Posts tagged ‘EDAR’

NEW TREATMENT PROCESS REDUCES PHOSPHOROUS IN PULP MILL EFFLUENT

Posted By  On Nov 28, 2012 In Water In EuropeWater Technology & Innovation

Researchers at Aalto University in Finland created a method designed to reduce phosphorous in pulp mill wastewater.

The process uses iron sulphate, which is added to the wastewater prior to the biological wastewater treatmentprocess. The phosphorus dissolved into the effluent is precipitated simultaneously with the biomass in the treatment plant.

Simultaneous precipitation does not require additional wastewater treatment units, according to the researchers. This eliminates additional treatment and results in energysavings. Iron sulphate is also an inexpensive chemical, which makes the process more affordable.

Professor Olli Dahl, one of the researchers, explained:

From the viewpoint of comprehensive environmental protection and sustainable development, the best method is always the one that saves energy and minimizes the amount of waste. With the help of the studied simultaneous precipitation method, it is possible to completely avoid additional stages of wastewater treatment, reduce the amount of solid waste and save energy. Simultaneous precipitation produces hundreds of thousands of euros worth of savings in operating costs, as energy consumption and the need for additional chemicals is reduced.

The phosphorus precipitated using this process is removed with the sludge. Since sludge is typically burned in Finland, any phosphorus would be contained in the ash, which could be reused as fertilizer.

The researchers conducted initial testing in the university’s laboratories. “The results were so promising,” noted researchers, “iron precipitation was also successfully tested at the wastewater treatment section of a pulp mill.”

Additional pilot stage experiments were made at a pulp mill where they used iron sulfates during the secondary treatment of elemental chlorine-free kraft pulp mill wastewater.

The researchers say the best result they achieved was an 81% reduction in phosphorus when adding 10 milligrams per liter of iron sulphate into the wastewater during the activated sludge process. “No notable change in either chemical oxygen demand (COD) or adsorbable organic halogen (AOX) reduction nor in the properties of sludge settling were observed during this experiment,” they noted. “Furthermore, no problems in sludge treatment due to increased iron concentrations in the waste sludge were reported.”

The kraft process is a chemical process used to convert wood into wood pulp. Wood chips are mixed with a solution of sodium hydroxide and sodium sulfide that breaks apart the lignin and cellulose present in the wood pieces. This process can also be referred to as kraft pulping, or the sulfate process.

Creating paper requires a great deal of water, which results in the generation of a nearly equal amount of wastewater. Pulp mill effluent typically can contain (link is PDF) not only the unwanted lignin, but also substances such as alcohols, tannins, dyes, and heavy metals. The wastewater also has high biological oxygen demand and dissolved organic carbon as well. The effluent typically requires additional polishing, usually as a tertiary process, to meet local water discharge standards.

Finnish government officials are mandating reduced industrial phosphorus emissions. Several manufacturers are using aluminum in an additional post-treatment precipitation stage; however, the resulting sludge is difficult to process.

The researchers note that forestry-industry-generated wastewater typically contains less phosphorus than municipal wastewater and the iron added during their treatment process “remains within reasonable limits.”

The researchers’ paper, “Simultaneous precipitation of phosphorus in a kraft pulp mill wastewater treatment plant,” was published in the journal Water Science & Technology.

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29 de noviembre de 2012 at 07:51 Deja un comentario

Prometedora nueva tecnología de Biofilm para el tratamiento de aguas residuales.

Posted By  On Nov 21, 2012 In Water Technology & Innovation

Notre Dame Wastewater Samples

Robert Nerenberg, an associate professor of civil and environmental engineering and earth sciences at the University of Notre Dame, hasdeveloped a method for wastewater treatment he says may significantly decrease the chemical costs and carbon footprint associated with conventional wastewater treatment.

A greater number of wastewater treatment plants use biological nutrient removal, which typically requires additional chemicals to work effectively. This might include a chemical that provides an external electron donor, or else a carbon source, such as methanol or ethanol. Typically, these types of chemicals are expensive, toxic, and also have a significant carbon footprint.

Gasses including hydrogenmethane, and oxygen are inexpensive and can help with microbial processes, including those that aid in water treatment. They have rarely been used as electron donors in wastewater treatment because they have a low solubility.

The biofilm reactor technology on which Nerenberg is working would directly deliver the gas to the biofilm, which eliminates these problems. He is studying the feasibility of using various inorganic or gaseous compounds — including sulfur, sulfur dioxide, sulfite, hydrogen sulfite, and methane — for delivery to membrane biofilm reactors.

As Nerenberg explained in a 2005 seminar presenation, membrane biofilm reactor (MBfR) technology “is a novel system that uses membranes to supply dissolved gas directly to a biofilm growing on the membrane surface.”

