So far So good!

Remember Modelling Story, well I am still busy with it! The main question to answer is why modelling? We model a system to predict system's behaviour with out doing any experimnetal work. If that is the answer, them I have got. For Estimation of trace elements release from fly ash three scenarios are provided:

1- Disposal in a percolation release regime
2- Utilisation as granular fill
3- Utilisation in road construction

Now there is use for the model. I am working on my results. Trying to find a way to use information from batch leaching test in order to estimate release of trace elements from fly ash samples under above scenarios. I think I know what I wnat to do. I don't want only to model fly leaching without any aim or objective, just showing my math skills! I was looking for a reason for it and I found it.

So full power ahead to solve it...Let you know the results when I got it.

Double diffuse layer!

Working on a theory to model trace elements release from fly ash particles. Please read:

Solid-liquid mass trasnfer during leaching of Ca from dilut slurries of fly ash

By: R. S. Iyer

1999


Let you know the results later!

Sunny day

Apart from my research, I had a wonderful time in Westorn park, close to the studnet union. I spent an hour there!

Transport processes

Looking to model transport processes from leachtes produced from fly ash lagoons! Well, I have to say that three processes are involved:

1- Advection
2- Hydrodynamic dispersion
3- Chemical recations

For modelling we need to right mass balance equation. It is very simple. The solution depends on your assumptions and it can be a simple diffusion equation to a 3D complex equation. For more details you can read Groundwater by Freeze.

A bottle of Argon

Well, another day, another story! Today I spent almost an hour to get permission to order two bottles of Argon for the ICP-MS equipment! As my supervisor was away today morning, I needed to ask somebody else to sign my order form. I learned that:

Stop doing any experiment and wait till your superviosr comes back!

No wonder some experiments takes so long!!!!!!!!

A visit to Brighton

First of all I learned not to trust BBC weather! or even Yahoo one! Don't ask me, just try it yourself. We double checked Friday weather, BBC said it should be sunny and hot. Well we all left Guildford head to Brighton.

First impression: It was not kind of the city that I expected. It was small and dirty. Even worse than Bradford!!!! I could not believe it, Brighton with beach...Oh you can't call it beach...No Sand...No sun...No babes...Sun No Sun.

Second impression: It has the best Fish and Chips...You don't believe me, try it yourself.

We returned to Guildford around 5 ish and I checked BBC website: it said Brighton is Sunny on Friday!!!

Poker in Guildford!

Playing poker in London with my best friends, far away from research and Lab! I needed it!

New model for batch leaching

Today I developed a new mathematical model for batch leaching test on the basis of Fick's law! Chemical reactions and diffusion have been included in this model. Finger cross for the model which I will put in practice next week!

No more research this weekend!

well, after two days hard work in the lab, carrying out Mass Transfer test and preparing the lab for nex week experiments (Leachin contact time), no more research this bank holiday weekend!

Third yera presentation, After it!

What a wonderful day! It was really great...Well the story: I was had 30 min which the guy before took 10 min of my time! So I had only 20 min for the presentation and question part! So I did it very fast. I talked like hell, a very short introduction, assuming that I am doing in a chemical engineering department, full of chemical engineers! But I slowed down in the rseults and discussion part, the mjor part of my work.

I undestood that no one listened to me! No one red the forst slide! No one knew my name except few people which I appreciate them. My supervisor is a great man, he always supports me and I appreciate his kindness and helps.

But the battle field was the question part, when the assessor asked an old question: Where is your model?

Just read his comment on my presentation:

Needs a outline (PS. I am sure he did not linsten ver well)
Thesis should have clear modelling and analysis of equilibrum.diffusion.

I have to add that in this project modelling was in the pbjectives. But I included Mass Transfer tests. Well, in reality, it is impossible to model leachability of trace elements from fly ash, where structure of a fly ash to another one is different. On the other hand, it will be useless to model leaching when the model will be applied on only one type of fly ash! There is no point in modelling fly ash leaching when to can not generilise it. I think the assessor does not know about these facts. He is assessing the project from his point of view and I strongly disagree with him.

Leaching Net

Check it out!

Third year presentation

Tomoroow I have to give a presentation on my PhD research. I am going to talk about batch leaching tests (Availability, TCLP and BS EN tests). I believe these tests do not present actual scenario happing in the environment! We need to design more real tests close to the enviornmnetal conditions. In addition to these, I will talk about leaching behaviour of UK fly ash and effects of pH and LS (Liquid-to-Soild) ratio on leaching process..

Free lime and Arsenic leachability

Well, after months working in the lab, today we found a relationship between free lime content of PFA (coal combustion fly ash) and arsenic leachability. I was very exciting. It was found that during combustion part of the CaO racts with As and the product is an insoluble form of arsein. On the other hand less arsenic will leach. For more information please contact.

Happy Nowruz

Happy New Year (Nowruz 1384) to all my friends and Iranian chemical engineers!

PS You can read more about Persia, persian culture and history on: www.iranchamber.com

Free lime in fly ash

We tried to determine free lime inside fly ash samples. It seems very difficult. Results showed very samll quantities of free lime in the first run! Chemical reactions are unknown at this time and we will try to identify them.

Haloscan commenting and trackback have been added to this blog.

Availability Test

Determining maximum leachable contituents from fly ash is a hard job. It takes at least 6 hours to carry on the test. During the experiment, solution or leachate can contact the atmosphere and some elements may precipitate! This may affect final results and leads to underestimation of all available elements to leaching! So I believe it would better to proceed the test in a closed environment.

The world without engineers
By MZ

World Press Photo

Have a look!

Redox Potential

pH, LS (liquid-to-solid) ratio, temperature and of course fly ash composition are the most important parameters affecting leachability of trace elements from coal fired fly ash. How about redox potential? I believe Eh (or pE) may influence the stability of trace elements in fly ash. However, pH and Eh are related together. On the other hand, decreasing pH leads to increasing Eh. So how can I measure effects of Eh on mobility of trace elements from my fly ash samples in constant pH! How can I keep pH constant and change Eh?