what does mle means in waste wastewater treatment

by Preston King Published 3 years ago Updated 2 years ago

What is MLE and how does it work?

The MLE process takes advantage of the carbon found in the influent waste stream to avoid the use of other carbon sources like methanol or acetate that must be purchased. Many utilities are modifying their disinfection method to eliminate the storage, use and handling of 100 percent gaseous chlorine.

What is the difference between denitrification and Mle?

Denitrification of the nitrate takes place with the addition of influent wastewater containing carbon, the nitrate recycle stream and the return sludge from the clarifiers. The MLE process takes advantage of the carbon found in the influent waste stream to avoid the use of other carbon sources like methanol or acetate that must be purchased.

How do wastewater treatment plants produce quality effluent?

Today’s emphasis on sustainability, together with more stringent discharge limits, has made producing quality effluent a top priority for treatment plant operators. To achieve these goals, many plants are focused on removing nutrients by lowering nitrogen and phosphorous levels through a range of advanced wastewater technologies.

What is influent wastewater treatment?

Influent The untreated wastewater or raw sewage coming into a wastewater treatment plant. Influent Screens Screens used to remove large inorganic solids from the waste stream. Innovative and Alternative (I&A) An EPA term for wastewater treatment systems that reuse all or part of the wastewater.

What is MLE wastewater treatment process?

The MLE process consists of modifying a conventional activated sludge process by creating or adding an anoxic zone upstream of the aerobic zone. An internal recycle pump system returns nitrate-rich mixed liquor created in the nitrifying aerobic zone to be mixed with the influent in the anoxic zone.

What is high rate activated sludge?

Abstract. The high-rate activated sludge (HRAS) process is a technology suitable for the removal and redirection of organics from wastewater to energy generating processes in an efficient manner.

What are the 3 stages of wastewater treatment?

There are three main stages of the wastewater treatment process, aptly known as primary, secondary and tertiary water treatment. In some applications, more advanced treatment is required, known as quaternary water treatment.

What is TN in wastewater?

Forms of Nitrogen in Wastewater. Total Nitrogen (TN) is the sum of nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), ammonia-nitrogen (NH3-N) and organically bonded nitrogen.

How do I increase bacteria in my aeration tank?

Increase aeration efficiency by converting from course bubble diffusers to full floor fine bubble aeration diffusers. Add fixed-film media to the aeration tank environment to increase the biomass concentration. Place additional aeration tanks into service to adequately process organic loadings.

How do you start activated sludge process?

An activated sludge plant can be started up at the design mixed liquor volatile sus- pended solids concentration, or with sufficient sludge for lower or higher initial suspended solids. Aeration basins can be started up partially or completely filled.

What is staging in STP?

The Sewage Treatment Process essentially includes three stages. The three stages can be divided into primary, secondary, and Tertiary. In each step, water is purified to the next level to access clean water for humans and the environment.

Why is ETP important?

Effluent treatment plant cleans industrial effluents, contaminated water from outlet pipes, reservoir, rivers, lakes etc and reclaim the water resource for using in different purposes. ETP are mostly installed in industries like textile industry, Medicine manufacturing, leather industry, and chemicals industry.

What is called sludge?

The residue that accumulates in sewage treatment plants is called sludge (or biosolids). Sewage sludge is the solid, semisolid, or slurry residual material that is produced as a by-product of wastewater treatment processes. This residue is commonly classified as primary and secondary sludge.

What is difference between TN and TKN?

As we know Total Nitrogen is sum of Total Kjeldahl Nitrogen (TKN), Nitrite and Nitrate also TKN is sum of Ammonium, Organic and Reduced Nitrogen. If we consider Organic and Reduced Nitrogen in low amount then TN will be the sum of Ammonium, Nitrate and Nitrate.

How can we reduce TN?

TreatmentCarbamazepine, an anticonvulsant drug, is the most common medication that doctors use to treat TN. ... Gabapentin, an anticonvulsant drug, which is most commonly used to treat epilepsy or migraines can also treat TN. ... Oxcarbazepine, a newer medication, has been used more recently as the first line of treatment.

What is TKN in wastewater treatment?

Total Kjeldahl Nitrogen (TKN) is the U.S. EPA-approved parameter used to measure organic nitrogen and ammonia. The TKN content of influent municipal wastewater is typically between 35 and 60 mg/L. Organic nitrogen compounds in wastewater undergo microbial conversion to NH3 and ammonium ion NH+ 4.

What is the process of denitrification of nitrates?

Denitrification of the nitrate takes place with the addition of influent wastewater containing carbon, the nitrate recycle stream and the return sludge from the clarifiers . The MLE process takes advantage of the carbon found in the influent waste stream to avoid the use of other carbon sources like methanol or acetate that must be purchased.

Why is chloramination used in disinfection?

Many utilities are modifying their disinfection method to eliminate the storage, use and handling of 100 percent gaseous chlorine. In order to prevent the formation of harmful disinfection byproducts , chloramination is gaining popularity, especially the production and use of monochloramine. What is the necessary ratio of chlorine to ammonia to form monochloramine?

Which type of blower allows both nitrification and denitrification simultaneously?

