HOW TO TREAT WATER WITH HIGH NTU (500 above) .

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There is one Water Treatment Plant where the water source is from river flowing mountain. When it rains , the river will take along debris like trees, mud and others to its retention pond. The treatment plant is not capable to treat such dirty and cloudy water therefore has to be shutdown. This resulted the consumer will not get water for consumption. Is there an effective way or ready system to treat this kind of water.   

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18 Answers

  1. Dear Zainal

    First you must analyze the water and 

  2. For high NTU waste water Roughing Filter (RF) is effective as a pre-treatment system for Slow Sand Filter (SSF) with coagulant dosing and mixing with raw water. This RF system can pre-treat high turbidity raw water (1000 NTU) to generate low turbidity (10 NTU) pre-treated water for SSF treatment. In the filter media, height of the filter media, filtration rate and coagulant dosing varied and the characteristics of each item evaluated and the design guidelines can be formulated. Water Treatment Plants (WTPs) consisting of pre-treatment with RF followed by SSF to treat river water can be  designed. As per attached diagram.

  3. Obviously the detail is a bit limited, but yes this is an issue that Rotaflow® could address.

     

    This is a similar process issue that we have already developed, where we use a layer of large gauge meshes to remove the large solids such as dead animals, trees etc reducing the contaminant to a specified SG level that the Rotaflow® could then reduce the contamination to levels measured in ppm before being introduced to the retention pond.

     

    In addition, we already have a development that could offer the treatment of this lightly contaminated water. This is a series of filters, including carbon block filters and if necessary RO filtration and finally UV treatment to kill any bacteria.

  4. All depend on what increase the turbidity :

     

    If it's minimal (sand...) : combine hydrocyclone with sand filters or disc filters 100 micron,

     

    If its organic : the process is different, (coagulation, flocculation, lamella, settler,) 

  5. Bonjour

    Entre le départ de la source et le traitement d’épuration, il y a trop de risques de déversement de polluants organiques, bio chimiques ou chimiques.

    Pour se faire il vaut mieux prévoir une canalisation qui récupèrerait directement à la source cette eau potable pour la transporter directement vers le consommateur sans risque ou avec un traitement simplifié. Cela n’empêche nullement de continuer l’infrastructure actuelle mais de l’isoler en cas de fortes pluies ou autres catastrophes de pollutions intempestives

     

    Hello
    Between the departure from the source and the purification treatment, there is too much risk of spillage of organic, bio-chemical or chemical pollutants.
    To do this, it is better to provide a pipeline that would collect this drinking water directly at the source to transport it directly to the consumer without risk or with simplified treatment. This in no way precludes continuing the current infrastructure but isolating it in the event of heavy rains or other disasters of untimely pollution

     

  6. We can treat this high NTU using CDS self cleansing and non blocking technology .We are now doing a sullage water treatment plant to treat to river water quality Class 2B standard. Please refer to our website www.ecoclean.com.my. please do not hesitate  to contact us if you need further assistance.

  8. You may need to identify an alternate poly/chemical for your flocculation/coagulation step during these high NTU periods - there are several available on the market. What works well is to establish a matrix from jar testing at various NTU levels as a reference as to when to alter the poly dosage and what dosage rates to apply. Then you may need to adjust sedimentation desludge and filter backwash regimes, hopefully the filter units are not compromised as sedimentation should still achieve desired target NTU, we apply <5NTU as sedimentation overflow target.

    You may need to contemplate other residuals in the high turbidity water relative to your normal flow NTU levels to ensure no other contaminant increase.

    Pre-sedimentation can also be considered, and can be in the form of pre-treatment storage.

    Regards

  9. Dear Zainal,

    According to my experience, the best treatment line for this kind of high charge of TSS/NTU surface water, is first stage with hydrocyclones and second stage disc filter 100 - 200 micron. The efficiency on this process is really high because the hydrocyclone removes all particles with more dense than water such as sand, soil, gravel, etc. and disc filter is able to remove small particles up to 100 micron for example.

    These systems well sized, ensure a high efficiency. On the other hand, TOTEX (CAPEX + OPEX) is very low.

