Sea water for toilet flushing

Published on by in Technology

Is it possible to use sea water for toilets instead of wasting the clean water for flushing?

Can the toilet wastewater afterwards be treated in an active sludge process or will the treatment require additional steps and technologies and be more complex?

Taxonomy

9 Answers

  1. I have new innovative technological solution for invisible leakage and contamination control system device for each house holds and others tap water users.

    Its pre-water leakage and contamination control system with out any professional support by users itself.

    It's the first technological solution in the field.. It's highly supportive for Global drinking water challenge. Its the first device which can participate all of tap users to do the water sectors partener for water management. So pls.let descuss discus about it.

    Many tanks!

    1 Comment

    1. Hi Dejene. The problem I described in my question is not the lost of the water due to the leakages but possibility to apply sea (salty) water to splush toilets and further treat such waste water (still salty) in bio-proces for purification. Thanks.

       

  3. We are using a Multi strain Aerobic bacteria for conversion of human fecal matter to neutral water and Co2 gas , this water if goes through a basic filter can be pumped back to use as flush water . Based on this principal we are making the Bio Toilets

  5. @ We will have to see infra-structure cost first. Other thing we see the chemical nature of sea water it contains 70000-75000 mg/L active dissolved salts which have tendency to form deposits when it come in contact with organic matter may creacte problem of maintenance.

  6. Yes it is. It is being used for toilet flushing in Hong Kong for many years. I understand the current level is 85% of all toilet flushing in Hong Kong is using seawater. As Steve has indicated the treated effluent is really only suitable for sea discharge as it can't be used for irrigation.

    1 Comment

    1. Hi Ciaran, I have found a paper on Hong Kong and sea water. Do they purify such effluent water somehow (with active sludge ?) or just pump it directly to the sea without any treatment? Do you maybe know this? 

      1 Comment reply

  7. Be careful.  You will probably end up increasing corrosion in the conveyance network and odour/corrosion in your treatment plant.

    We have found increased odour and corrosion from one of our plants which has a high level of sea-water infiltrations.  The sulphate gets reduced to H2S, which then makes the biogenic sulphuric attack on the concrete sewer pipes worse.  We also found the higher salinity means you can't use the effluent for land irrigation - the operators did a trial a few years ago and quickly realised why the golf course grass was going brown!

  8. Dear Rosemary, Thank you for your answer. I was afraid nobody reads my posts. I put it few weeks ago.

    Grey water is not available. My problem deals with an area where is no fresh water at all and the fresh one (from rains) is being expensive and used for cooking and drinking (if any surplus for washing). There is but a plenty of sea water. Instead of sending it back to the ocean (I consider it too) think if an active sludge process could be applied for such a "waste sea water" similarly like for sewage of fresh water, or the presence of salt unable it.

    2 Comments

    1. In case you still have not sorted this, I think you need a low tech, no chemicals and zero carbon desalinator working most of the time. Please email for details. 

    2. I don't know much about introducing salt water where it is not usually found, but it worries me that once you do that you are contaminating for the future. Solar desalination can be inexpensive and low tech, and please let me know if you need further examples. There are some great designs like the water pyramid used in Africa.

      1 Comment reply

      1. Dear Resemary,

        1) Thanks for the reply. In fact I do not add salt to the water but look for a possibility to apply 100% sea water (directly from the sea) for toilets. Such a waste sea water could be send back to the sea (like sewage from fresh water goes to rivers). I wandered if I could clean it, without desalination !!! , before sending back to the sea (ocean) ? In such a case I would not contaminate the sea. I believe there are some bacteria in sea water which live there naturally and maybe they look for any nutrients from the sewage to to digest (similar to bacteria which deal with sewage from fresh water). This is my basic question if such a process could work or maybe it is already applied somewhere?

        2) Please tell me few words about "water pyramid". I do not know this project.

  9. Better use grey water. Better if it is solar boiled.

    1 Comment

    1. Dear Rosemary,​ Thank you for ​your answer. Grey water is ​not available. ​My problem ​deals with an ​area where is ​no fresh water ​at all and the ​fresh one (from ​rains) is being ​expensive and ​used for ​cooking and ​drinking (if ​any surplus for ​washing). There ​is but a plenty ​of sea water. ​Instead of ​sending it back ​to the ocean (I ​consider it too)​ think if an ​active sludge ​process could ​be applied for ​such a "waste ​sea water" ​similarly like ​for sewage of ​fresh ​water, or the ​presence of ​salt unable ​it.