High Altitude Wastewater Treatment

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Hi Everyone;

I have a rather unique problem and am trying to identify the best WWTP solution for high altitude projects to try and prevent environmental pollution in the Himalayas. The requirements are:

1. To be installed at elevations greater than 3000m.

2. Must be able to function in low oxygen environments.

3. Must be compact due to difficulty of getting equipment to site.

4.Loads per site will range from 1 - 100 KLD

If anybody out there has any experience with such WWTP please tell me what you propose. They are currently using soak pits with the runoff flowing downslope.

Sanjay

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7 Answers

  1. Sanjay, 

    I'm currently working on the Concordia Station in Antarctica which is operating @ 3200m and have found it very challedging. I have found that normal aeration techniques from a blower not to be effective with the amount of power that we have available at the site.  We have found the venturi areation to be far more effective increasing the DO and providing a higher saturation of oxygen. Unfortunatly the wastewater here is extremelly concentrated with Ammonia levels well over 900mg/L which I am finding very challenging. I would defiantly like to hear of other aeration techniques at higher altitudes and if anyone has noticed a difference in the microbial colonies. The altitude here has significantly affected me and I was wondering if anyone has been able to have a closer look at the behavior of the microbes at higher altitudes.  

     

    Thanks,

     

    Peter Christou

    @Swirltex

  2. You should know that the principle of wastewater storage already looks like what is practiced for ages in septic tanks. Feces putrefy and turn into mud. The device emits stinking. The mud is an organic material which does not address. Mud is, mud remains. If it contains hazardous chemicals microphones, it is a crime against humanity to disperse in the environment. Incineration emits REFIUM in the atmosphere polluting the air we breathe. The concept of Sanitation Biologhique installs restricted sites whose implementation is easy. The treatment of excreta is immediate, there is no need stocage and palliative treatments. The water remaining rejected the concept is used to water the surrounding biodiversity, see a vegetable garden. The financial cost of implementation is minimal. The concept of this treatment sites suitable places: Kitchen hotellerie restoration toilet. Each producer wastewater is responsible for the management and maintenance of the device. The goal: all treatment systems must be sufficient in themselves for a comprehensive, final. Regarding the implementation We play on the slope disbursement to generate the least amount of work to install. Then it is easy to construrie around devices insulation for the winter period. At least 10 °, at 1850 meters, completely buried, the temperature of a Biological Remediation site, was 16: 5. If the device is powered continuously there only during the period of extreme cold or you have to monitor the release of water. The concept does not require on-site personnel.

  3. Sanjay, It seems that you have before you the whole range of sanitation alternatives: from ventilated pit privies or lagoon treatment to membrane bioreactors or granular sludge systems. I suggest that you follow a systematic consideration of a wide range of possible solutions starting with a coarse screening to determine the most feasible alternatives and then proceeding to more detailed evaluation of these. If you are not familiar with it, you might start with the EAWAG Sanitation Systems Compendium (http://library.eawag.ch/EAWAG-Publications/openaccess/Eawag_08276.pdf). This gives a basic description of many systems. I produced a similar document in the 1990s for the UNEP (http://www.cep.unep.org/pubs/Techreports/tr40en/chapter1.html) but the EAWAG document is more current and of higher quality! Clearly your environmental conditions are challenging and should be the start for your analysis. Starting from the most low tech of solutions you might consider an anaerobic pit system followed by a facultative lagoon. Snow cover may require long-term winter storage, however. This system will produce basic treatment with little or no power required, but with rock in the environment, excavation could be very expensive. This type of system is the typical system in small villages in the Kathmandhu Valley. At the high tech end of the spectrum membrane bioreactors are very compact and produce excellent water quality effluent, but at the cost of high power consumption. If a powered system is not out of the question, the most up-to-date approach these days might be a granular sludge system (http://www.royalhaskoningdhv.com/en-gb/projects/nereda-the-natural-way-of-treating-wastewater/106). You might also consider one of the "Reinvent the Toilet" solutions, for example, EAWAG's Blue Diversion toilet: http://www.bluediversiontoilet.com/on-site-recovery.html. Best wishes in your search. Regards, Randal

    1 Comment

  4. Hi Sanjay, may be find out what do they use for heating the buildings (gas?). It could be possible to use the same heating for keeping the temperature in the TP above whatever we need for the chosen treatment process. It could also facilitate the TP (bacteria loves warmth..). You can also consider dilution with melted snow prior to discharge. Regards, Iouri

