Smart water for smart cities
Can you imagine a world where your water bill is astronomically low? How about a city where anyone can search up the quality of their water instantaneously? Imagine Smart Cities!
Technology is advancing rapidly! Moore’s Law is famous in describing computer chips exponential transistor growth but it isn’t special. Our technologies ability to connect, collection, and process are rapidly increasing as well!
As our ability to interconnect technology and collection data evolves, we are able to design our cities with technologies that make more informed decisions based upon greater amounts of factors. This will allow technology to be more flexible to serve greater and more diverse needs within the community!
#SmartFuture #SmarterWater
One amazing example of how this is happening is with AT&Ts Hydro Pump shut down using the Internet of Things! Not too long ago, sprinklers irrigation on properties was controlled by manual valves. These valves would send through a fixed amount of water and would have little regard for how much water was actually needed. AT&T used an IoT machine-to-machine system which assessed factors such as the climate and water needs to efficiently control the valves. This has resulted in clients saving billions of gallons of water and millions in MONEY!
#wastewaterthinking
Decentralised wastewater treatment
The World Commission on Water estimated that by 2025 more than half of the world’s population will be without sustainable water resources1. In many cases, the wastewater treatment sector resembles a risk-averse elderly person that isn’t willing to consider new technology and tends to persist with age-old ways that are ‘tried and tested’. While the traditional methods (sewage systems) have worked extremely well in the past, the conditions of our world are changing and a new wave of challenges means that it is time to embrace new technology.
Decentralization is a move towards site-specific wastewater treatment – it is a technical approach rather than a blanket strategy. Decentralized wastewater treatment systems (DWTS) are a proven technology with well-established science… Not to mention DWTS have the ability to treat wastewater to the same quality as centralized systems at a much lower cost2!
Modern design techniques are being used around the world to treat domestic wastewater on a scale of singles homes to small communities3. Two perfect examples of this can be seen in the Gold Coast, Australia, where two communalities4 – Capo di Monte (CDM) and Currumbin Ecovillage (CEV) – run off DWTS. The two communities systems are:
- CDM: 46 lots, communal rainwater tanks with bore water top-up and cluster scale wastewater treatment and recycling
- CEV: 110 lots, rainwater tanks at each house for potable water and reuse of wastewater treated on a communal scale plant for non-potable purposes.
These decentralised systems treat water to the regulated level, even better than centralised systems at CDM! The recycling and rainwater harvesting systems provide 90% of the community’s water needs, with the remainder made up an on-site bore.
When you can get the right ingredients you have to change the recipe… so when conditions surrounding water are changing why aren’t we changing the systems?
Keep #wastewaterthinking
References
1 – https://publications.csiro.au/rpr/download?pid=csiro:EP129965&dsid=DS5
2 – https://www.epa.gov/sites/production/files/2015-06/documents/20130306mou_webinar_casey.pdf
4 – https://publications.csiro.au/rpr/download?pid=csiro:EP129965&dsid=DS5
Greenhouse gas emissions from wastewater
As can be seen in the above picture, the amount of carbon dioxide released into the atmosphere as a result of wastewater treatment plants is staggering. Statistics have been taken from 7 different treatment plants in Denmark. In the past years, in order to improve the conduct of wastewater treatment plants, efforts have been mainly focused on producing a good effluent quality.
Recently though, more pressing issues have popped up to satisfy the economical as well as the environmental challenges. More specifically, the emission of GHGs. Most commonly, carbon dioxide, methane and nitrous oxide are released during the treatment process of wastewater plants. To put into simple terms, carbon dioxide is the product released when energy is consumed in order for the plant to operate. Nitrous oxide is emitted during the process in which nitrogenous compounds are removed from the wastewater and methane is released as the exhaust gas from wastewater treatment plants. Wastewater systems account for approximately 3-4 percent of total energy use.
From this statistic, you can only imagine how much carbon dioxide is being emitted solely from wastewater treatment. Not to mention the other two gasses, methane and nitrous oxide emissions from other processes. As such, there is need to think about the potential solutions to tackle this issue.
What are some possible solutions you can think of?
#wastewaterthinking
Could AI be used in wastewater treatment?
