Category: Case Studies

Hydrogen Peroxide Turn-key Program Helps Refinery through Aeration Basin Maintenance Outage

[vc_row][vc_column][vc_column_text]US Peroxide’s 27% Hydrogen Peroxide Treatment Program offered the refinery several benefits:
  • US Peroxide’s turnkey supply scope provided a safe and cost effective solution for supply of supplemental dissolved oxygen to this large refinery during the maintenance outage.
  • The biological treatment system’s performance during the outage  convinced the refinery to maintain the hydrogen peroxide storage and dosing system on site to provide supplemental dissolved oxygen (DO) on as “as needed” basis during periods of high BOD/COD loading, upstream process upsets, and filamentous bulking episodes.
In the summer of 2010, a large refinery complex in the Northeast was a facing a 2-3 month maintenance outage on one of two aeration basins in their activated sludge wastewater treatment system. During the outage, all of the refinery wastewater would need to be routed through the one remaining aeration basin.  Since the refinery periodically had difficulty maintaining dissolved oxygen (DO) levels with both aeration basins in service, they needed a temporary (and non-capital) means to provide the biological treatment system with supplemental DO during the maintenance outage. Hydrogen peroxide has been used as a source of supplemental dissolved oxygen (DO) in activated sludge treatment systems for decades. In the aeration basin mixed liquor, H2O2 converts to DO according to the following reaction:

2  H2O2   →  O2  + 2 H2O

This decomposition to DO occurs very rapidly due to the catalytic effect of enzymes (i.e. catalase) present in all activated sludge mixed liquors, and thus provides an immediate source of DO to the biomass.  Since hydrogen peroxide is a liquid, and infinitely soluble in water, the amount of DO provided is not limited by mass transfer of oxygen from the gas phase to the liquid as is the case with mechanical aeration.  More information on this application is provided at this link: Supplemental Dissolved Oxygen. Read More Download Case Study_Refinery-Turnkey-Aeration-15-HR (pdf)[/vc_column_text][/vc_column][/vc_row]

Re-Refinery Used Oil | Sour Water Treated with Hydrogen Peroxide

[vc_row][vc_column][vc_column_text]In North America, approximately 1 billion gallons of used oil are collected annually from generators such as quick lubes, truck fleets, and manufacturers.  Several companies have begun the process of re-refining this hydrocarbon-rich waste product.  Re-refining allows the lubricating oil to be repeatedly re-used as a higher value product. Re-refining involves operations which will separate and remove contaminants in the used oil so that this oil becomes suitable for reuse. The re-refining process is much like that of a traditional refinery with similar waste treatment requirements.  Such was the case for a major used oil re-refinery facility in the mid-west.  They had a “sour water” treatment system that was not performing as designed, resulting in operational problems and safety concerns.  Sour water is hydrogen sulfide rich wastewater water that is generated from a variety of sources including hydrotreaters, reformers and hydrocrackers. Hydrogen peroxide has been shown to be a convenient, cost effective and environmentally friendly part of hydrogen sulfide gas scrubbing technologies.  Scrubbing of hydrogen sulfide using sodium hydroxide and hydrogen peroxide is a well-established technology. A typical scrubbing solution consists of dilute sodium hydroxide to which enough hydrogen peroxide is added to react with the hydrogen sulfide according to the equation:

4H2O2 + H2S → H2SO4 + 4H2O

The above reaction predominates at pH > 9.2, and yields soluble sulfate as the reaction product. The stoichiometry calls for 4.25 lbs H2O2 per lb S 2– and it is not unusual for reaction efficiencies to approach 100%, provided that the hydrogen peroxide is added in a controlled fashion and the reaction medium is thoroughly mixed. Enough sodium hydroxide must be present to neutralize the sulfuric acid formed according to the equation:

2NaOH + H2SO4 → Na2SO4 + 2H2O

This indicates that for each weight part of hydrogen sulfide, approximately 2½ weight parts of sodium hydroxide are needed. USP Technologies provides a full scope of supply (chemicals, equipment and services) to support emergency and ongoing applications for hydrogen peroxide and a range of water and wastewater treatment chemicals.[/vc_column_text][/vc_column][/vc_row]

