Patent · US Expired

Acid wastewater treatement

US5645730A · kind A · utility

40Cited by
13References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 29, 1996
Grant dateJul 8, 1997
Priority date
Expiry dateApr 29, 2016

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S210/912
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

A process for treating acid wastewater containing heavy metals has been invented, the process including adding fly ash to the acid wastewater to reduce heavy metals content of the acid wastewater. In one aspect the acid wastewater contains soluble iron and adding fly ash reduces the level of soluble iron. In one aspect the acid wastewater contains sulfate ions and adding fly ash reduces the sulfate ion level. In one aspect solid silicate salts are added to the acid wastewater. Preferably undesirable very hydrous iron hydroxide precipitate is not formed. In certain aspects the pH of the acid wastewater is raised to an environmentally acceptable level. In one aspect the process is a batch process. In another aspect the process is a continuous process.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.