US 5,647,986 A · Apparatus and process for distributed treatment of wastewater

Abstract

An automated wastewater treatment miniplant intended for installation and use with individual residences. Wastewater such as raw sewage is received in a settling tank to remove suspended solids, and then flows to an intermediate tank where the sewage is aerated and churned to promote aerobic treatment of organic materials in the sewage. When the wastewater in the intermediate tank reaches a predetermined level, a batch of that wastewater is transferred to an aerator-clarifier tank where further aerobic treatment of the batch wastewater occurs under controlled conditions, without dilution with incoming wastewater. Further aerobic decomposition of the wastewater takes place in the aerator-clarifier tank. Sludge is allowed to settle in that tank, and supernatant liquid within that tank is periodically withdrawn for dispersal in a drain field. Sludge is periodically returned to the intermediate tank to augment the biomass in that tank. Some sludge is periodically wasted from the system. The wastewater treatment miniplant optionally includes a separate tank for receiving and disinfecting supernatant liquid withdrawn from the aerator-clarifier tank. That disinfected liquid is dispersed in an underground irrigation field or in a drain field. The miniplant is automated under microprocessor control, and can report faults to a central location and exchange other information with the central location.

Claims42

Dependent claims

A process for aerobic treatment of wastewater containing organic matter, comprising the steps of:

collecting wastewater flowing into a first tank;
aerating the wastewater in the first tank to promote aerobic treatment of organic matter in the wastewater;
when a predetermined amount of wastewater is in the first tank, transferring a batch of wastewater from the first tank to a second tank until a predetermined level of wastewater is reached in the second tank;
aerating the batch of wastewater in the second tank for further aerobic treatment of organic matter remaining therein, while continuing to collect wastewater flowing into the first tank, and then;
clarifying the aerated batch of wastewater in the second tank by allowing the wastewater to settle so that sludge remaining in the wastewater settles to the bottom of the second tank and a clear supernatant liquid from the treated wastewater overlies the settled sludge in that tank;
transferring the clear supernatant liquid from the second tank for dispersal;
transferring the settled sludge from the second tank to the first tank so that the transferred sludge combines with organic matter in the wastewater continuing to enter the first tank, thereby augmenting an aerobic biomass in the first tank;
and
adding no wastewater to the second tank during the steps of aerating the batch in the second tank, clarifying the aerated batch, transferring supernatant from the second tank, and transferring sludge from the second tank, whereby the batch of wastewater undergoes treatment in the second tank without disturbance or dilution by incoming wastewater.

6 more elements

A process for aerobic treatment of wastewater containing organic matter, comprising the steps of:

collecting the wastewater in a settling tank to allow removal of settleable solids from the wastewater by sedimentation;
flowing wastewater from the settling tank to an intermediate tank;
aerating the wastewater in the intermediate tank to mix the wastewater and to promote aerobic treatment of organic matter in the wastewater;
transferring a batch of wastewater from the intermediate tank to an aerator-clarifier tank until a predetermined level of wastewater is reached in the aerator-clarifier tank;
allowing the batch of wastewater in the aerator-clarifier tank to stand undisturbed to allow scum that forms in the wastewater to separate and float to the surface, and then;
removing a top layer of liquid from the aerator-clarifier tank so as to remove the floating scum;
retaining the remainder of the batch of wastewater in the aerator-clarifier tank for a predetermined time while aerating the wastewater for further aerobic treatment of organic matter remaining therein, and then;
clarifying the aerated batch of wastewater in the aerator-clarifier tank by allowing the wastewater to settle so that sludge remaining in the wastewater settles to the bottom of the aerator-clarifier tank and a clarified supernatant liquid from the treated wastewater overlies the settled sludge;
transferring the clarified supernatant liquid from the aerator-clarifier tank for dispersal;
and
transferring the settled sludge from the aerator-clarifier tank to the intermediate tank so that the returned sludge combines with organic matter in the wastewater entering the intermediate tank from the settling tank, thereby augmenting an aerobic biomass in the intermediate tank.

8 more elements

Apparatus for aerobic treatment of wastewater containing organic matter, comprising:

a first tank operative to receive a continuing flow of wastewater;
a source of air supplied to the wastewater in the first tank so that said wastewater undergoes aerobic treatment to create an aerobic biomass;
a second tank;
means selectively operative to transfer a batch of the treated wastewater from the first tank to the second tank until a predetermined level of wastewater is reached in the second tank;
means operative to allow the batch of wastewater to stand undisturbed in the second tank so as to allow scum that forms in the wastewater to separate and float to the surface, and then operative to remove a top layer of liquid from the second tank so as to remove the floating scum;
means supplying a source of air for a predetermined time to the batch of wastewater in the second tank so that the wastewater undergoes further aerobic treatment followed by clarification after the air no longer is supplied to the batch, whereupon sludge remaining in the wastewater settles to the bottom of the second tank and a clear supernatant liquid from the treated wastewater overlies the settled sludge;
means operative to remove a top layer of the clear supernatant liquid from the second tank and transfer the removed liquid for dispersal;
and
means operative to transfer settled sludge from the second tank to the first tank so that the transferred sludge combines with organic matter in the continuing flow of wastewater entering the first tank, thereby augmenting the aerobic biomass in the first tank.