He adds:

MBfRs are not membrane bioreactors (MBRs). An MBR is a biological treatment process where a membrane is used to separate biomass from the effluent water, substituting for a clarifier. Because MBRs act as filters, they are susceptible to fouling by biofilms or other materials that accumulate at the membrane surface. In contrast, in MBfRs a gaseous substrate moves across the membrane, while the naturally-forming biofilm on the outer surface catalyzes desired reactions. Since the pores of the membrane are hydrophobic, water and bacteria do not penetrate and block them. The combination of a membrane for gas delivery as well as for biofilm support led to the name Membrane-Biofilm Reactor.

As the university explains in a press release:

Many of these compounds are waste products of other industries and can be much more cost effective and sustainable than the carbon compounds currently used in BNR processes. Elemental sulfur, for example, is a waste product from a number of industries, including oil refining and coal or gas-burning refining plants, and in many cases these industries would be happy to provide the sulfur for free to entities willing to remove it. The research thus also offers a means to transform a waste product into a valuable resource.

Membrane-biofilm reactor technology has been demonstrated in pilot testing. The approach is being scaled to work in larger treatment operations.

Robert Nerenberg

Nerenberg received the Water Environment Research Foundation Endowment for Innovation in Applied Water Quality Research 2012 Paul L. Busch Award. This award of $100,000 “recognizes an outstanding individual whose ongoing efforts contribute significantly to water quality research and its practical application in the water environment.”

This funding and recognition should help the work move forward. Nerenberg is reportedly focusing now on applying the approach to work with sulfur and sulfur dioxide, which he says possess the greatest potential for immediate application. He is working with the Hampton Roads Sanitation District in Virginia, where there have been preliminary denitrification tests with both sulfur and sulfur dioxide.

The research should ultimately determine the optimal applications and configurations of membrane-biofilm reactor technology that would be able to decrease wastewater treatment costs while increasing the operation’s sustainability.

Images courtesy The University of Notre Dame.

22 de noviembre de 2012 at 07:11 Deja un comentario

RESIDUOS DE PETRÓLEO PROMETEDORES EN EL TRATAMIENTO DE AGUAS RESIDUALES INDUSTRIALES

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Investigadores en los Emiratos Arabes Unidos están trabajando para determinar cómo se podrían utilizar los lodos remanentes cargados con bacterias provenientes de la producción de petróleo para el tratamiento de aguas.

Salman Ashraf, profesor asociado de bioquímica de la Universidad de los Emiratos Arabes Unidos, fue premiado con AED750.000 (USD$204.000) por la Fundación Nacional de Investigaciones para explorar este tema.

Ashraf y su equipo están analizando a las bacterias que viven en los residuos producidos por la refinería Ruwais para determinar cuál bacteria o combinación de ellas podrían trabajar mejor. Y dijo:

En este momento tenemos ocho bacterias que hemos aislado de esa fuente, de los lodos contaminados con petróleo. […] Estamos actualmente experimentando con estas bacterias para ver si pueden degradar diferentes tipos de contaminantes. Estamos en una etapa preliminar pero los resultados parecen ser muy prometedores.

Anteriormente había determinado que la bacteria Brevibacillus sp. podía degradar al Toluidino azul, una tintura textil de uso muy difundido. Estos hallazgos originales fueron publicados en el año 2007.

Glen Brezius, un químico de los Estados Unidos escribiendo online en el año 2010, observó:

La química orgánica creció a partir de las fábricas de tinturas de Europa pero a pesar de todo el progreso que se logró en el campo de los colorantes en los últimos doscientos años, un acuciante problema continúa pendiente: ¿Cómo disponer en forma adecuada las aguas residuales con brillantes colores que salen de los molinos textiles? […] En tiempos no tan lejanos, era aceptable simplemente arrojar las aguas residuales al océano y olvidarse de ellas. No obstante, ese tipo de conducta ya no es más tolerada y las plantas textiles comenzaron  a enfrentar este problema de tipo muy real. Es un hecho que la mayoría de los ciudadanos simplemente no aceptan que sus ríos y lagos se conviertan en psicodélicos paisajes con manchas de colores púrpura, verde y rosa.

Ashraf dijo que planea explorar la utilización de las bacterias en 10 clases diferentes de contaminantes orgánicos.  Estos incluyen al trifenilo y a los colorantes azoicos. Esta última tintura está entre los pigmentos más comúnmente utilizados en la industrial textil.

Los colorantes textiles son una de las fuentes principales de contaminación de las aguas en el mundo en desarrollo, afirma Ashraf. Aproximadamente un millón de toneladas de tinturas orgánicas se producen anualmente. De esta cantidad, explica Ashraf, como mucho el 20% se pierde en efluentes creados en la fabricación de tinturas y en los procesos de aplicación. Si se liberan al ambiente, estos efluentes industriales constituyen un peligro para la salud pública ya que pueden ocasionar problemas graves a las personas tales como enfermedades de la piel y cáncer.

