SYSTEM AND METHOD FOR THE TREATMENT OF WASTEWATER

• US 20160107902A1
• Filed: 12/30/2015
• Published: 04/21/2016
• Est. Priority Date: 07/20/2012
• Status: Active Grant

• Current Assignee: Evoqua Water Technologies LLC
• Original Assignee: ProAct Services Corporation (Evoqua Water Technologies Corp.)
• Inventors: Smiddy, Gerard Willem, Smiddy, Frank Leslie
• Granted Patent: US 10,160,664 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C02F 1/004 using large scale industrial sized filters
• CPC Class Codes: C02F 1/281 using inorganic sorbents
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 1/288 using composite sorbents, e.g. coated, impregnated, multi-layered
• CPC Class Codes: C02F 1/38 by centrifugal separation
• CPC Class Codes: C02F 1/52 by flocculation or precipitation of suspended impurities C02F1/463 takes precedence
• CPC Class Codes: C02F 1/74 with air aeration of stretches of water C02F7/00
• CPC Class Codes: C02F 2001/007 Processes including a sedimentation step
• CPC Class Codes: C02F 2101/203 Iron or iron compound
• CPC Class Codes: C02F 2101/32 Hydrocarbons, e.g. oil
• CPC Class Codes: C02F 2103/10 from quarries or from mining activities
• CPC Class Codes: C02F 2201/008 Mobile apparatus and plants, e.g. mounted on a vehicle for biological treatment C02F2203/008
• CPC Class Codes: C02F 2209/00 Controlling or monitoring parameters in water treatment
• CPC Class Codes: C02F 2209/40 Liquid flow rate
• CPC Class Codes: C02F 2303/16 Regeneration of sorbents, filters
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage
• CPC Class Codes: C02F 9/20 Portable or detachable small-scale multistage treatment devices, e.g. point of use or laboratory water purification systems

Abstract

A system and method for backwashing a sand filter in a wastewater treatment system. In one aspect, the invention can be a system for backwashing a sand filter comprising: a sand filter configured to remove solids from an untreated wastewater; a container storing chlorine fluidly coupled to the sand filter by a chlorine supply manifold; a flow control mechanism positioned on the chlorine supply manifold between the container and the sand filter, the flow control mechanism alterable between a first position whereby chlorine cannot flow from the container to the sand filter and a second position whereby chlorine flows from the container to the sand filter, the flow control mechanism being biased into the first position; and a processor operably coupled to the flow control mechanism and configured to automatically actuate the flow control mechanism into the second position upon detecting that the sand filter is being backwashed.

Claims

1-20. -20. (canceled)

21. A method of backwashing a sand filter in a wastewater treatment system, the method comprising:

a) flowing wastewater through at least one sand filter in a first flow direction;

b) backwashing the at least one sand filter to form backwashed water; and

c) upon initiation of step b), automatically injecting chlorine into the at least one sand filter.

22. The method of claim 21 wherein steps b) and c) occur contemporaneously.

23. The method of claim 21 wherein step b) comprises flowing a fluid through the at least one sand filter in a second flow direction, the second flow direction being opposite the first flow direction, and wherein step c) comprises automatically injecting the chlorine into the fluid before the fluid enters the at least one sand filter to form a chlorinated fluid.

24. The method of claim 23 wherein steps b) and c) occur contemporaneously and comprise automatically flowing the chlorinated fluid through the at least one sand filter in the second flow direction.

25. The method of claim 21 further comprising:

step a) further comprising;

a-1) flowing the wastewater through a first sand filter in the first flow direction; and

a-2) flowing the wastewater through a second sand filter in the first flow direction;

step b) further comprising;

b-1) continuing to flow the wastewater through the first sand filter in the first flow direction to form sand filtered wastewater as an effluent from the first sand filter; and

b-2) discontinuing flow of the wastewater through the second sand filter in the first flow direction; and

step c) further comprising;

c-1) automatically injecting the chlorine into the sand filtered wastewater to form a chlorinated wastewater; and

c-2) flowing the chlorinated wastewater through the second sand filter in a second flow direction to backwash the second sand filter, the second flow direction being opposite the first flow direction.