  5. Hi Sanjay, thanks for the quick response. Understand that the sewage will be a combination of kitchen and domestic shower/toilet waste. Do you know what is the average temperature of the inflow sewage? As long as we keep it within the building - should be above freezing point. However, if we want to transfer sewage between the buildings - it could be tricky - the sections of external pipes can freeze (likely in the time when there is no flow through) as the flow is intermittent (not constant). May be you need to consider individual TP at each building, however it might be impractical if there are too many small buildings. What are the minimum treatment requirements (WQ prior to discharge into the environment)? Where do they source potable water - (snow melt?). Is re-use of waste water - an option (e.g. for toilet flush)? As to the treatment process - guess if you place the TP inside the building(s) (basement) - the water should be kept above freezing point. Then we have a low oxygen challenge - but it should be solvable for a (compulsory) biological stage - in worst case - you can use a blower to inject air bubbles. Subject to good engineering - should be able to get it all working. Sorry for my generic comments, understand you are looking for practical (off the track) solutions - but not sure if we can find one that is proven and will fit perfectly into your situation. Hence - I concentrated more on the general concept - hope it will be of some help. Regards, Iouri

    1 Comment

    1. Hi Iouri; I agree and I thought I might try anaerobic digestion in underground tanks. With the low temp may get 50-65% digestion. The question was after that what? It may actually come to a situation where some treatment is better than nothing... Never thought where the fresh water comes from but as you said suspect snow melt as well as its the most likely. Doubt reuse is an option as the quality of treated water standard is probably not cost effective because of the small unit sizes.

  6. French English Le mot 'station d'épuration' est attaché à l'assainissement collectif qui comrpend l'implantation d'un réseau de collecte qui regroupera toutes les eaux usées sur un site de traitement appelé: station d'épuration. C'est un dispositif complexe surtout en haute altitude où la station d'épuration va énormément souffrir en hiver. A cela il faut y ajouter les coût de gestion et de maintenance. Pour ce genre de situtation il faut des systèmes individuels dont l'infrastructure de collecte se trouve proche du lieu d'émission. Dans l'habitat l'eau usée rejeté aura une température entre 10° ET 12°. Elle rejoindra le site de traitement enterré qui lui aura une température positive. C'est la condition siné qua non d'un traitement -biologique- pour une élimination complète de la matière organique. Ensuite il est important de définir la zone de réception du reliquat d'eau qui va geler pratiquement 6 mois sur 12. De la biodiversité végétalisée locales serait le bienvenu. Question S'git il de maison individuelle, de restauration, d'hotellerie, de camp de vacances, de lieu de passage,? Combien de personnes produisent ces eaux usées ? Jean Marius The word 'sewage' is attached to the sewerage which includes the implementation of a collection system that will bring together all the wastewater to a treatment site called: sewage plant. Question: what becomes of the sludge at this altitude? It is a complex device especially in high altitude where the treatment plant will suffer in winter. To this must be added the cost of management and maintenance. For this kind of situtation must be individual systems whose collection infrastructure is near the place of issue. In residential waste water has a temperature between 10 ° and 12 °. She will join the underground treatment site which does have a positive temperature. This is the prerequisite dered a -biologique- treatment for complete removal of organic matter. Then it is important to define the reception area of the water balance which will freeze almost six months out of 12. Of the vegetated local biodiversity would be welcome. Issue S'git about house, catering, hotel industry, summer camp, a passageway ,? How many people produce these wastewater? Jean Marius

    1 Comment

  7. Hi Sanjay, interesting situation you have! Understand that the site is also subject to freeze and thaw, given the altitude? My initial thoughts: - need to understand the inflow patterns, especially during the winter time (how many people/toilet blocks per day/week/month? - some kind of a balance storage for inflows during winter could be helpful - is there electricity on site? - what is the range of temperatures over the four seasons? - is stormwater collected on site? - what is the terrain (how deep can you excavate?) - is there anyone to service the WWTP? Sorry, more questions than answers at this stage. Regards, Iouri

    2 Comments

    1. Louri,
      I'm a big fan of freeze and thaw dewatering and it is the way that we implement biosolids management all the time in the arctic. I was wonder if that what you meant by freeze and thaw our where you suggesting to consider structural aspects of freeze and thaw cycles?
      Thanks,
      Peter Christou

    2. Hi Iouri; No fewer questions then I have... so let me go in sequence. Q1 need to understand the inflow patterns, especially during the winter time (how many people/toilet blocks per day/week/month? A1: Variable but these are basically catering to toilets, kitchen and some bathing in winter so in the range of 50 LPCD. Populations will vary from 15-100 daily depending on site. Think in terms of mountaineering camps, trekking campsites, etc. Q2: some kind of a balance storage for inflows during winter could be helpful - A2: What do you suggest? Q3: is there electricity on site? - A3: Yes otherwise generators can be used or solar can be looked at as well. Q4: what is the range of temperatures over the four seasons? A4: 20C to -30C Q5: is stormwater collected on site? A5: No and Not required Q6: - what is the terrain (how deep can you excavate?) A6: Rock surface unless there is snow cover (3-5m permanent at higher elevations) Q7: is there anyone to service the WWTP? A7: Yes, people can be trained.