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NCAB Decisions 2010

11/2010 |09/2010 | 07/2010 | 02/2010 | 01/2010 |.

Decisions of the National Coal Ash Board (NCAB) 11/2010

At the meeting of the National Coal Ash Board held in November 2010, it was decided to continue to advance and promote research and development on the following subjects:

  • Sewage – Bottom ash as a substrate for a constructed wetland
  • Agriculture – Bottom ash as a substrate for the growth of mango trees

These are the resolutions that were passed:

Bottom ash as a substrate for a constructed wetland The application of bottom ash as a substrate for biological membranes in a sewage treatment system. A four-year study in the Science Park in Ariel, run by Dr. Yaakov Anker of the Samaria and Jordan Rift R&D Center.
 
Brief description
An examination of the suitability of various bottom ash particle sizes to be used as a substrate for biological membranes in sewage purification pools using various methods:

  • Artificial Activated Aquistrata – a biological filter that simulates the natural purification process by filtering underground.
  • Activated underground wetland – wastewater recirculation through oxidized and oxygen-depleted layers, within the reactor, reinforced by the roots of unique water plants to neutralize certain elements.
  • An underground artificial horizontal gravitational wetland – An experimental facility to provide a local solution to a neighborhood disconnected from the sewage system in Revava.

The study has two phases:
Phase 1 – Proving the feasibility of obtaining the required environmental values in the first year of the study.
Phase 2 – Testing its advisability in comparison to the use of other available aggregates (gravel, tuff, basalt) in more than three years of research.

Bottom ash as a substrate for the growth of mango trees A multi-year observation of the development of mango trees grown on bottom ash substrate, compared to a control tuff and local soil substrate, by Eli Haish in Netiv Hagedud.
 
Brief description
A multi-year (four years or any other period as recommended by the professional supervisory team) observation to be carried out on an area of 10,000 square meters out of an area of 50,000 square meters, planned by Eli Haish of Netiv Hagedud, for the planting of mango trees in 2011, to be considerably expanded in the coming years, involving the planting and growing of trees on a substrate of coarse bottom ash mixed with compost in feeding pits. The observation, which will be carried out in comparison to the growing of trees on a substrate of tuff and local soil, will serve to provide experience and demonstrate the use of coal ash, in preparation for its integration in future developments.

Decisions of the National Coal Ash Board (NCAB) 09/2010

At the meeting of the National Coal Ash Board held in September 2010, it was decided to continue to advance and promote research and development on the following subjects:

  • Environment – Radiation from concrete as tested against the Dutch standard
  • Environment – Radiation from construction blocks containing bottom ash
  • Environment – Monitoring dust in the manufacture of blocks containing bottom ash
  • Environment – Test for dioxins in milk of cows lie on bottom ash bedding

These are the resolutions that were passed:

Radiation from concrete with and without coal ash as tested against the Dutch standard Comparison of the findings of radiation (gamma and radon) from concrete, with and without coal ash, according to the Israeli Standard for radiation from building products to corresponding findings from the same concrete objects according to the Dutch method; carried out by Dr. Peter de Jong, NRG laboratory, Arnhem.
 
Brief overview
Israeli Standard 5098 – regulating the content of natural radioactive elements in building products, determines the measurement method and limitations of exposure to external (gamma) and internal (radon) radiation. The measurement method according to the standard is especially important for the integration of coal ash in concrete. According to studies carried out throughout the world and in Israel, the addition of coal ash to concrete considerably reduces the exhalation of radon from the concrete. A study on this subject is being carried out at this time, commissioned jointly by the National Coal Ash Board and the Ministry of Construction and Housing, by the Soreq Nuclear Research Center and the National Building Research Institute in the Technion (decision of the National Coal Ash Board in January 2009).

Whereas the measuring method for radon developed for the purpose of the Israeli standard suffers from lack of experience, a meager database and an absence of international scientific review, the Dutch method is based on the rich experience of many years and has been tested academically in numerous studies and publications in international professional journals. A comparison of the findings of tests using both methods – the veteran Dutch system and the young Israeli one – will make it possible to test the scientific validity of the Israeli method.

Radiation from construction blocks containing bottom ash Radiation tests for construction blocks containing bottom ash according to Israeli Standard 5098 – regulating the content of natural radioactive elements in building products, carried out by System Progressive Laboratories.
 
Brief overview
The National Coal Ash Board decided to advance the use of bottom ash as a raw material to replace sand in building products, in particular the manufacture of construction blocks (decision of the National Coal Ash Board in July 2010). In accordance with the policy to develop uses, the National Coal Ash Board takes upon itself to conduct the necessary tests for the licensing of products containing coal ash, including radiation tests in accordance with Israeli Standard 5098.
Monitoring dust in the manufacture of blocks containing bottom ash Comparative dust monitoring in construction block factory during manufacturing with and without bottom ash; carried out by the Life Science Research Israel.
 
Brief overview
In the context of the conditions for the licensing of the use of bottom ash in the manufacture of construction blocks, the Ministry for Environmental Protection asked the National Coal Ash Board to carry out a comparative monitoring of dust during the manufacture of construction blocks with and without bottom ash. The monitoring is to be carried out in summer conditions, further to previous monitoring carried out in the winter season. The goal is to demonstrate to the contribution of bottom ash to the dust created in the plant during the manufacturing process.
Test for dioxins in milk of cows lie on bottom ash bedding Test for the presence of dioxins in the milk of cows that have spent considerable time lying on a bedding containing bottom ash; carried out by a laboratory in the Czech Republic, by means of KTE.
 
