Abstract: A method for purifying contaminated liquids, especially waste water with high TKN/BOD concentrations, by first introducing, into the contaminated liquid, an acidic coagulant such as a metal salt and then introducing a second alkaline coagulant, into the contaminated liquid which dramatically increases the speed and effectiveness of subsequent coagulation and flocculation and thereby removal of TKN/BOD. By comparing the total (molar amount of acidic coagulant cation+alkaline coagulant cation) with an equal molar amount of the acidic cation, superior removal of TKN/BOD are achieved due to a synergy between the acidic and alkaline coagulant versus using just an acidic metal coagulant.

Abstract: A retractable hat tether apparatus for a hat having a cap portion. The tether apparatus includes a guide base movably mounted to the cap portion for movement thereof along a fixed path between a first position and a second position. A flexible tether includes a first end and an opposite second end thereof mounted to the guide base. A clip device is configured for releasable attachment to a user's clothing. The clip device is mounted to the first end such that, when the guide base moves along the fixed path between the first position and the second position, the tether and the clip device move between a retracted condition, positioning the tether substantially along the fixed path, and an extended condition, positioning the tether at an exterior of the cap portion to enable the clip device to be mounted to the user's clothing.