6 more elements

A microprocessor-controlled apparatus for aerobic treatment of wastewater containing organic matter, comprising:

a settling tank receiving the wastewater and allowing solids to settle within the tank;
an intermediate tank receiving a continuous outflow of wastewater liquid and floatable material from the settling tank so as to undergo aerobic treatment to create an aerobic biomass in the intermediate tank;
an aerator-clarifier tank;
first liquid transfer means including an inlet for withdrawing wastewater material from the intermediate tank and transferring that material to the aerator-clarifier tank so that the wastewater undergoes further aerobic treatment and clarification in the aerator-clarifier tank;
second liquid transfer means including an inlet to withdraw a supernatant layer of liquid from the aerator-clarifier tank and transfer the removed liquid for subsequent dispersal;
third liquid transfer means including an inlet for withdrawing material at the bottom of the aerator-clarifier tank and transferring that material to the intermediate tank;
and
a microprocessor operatively associated with the first, second, and third liquid transfer means and programmed to form means to transfer a predetermined batch of wastewater from the intermediate tank to the aerator-clarifier tank via the first means;
means to clarify the batch of wastewater in the aerator-clarifier tank by allowing the wastewater to settle so that sludge in the wastewater settles to the bottom of the aerator-clarifier tank and a supernatant liquid from the wastewater;
means to transfer the supernatant liquid from the aerator-clarifier tank via the second means for dispersal;
means to transfer the settled sludge from the aerator-clarifier tank to the intermediate tank via the third liquid transfer means so that the returned sludge combines with organic matter in the wastewater entering the intermediate tank from the settling tank, thereby augmenting the aerobic biomass in the intermediate tank;
and means to transfer no wastewater to the aerator-clarifier tank during operation of the means to clarify, the means to transfer supernatant liquid, and the means to transfer settled sludge, so that the batch of wastewater undergoes treatment in the aerator-clarifier tank without disturbance or dilution by additional wastewater.

9 more elements

A process for aerobic treatment of wastewater containing organic matter, comprising the steps of:

collecting the wastewater in an intermediate tank;
aerating the wastewater in the intermediate tank to mix the wastewater and to promote aerobic treatment of organic matter in the wastewater;
transferring a batch of wastewater from the intermediate tank to an aerator-clarifier tank until a predetermined level of wastewater is reached in the aerator-clarifier tank;
allowing the batch of wastewater in the aerator-clarifier tank to stand undisturbed to allow scum that forms in the wastewater to separate and float to the surface, and then;
removing a top layer of liquid from the aerator-clarifier tank so as to remove the floating scum;
retaining the remainder of the batch of wastewater in the aerator-clarifier tank for a predetermined time while aerating the wastewater for further aerobic treatment of organic matter remaining therein, and then;
clarifying the aerated batch of wastewater in the aerator-clarifier tank by allowing the wastewater to settle so that sludge remaining in the wastewater series to the bottom of the aerator-clarifier tank and a clarified supernatant liquid from the treated wastewater overlies the sealed sludge;
transferring the clarified supernatant liquid from the aerator-clarifier tank for dispersal;
and
transferring the settled sludge from the aerator-clarifier tank to the intermediate tank so that the returned sludge combines with organic matter in the wastewater entering the intermediate tank from the settling tank, thereby augmenting an aerobic biomass in the intermediate tank.

7 more elements

A process for aerobic treatment of wastewater containing organic matter, comprising the steps of:

collecting wastewater flowing into a first tank;
aerating the wastewater in the first tank to promote aerobic treatment of organic matter in the wastewater;
when a predetermined amount of wastewater is in the first tank, transferring a batch of wastewater from the first tank to a second tank until a predetermined level of wastewater is reached in the second tank;
aerating the batch of wastewater in the second tank for further aerobic treatment of organic matter remaining therein, while continuing to collect wastewater flowing into the first tank, and then;
clarifying the aerated batch of wastewater in the second tank by allowing the wastewater to settle so that sludge remaining in the wastewater settles to the bottom of the second tank and a clear supernatant liquid from the treated wastewater overlies the settled sludge in that tank;
transferring a quantity of the settled sludge from the second tank to the first tank at periodic intervals during the step of clarification before the sludge begins to undergo denitrification in second tank;
transferring the clear supernatant liquid from the second tank for dispersal;
and then
transferring to the first tank the settled sludge remaining in the second tank at the end of the step of clarification;
so that the transferred sludge combines with organic matter in the wastewater continuing to enter the first tank, thereby augmenting an aerobic biomass in the first tank.

