Zimpro/passavant Inc.

Sterling Drug Inc.

Zimpro Inc.

Thomas J Vollstedt

William M Copa

John A Meidl

A two-stage process for purifying wastewater includes the steps of biophysical anaerobic treatment to remove the majority of the COD, followed by biophysical aerobic treatment to further purify the wastewater. A powdered adsorbent, preferably powdered activated carbon, is used with biological solids in each treatment step. Excess biophysical solids from the aerobic step are transferred to the anaerobic step for digestion. Fresh powdered adsorbent is added to the aerobic treatment step to compensate for that transferred to the anaerobic treatment step. Solids concentration in the anaerobic step is controlled by wasting solids to disposal.

Two-stage anaerobic/aerobic treatment process

A two-stage, batch process for purifying wastewater containing organic and adsorbable pollutants includes the steps of introducing a predetermined quantity of the wastewater into an aeration and settling zone of a primary treatment zone and aerating therein in the presence of a powered absorbent, such as activated carbon, and biologically active solids, terminating aeration and retaining the thus-treated wastewater in the aeration and settling zone a sufficient time for a substantial portion of the suspended solids to settle by gravity. A predetermined amount of the partialy-treated wastewater is withdrawn from the aeration and settling zone and introduced into a contact zone wherein it is agitated, preferably by aeration, in the presence of a powered adsorbent, agitation is terminated and the solids are allowed to settle by gravity. After completion of settling, clarified, substantially solids-free water is withdrawn from the contact zone.

Two-stage batch wastewater treatment

A two-stage process for purifying wastewater containing organic and adsorbable pollutants includes the steps of first aerating the wastewater in the presence of a powdered adsorbent, such as activated carbon, and biologically active solids in the aeration zone of a primary treatment zone which also includes a quiescent zone. The thus-treated water passes from the aeration zone to the quiescent zone where it is retained a sufficient time for a substantial portion of the suspended solids to settle by gravity. The partially-treated wastewater overflowing from the quiescent zone is introduced into one or more contact zones wherein it is agitated, preferably by aeration, in the presence of a powdered adsorbent, agitation is terminated and the solids are allowed to settle by gravity and, after completion of settling, clarified, substantially solids-free water is withdrawn from each contact zone.

Two-stage wastewater treatment

A blowdown pot is provided with an inlet pressure control valve through which the pot receives unwanted residue e.g., ash from a high pressure chemical reactor, and this reactor residue can thereby be continuously or semi-continuously blown out from the high pressure, high temperature chemical reactor into the relatively low pressure blowdown pot which includes means maintaining a liquid level therein minimizing steam flashing and vessel wear. At the same time the reactor residue is removed from the pot with a liquid overflow.

Blowdown pot for a reactor

A method of cleaning sand or multi-media filters which comprises a process of backwashing the filter with water containing a high concentration of chlorine or ozone.

Growing community of inventors

Schofield, WI, United States of America

Thomas J Vollstedt