Automated process for treatment of refinery wastewater

Patent metadata

Field	Value
Publication number	US-12583775-B2
Application number	US-202318237205-A
Country	US
Kind code	B2
Filing date	Aug 23, 2023
Priority date	Aug 24, 2022
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

The present invention relates to a process for refinery wastewater treatment. More particularly, the present invention relates to an automated process for treatment of refinery wastewater. The process of the present invention provides complete automation for controlling different critical parameters that enhance biological activity of activated sludge process (ASP) and helps in significant reduction in sludge recycling that increases the treatment efficiency.

First claim

We claim:

1 . An automated process for treating refinery wastewater, the process capable of surpassing, or withstanding shock loads, the process comprising:
(i) treating the refinery wastewater in an aeration tank having a mixed liquor suspended solids (MLSS) in a range of 800-1200 ppm, wherein the aeration tank is provided with a first set of sensors comprising a pH sensor, a TDS/conductivity sensor, a dissolved oxygen (DO) sensor, a total organic carbon (TOC) sensor, a cell count or an MLSS sensor, a sludge volume index (SVI) sensor, a specific oxygen uptake rate (SOUR) sensor, an electrochemical sensor, a nitrogen and phosphorus sensor, an ammonia sensor, a temperature sensor, and a level sensor, wherein the electrochemical sensor is configured to monitor a cell voltage and an anode potential of an electrochemical cell, wherein the aeration tank is connected to a hybrid packed bed reactor, and wherein the hybrid packed bed reactor has a plurality of chambers; (ii) monitoring and identifying shock loads and toxic ingressions in the aeration tank continuously; (iii) dosing an active culture of microbes from a microbial dosing system connected to an on-site customized microbe generation system to obtain treated water, and sludge; (iv) polishing the treated wastewater; and (v) recycling 1-8% of the sludge produced in the hybrid packed bed reactor to the aeration tank; wherein the process parameters are controlled through a distributed control system (DCS) based integrated system, and wherein an increase in the cell voltage and the anode potential beyond a threshold value, as identified by the electrochemical sensor, is responded by immediate dispensing/dosing of the active culture of microbes by the microbial dosing system to increase the MLSS in each of the plurality of chambers of the hybrid packed bed reactor to 1200 mg/l-1800 mg/l, and by increasing air purging to maintain the dissolved oxygen (DO) to a level of 4-8 ppm, and wherein a decrease in the cell voltage and the anode potential beyond the threshold value, as identified by the electrochemical sensor, is responded by immediate dispensing/dosing of H 2 O 2 from a feed tank and by immediate dosing of the active culture of microbes by the microbial dosing system to oxidize sulfides and ammonia produced during treating the refinery waste water.

2 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the sludge recycling is about 3%.

3 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the MLSS in the aeration tank is 1000 ppm.

4 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the polishing of the treated wastewater is carried out in a last chamber of the plurality of chambers of the hybrid packed bed reactor having a modified super hydrophobic and oleophilic foam.

5 . The process for treating the refinery wastewater as claimed in claim 4 , wherein the modified super hydrophobic and oleophilic foam is selected from the group consisting of polystyrene, polyurethane, polypropylene, expanded polyethylene and ceramic.

6 . The process for treating the refinery wastewater as claimed in claim 4 , wherein preparing the modified super hydrophobic and oleophilic foam comprises:
soaking the super hydrophobic and oleophilic foam in 15% hydrogen peroxide (H 2 O 2 ) for one hour followed by washing with water; soaking in media comprising a mixture of 5% organic silicone and 2% powdered conductive material in water for 2 hours to obtain the modified super hydrophobic and oleophilic foam.

7 . The process for treating the refinery wastewater as claimed in claim 6 , wherein the organic silicone is polydimethylsiloxane or polymethylhydrosiloxane, and the powdered conductive material is powdered activated carbon, graphite powder, graphene, or carbon nanotubes.

8 . The process for treating the refinery wastewater as claimed in claim 4 , wherein the modified super hydrophobic and oleophilic foam is arranged in corrugated layers.

9 . The process for treating the refinery wastewater as claimed in claim 8 , wherein a voidage of the corrugated layers is at least 0.8.

10 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the pH sensor is connected to a pH controller, wherein the pH controller is configured to maintain the pH in a range of 6.5-8.5 by automatically dosing an acid or a base.

11 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the dissolved oxygen (DO) sensor is connected to a DO controller, wherein the DO controller is configured to maintain the dissolved oxygen in a range of 5-6 ppm.

12 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the plurality of chambers of the hybrid packed bed reactor is about 4 to 6 in number and the plurality of the chambers are inter-connected chambers operating in a plug flow mode.

13 . The process for treating the refinery wastewater as claimed in claim 1 , wherein each of the plurality of chambers, except a last chamber of the plurality of chambers, has a first part and a second part, wherein the first part comprises 75% of volume of each of the plurality of chambers, and the second part comprises 25% of volume of each of the plurality of chambers, and wherein the first part is a packed bed reactor, and the second part is a stirred tank reactor.

14 . The process for treating the refinery wastewater as claimed in claim 13 , wherein the electrochemical cell is placed in the stirred tank reactor.

15 . The process for treating the refinery wastewater as claimed in claim 14 , wherein the electrochemical cell is constructed in an open-ended cylinder and is equipped with two electrodes separated by conductive separator.

16 . The process for treating the refinery wastewater as claimed in claim 15 , wherein the open-ended cylinder of the electrochemical cell comprises acrylic, or polypropylene.

17 . The process for treating the refinery wastewater as claimed in claim 1 , wherein a second set of sensors are provided when a length of a wall of each of the plurality of chambers is more than 4 meters and when a depth of each of the plurality of chambers is more than 3 meters.

18 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the first set of sensors and the second set of sensors are placed at a frequency of 4×3 m 2 .

19 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the SOUR sensor is connected to an air sparger and configured to work in association with the DO sensor to maintain the active culture of microbes in in each of the plurality of chambers of the hybrid packed bed reactor.

20 . The process for treating the refinery wastewater as claimed in claim 1 , wherein the conductivity sensor is configured to monitor conductivity of the refinery wastewater to be treated and to optimize dosage of chemicals to be used to treat the refinery wastewater.

Assignees

• Indian Oil Corp Ltd

Inventors

• Kumar Manoj
• Sandipam Srikanth
• Gupta Ravi Prakash
• Bhattacharyya Debasis

Classifications

• Y02W10/10

  Biological treatment of water, waste water, or sewage · CPC title

• C02F2209/42

  Liquid level · CPC title

• C02F2209/22

  O2 · CPC title

• C02F2209/20

  Total organic carbon [TOC] · CPC title

• C02F2209/10

  Solids, e.g. total solids [TS], total suspended solids [TSS] or volatile solids [VS] · CPC title