“Just as electric vehicles and AI-powered autonomous driving technology are disrupting the auto industry as we speak, Pluto AI hopes to disrupt the stagnant water treatment industry where over 2.1 trillion gallons of clean water is lost each year in the US alone.” – https://cleantechnica.com/2017/04/19/pluto-ai-transforms-wastewater-treatment/
Machine learning and artificial intelligence technology could be extremely useful in combating the constantly growing number of constituents of concern. Artificial intelligence as a developing technology can be paired with other technology such as sensors to give us real time monitoring of wastewater situations and constituents.
Significant decisions need to be made on the fly in response to real time data on water quality, this requires operators to analyse and predict, often based on experience and intuition. Consistently relying on these decisions could result in sub-optimal decisions under pressure. Causing significant losses from the lost time.
AI will continue to develop exponentially in coming years and see wide use in many industries. Low maintenance is required to maintain the systems and can be updated on a connected cloud server.
It’s easy to scale as it is often in the form of computer programs, AI continues to learn and update itself. Machine learning improves efficiency, reduces waste and energy consumption all while providing greater visibility of data.
AI doesn’t need to be used to develop solutions, it could be utilised broadly for other helpful means. AI allows for automated reporting of current issues as well as predictions or projections of what resources need refilling, or alert the operators of any other abnormalities.
Our planet, our responsibility
Earth is home to millions of species but only We dominate it. Our cleverness, our inventiveness and our activities have modified almost every part of our planet. In fact, we are having a profound impact on it. Indeed, our cleverness, our inventiveness and our activities are now the drivers of every global issue we face. And every one of these issues is accelerating as we continue to grow towards a global population of 10 billion. At the present, the main problem is wastewater management and we are not doing enough to save water for our future generations and creating more bigger water problems for them.
At this stage, if we won’t reuse our wastewater then the world will end up soon with no water. Most of us believe that the ultimate solution to save water is decentralization of treatment plants. Now decentralizing means to install this system in each and every house so that water consumption decreases automatically, and people will easily be able to recycle their own consumed water again and again. The cycle of treatment plant in house is shown in figure 1.
Majority of us think that it is difficult to install treatment plants in every house because in under developed countries the poor part of society cannot afford it. For this government should give subsidies on these products and invest a portion of their collected taxes in this project to make sure that everyone installs these plants and maintain it properly.
Well the sole issue after decentralization of treatment plant is RESPONSIBILITY. Using this very delicate system, it will require some serious amount of accuracy and precision of maintenance. Every person should be responsible enough to use this system carefully, if not used responsibly the idea of decentralization of treatment plants will be in vain. The famous saying is that:
” You cannot escape the Responsibility of tomorrow by evading it today.”
I know few of us would not like to take the responsibility to maintain these treatment plants but there is no other best solution to save water for future generations except decentralization of treatment plants.
Now, I believe that:
“If you Love your next generations then you have to be Tough.”
Furthermore, the rights of citizenship can be balanced with responsibilities. The governments should frame out a draft of rules (A sort of Bill of Responsibility) specifically designed for executing out the procedure in order to start the system and mainly for using the body responsibly.
Understanding the term ‘responsibility’ is very simple but if illustrated and elaborated the term can be categorized into many aspects and the integral ones are as follows; which are needed to be mentioned in the draft.
- Role responsibility: role responsibility is referred to some social responsibility such as the dean of a faculty is role-responsible for the well-being of the faculty.
- Casual responsibility: casual responsibility simply means when a result is attributed to some event, which is known to be the cause of the result.
- Liability responsibility: means the one who has to tolerate the consequences. In criminal law it typically means liability to be punished.
- Capacity responsibility: concerns the possession of certain capacities without which an agent cannot be considered liable for his actions.
These above four are the integral aspects of being responsible and can be adapt in Bill of responsibility for treatment plants. With the law of having responsibility for looking after the treatment plants, we can get the finest results in saving water by reusing wastewater again and again. If someone is not taking care of his treatment plant, he should be warned first then lead to some plenty. Being responsible while using the system is the only way we can save water or else we should wait for a time to arrive when people will literally be deprived of all the water-dependant necessities. We collectively must be responsible enough to use this system carefully so that we can make it easy for our future generations to sustain life with ample amount of water. In the last I would like to say:
“A hero is someone who understands the responsibility that comes with his freedom.”
