocyanurate (SDIC, CAS 2893-78-9, also written NaDCC) is the solid chlorine donor that replaced bleach in most of the places where bleach was inconvenient: emergency water treatment, pool shock, farm biosecurity, hospital spill kits, cooling towers. It carries about 56% available chlorine against 10 – 15% for liquid hypochlorite, it stores dry for a

Search for “polyamine water treatment” and you will mostly find product pages that describe polyamine as a chemical: CAS 42751-79-1, cationic polyelectrolyte, 50% solids, viscosity by grade. None of that answers the question a plant engineer actually has, which is where in the treatment train do I dose it, at what point relative to the

Hydrazine hydrate earns its place in industry because it is an unusually clean reducing agent: in most of its reactions the by-products are nitrogen and water, which is why it is used where dissolved solids or residues cannot be tolerated. The same reactivity makes it hazardous to handle. This page covers the main applications in

Hydrazine hydrate is one of the chemicals where the compliance question has a precise numeric answer, and most of the confusion comes from quoting the wrong number. Export control, transport classification and hazard communication are written on the hydrazine content of the product, while the commercial specification is usually written on the hydrate content. For

Hydrazine hydrate is a small molecule with an outsized regulatory footprint. The technical content is straightforward – it is a strong reducing agent and a convenient nitrogen source – but almost every commercial decision around it depends on one question: what concentration of hydrazine, as distinct from hydrazine hydrate, is in the drum. This guide

Demineralisation is where ion exchange stops being a single-vessel operation and becomes a train. A strong acid cation resin in the hydrogen form converts dissolved salts into their acids; a strong base anion resin in the hydroxide form takes those acids out and leaves water. Everything between those two points – degassing, weak resin stages,

Water softening is the largest single use of ion exchange resin, and it is also the one most often designed by rule of thumb. The chemistry is simple – a strong acid cation resin in the sodium form swaps calcium and magnesium for sodium – but the sizing, the salt consumption and the failure modes

Ion exchange resins are engineered polymers that remove dissolved ions from water and process streams by swapping them for ions they already carry. Unlike a filter, they are not consumed in normal service – they are regenerated and used again, often for years. The engineering problem is therefore not “which resin removes the ion” but