Advanced Oxidation for High Strength Caustic Wastewater

A refinery in the Northeast was looking at options to dispose of 10,000 bbls of a high strength, high pH caustic wastewater that had been stored in one of its tanks.  The wastewater had very high phenol levels (14,000 mg/L), which did not allow for processing through the activated sludge system due to biological toxicity issues. Off-site hazardous waste treatment options were available, but would have cost over $600,000.  A less expensive, temporary, non-capital and on-site treatment approach that would eliminate the phenols and allow for processing through the activated sludge system was evaluated and implemented at this facility. Earlier in the year, the refinery had a major activated sludge system upset caused by high chemical oxygen demand (COD) loading that killed the nitrifying bacteria and lowered the dissolved oxygen (DO) levels, which made it difficult to recover and achieve required ammonia removal.  USP Technologies (USP) successfully solved this problem using hydrogen peroxide for sulfide oxidation and supplemental DO, which helped the activated sludge system recover and created an environment that allowed the nitrifying bacteria to reestablish.  Having successfully solved this problem, USP was asked to look at the high strength, high pH caustic water in order to determine if it could be treated on-site and processed through the activated sludge system in a safe and economic manner. Read More Download the Complete Case Study on Advanced Oxidation for High Strength Caustic Wastewater (pdf)

Large Ponds Hydrogen Sulfide Odor Control

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Project Scope

A sugar processing facility was experiencing hydrogen sulfide (H2S) odor issues in their process water stabilization ponds due to anaerobic conditions. The facility’s four identical ponds are 2,500 feet long, 400 feet wide and up to 12 feet deep, with a finger dike down the middle making each pond C-shaped. Each pond can hold approximately 80 million gallons when completely full. Anaerobic conditions develop in the lower layers of these ponds, leading to H2S generation and volatilization. The facility faces stringent seasonal perimeter ambient air quality standards for H2S concentration and is subject to escalating fines with every violation.

In addition, the pond treatment needs are highly variable as high chemical oxygen demand (COD) slugs and/or factory upsets mean that treatment decisions need to be made in real-time, based on measured and expected levels of sulfide, dissolved oxygen, ORP, COD, pH and temperature. Previously, the facility had been utilizing various chemicals, including peracetic acid and catalyzed hydrogen peroxide (H2O2) in totes to mitigate H2S, however, the facility was experiencing difficulty maintaining control of the H2S and was concerned with violating their permit. Given the large surface area and volume of the ponds it was essential that a cost-effective control method be identified and implemented. USP Technologies (USP) was contacted to provide a long term, viable solution.

Technology

Hydrogen sulfide (H2S) is a colorless gas with the characteristic foul odor of rotten eggs; it is heavier than air, poisonous, corrosive, flammable, and explosive. Many facilities, such as this sugar processor, have limits imposed on H2S emissions. Sulfide is generated by sulfate reducing bacteria (SRB’s) in the anaerobic layers of the ponds. H2O2 treats H2S by creating a zone of oxidation in which sulfides are oxidized before being released to the atmosphere. The reaction is as follows:

H2O2 + H2S → S0 + 2H2O

Sufficient dosing of H2O2 also prevents the formation of H2S by boosting dissolved oxygen and creating aerobic conditions hostile towards SRB’s per the following reaction:

2 H2O2 → O2 + 2 H2O

Solution

The sugar facility conducted an extensive survey of possible control methods and evaluated options on a lab scale prior to pilot testing. H2O2 was found to be the most cost-effective sulfide control agent in the ponds because of its low H2S treatment cost, ability to preferentially oxidize sulfide, including iron sulfide (FeS)

present in the water, permitting long-acting sulfide control by regenerating free ferrous iron (Fe+2) to bind more H2S.

USP provided a program demonstration in 2014, which first involved bringing in tanker truck quantities of H2O2 and pumping this directly into the ponds through fabricated floating distribution nozzles. The desired amount of H2O2 was pumped into specific sections of the ponds, which had anaerobic conditions prevailing, and then the truck would move on to the next section requiring treatment. This provided improved mixing, a lower cost of treatment per gallon, better sulfide control and lowered staff labor costs.

Building off of the success of the tanker treatment method, USP developed an engineered storage and dosing equipment system for H2O2 on each of the four ponds. This allows for treatment to be conducted whenever and wherever conditions warranted. Each of the systems have two floating manifold dosing lines, dubbed PeroxidonsTM, into which H2O2 and pond water are pumped. These lines stretch along the length of each half of the C-shaped ponds, with outlets spaced to distribute H2O2 across the surface of the entire pond. In addition, on each pond 6 – 8 additional dosing lines were installed that allow for concentrated treatment of hotspots including dead zones and the incoming flows. As a result, performance, ease of operation and cost-effectiveness could be improved with the ability to target treatment to specific sections of the pond.

Overall, USP’s full-service hydrogen peroxide program has saved the plant a significant amount of money in fines and operations. USP also maintains a consistent presence on-site, aiding in the daily collection of water and air data, which unburdens plant staff and improves the sulfide control decision-making process. In a collaborative and results-focused approach, USP continues to work closely with plant staff to find ways to improve the program’s effectiveness and to continue lowering the overall cost of treatment.

Treatment results include significant reductions in H2S, increased dissolved oxygen, cost savings compared to previous year’s solutions, reduced in-house labor associated with pond treatment and improved safety over tote handling.