Closing the loop
At present, challenges abound around wastewater management in the urban environment under the context of drying climate and growing population. One of the heated topics is on wastewater reuse, i.e. a closed water cycle loop has not been fully developed. The formation of a closed water cycle loop in an urban environment can save the costs of water delivery to end users, operation, maintenance and ease the monitoring process systematically. Figure 1 shows three different scenarios on water usage. In mode c, not only a closed loop is established, but also wastewater is further exploited for irrigation and cooling.
By encouraging the direct use of treated wastewater, the cost for treatment of natural water can be exempted (see Table 1) while reducing the abstraction of limited groundwater, as well as reducing risks of being exposed to unknown pathogens in the natural water body.
At this stage, endeavors have been made on aquifer recharge from wastewater, but no attempt has been made on the reuse of potable water directly from wastewater despite the quality of treated wastewater after tertiary treatment process is, in most cases, better than natural water from the environment (illustrated in Figure 2).
The main problem is the strong opposition from the public as treated wastewater is still regarded as ‘inferior’ than natural water and the thought of ‘drinking defecation or waste’ is distasteful. Education on water literacy plays a significant role in pushing this scheme forward but it could take decades to achieve the goal.
Figure 4 demonstrates the wastewater treatment processes applied in Windhoek for direct potable water use in which a multiple-barrier system was adopted. Surprisingly, the public in Windhoek are incredibly proud of the system in that it leads the world in the direct use of wastewater for drinking purposes.
Finally we’ll leave you with this diagram and a decision,
Which side do you want to live on?
#wastewaterthinking
Reference
Jones, O.A., Green, P.G., Voulvoulis, N. 2007. Questioning the excessive use of advanced treatment to remove organic micropollutants from wastewater, Environ Sci Technol, 41, 5085-5089.
Wastewater and the Economy
Any question about wastewater treatment is also a question about the economy. When we discuss a new method, new technology, new materials, and new systems, we not only care about the upgrade of the technology itself, but also the cost. What is efficient, most people think that the most advanced technology is the most efficient, but often not in practical applications. The most mature technologies are often the most efficient. In today’s fierce market competition, cost control is very strict. The solution that companies want is to achieve the desired results with limited funding conditions. In the industrial field, especially papermaking, printing and dyeing and food processing industry water costs are an important part of cost, including the purchase of suitable industrial water and wastewater treatment.
For industrial wastewater, traditional chemical methods and physical methods have a complete system. These methods are mature in technology and stable in operating costs. As emission standards increase, the operating costs of these traditional methods will become higher and higher. If the amount of chemical used can be reduced, or the chemical is not applied at all, the cost of wastewater treatment will be greatly reduced. Personally think that biotechnology has given us a good research direction.
Biochemical treatment is not only the treatment of papermaking wastewater, but also an important part of any industrial wastewater treatment. About 80% of the organic pollutants in wastewater are degraded during biochemical treatment. The treatment efficiency of biochemical treatment unit is the highest in water treatment system. . Therefore, the biochemical treatment efficiency determines the operating efficiency of the overall sewage treatment system, and also affects the overall wastewater effluent effect.
Biological treatment method
The biological treatment method is that the microorganisms use the organic matter in the water as their own living organisms, and the pollutants are gradually transformed or degraded by the adsorption and digestion of the organisms, thereby purifying the pollution. According to the classification of microorganisms and metabolic methods, biological treatment methods can be divided into biofilm method, aerobic treatment method, anaerobic treatment method, addition of special biological and enzyme treatment methods.
Aerobic microorganisms use organic pollutants in water under aerobic conditions as a nutrient source to adsorb or degrade organic pollutants, and finally achieve a method of purifying water quality. Commonly used aerobic methods include biological contact oxidation, activated sludge method, oxidation ditch method, biological fluidized bed, etc. The anaerobic method uses anaerobic microorganisms to decompose organic matter in water into methyl burning under anaerobic conditions. Carbon dioxide, water and ammonia sulfide, so as to achieve the purpose of eliminating pollution. Several plants in Canada use the anaerobic-SBR process to treat pulp and paper wastewater. The removal rate of BOD5 in all systems can reach 90%, and the COD removal rate can reach over 80%
The biofilm method refers to the microbe attached to the surface of the medium to form a biofilm. After the sewage flows through the biofilm, a part of the organic pollutant is adsorbed and converted into microbial cell material, and another part is converted into an inorganic substance such as H2O, CO2, NH3, etc., thereby purifying the water quality.