C) The aeration basin blowers or mechanical aerators are operated in an on-and-off cycle which allows both nitrification and denitrification simultaneously.

How does MLE work?

What is MBR treatment?

MBR treatment plants can produce a consistent, high-quality effluent that is excellent for public access reuse, urban irrigation and other reclaimed water uses. It is also suitable for discharge to coastal, surface or brackish waterways. 4. Sequencing Batch Reactors (SBR)

What happens after a SBR tank is decanted?

After the SBR tank has decanted a portion of its total liquid volume, it is ready to treat another batch of influent wastewater. An SBR treatment facility does not have secondary clarifiers or RAS pump systems, and can meet very strict effluent limitations on a small land footprint. 5.

What is IFAS in wastewater treatment?

IFAS technology is the first process specifically designed for ideal operation in municipal wastewater treatment/activated sludge processes . Typically, IFAS is a retrofit solution for conventional activated sludge systems that are at or beyond capacity, providing minimal plant downtime, zero facility construction and optimization of existing equipment.

What is MBBR process?

The MBBR process uses thousands of polyethylene biofilm carriers operating in mixed motion within an aerated wastewater treatment basin. Each biocarrier provides a protected surface area to support the growth of bacteria; the high-density bacteria population, in turn, helps achieve high-rate biodegradation within the system, thus supporting BOD reduction, nitrification and total nitrogen removal.

What is a membrane bioreactor?

Membrane bioreactors are a unique wastewater treatment process designed for municipal and industrial uses. They are a combination of a membrane process, like microfiltration or ultrafiltration, with a suspended-growth bioreactor.

Is aerated wastewater mixed with RAS?

In the anaerobic zone , only RAS from the clarifiers and influent wastewater are mixed, not aerated. Bacteria called phosphate-accumulating organisms (PAOs) compete for the available carbon, but must release their molecules of polyphosphate from their own cells to allow for the food to be taken into the cell.

What is wastewater permit?

These terms refer to the amount of wastewater flow over a given time period. Most wastewater permits include daily flow limits, so facilities track the flow of treatment systems to stay within overall permit parameters.

What is an indirect reading of the organic content present in wastewater?

Specifically, it refers to the amount of oxygen consumed to biologically degrade the organic material. It’s very expensive to treat, typically requiring a biological treatment technology like activated sludge.

What is a control parameter for treating hexavalent chromium wastewater?

A measure that indicates the capacity of wastewater to gain or reduce electrons during a chemical reaction. It is used as a control parameter for treating hexavalent chromium wastewater in the metal finishing industry.

What are the heavy metals in wastewater?

Other heavy metals include: Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), and Zinc (Zn).

Why is UV light used in wastewater treatment?

In some industries, ultraviolet light is used to sterilize water treated wastewater prior to reuse or recycling. UV light keeps algae and other bacteria from growing in the recycled wastewater.

What is biological water treatment?

A biological water treatment technology commonly used in municipal wastewater treatment systems. Sometimes private industry will harness this technique to reduce certain pollutants, such as BOD and COD (see definitions below), but usually only due to compliance concerns.

What are visible solids in wastewater?

Visible solids present in wastewater that can be filtered out through traditional physical treatment technologies. In the metal finishing industry, for example, FOG (fats, oils and grease) and dirt particles might make up part of the total suspended solids.

What is the process of adding a substance to wastewater?

The process whereby a chemical or other substance is added to wastewater to trap or attract the particulate suspended solids into clusters or clumps of floc or flocculent, wooly looking masses.

What is a tank in wastewater treatment?

Usually in municipal wastewater treatment, a chamber or tank in which primary influent is slowed down so heavy typically inorganic solids can drop out, such as metals and plastics.

What is industrial ecology?

Industrial Ecology (IE) focuses on combining perpetually desirable outcomes in environment, economy and technology sustainably. The primary tenet is that all systems mimic nature and are thus closed loop, continuous, circular. In wastewater treatment industrial ecology would mean that all so called "waste" is re-input into the same or other process. For example, biosolids as fertilizer can be considered a use of sludge consistent with industrial ecology. Recycling wastewater into the treatment plant, manufacturing or other process is another example.

What is floc in wastewater?

Particulate and or bacterial clumps forming wooly looking clusters in wastewater. In biological processes such as extended aeration or activated sludge and others the floc contains aerobic or anaerobic microorganisms. For industrial applications flocculants are used.

Is wastewater treated industrial or municipal?

Paper and pulp mills' treatment of wastewater is an example of industrial wastewater treatment. Municipal wastewater treatment would be an example not considered to be industrial.

Oxidation Reduction Potential (ORP)

Measuring the oxidation reduction potential (ORP) is such an easy, insightful test to perform, it’s a shame this poorly understood parameter is so underutilized. Of course, it’s that very lack of understanding that leaves ORP testing hidden away in the shadows.

ORP Measurements In the Field

When I measure the oxidation-reduction potential at a wastewater plant I like to present the data as shown in the graphic below. This simple bar graph communicates a lot, easily and quickly, letting you know at a glance if there are any potential problems.

Rotary Disk Aerator

The charts and table on this page may be a little difficult to read. If you click here (or on any of the graphics above) you can open up a PDF for easier viewing/printing.