Method for the purification of sewage waters

Claim 1

A method of purifying sewage waters which contain ammonia, compounds containing ammonia or both, comprising: in a first purification stage, passing said sewage waters through at least one sewage water pond, aerating said sewage waters as said sewage waters pass through said sewage water pond and adjusting the pH of said sewage waters to a value in the slightly alkaline regimen to stimulate the growth of ubiquitous nitric bacteria, whereby at least a major portion of said ammonia, compounds containing ammonia or both is oxidized to nitrate and pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both are formed; passing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both from said sewage water pond of said first purification stage into contact with a reaction medium of a subsequent, second purification stage, said reaction medium having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen; and in said subsequent, second purification stage, flowing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both through said reaction medium having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen and thereby converting at least a predominant portion of said residual ammonia, residual ammonia containing compounds or both and at least a predominant portion of said nitrate to nitrogen.

Claim 2

A method of purifying sewage waters which contain ammonia, compounds containing ammonia or both, comprising: in a first purification stage, passing said sewage waters through at least one sewage water pond, aerating said sewage waters as said sewage waters pass through said sewage water pond and adjusting the pH of said sewage waters to a value in the slightly alkaline regimen to stimulate the growth of ubiquitous nitric bacteria, whereby at least a major portion of said ammonia, compounds containing ammonia or both is oxidized to nitrate and pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both are formed; passing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both from said sewage water pond of said first purification stage into contact with a reaction medium of a subsequent, second purification stage, said reaction medium having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen; and in said subsequent, second purification stage, flowing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both through said reaction medium having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen and thereby converting at least a predominant portion of said residual ammonia, residual ammonia containing compounds or both and at least a predominant portion of said nitrate to nitrogen.

Claim 19

A method or purifying sewage waters which contain ammonia, compounds containing ammonia or both, comprising: in a first purification stage, passing said sewage waters through at least one sewage water pond, aerating said sewage waters as said sewage waters pass through said sewage water pond and adding suspended matter to said sewage waters in said sewage water pond to adjust the pH of said sewage waters to a value in the slightly alkaline regimen and thereby stimulate the growth of ubiquitous nitric bacteria whereby at least a major portion of said ammonia, compounds containing ammonia or both is oxidized to nitrate and pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both are formed; passing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both from said sewage water pond of said first purification stage into a stationary mineral bed of a subsequent, second purification stage, said stationary mineral bed being planted with emersed helophytes and in a substantially completely hydromorphous condition and thereby having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen; and in said subsequent, second purification stage, flowing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both through said stationary mineral bed and thereby converting at least a predominant portion of said residual ammonia, residual ammonia containing compounds or both and at least a predominant portion of said nitrate to nitrogen.

Claim 20

A method or purifying sewage waters which contain ammonia, compounds containing ammonia or both, comprising: in a first purification stage, passing said sewage waters through at least one sewage water pond, aerating said sewage waters as said sewage waters pass through said sewage water pond and adding suspended matter to said sewage waters in said sewage water pond to adjust the pH of said sewage waters to a value in the slightly alkaline regimen and thereby stimulate the growth of ubiquitous nitric bacteria whereby at least a major portion of said ammonia, compounds containing ammonia or both is oxidized to nitrate and pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both are formed; passing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both from said sewage water pond of said first purification stage into a stationary mineral bed of a subsequent, second purification stage, said stationary mineral bed being planted with emersed helophytes and in a substantially completely hydromorphous condition and thereby having areas rich in atmospheric oxygen and areas poor in atmospheric oxygen; and in said subsequent, second purification stage, flowing said pretreated sewage waters containing nitrate and residual ammonia, residual ammonia containing compounds or both through said stationary mineral bed and thereby converting at least a predominant portion of said residual ammonia, residual ammonia containing compounds or both and at least a predominant portion of said nitrate to nitrogen.