پژوهشکده مهندسی عمران آبادان » WATER آّب

 

 

water in the future

دسته : (WATER آّب) توسط روح الله افشارپور در ۰۷-۱۰-۱۳۹۵

Water scarcity in the Middle East
Ruli Afsharpour
Research Assistant at Technical University of Munich

Biogas

دسته : (WATER آّب) توسط روح الله افشارپور در ۰۶-۰۹-۱۳۹۵

Today I want to talk about biogas, you might have heard about it but maybe you don’t know how it works exactly!Simply saying to produce biogas, you put organic material (waste) in a closed room (digester) and microorganisms will do the rest.

It is not only used to produce biogas but also to some how get rid of the sludge in waste water treatment plants (WWTP), because disposal of sludge in WWTP represents up to 50 percent of the current operating cost of the plant so through the anaerobic digestion (no Oxygen) you can protect the environment and optimize the WWTP costs and also produce biogas to generate electricity!

In the picture below you can see the different stages of a typical WWTP:

wwtp

So as I said it would be very beneficial, as you can reduce the amount of final sludge, produce biogas for electricity or heating and you will also have some co-products like fertilizer or nutrients.

biogas_system

At the end I would like to cite a paragraph from a paper published by M. Mohammadi et al; “The potential of biomass sources in Iran is estimated to be 132 million ton (oil equivalent) in the form of agricultural and forest wastes, livestock wastes, municipal wastes, sewage and industrial wastes. Taking into account the usual amount of biogas yield from agricultural wastes, animal wastes, municipal wastes and industrial and municipal wastewater and with good safety factor, biogas in Iran will generate about 16146.35 million m3 which is approximately 323 peta joule (10^15) of energy. Iran is among the countries which have vast resources for biogas production. Despite high biogas potential and simple technologies of generators and reactors of biogas, unfortunately, the use of these resources in the country is limited. So it means that more attention and research is needed in this field.”

water crisis

دسته : (WATER آّب) توسط روح الله افشارپور در ۰۶-۰۸-۱۳۹۵

You might have heard that the world is going to face a crisis as a result of climate change in the near future! As you can see in the picture some regions will experience water scarcity like our region Middle East (red parts) and others will experience more rain events and maybe more flood events (blue parts). 

 

water-crisis

precipitation change as a result of climate change

We are sure that these changes are happening but what should we do? One solution is decreasing the production of greenhouse gasses. But still we will face the problem as we can see signs of water scarcity in our country Iran! 

The situation would be critical in the future and we might think about some advanced technologies like desalination to get drinking water from seawater. There are many people just saying yeah!! We can build some fancy desalination plants in south of Iran and get nice and pure water! But the question is do you even know how much energy consuming and costly it is? Do you know in one liter typical seawater sample 35 grams of salt exists. So if you think of membrane technology you will need lots of energy to provide the pressure for membranes and you will produce lots of salt. As far as I know each person in Iran consumes 170 liters water per day. So if we want to produce that much water from seawater we will end up with about 6 Kg salt for each person per day. It means a family of 5 members equals to 900 Kg of salt per month! Of course membrane concentrates salt as a solution not powder but still you need to dump it to the nature again (not another planet). This huge amount of salts and also other anti scaling chemicals would endanger the environment of Persian gulf. Another issue is that for these kind of plants you need lots of energy and to provide the pressure and obviously you need to burn more fossil fuels since we don’t have that much renewable energy production in Iran and that means creating more greenhouse gasses and making the situation worse by speeding the climate change!

I don’t say that desalination doesn’t work, of course it works but you should think about sustainability  like solar powered desalination plants otherwise you will stuck in a stupid cycle of paying more and more not to solve the problems but to buy everything with cash (which is not a bad idea for developed countries). What we need in Iran is better water resources management, water recycling and support of desalination or other methods.

It’s been a long time that we only talk and wait to first see the dire consequences of a disaster and then think about the solutions, no wonder there would be no easy solution on that time. If every single country acts like this the whole world encounters a catastrophe.So please forget about those stupid ideas like bringing water from Caspian sea, moon other galaxies or whatever. Please forget about building tons of fancy desalination plants. First better water resources management and water recycle, and then other miracles. 

I will write about water recycling and water resource management in the near future…

COD: Chemical Oxygen Demand

دسته : (WATER آّب) توسط روح الله افشارپور در ۲۹-۰۷-۱۳۹۵

For today I thought it is good to talk about a simple calculation that you might need during problems related to water treatment section. So we are going to learn how to calculate COD. But wait a second, what is COD, you might ask!

COD stands for Chemical Oxygen Demand. Ok, ok don’t panic I will explain a bit more.

first we should know that creatures like fish need Oxygen just like us to live and the amount of Oxygen in water like river is called DO (dissolved Oxygen) and when this DO gets lower and lower these poor creatures die. Ok, what does it have to do with COD. Well, COD represents the amount of Oxygen needed for oxidization of stuff in water like organic matter.

So if we want to know about these things we need to be able to estimate the COD for each compound, for example we will do it for Glucose (C6H12O6). To calculate that we need to know about the reaction:

cod-for-glucose

To do the calculation we need to know how much Oxygen is needed and as we can see from the balanced reaction for 1 mol Glucose ,6 mol Oxygen is consumed so the COD is a ratio between them and we need the atomic mass of each element which is equivalent to the number of protons and neutrons in the atom and then as it is shown in orange box and blue box the atomic mass of Oxygen and Glucose are calculated and then the COD is determined 1.07 gram cod per gram Glucose. 

I hope you could learn it, wanna know if u learned? So as a practice, determine COD for Acetic acid (C2H4O2) and post it below.

WATER

دسته : (WATER آّب, اخبار) توسط روح الله افشارپور در ۲۷-۰۷-۱۳۹۵

I think everybody knows today about water situation in the world and many problems that countries like Iran are facing in regards to the lack of water resources.

As a researcher at Technical University of Munich I decided to share some information with you through my website. Since there might be other interested experts from non-Persian speaking countries I am writing in English.

I believe most of the students or experts who are now reading these notes are civil engineers so I will focus on important issues mostly about Water Treatment and Water Management.

water

If you have any question please write a comment below.