Research direction of using biotechnology to reduce wastewater treatment costs
Microbial growth-promoting technology can promote the metabolism of microorganisms in aerobic biochemical systems, so that microorganisms can grow rapidly and in large quantities in a changing environment, improve microbial degradation efficiency, improve microbial toxicity tolerance, and improve wastewater treatment efficiency. This technology will achieve the goal of shortening the cell cycle, optimizing aerobic biota, and increasing biological species in wastewater. Through the optimization of aerobic biological groups, prolonging the food chain or improving the circulation efficiency of the food chain, giving full play to the synergistic effect of the biological population in the degradation process, more thoroughly degrading organic pollutants during the residence time of the water, thereby improving the biodegradability of the wastewater effluent, Reduce the cost of advanced wastewater treatment.
Bio-promoting technology is a safe and green technology that can effectively avoid ecological problems such as bio-competition due to the addition of exogenous micro-organisms. By improving the original micro-organisms in the water environment, the treatment effect can be improved, and no pollutants can be realized. Therefore, according to the good performance of bio-promoting technology in other industrial wastewater treatment, it is of practical significance to apply it in the treatment of papermaking wastewater.
Reference：
Fox, M., & Noike, T. (2004). Wet oxidation pretreatment for the increase in anaerobic biodegradability of newspaper waste. Bioresource technology, 91(3), 273-281.
https://www.fluencecorp.com/what-is-biological-wastewater-treatment/
https://www.cell.com/trends/microbiology/fulltext/S0966-842X(16)30074-9
Future Energy in Wastewater
Activated sludge processes are commonly used for efficient treatment of municipal wastewater. The essential mechanism of traditional activated sludge processes is respective transform of pollutants and energy. However, the issue of these processes is the high energy consumption (fossil fuel) and emission of much greenhouse gases (GHG). And the potential organic chemical energy (about 1.5－1.9 kW·h /m3) contained in wastewater has not been explored and utilized．So the wastewater cannot be simply considered as‘waste’, but a valuable resource full of energy, valuable materials and clean water. The direction of future wastewater treatment plant is to put the nutrients，energy and reuse water in one plant, e.g .‘three plants in one’mode. The wastewater treatment plant ( WWTP) would be changed from energy consuming to energy neutral or even energy producing．
The first key point of wastewater treatment process is sludge anaerobic digestion; the second is the capture /separation of influent organic carbon to the maximum extent, and adoption of coupling technology of high efficient sludge anaerobic digestion and cogeneration of heat and power (CHP), which can realize the conversion of COD organic chemical energy to electrical energy. Recently COD capture and carbon redirection technology has emerged around the world. And the projects with COD capture and carbon redirection have been built already. Then, the current ‘carbon capture’ technology was put forward. Based on this the future sustainable wastewater treatment technology route map has been displayed. We are expecting to provide references for the domestic wastewater treatment plant‘carbon neutral’operation, for the development of future sustainable WWTP and ecological recycling water plant．
The electricity consumption in the sewage treatment process accounts for about 1% to 3% of the total electricity consumption of the whole society, but at the same time, the huge “chemical energy” and “heat source” contained in the sewage are far from being extracted and utilized.
The carbon dioxide produced by the electricity consumed in the wastewater treatment process and the chemical energy contained in the wastewater COD are all energy sources that can be reused by humans in the future.
On the other hand, water reuse, policies and partnerships, and emerging disruptive technology solutions are vital to the cause. Specifically, there is an urgent need to shift how we view wastewater treatment and move to sustainable, strategic infrastructure solutions. Wastewater treatment plants are not waste disposal facilities, but rather resource recovery facilities that have the potential to produce clean water, recover nutrients (such as phosphorus and nitrogen), and reduce the dependence on fossil fuels through the production of renewable energy.
