초록 ▼

Arsenic and TOC are removed from drinking water or wastewaters by use of finely-divided metallic iron in the presence of powdered elemental sulfur or other sulfur compounds such as manganese sulfide, followed by an oxidation step. A premix may be produced for this process, by adding the iron, sulfur

Arsenic and TOC are removed from drinking water or wastewaters by use of finely-divided metallic iron in the presence of powdered elemental sulfur or other sulfur compounds such as manganese sulfide, followed by an oxidation step. A premix may be produced for this process, by adding the iron, sulfur and oxidizing agent to water in a predetermined pH range. The iron and sulfur are mixed for a period of time dependent upon the temperature and pH of the water and the presence of complexing or sequestering minerals and organic acids in the water. An oxidizing agent is added to the mixture and agitating is continued. In a preferred embodiment the oxidizing agent is hydrogen peroxide. Water is decanted from the mixture after a sufficient reaction time, to produce a concentrated premix. This premix can be added to water intended for drinking or to industrial effluents containing toxic materials.

대표청구항 ▼

A method for removing arsenic from drinking water, comprising, establishing the pH of the water substantially within a pH range from about 3.5 to about 8.5, including adjusting the pH if necessary, adding elemental powdered sponge iron to the water, adding dry powdered adding sulfur to the water, ag

A method for removing arsenic from drinking water, comprising, establishing the pH of the water substantially within a pH range from about 3.5 to about 8.5, including adjusting the pH if necessary, adding elemental powdered sponge iron to the water, adding dry powdered adding sulfur to the water, agitating the water to maintain a slurry with the iron and sulfur dispersed in the water, the amounts of the powdered iron and of the sulfur being selected in combination to permit recovery of arsenic with additional steps of: continuing to agitate the slurry, after a period of time within which the pH of the slurry rises and then substantially stabilizes, oxidizing the slurry sufficiently to effect arsenic recovery as a precipitate including arsenic absorbed and absorbed onto sulfur-activated sponge iron particles, and continuing to agitate the slurry substantially continuously, and separating the recovered, precipitated arsenic to produce a treated water with reduced arsenic.