Read More Download Large Ponds Hydrogen Sulfide Odor Control (pdf)[/vc_column_text][/vc_column][/vc_row]

Cooling Towers and Process Water System Cleaning Applications Using Hydrogen Peroxide

[vc_row][vc_column][vc_column_text]The unique properties of hydrogen peroxide (H2O2) make it a good technology for keeping cooling loops, process water loops and heat exchangers clean from fouling that can occur due to various contaminants in the water. Hydrogen peroxide works well in removing organic fouling on surfaces through mechanical means and in specific applications through biocidal mechanisms. Hydrogen peroxide can be used in a shock treatment mode where it is fed based on a timer set-up. It can also be used occasionally at higher concentrations for maintenance cleaning purposes of fouled heat exchangers, cooling water loops and process water loops. Performing an occasional shock cleaning of a heat exchanger with hydrogen peroxide can remove buildup from surfaces and can result in improved heat transfer efficiency. By removing surface fouling, hydrogen peroxide may also improve the efficiency of other biocides such as bleach, bromine and non-oxidizers.

Before and After Cleaning

  Download our Case Study for Cooling Tower Cleaning (pdf)[/vc_column_text][/vc_column][/vc_row]

Rapid Response: High BOD/COD Levels

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On a late Friday afternoon in June, a call came in to USP Technologies: a major poultry processing plant in the Southeast was in danger of violating their wastewater discharge permit.  They needed a solution fast or face fines, a temporary shutdown of operations and significant lost revenue.

The poultry plant’s 3.5 million gallon aerated wastewater treatment lagoon was unable to maintain sufficient dissolved oxygen (DO) and was unable to achieve ammonia and biological oxygen demand (BOD) removal requirements.  These conditions were brought about by a combination of warm seasonal temperatures of over >90 F, (lower O2 solubility) and higher than normal chemical oxygen demand (COD) loading to the treatment system.  In addition, the oxygen depleted lagoon was generating significant hydrogen sulfide (H2S) odors.

The solution was a turn-key hydrogen peroxide dosing program to supplement the plant’s aeration equipment and get the lagoon DO levels back to a target range of 2 – 3 mg/L .  (See Supplemental Dissolved Oxygen for chemistry details on use of H2O2 for supplemental dissolved oxygen in biological treatment systems)

The USP Technologies’ Engineering team reacted quickly, working over the weekend to prepare an appropriately designed storage and dosing system and overnight shipping it to the site for installation in the field. The Team mobilized on Sunday to install and prepare the systems for a Monday start-up.  By Monday afternoon, the hydrogen peroxide system was fully installed and dosing started at about 3:00 pm, a mere 72 hours from the initial phone call from the poultry plant.

Sampling of the lagoon by USP Technologies demonstrated that, within 24 hours, the hydrogen peroxide addition to the aerated lagoons resulted in measurable increases in DO and elimination of H2S odors.  With continued dosing of hydrogen peroxide, the DO levels increased incrementally over the next several days. By the following weekend, DO levels were back in the 2 – 3 mg/L target range and the ammonia and BOD levels were trending downward.  The plant was out of discharge violation danger.  This poultry plant continued to use hydrogen peroxide for supplemental DO throughout the summer and early fall until cooler temperatures and lower COD loading to the lagoons allowed their aeration systems to maintain required DO levels on their own.  USP Technologies removed the storage and dosing systems at the conclusion of the project.

Read More Download our Case Study for Lagoon Supplemental DO (pdf)[/vc_column_text][/vc_column][/vc_row]

Eliminate Visual NOx Emissions during Plant Start-ups

[vc_row][vc_column][vc_column_text]Two nitrate products producers were looking for a solution to their visual NOx emission plumes during frequent plant start-ups that would satisfy both public and regulatory expectations. USP Technologies was brought in to design a proprietary technology solution which introduces dilute H2O2 into the NOx absorber during start-ups to reduce emissions of NOx compounds such as NO and NO2. Removals of >90% are achieved, with the NOx being converted to high quality HNO3 product. The process is offered under license designed to minimize risk and disruption to operations. The license includes chemical storage and feed equipment, piping and instrumentation, process safety controls, installation and maintenance, training and documentation as well as H2O2 supply service. USP performed a thorough Process Hazards Analysis on the process, which has resulted in several interlocks and controls being incorporated into the basic design. The process is currently used safely in over 30 start-ups per year at two HNO3 manufacturing units. All piping, components, and controls needed to operate the process safely are included with the license and are installed by experienced H2O2 specialists. The H2O2 storage and feed systems are of modular design and are code-compliant, with years of safe operating history.[/vc_column_text][/vc_column][/vc_row]

