Abstract: A method for effecting a comprehensive removal of heavy metals from wastewater in a two stage process in which the wastewater is contacted in a first stage with a source of ferric ions under mildly acidic conditions (pH 5 to pH 8), preferably followed by the removal of the precipitated solids using a solid-liquid separation; a second stage follows in which the wastewater from the first step is contacted with a source of ferric ions under alkaline conditions (pH 8+) followed by the removal of the precipitated solids using a second solid-liquid separation. Used in conjunction with an initial oxidation step, the present method makes possible the removal of a whole suite of heavy metals present in both the anionic and cationic form in refinery wastewater. The treatment also removes metal compounds in the particulate phase. Metals concentrations can be significantly decreased from the mid to high ppb (parts per billion) range down to the low ppb range to meet the quality criteria for discharge.

Abstract: A modular table tennis game includes a plurality of paddles, a table tennis ball, and an adjustable table, or multiple adjustable tables. The table(s) may be mounted on a support system such as a tripod or other support structure that allows the table(s) to be adjusted in height and tilt. The top of the table(s) may have an opening or openings larger than the table tennis ball penetrating therethrough.

Abstract: A modular table tennis game includes a plurality of paddles, a table tennis ball, and an adjustable table, or multiple adjustable tables. The tables may be mounted on a support system such as a tripod or other support structure that allows the tables to be adjusted in height and tilt. The top of the tables may have an opening or openings larger than the table tennis ball penetrating therethrough.

Abstract: A modular table tennis game includes a plurality of paddles, a table tennis ball, and an adjustable table, or multiple adjustable tables. The tables may be mounted on a support system such as a tripod or other support structure that allows the tables to be adjusted in height and tilt. The top of the tables may have an opening or openings larger than the table tennis ball penetrating therethrough.