    Hope that helps you.

    Best regards,

    Pablo

  10. Pentair X-Flow has a Direct High Solids Ultra Filtration System with tubular membranes working in dead end mode that is able to handle such turbidity. Nevertheless, it would be convenient to know the rest of parameters (such as TOC, TSS, TDS, etc) to know if just one treatment could be enough to produce drinking water. 

  12. Without mentioning the raw water characteristics, its difficult to advise on process scheme, though high turbidity of water is a common phenomenon during rainy seasons. Most economical way to handle such high turbid water is by enhanced primary coagulation (providing an additional clari-floculator) which can be specially operated during rainy seasons only

  13. I think you can use these methods. 1. Converting saline water to fresh water using micro algae. 2-Use of carbon Nano tubes 3- Electro dialysis (ED), evaporation and distillation, reverse osmosis (RO), sand filter (used to reduce the grain size of water solutes to 50 microns), charcoal or activated carbon filter (to remove grease, taste, color, turbidity and Also removes chlorine from water) and ultra-filtration. 4- Desalination of saline water by capacitive deionization method. 5- Use proper filters on the pond floor Such as washed coarse grains, activated carbon filters, garnets, anionic and cationic resins, use of calcium sulfate or gypsum. 6- The effect of common ions 7- Electric shocks and nanotechnology (by paddy husk and almond shell)
    I think you can use these methods. 1. Converting saline water to fresh water using micro algae. 2-Use of carbon Nano tubes 3- Electro dialysis (ED), evaporation and distillation, reverse osmosis (RO), sand filter (used to reduce the grain size of water solutes to 50 microns), charcoal or activated carbon filter (to remove grease, taste, color, turbidity and Also removes chlorine from water) and ultra-filtration. 4- Desalination of saline water by capacitive deionization method. 5- Use proper filters on the pond floor Such as washed coarse grains, activated carbon filters, garnets, anionic and cationic resins, use of calcium sulfate or gypsum. 6- The effect of common ions 7- Electric shocks and nanotechnology (by paddy husk and almond shell)
    
    

    

    

                        
  14. 
                            
    
    
     The content of sludge, sand and silts in surface water can reach several thousand milligrams per liter. Chemical precipitation and flocculation produce important amounts of solids. 
     An economic process to remove this pollution is parallel plate settling (sedimentation). Multiple sedimentation planes within one tank reduce the size and cost of the tanks. 
     Tube settlers, like TubeDEK are an ideal product for this application. It can be adapted to process design requirements by variation of inclination, length of tubes and module sizes. The already mentioned Jar test is definitly the right approach.  
    
    

    

    

                        
  15. 
                            
    
    
    Usually in Malaysia, when turbidity is high which is more than 500NTU, what we need to look at is the optimization of coagulant dose (Liquid Alum, PACl and ACH). If primary coagulant is not enough for the flocs  to settling down, then coagulant aid is needed. Coagulant aid is a polymer usually polyacrylamide. There are many types of polyacrylamide (charge, molecular weight, etc). Then, we need to look on the sizing of your sedimentation tank retention time. Study on this 1. Coagulant and coagulant aid 2. Sedimentation time 3. Water quality when conducting test. Use Jar Test to determine this first, then only conduct for a plant trial. 
    
    

    

    

                        
  16. 
                            
    
    
    Debes hacer tu prueba de jarras para conocer la cantidad de coagulante que deberas aplicar para el proceso de floculación (mecánica e hidráulica de preferencia) que te permita una sedimentación de alta tasa antes de que pases el agua al filtro multimedia.
    
    

    

    

                        
  17. 
                            
    
    
    What are you doing now for treatment? Filtration is the best way but with high influent turbidity, you may need coagulation and sedimentation or the filters will clog quickly. If they operators aren't very sophisticated, slow sand filters may be an option.
    
    
    
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  18. 
                            
    
    
    You should provide for a screen,  primary sedimentation tank with a continous drain at the bottom. I hope that this will help reduce turbidity. Please share raw water quality results at one such time. My assumption is that you already have a working coagulation, flocculation and filtration process in place, so you want turbidity reduced to levels to avoid plant shutdown