Turn-Key H2O2 Bulk System for Contact Loop Tote Replacement

[vc_row][vc_column][vc_column_text] A steel mill was having issues with their sodium hypochlorite and tote hydrogen peroxide system. USP Technologies (USP) was brought in to design a bulk full-service, turnkey system to support the contact loop biodispersant and oil removal applications (filter backwash and cleaning application). USP designed and provided 50% hydrogen peroxide (H2O2), a 3,000 gal H2O2 storage and dosing equipment system, remote tank monitoring & product inventory management, equipment start-up & maintenance, on-site applications support and product safety training.[/vc_column_text][/vc_column][/vc_row]

Fenton’s Reagent Application for Phenols Treatment

[vc_row][vc_column][vc_column_text]This specialty chemical manufacturer was experiencing discharge violations (phenols, bio-toxicity) resulting from ineffective treatment with their existing processes and needed to pre-treat a wastewater stream to reduce phenols by 90% prior to mixing with higher flow waste streams. USP Technologies was tasked to design and provide a Fenton’s treatment program whereby the iron catalyst is added to the wastewater stream in-line (static mixer), with the hydrogen peroxide injected (with mixing) into the first cell of a baffled reaction vessel. The baffled reaction vessel helps eliminate short-circuiting and provides sufficient reaction time. The hydrogen peroxide and iron catalyst dosing modules are interlocked with the wastewater pumps to ensure chemical feed stops with an interruption in wastewater flow. USP personnel worked with a major environmental consulting firm and the manufacturer on lab scale “treatability” tests as well as design of the full-scale process. USP also conducted a successful 6-month full-scale demonstration of the technology resulting in optimization of chemical dose requirements. USP supplies the iron catalyst, hydrogen peroxide, and turnkey storage and dosing systems for both chemicals. Supply scope includes ongoing equipment maintenance, remote tank monitoring/inventory management, and applications services. The Fenton’s process is now a permanent part of the overall facility wastewater treatment process and has consistently achieved >90% removal of phenols from this stream as well as eliminated bio-toxicity violations and public relations issues.[/vc_column_text][/vc_column][/vc_row]

Sulfide Control with Cloevis Biofilm Removal Service

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Project Scope

A major city in Florida had been experiencing chronic hydrogen sulfide (H2S) odor and corrosion problems at a forcemain discharge manhole and further downstream at a lift station, resulting in community complaints and collection system corrosion. Furthermore, the forcemain was located in the median of a busy roadway with no place to store a permanent chemical injection system. USP Technologies (USP) performed a system trial utilizing Cloevis Biofilm Removal Service. The trial quickly reduced H2S to desired levels at both control points and eliminated all odor complaints.

Technology

Cloevis Biofilm Removal Service (Cloevis BRS) is an innovative technology offering that removes the biofilms that adhere to the inner surfaces of wastewater forcemain walls, including the underlying Sulfate Reducing Bacteria (SRB) that produce hydrogen sulfide. As a result, gaseous hydrogen sulfide (H2S) production is eliminated. The treatment requires an initial conditioning period when the biofilm that harbors the SRB’s is removed, followed by maintenance treatments that are repeated as monitored lines show signs of SRB reformation.

Control of H2S has been achieved in wastewater collection systems with the utilization of many different technologies such as oxidation, precipitation, pH adjustments and vapor-phase systems. Cloevis BRS offers the benefits of lower cost, avoidance or minimization of on-site chemical storage, is unaffected by sulfide loading, retention time or oxygen uptake and has no labor/ maintenance demand. Other benefits include complete removal of sulfide odors for up to three weeks after treatment cycle and elimination of methane production within the treated segment as well as no downstream adverse impacts due to residual treatment chemicals. In addition, the effective cost of Cloevis BRS is similar to caustic shocking and less than conventional continuous chemical feed alternatives such as nitrate and iron salts.

Solution

The City’s forcemain length is 8,600 feet with a diameter of 8-10 inches and a retention time of 4-6 hours. It has a wastewater flow of 0.128 MGD, and prior to Cloevis BRS treatment, had baseline H2S vapor levels at 50-119 ppm and total liquid sulfide levels at 7.8 mg/L at the control location.

The initial conditioning period involved two separate 24-hour treatments which were completed two days apart. Maintenance treatments included one 12-hour treatment after the first 12 days and one 8-hour treatment after an additional 24 days. Ongoing maintenance Cloevis BRS treatments are completed every 3-4 weeks, depending on the rate of biofilm regeneration. Since the initial conditioning period, H2S average levels have steadily been at 5 PPM or less at the forcemain discharge manhole and sulfides at the downstream lift station have been greatly reduced. Additionally, odor complaints have ceased at these locations since USP began Cloevis BRS treatment.

Read More Download Sulfide Control with Cloevis Biofilm Removal Service (pdf)[/vc_column_text][/vc_column][/vc_row]

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5640 Cox Rd.

Glen Allen, VA 23060

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