Oxidation agents, free radical sources and anti-slime agents

Water and Wastewater Treatment

Nothing is more important than safe, clean water. Evonik's portfolio of environmental treatment technologies includes safe chemistries to eliminate impurities and disinfect water. More importantly, our water treatment chemistries are backed by the robust technical expertise and years of experience of our scientists.

Different methods for the treatment of water and wastewater

Wastewater Treatment with Peracetic Acid

We understand the need to disinfect wastewater with treatment chemicals that address the concerns associated chlorination – safety, toxicity, by-product formation and cost. That’s why we’ve developed VIGOROX® WWT II wastewater disinfection technology, the environmentally responsible and economically minded alternative disinfectant to chlorine and UV disinfection. VIGOROX® WWT II, a formulation containing 15% peracetic acid and 23% hydrogen peroxide, represents an innovative solution in industrial wastewater treatment.

We have recently worked with the Standard Methods Organization for the examination of water and wastewater and other industry professionals to develop a method for the analysis of peracetic acid (PAA) residuals. This PAA-specific method will enable wastewater professionals to accurately measure residuals in a plant’s outflow to meet their National Pollutant Discharge Elimination System permit. Method 4500-PAA is now available for use and can be found at standardmethods.org.

Hydrogen peroxide is a strong oxidizing agent that is used in pre-oxidation for algae control, precipitation of iron and manganese and for the oxidation of many kinds of dissolved substances, both organic and inorganic.

Furthermore, in biologically active wastewater, hydrogen peroxide will readily decompose to water and oxygen. The release of oxygen can assist in biological oxygen demand (BOD) reduction by allowing the aerobic bacteria to function more efficiently.

This mechanism is especially important in cases where an oxygen deficiency exists due to high biological oxygen demand / chemical oxygen demand (COD) / Total organic carbon (TOC) loadings and / or insufficient aeration.

In the Advanced Oxidation Process (AOP) hydrogen peroxide is activated by additional components, such as iron salts (Fenton`s reagent), ozone or ultraviolet light. The AOP technology is one of the most commonly applied approaches for waste water treatment. It is successfully used for the degradation of recalcitrant pollutants in various refinery effluents and waste water especially from chemical or pharmaceutical facilities.
The high efficiency of this process is based on the oxidation power of highly reactive hydroxyl radicals, which are formed by the activation of hydrogen peroxide.

Water recycling is one of the most suitable methods for saving drinking water and reducing wastewater. In many applications, it is possible to recycle the process or rinse water. Therefore, this approach has an enormous beneficial impact on environment. On the other hand, users are faced with the challenge of reducing the increased level of contaminants in recycled water. The presence of biodegradable organic compounds can result in the proliferation of microorganisms along with associated visual and and odor problems.

Good examples are car wash facilities in which the majority of the washing water is recycled.
Bad odors resulting from the metabolic processes of microorganisms can be avoided by continuously dosing small amounts of biocides, e.g. peracetic acid into the recycled water. In case of acute odor issues, it is also possible to carry out a shock dosage of peracetic acid. The application of peracetic acid permits the successful use of recycled water and therefore has a direct benefit for the environment.

Products

Formulations of peracetic acid are effective against a wide range of harmful aquatic organisms and to those which cause problems in industrial processes. Peracetic acid solutions are used for a wide range of water treatment applications such as the treatment of cooling water and industrial or municipal waste water. Waste water is usually disinfected prior to discharge to remove pathogenic species. Products containing peracetic acid offer an alternative to common chlorine-based disinfectants such as sodium hypochlorite. Utilization of a chlorine-free disinfectant prevents the formation of toxic chlorinated side products.

VIGOROX® WWT II is a strong chemical disinfectant for use in wastewater treatment that can replace chlorine or UV disinfection. VIGOROX® WWT II, a peracetic acid-based formulation, is an equilibrium mixture of acetic acid (vinegar), hydrogen peroxide and water. The resulting solution contains a mix of 15% peracetic acid (PAA) and 23% hydrogen peroxide.

The PAA molecule is a strong oxidant that, similar to chlorine, will attack and kill pathogenic organisms of concern in wastewater treatment such as E-coli, fecal coliforms and Enterococci by disruption of the cell membrane.

VIGOROX® WWT II is offered as a complete solution including chemical supply; storage, feed and control equipment; and installation, startup and maintenance services. This system minimizes or eliminates capital expenses associated with replacing chlorination with alternative disinfection technologies.

VIGOROX® WWT II has several other attributes that make it desirable as a wastewater disinfectant, including its ease of operation, lower toxicity to aquatic life, low capital costs, efficacy against a broad range of pathogens and rapid disinfection rate.

KEY BENEFITS

  • A proven, more powerful alternative to chlorine
  • Broad spectrum biocide
  • Produces none of the harmful by-products associated with chlorine (THMs)
  • A compliance guarantee and turnkey solution

BROAD SPECTRUM BIOCIDE

VIGOROX® WWTII is a highly effective biocide demonstrating superior microbial reductions of fecal coliform compared to gaseous chlorine or bleach at lower usage rates and shorter contact times, producing no chlorinated by-products (THMs).

ADDITIONAL BENEFITS

  • No need to de-chlorinate prior to discharge
  • Low capital storage and handling systems
  • Effective over a wide pH range
  • Effective in turbid waters

POTENTIAL APPLICATIONS

  • Primary, secondary, or tertiary effluent treatment
  • CSO / Storm water
  • Re-use streams
  • Enhancement of UV systems

B-Cap Antimicrobial Agents are EPA registered and may be used for biofouling control in cooling and process water systems, as a paper mill biocide and for general slime control. Some grades are registered for manufacturing and can be used in any FIFRA registered product formulation using hydrogen peroxide as an active ingredient.

OHP® Grade hydrogen peroxide is an environmentally safe grade of hydrogen peroxide specially developed for its use in OHP wastewater treatment plants or in Fenton chemical oxidation treatment processes for reduction of COD and TOC in wastewaters. A clear, transparent and slightly viscous liquid, it is completely miscible in water in all proportions. It has been proven stable at room temperature and it does not create residue when it decomposes into water and oxygen.

OxyPure is used for removal of iron and hydrogen sulfide in ground water, for taste and odor control, and for destroying ozone and chlorine residuals in potable water treatment. OxyPure Hydrogen Peroxide is the National Sanitary Foundation (NSF) approved product for drinking water applications.

Removal of iron – OxyPure is effective in oxidation and precipitation of iron, by oxidizing the iron to form dense solids, which are easily removed. Iron could otherwise discolor water, spot laundry, stain plumbing fixtures, and if bacteria were to grow, an abnormal taste, odor and biofouling could develop in the water system.

Removal of hydrogen sulfide (H2S) – OxyPure can oxidize the H2S, commonly found in underground potable water sources, and remove the taste and odor associated with sulfides.

Use for Residual Ozone Destruction – It can be added to ensure destruction of small quantities of residual ozone that could be otherwise released into the atmosphere during certain water treatment plant stages.