Figure 3. Nitrogen cycle in the process of wastewater treatment.
The Future Of Energy And Water
As water and energy demand and supply continue to shift, managing the two resources in tandem will help regions worldwide maintain reliable and sustainable supplies of both. This is of critical importance as the global economy continues to explore new energy and renewable energy sources. But to sustain energy production and a dependable water supply, we must all gain even more detailed understanding of the interdependencies of water and energy systems, balance the needs of all users, and continue to develop technologies that reduce water use and enable water recycling while neutralizing or even creating energy.
Reference：
Jeff Peeters, PE, (2015). The Future Of Energy-Neutral Wastewater Treatment Is Here. Water online : Guest Column. [online] Available at <https://www.wateronline.com/doc/the-future-of-energy-neutral-wastewater-treatment-is-here-0001
By Ji Han
The Future Social Value of Wastewater
Wastewater is just a compound of numerous valuable stuff, which contains energy and resources. In the future, the social value of wastewater might be changed if every single family were able to make use of wastewater, in other words, people may regard wastewater as valuable rather than waste. To achieve this goal, people’s value about wastewater should be changed and it needs special regulatory framework and advanced technology.
Decentralization of regulation to communities as small as possible will lead to the best result of addressing wastewater issue. From my personal point of view and experience, the best regulatory framework of something is that decentralize the regulatory responsibility to every single person then everyone is responsible for it, which in other words, everyone believe his benefit or life is closely related to that thing then every individual will take the responsibility of regulating that thing well spontaneously. This is the cheapest and most effective way to solve a problem thoroughly and it will not have potential risks along with this solution, however, it is also the most difficult way because it needs to change people’s value of something, and we all know that people’s value is not a thing that can be changed easily in a short period of time.
My personal experience is that when I was a kid, I lived in a remote rural area in China. And in that time, most of people there made a living by farming and there was no wastewater infrastructure there in the village, but the rivers and lakes nearby were in pristine condition. One very important reason of this was the regulation of wastewater was decentralized to every single family instead of regulating the wastewater by a unit of community or city like in the urban areas. How come? The condition was that everyone in the village thought that domestic wastewater was valuable. Every family in the village had a toilet in the backyard outside the house, and it was used to reserve toilet wastes and leftover wastewater. After a period of time, fermentation of the wastewater will produce very good fertilizer for growing the crops. Due to this reason, everyone in the village treasured domestic wastewater and no one would like to discharge it into the rivers and lakes, it was all reserved in the toilet. What’s more, occasionally there were some people roaming between villages with a cart drawn by a mule to collect poos, because it was a great fertilizer for their crops and vegetables. And the wastewater was regulated perfectly well and no one or community was worried about the domestic wastewater would pollute the environment, because all the people had the value that wastewater was valuable and they were going to make use of it instead of waste it.
I know that the condition is very much different and difficult in the cities compared with in some specific rural areas, but this phenomenon at least indicates that there might be a perfect way to regulate wastewater without massive money cost and complicated policy legislations. The only thing we need to do is to change people’s value of wastewater, to make people realize that the wastewater is valuable and it can be even traded for money. If one day, everyone has a strong sense of ownership of the wastewater he or she produced, there might be no wastewater issue about polluting the field and the oceans. To achieve this goal, I think the first difficulty we face is that let every family has the ability to make use of their domestic wastewater. And technology might be a method to address this issue: there could be some kind of device which can convert the wastewater to purified water and fertilizer. The purified water can be reused by the family while the fertilizer could be use for fertilizing vegetables if they got a vegetable patch in the backyard or simply sell it to the farmers. By this way, a lot of water is saved, byproduct of wastewater can be traded for something useful or money, and the possibility of wastewater pollution is eradicated.
In conclusion, in the future wastewater could be valuable rather than waste and decentralize the regulatory obligation is a practical way to regulate wastewater well and the ultimate condition of this is to make every single individual be responsible for the wastewater they produced. And to achieve this goal, people’s value of wastewater should be changed. And new advanced technology is a possible way to make people realize wastewater is valuable which will increase people’s sense of ownership of their wastewater.
by Jianfeng Tian
wastewater thinking 