Distillation replicates Mother Nature’s hydrologic cycle and is one of the oldest means for purifying water. Distillation effectively removes inorganic compounds (e.g. lead and nitrate) as well as nuisance particles like iron and hardness from polluted water as well as some bacteria and viruses that might otherwise pollute it.
Household distillation units typically consist of a boiling chamber and condensing coil, from which steam rises through an outlet to be collected into an external container of clean water storage. Boiling kills bacteria, viruses and protozoan cysts before condensate containing pure water cools to become liquid again before flowing off through its outlet spigot as distilled water.
Distillation’s effectiveness at removing organic contaminants depends on their chemical properties. For instance, volatile organic chemicals with boiling points close or lower than that of water can recontaminate distilled water unless another process such as activated carbon filteration (G1489) can be employed prior to condensation. For more information about eliminating VOCs from water sources please see NebGuide Drinking Water Treatment: Activated Carbon Filtration (G1489).
Domestic distillation units should be regularly cleaned to prevent scale accumulation. On continuously running units, this involves inspecting the boiler chamber and heating element every week; for countertop units it should be checked after each distillation cycle. Furthermore, it’s crucial that solids from the boiling chamber be sent directly to waste in order to avoid recontaminating water supplies and decrease BOD rates in wastewater systems.