公开(公告)号：DE2613128A1

公开(公告)日：1977-09-29

申请号：DE2613128

申请日：1976-03-27

Applicant: HOECHST AG

Inventor： KRIEG MARTIN DIPL CHEM DR ,  OLFFERS THEO

IPC: C02F1/70 ,  C02F1/76 ,  C02F9/00 ,  C02C5/02

Abstract: A process is disclosed for reducing Hg content of industrial waste water. Total Hg present is first converted to ionogenic, divalent oxidn. step, by setting up, in the waste water, an active Cl concn. of 2-50 mg/l. This is achieved by adding Cl2, HCl or NACL to the inorganic acid medium. Fe (II)-ions are then added until their concn.in waste water reaches 0.1-1.5 g/l.- A redox potential of -0.1 to -0.8 v, w.r.t. standard H electrode, is then set up, by adding pH-raising chemicals. Hg is reduced, pptd. and deposited together with the Fe hydroxides generated at the same time.Pptn. products are finally sepd.- Process is partic. suitable for treating waste waters from chlor-alkali electrolysis by amalgam process. Good results, e.g.99.97% Hg removal, are obtd. even with a 14000 times NaCl excess w.r.t. Hg wt./ml. waste water.- The Hg (I) salts obtd. are flocculated by mixt. of Fe hydroxides formed. Setting of redox potential and separation of pptd. products pref. take place in an O2-free atmos

公开(公告)号：DE4021408A1

公开(公告)日：1992-01-09

申请号：DE4021408

申请日：1990-07-05

Applicant: HOECHST AG

Inventor： FREYER WALTER DR ,  OLFFERS THEO ,  RIEDEL ALFRED DR

IPC: B01D53/68 ,  C01B7/01 ,  C01B7/07

公开(公告)号：DE3832804A1

公开(公告)日：1990-03-29

申请号：DE3832804

申请日：1988-09-28

Applicant: HOECHST AG

Inventor： FREYER WALTER DR ,  OLFFERS THEO

IPC: C01B7/01 ,  C01B7/07

公开(公告)号：PT98206A

公开(公告)日：1992-05-29

申请号：PT9820691

申请日：1991-07-04

Applicant: HOECHST AG

Inventor： FREYER WALTER ,  OLFFERS THEO ,  RIEDEL ALFRED

IPC: B01D53/68 ,  C01B7/01 ,  C01B7/07

公开(公告)号：DE58908648D1

公开(公告)日：1994-12-22

申请号：DE58908648

申请日：1989-09-26

Applicant: HOECHST AG

Inventor： FREYER WALTER DR ,  OLFFERS THEO

IPC: C01B7/01 ,  C01B7/07

公开(公告)号：CA1076276A

公开(公告)日：1980-04-22

申请号：CA274773

申请日：1977-03-25

Applicant: HOECHST AG

Inventor： KRIEG MARTIN ,  OLFFERS THEO

IPC: C02F1/70 ,  C02F1/76 ,  C02F9/00 ,  C02C5/02

Abstract: HOE 76/F 806 PROCESS FOR REDUCING THE MERCURY CONTENT OF INDUSTRIAL WASTE WATERS The invention deals with the reduction of the mercury content of industrial waste waters, especially those from a chlorine-alkali electrolysis using the amalgam process. According to the invention all mercury present in the waste water is converted to the form of Hg++ ions by adding chlorine. Subsequently Fe++ ions are added. The pH of the solution is raised until a redox potential of from - 0.1 to - 0.8 volts, relative to the normal hydrogen electrode, is obtained. The mercury precipitated and the iron oxide hydrate formed may be filtered from the waste water. Residual mercury contents in the filtrate of about 50 mg/m3 may be obtained.