7 more elements

A microprocessor-controlled apparatus for aerobic treatment of wastewater containing organic matter, comprising:

an intermediate tank receiving a continuous flow of wastewater so that the wastewater undergoes aerobic treatment to create an aerobic biomass in the intermediate tank;
an aerator-clarifier tank;
first liquid transfer means including an inlet for withdrawing wastewater material from the intermediate tank and transferring that material to the aerator-clarifier tank so that the wastewater undergoes further aerobic treatment and clarification in the aerator-clarifier tank;
second liquid transfer means including an inlet to withdraw a supernatant layer of liquid from the aerator-clarifier tank and transfer the removed liquid for subsequent dispersal;
third liquid transfer means including an inlet for withdrawing material at the bottom of the aerator-clarifier tank and transferring that material to the intermediate tank;
and
a microprocessor operatively associated with the first, second, and third liquid transfer means and programmed to form means to transfer a predetermined batch of wastewater from the intermediate tank to the aerator-clarifier tank via the first means;
means to clarify the batch of wastewater in the aerator-clarifier tank by allowing the wastewater to settle so that sludge in the wastewater settles to the bottom of the aerator-clarifier tank and a supernatant liquid from the wastewater, means for transferring a quantity of the settled sludge from the aerator-clarifier tank to the intermediate tank via the third liquid transfer means at periodic intervals during the clarification before the sludge begins to undergo denitrification in the aerator-clarifier tank;
means to transfer the supernatant liquid from the aerator-clarifier tank via the second means for dispersal;
means to transfer to the intermediate tank via the third liquid transfer means the settled sludge remaining in the aerator-clarifier tank at the end of clarification, and means to transfer no wastewater to the aerator-clarifier tank during operation of the means to clarify, the means to transfer supernatant liquid, and the means to transfer settled sludge, so that the batch of wastewater undergoes treatment in the aerator-clarifier tank without disturbance or dilution by additional wastewater
so that the returned sludge combines with organic matter in the wastewater entering the intermediate tank from the settling tank, thereby augmenting the aerobic biomass in the intermediate tank.

8 more elements

A microprocessor-controlled apparatus for aerobic treatment of wastewater containing organic matter, comprising:

an intermediate tank receiving a continuous flow of wastewater so that the wastewater undergoes aerobic treatment to create an aerobic biomass in the intermediate tank;
an aerator-clarifier tank;
first liquid transfer means including an inlet for withdrawing wastewater material from the intermediate tank and transferring that material to the aerator-clarifier tank so that the wastewater undergoes further aerobic treatment and clarification in the aerator-clarifier tank;
second liquid transfer means including on inlet to withdraw a supernatant layer of liquid from the aerator-clarifier tank and transfer the removed liquid for subsequent dispersal;
third liquid transfer means including an inlet for withdrawing material at the bottom of the aerator-clarifier tank and transferring that material to the intermediate tank;
a microprocessor operatively associated with the first, second, and third liquid transfer means and programmed to form means to transfer a predetermined batch of wastewater from the intermediate tank to the aerator-clarifier tank via the first means, means to clarify the batch of wastewater in the aerator-clarifier tank by allowing the wastewater to settle so that sludge in the wastewater settles to the bottom of the aerator-clarifier tank and a supernatant liquid from the wastewater, means for transferring a quantity of the settled sludge from the aerator-clarifier tank to the intermediate tank via the third liquid transfer means at periodic intervals during the clarification before the sludge begins to undergo denitrification in the aerator-clarifier tank, means to transfer the supernatant liquid from the aerator-clarifier tank via the second means for dispersal, and means to transfer to the intermediate tank via the third liquid transfer means the settled sludge remaining in the aerator-clarifier tank at the end of clarification,
so that the returned sludge combines with organic matter in the wastewater entering the intermediate tank from the settling tank, thereby augmenting the aerobic biomass in the intermediate tank;
and
the microprocessor is further programmed to form means to repeat the steps of allowing the wastewater to settle in the aerator-clarifier tank, periodically transferring a quantity of settled sludge to the intermediate tank before denitrification begins, and transferring supernatant liquid from the aerator-clarifier tank at least once before transferring the remaining settled sludge from the aerator-clarifier tank to the intermediate tank.

6 more elements

Dependencies are inferred from the claim text.

Apparatus and process for distributed treatment of wastewater

Life of this patent

Apparatus and process for distributed treatment of wastewater

Life of this patent

Abstract

Claims42