Brief overview
Bottom ash is used as a bedding for animals in the context of a controlled project for a number of years, after it was proved that there is no fear of soil or groundwater pollution originating from the ash in this application. Under the guidance of the National Food Service, tests were conducted for concentrations of pollutants (heavy metals and radionuclides) in agricultural product (milk, tissues) of cows that spent considerable time on bedding containing bottom ash, and it was found that these concentrations were significantly lower than the maximum permitted amount as determined for them by the Food Service.

The National Food Service has recently presented a further demand – to test for concentrations of dioxins in the milk of cows participating in the experiment. This demand comes in wake of a decision by the Veterinary Service to carry out a national survey of dioxin concentrations in cow milk in Israel.

Decisions of the National Coal Ash Board (NCAB) 7/2010

At the meeting of the National Coal Ash Board held in July 2010, it was decided to continue to advance and promote research and development on the following subject:

  • Construction – Characterizing bottom ash properties as a raw material for building products

These are the resolutions that were passed:

Characterizing bottom ash properties as a raw material for building products Investigate the knowledge needed to standardize the use of coal ash as a sand replacing aggregate in building products, using Isotop laboratory, under the supervision of engineer Nehemia Masuri.
 
Brief overview
Bottom ash has physical properties (weight and isolation capability) that are preferable to those of sand (dune and quarry). Bottom ash that is sifted to a grain size below 4.75mm can serve as sand replacement in precast concrete products (blocks, curbstones and interlocking paving stones, before covering, etc.). And indeed, in different places in the world, especially in England, bottom ash is used as an ingredient (fine aggregate to replace sand) in the mixtures of raw materials for the casting of building products in general, and especially concrete blocks.
The European standard updated to 2002 includes, unlike the previous standard from 1994, artificial aggregates from industrial sources, including recycled aggregates. Based on this standard, the Israel Standard 3 can be completed and applied to aggregates such as bottom ash.

Decisions of the National Coal Ash Board (NCAB) 2/2010

At the meeting of the National Coal Ash Board held in February 2010, it was decided to continue to advance and promote research and development on the following subject:

  • Industry – Resourcing industrial sludge using fly ash for civil engineering purposes

These are the resolutions that were passed:

Resourcing industrial sludge using fly ash for civil engineering purposes Applied study to explore the resourcing of hazardous acidic industrial waste using fly ash, carried out by Prof. Haim Cohen and Dr. Ariel Goldman at the Ariel University Center.
 
Brief overview
The research group headed by Prof. Haim Cohen at Ben-Gurion University and the Ariel University Center has been working for a few years on assessing the exploitation of fly ash to neutralize and fixate acidic industrial waste as the environmentally and economically preferred solution in comparison to existing solutions.

In addition, the study examined the possibility of using the product of the fixation as an aggregate in the production of monoliths from concrete, and it was found that it can be used as an alternative for up to 15 wt% of the sand used in the concrete mix without deterioration in the mechanical strength required for concrete. This observation indicates that it can be effectively used in the construction industry without environmental limitations of pollutant leaching.

In an investigation conducted with Haifa Chemicals and Rotem Amfert, interest was expressed in the neutralizing and fixating technology using fly ash on waste that has its source in the manufacture of phosphoric acid from rock phosphates. The research proposal focuses on the application of the fixation products as a partial alternative to sand and aggregates in concrete, and it will test the extent to which it meets technological and environmental construction standards.

Decisions of the National Coal Ash Board (NCAB) 1/2010

At the meeting of the National Coal Ash Board held in January 2010, it was decided to continue to advance and promote research and development on the following subjects:

  • Paving – Bottom ash in asphalt
  • Industry –Abrasive blasting using coal slag

These are the resolutions that were passed:

Bottom ash in asphalt Completion of technology feasibility tests, carried out in the construction and infrastructures test laboratories of the Technion, Haifa, under the supervision of Prof. Ilan Ishai (further to the decision of the National Coal Ash Board of March 2007).
 
Brief overview
Initial findings obtained in preliminary study point to technological feasibility in all tests, and even an improvement in certain features (strengthening over time and improvement of durability capability), although within certain economic limitations due to the increase in the level of bitumen required for the asphalt mixture. In light of these findings, the results of the preliminary study have been summed up as favorable in relation to the effect of a measured addition of fine bottom ash (smaller than 5mm) at a rate of 10 percent (representing 1/2-1/3 of the sand fracture) to the regular asphalt mixes.

It is proposed to carry out test to examine how it meets standard resistance to long-term abrasion. Based on the assessment that coal ash has a higher level of resistance to abrasion than quarry sand, the findings of the test will help to establish the technological advantage of coal ash and improve its cost-effectiveness as a preferred choice upon sand for long-term considerations.

Abrasive blasting using coal slag Literature survey and preparation of a preliminary test program carried out by Dr. Fredy Ornath
 
Brief overview
Coal slag is used throughout the world as a raw material to blast clean surfaces. The bottom ash that is produced as a result of the combustion technology used in Israel is characterized mainly by fine particles that attached to one another, creating larger particles that crumble fairly easily. And indeed, in an applied test carried out in the Israel Electric Corporation involving the cleaning of surfaces using coal slag, the slag fragmented and caused dust.

Dr. Fredy Ornath, an expert on materials and the development of industrial processes, raises the possibility that with the appropriate industrial processing, the features of the bottom ash can be improved and further adapted for this use.