What is the optimal solution for a wastewater plant facing a big difference in flow during the year?
Many coastal cities are facing the increase in the number of residents in the summer, in comparison to winter. I live in Nador, Morocco and during the summer season the number of people multiplies 10 times, reaching 1 million.
What's the best solution for the wastewater network and plant design in this case?
In this case, you must have equipment that can cope with such a volume of water. To increase the aeration tanks does not make sense. I offer equipment that runs periodically and may remove load from sewage treatment plants. Moreover, after processing by our equipment, the water can be used for irrigation, in terms of Morocco I think will be in demand. This equipment is SIX times less land than biological treatment, and in conditions of operating facilities can be "built" into the system ochistki and not take up extra space. It does not require training to launch, and immediately after the start to clear drains. Power inputs for cleaning of m3 is FIVE times lower cost for biology. This will help You to solve the problem of wastewater treatment without increasing space . Send me Your e mail and I can send You pictures of our equipment. Just don't be surprised that it looks like this. This equipment for over 7 years, working at various wastewater treatment plants. my email address posts tumentsev@inbox.ru
Water flow into the collection system is comprised of
Sanitary wastewater from residential and commercial sources,
Groundwater infiltration, and
Rainfall derived inflow from surface sources. Sewer systems will experience some level of infiltration and inflow (I/I) as a result of age, installation quality, and proximity to I/I sources such as creeks, rivers, lakes, and storm water channels. Small quantities of I/I are acceptable and incorporated into the design of collection and treatment systems.
However, large quantities of I/I put undue strain on the collection and treatment systems, which, in turn, affect the District’s operation and capital budgets and directly impact services rates. Although I/I is typically low in solids, I/I causes dilution of the wastewater resulting in decreased solids removal efficiencies and increased pumping power costs. Maintaining wastewater collection infrastructure – pump stations, force mains, and sewers – is an integral component of the proper management of a treatment system and critical to preventing illegal wastewater releases. Inflow and infiltration (I&I) happen when water from the environment that does not need to be treated enters the sewage system. Infiltration refers to groundwater entering the system. Inflow refers to rainwater (stormwater) entering the system. wastewater collection system conveys an average daily flow of 100,000 gallons per day to the Town's Wastewater Treatment Facility. During major rain events this flow can increase to 500,000 gallons per day. Excess water that flows into sewer pipes from groundwater and stormwater is called infiltration and inflow or I/I. Groundwater infiltration seeps into sewer pipes through holes, cracks, joint failures, and faulty connections. Stormwater inflow rapidly flows into sewers via roof drain downspouts, foundation drains, storm drain cross-connections, and through holes in manhole covers. Most I/I is caused by aging infrastructure that needs maintenance or replacement.
Know where your sewer lateral is on your property
Avoid planting trees and shrubs over sewer laterals as roots seek water and can damage sewer pipes
Check your gutters and drains to ensure they are not connected to the sanitary sewer system.
Disconnect roof downspouts from the sanitary sewer system. Even better, install a rain barrel under your roof leader, if conditions permit
Disconnect foundation drains and groundwater sump pumps from the sanitary sewer system
Have your property's sewer lateral inspected. Replace any known broken, leaky or problem sections of your property's sewer lateral. Maintaining and repairing the lateral is the homeowner's responsibility and can reduce I&I and prevent sewer backups into your home.
It is usual that for WWTPs located on coast and in mountains (ski station) the selected process is biofiltration. Indeed biofilters can be easily and "quickly" stopped and started to be close from the inlet load to treat.
Within SUEZ, for example this technology is named Biofor (C and N removal).
C'est la plus grande énigme jamais résolue. Quand on créé un assainissement collectif on dimention la capacité de traitement de la STEP. Elle est incapable de résoudre l'affluence estivale qui varie d'une année sur l'autre, d'un climat politique sur l'autre, des conditions atmosphériques, etc
Il y a bien une solution
Diversifier l'assainissement en implantant en parallèle de l'assainissement non collectif. Cela réduit le pourcentage d'eaux usées qui arrive sur la STEP et met la STEP en mesure de pouvoir pallier à une abondance estivale
Hello this is the biggest ever solved Enigma. When on created a collective sanitation on the treatment capacity of the STEP size. She is incapable of solving the summer influx, which varies from one year to the next, one political climate on the other, weather conditions, etc.
There is a solution to diversify sanitation by implementing parallel of non collective sanitation. This reduced the percentage of wastewater that arrive on the STEP and met the not able to patriia to a summer abundance
Adding a MBR is an expensive, but good option. You could also evaluate adding media to convert the system to a MBBR type system.
Other seasonal high loading facilities have used bioaugmentation to rapidly build needed biomass. If you system is large enough for the full resort population flow, this could be a lower cost option than either a MBR or MBBR
Try thinking about balancing the flows with resevoirs so you will get more moderate changes, it is all depends on the volume and speed of the increase.
If you want to treat all the wastewater coming in the Summer Season which is 10 times more then in Winter Season. And as I assume you have a longer Summer Season say for 6 - 8 months.
In this case, you could have a couple of options;
1) Your Municipality needs to have additional Treatment Plants by making Modular Type System which will enable to run only one stream in Winter and in Summer it could use all the modules.
2) Convert your existing Biological System to MBBR System, thus may increase this system capability within the same civil structure (aeration tank) to treat approximately 3 times then existing plant capacity.
3) Convert your existing Biological System to MBR System, so you could run your existing Aeration at a Higher MLSS 12,000 - 15,000mg/l thus increasing the current bioreactor to treat 4 times or more wastewater within the same reactor.
4) If your WWTP Plant is outside the City and has no population nearby the plant and ample land is available, then you could opt for Constructed Vertical Wetland which is far cheaper than all the above solutions.
Obviously in all cases, there will be needed some more essential addition of pumps/equipment as well as other alterations.
Everything need to be looked out, I just floated the idea to you.
The Neptune system tanks hold 2 5,000,000 m³ of water or effluent if needed for water harvest. We have created a design to store water in the winter and use effluent recycling in the summer. The tanks situated above ground is easy to install and can be moved to any location numerous times
In Italy we have many WWTP facing this challenge. As examples of best practices see the WWTP Santa Giustina (Rimini) and Borghetto Santo Spirito (Imperia). Both use membranes (MBR) on several parallel lines. Only a few lines are active during winter (low season). At the beginning of the high season, the load is increased and the waste sludge is retained and some is used as inoculum for the other lines.
you may also consider that installing an advanced treatment process like MBR willenable you to reuse the water for irrigation, which in summer could have some attractive benefits
One of the states with similar problem during summer is Montenegro.
Our approach to WWTPs design, after detailed analysis of number of tourist (weekend visits, overnight stays and only summer residents), is based on optimisation of number of treatment lines on the WWTP in operation and adjustment of process parameters due to temperature difference.