January 16, 1806: Death of Nicolas Leblanc. “French surgeon and chemist who in 1790 developed the process for making soda ash (sodium carbonate) from common salt (sodium chloride). This process, which bears his name, became one of the most important industrial chemical processes of the 19th century. In the Leblanc process, salt was treated with sulphuric acid to obtain salt cake (sodium sulphate). This was then roasted with limestone or chalk and coal to produce black ash, which consisted primarily of sodium carbonate and calcium sulphide. The sodium carbonate was dissolved in water and then crystallized. The Leblanc process was simple, cheap, and direct, but because of the disruption of the French Revolution, he profited little from it. He died by suicide in 1806.”
Commentary: Soda ash is one of the common treatment chemicals used in precipitative water softening plants.
January 16, 1913: Engineering News editorial– Far Reaching Decision Respecting the Use of the Chicago Drainage Canal. “The denial by the Secretary of War of the application of the Sanitary District of Chicago for authority to withdraw 10,000 cu. ft. per sec. from Lake Michigan in place of the 4167 ft. authorized by a previous Secretary which we print in full elsewhere in this issue, seems to leave Chicago only two alternatives. Either it must fight the question out in Congress, and if successful there which is very doubtful, it must then fight it out again in a probable arbitration proceeding between the United States and Canada with possibilities of a fight with navigation and other interests in the courts as well. Otherwise Chicago must, at an early date, begin the construction of a plant to purify its sewage, at least partially, before discharging it into the drainage canal, and this plant must eventually become one of the largest sewage-treatment plants in the world.
The necessity for purifying its sewage arises not alone from the doubt whether the city will be permitted to permanently divert from Lake Michigan even the amount of water it is now taking but because the towns and cities along the course of the Illinois River will be apt to begin litigation if Chicago sends its sewage past their doors diluted with a smaller proportion of water than that agreed upon when the state legislation authorizing the construction of the sanitary canal was enacted.”
Reference: “Far Reaching Decision Respecting the Use of the Chicago Drainage Canal.” Engineering News. 69:3(January 16, 1913): 125.
Commentary: Even 13 years after the opening of the Chicago Drainage Canal, it was clearly a large point of contention between Chicago and its neighbors to the south. Ultimately, of course, Chicago had to build one of the largest sewage treatment plants in the world.