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A brief history of water treatment

2014 - SOG trickling filter

2014 – SOG trickling filter

HWT patented the trickling SOG filter
2012 - Zero Liquid Discharge

2012 – Zero Liquid Discharge

ZLD – not for the faint hearted. An extremely expensive procedure whereby all water in an industrial process is re-used. Pollutants in the waste streams are recovered in solid form and taken to land-fill or recycled where possible. Most costly part is removal of salts from brine.
Evapouration and crystallization process steps required, with attendant and large energy bills.
1999 - Activated sludge bulking

1999 – Activated sludge bulking

The mysteries of activated sludge bulking unraveled by Casey, Ekama et al
  • Filamentous organism bulking in nutrient removal activated sludge systems
  • 1910 - Lyster bag

    1910 – Lyster bag

    Major (later Col.) William J. L. Lyster (1869-1947) of the US Army Medical Dept. used a solution of calcium hypochlorite in a linen bag to treat water. Lyster's method became the standard for U.S. ground forces in the field and in camps, implemented in the form of the Lyster Bag.
    1774 - Chlorine

    1774 – Chlorine

    Because chlorine is so reactive, it is almost never found in nature in its pure form. Ever abundant in rocks and in the sea, chlorine is a safely bound in salt formation.
    Chlorine (Cl2) was first prepared in pure form by the Swedish chemist Carl Wilhelm Scheele in 1774. Scheele heated brown stone (manganese dioxide; MnO2) with hydrochloric acid (HCl). When these substances are heated the bonds are broken, causing manganese chloride (MnCl2), water (H2O) and chlorine gas (Cl2) to form.

    Reaction mechanism:

    MnO2 + 4HCl -> MnCl2 + Cl2 + 2H2O

    Scheele discovered that chlorine gas was water-soluble and that it could be used to bleach paper, vegetables and flowers. It also reacted with metals and metal oxides. In 1810 sir Humphry Davy, an English chemist who tested fundamental reations of chlorine gas, discovered that the gas Scheele found must be an element, given that the gas was inseperable. He named the gas ‘chlorine’ (Cl), after the Greek word ‘chloros’, which means yellow-greenish and refers to the color of chlorine gas (White, 1999. Watt, 2002)
    485 BC - The Hippocrates sleeve

    485 BC – The Hippocrates sleeve

    A cone shaped sleeve made of clothing material used to filter boiled water. In this simple practise, two birds are knocked off their perch with one stone – water clarity and disinfection. By far the most useful was disinfection; by far the most appreciated was water clarity.

    Let food be thy medicine and medicine be thy food.
    1581 BC - Bitter water in the Sinai - Marah

    1581 BC – Bitter water in the Sinai – Marah

    Marah – the Hebrew word for bitterness was the name given to a fountain at the sixth station of the Israelites in their epic escape from Egypt and crossing of the Sinai desert. The water of this well was so bitter that, in spite of great thirst, they would not drink from it. On this account they murmured against Moses, who, under divine direction, cast into the fountain "a certain tree" which took away its bitterness, so that the people drank of it.

    —Easton's 1897 Bible Dictionary