Tal como Ashraf lo explicó a The National, el uso de contaminantes coloreados puede también ayudarlos a evaluar más fácilmente el proceso que están desarrollando:

Estamos utilizando contaminantes textiles como modelos debido a que al ser de colores, es fácil ver si el color disminuye, es decir, si está funcionando. […] La idea fue utilizar este paso experimental y aplicarlo en la vida real con contaminantes del petróleo. La prueba real de su efectividad se hará en los propios cuerpos de agua, tales como el arroyo Dubai, en donde el agua está muy contaminada.

Ashraf dice que las bacterias podrían ser también capaces de degradar otro tipo de contaminantes, incluyendo residuos de combustibles que son químicamente similares y que podrían descargarse de las refinerías o de camiones cisterna al mar.

Todavía deben escalar el proceso para que el enfoque sea el adecuado para su utilización en una planta piloto.

Parte de este trabajo fue presentado en forma reciente durante el UAE-Swiss Research Day (el vínculo es un PDF) que se desarrolló en Dubai.

15 de noviembre de 2012 at 01:25 Deja un comentario

Reducción del coste de tratamiento de aguas residuales

An award-winning ABB medium voltage drive has reduced the energy consumption of the aeration blowers at a US wastewater treatment plant by more than 1 million kilowatt-hours a year – a reduction of more than 30 percent that saves the city utility $75,000 annually.

By ABB Communications

The aeration basins (left) and aeration blower system (right) at the City of Beloit Water Pollution Control Facility, Wisconsin

The ACS 2000 medium voltage variable speed drive was installed in July 2011 and has achieved some remarkable results within its first year of operation at the City of Beloit Water Pollution Control Facility (WPCF) in Wisconsin, United States.

The facility treats an average of 5.5 million gallons (20.8 million liters) of wastewater a day from the city’s 37,000 inhabitants, as well as industrial waste from local businesses and biological waste from food processing plants.

Like many wastewater treatment plants, Beloit uses a conventional activated sludge process for treating the wastewater. At the heart of this process are the aeration basins in which microorganisms break down the organic matter in the wastewater. These bacteria require oxygen to survive, which is provided by huge aeration blowers that blow air through diffusers at the bottom of the basin.


ACS 2000
Winner of the 2010 Frost & Sullivan European Medium Voltage Drives
New Product Innovation Award


Aeration blowers typically account for 50 percent or more of the electricity consumed by a wastewater treatment plant, and Beloit is no exception. Prior to the installation of the ACS 2000, the aeration blower system at Beloit WPCF was controlled by an inlet throttling valve – a common solution for blower control that operates at fixed speed and does not offer the same operating and cost benefits as variable speed drives.

For Beloit WPCF these benefits are wide-ranging and include soft start capability, ease of installation, direct-to line (transformerless) connection to the power supply network, minimal harmonic distortion, non-requirement of medium voltage power factor correction, compact and lightweight footprint, short payback time and low total cost of ownership.

These benefits are enhanced by an ABB DriveMonitor™ intelligent diagnostic system that performs remote and real-time monitoring and diagnostics of the drive via a wall-mounted PC connected to the telephone line.

Once the ACS 2000, was installed the power consumption of the aeration blower system dropped by more than 30 percent and total plant energy consumption by 15 percent, which is more than 1 million kilowatt-hours a year. At an average composite rate of $0.62/kWh, the annual savings for the City of Beloit amount to $75,000.

2 de noviembre de 2012 at 10:11 Deja un comentario

Usan café para remover metales pesados del agua

Los metales pesados están entre los principales contaminantes del agua y que causan daños a los suelos expuestos a esas aguas
 
 
 

Purifican agua con algas marinas :: El Informador

Purifican agua con algas marinas :: El Informador

vía Purifican agua con algas marinas :: El Informador.

28 de agosto de 2012 at 21:33 Deja un comentario

INVESTIGADORES ALEMANES CREAR ABONO APARTIR DE LODOS DE AGUAS RESIDUALES

 

German Researchers Create Fertilizer From Sludge, Wastewater .

18 de agosto de 2012 at 15:31 Deja un comentario

La Confederación Hidrográfica del Duero destina 103 MM a 40 proyectos del Plan de Calidad de las Aguas

 

vía La CHD destina 103 MM a 40 proyectos del Plan de Calidad de las Aguas | Castilla y León | elmundo.es.

9 de agosto de 2012 at 09:24 Deja un comentario

Inaugurada la primera depuradora subterranea construida en Espana – Inmodiario

 

vía Inaugurada la primera depuradora subterranea construida en Espana – Inmodiario.

8 de agosto de 2012 at 01:02 Deja un comentario

El IMIDA y la UMU desarrollan un proyecto para ” limpiar ” mediante fotocatálisis solar aguas contaminadas con plaguicidas

 

vía El IMIDA y la UMU desarrollan un proyecto para ‘limpiar’ mediante fotocatálisis solar aguas contaminadas con plaguicidas.

7 de agosto de 2012 at 23:58 Deja un comentario

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