26. The method of claim 21 further comprising:

d) flowing the backwashed water from the at least one sand filter to at least one hydrocyclone to separate the backwashed water into solid material and liquid.

27. The method of claim 26 further comprising, before step d), injecting a clarifying agent into the backwashed water to induce flocculation of particles suspended in the backwashed water.

28. The method of claim 26 further comprising:

e) flowing the solid material from the at least one hydrocyclone into a slop tank for temporary storage of the solid material;

f) flowing the liquid from the at least one hydrocyclone into a settling tank; and

g) flowing the liquid from the settling tank and into a holding tank.

29. The method of claim 28 wherein the holding tank stores a mixture of the liquid of the backwashed water and untreated wastewater that is introduced into the holding tank from a source of the untreated wastewater.

30. The method of claim 29 wherein step a) comprises flowing the mixture of the liquid and the untreated wastewater from the holding tank to the at least one sand filter.

31. The method of claim 28 wherein the at least one sand filter, the settling tank and the at least one hydrocyclone are positioned on a wastewater treatment trailer and wherein the slop tank is positioned external and adjacent to the wastewater treatment trailer.

32. A system for backwashing a sand filter comprising:

at least one sand filter configured to remove solids from an untreated wastewater;

a container storing chlorine therein, the container being fluidly coupled to the at least one sand filter by a chlorine supply manifold;

a flow control mechanism positioned on the chlorine supply manifold between the container and the at least one sand filter, the flow control mechanism alterable between a first position whereby chlorine cannot flow from the container to the at least one sand filter and a second position whereby chlorine flows from the container to the at least one sand filter, the flow control mechanism being biased into the first position; and

a processor operably coupled to the flow control mechanism and configured to automatically actuate the flow control mechanism into the second position to flow the chlorine from the container into the at least one sand filter upon detecting that the at least one sand filter is being backwashed.

33. The system of claim 32 wherein the flow control mechanism comprises a pump.

34. The system of claim 33 further comprising:

a first sand filter and a second sand filter, the first sand filter fluidly coupled to the container by a first chlorine injection conduit and the second sand filter fluidly coupled to the container by a second chlorine injection conduit;

a first valve positioned on the first chlorine injection conduit, the first valve operably coupled to the processor and alterable between an open position and a closed position, the first valve being biased into the closed position; and

a second valve positioned on the second chlorine injection conduit, the second valve operably coupled to the processor and alterable between an open position and a closed position, the second valve being biased into the closed position.

35. The system of claim 34 wherein the processor is configured to automatically actuate the flow control mechanism into the second position and actuate the first valve into the open position while leaving the second valve in the closed position when the first sand filter is being backwashed.

36. The system of claim 32 wherein the processor is configured to automatically backwash the at least one sand filter based on preset criteria selected from the group consisting of a preset time interval and a predetermined pressure differential being measured across one of the first and second sand filters.

37. The system of claim 32 further comprising:

wherein when the at least one sand filter is being backwashed, backwash wastewater flows from the at least one sand filter through a backwash conduit; and

at least one hydrocyclone having an inlet port fluidly coupled to the backwash conduit for receiving the backwash wastewater, the at least one hydrocyclone configured to separate the backwash wastewater into solid material and a liquid.

38. The system of claim 37 further comprising:

the at least one hydrocyclone having a first outlet port fluidly coupled to a settling tank and a second outlet port fluidly coupled to a slop tank; and

wherein the liquid flows from the at least one hydrocyclone through the first outlet port and into the settling tank and wherein the solid material flows from the at least one hydrocyclone through the second outlet port and into the slop tank.

39. The system of claim 38 wherein the at least one sand filter, the at least one hydrocyclone and the settling tank are positioned on a trailer.

40. The system of claim 37 further comprising a clarifying agent injection port positioned on the backwash conduit between the at least one sand filter and the at least one hydrocyclone for injecting a clarifying agent into the backwash wastewater.

41-81. -81. (canceled)