Smart cities turn trash into a resource

The mobilization of the cities for such tasks is a logical step for them. Cities like New York, Mexico City and Beijing have more people than many countries, and the urban landscape is the environment where the challenges involved in managing human life are concentrated. Cities can establish themselves in leadership positions because they are able to quickly implement solutions on a large scale, and because they serve as living laboratories for testing ways to improve the quality of life without consuming the earth's resources, polluting the air and water, and in the process harming human health.

Huge amounts of energy, carbon dioxide, food, water, space and time are wasted in cities. It is possible to solve several problems at once, and ensure a sustainable future for billions of people, by reducing each of these waste streams and managing them as a resource rather than an economic expense.

Pollution as a solution

There is much to learn from history about waste management. The London doctor Jon Snow, discovered that the cause of the terrible cholera epidemics that broke out in London in 1848 and 1854 was that sewage contaminated the public water wells. Building a sewer system was an obvious solution, but political leaders rejected Snow's findings because they did not match the prevailing narratives and because the actions required to deal with the problem he revealed were considered too expensive. Today we are witnessing similar reactions to the warnings of climate scientists who explain to us once again that waste is killing us, even if indirectly and much more slowly, and that correcting the problem will require considerable investment in new infrastructure. Later, Snow gained hero status (perhaps the same future awaits today's scientists) after new leaders initiated an ambitious engineering operation that compressed a 2,000-kilometer sewer system into a dense city of three million inhabitants and put an end to the cholera problem. This operation also gave the river banks outside London their beautiful appearance. They are identified with the city and many people walk along them.

But these days, flushing the waste down the drain is no longer enough. After we reduce the amount of waste generated in the cities, we will also have to close the circle, and use the remaining waste again. First reduce the amount of waste and then put it to beneficial use.

These new ideas begin with a redefinition of what we perceive as pollution. Raj Bhattarai, a well-known engineer at the Municipal Water Authority in Austin, Texas, taught me to define pollution in a new way: misplaced resources. When harmful substances are absent, they are found in their proper place: in our bodies, in the air, or in the water. But when they are in the right place, they are useful. For example, instead of sending our solid waste to a landfill site, and bearing the costs associated with burying it, it can be burned to generate electricity; Whereas from the sewage funnels of a city with a million inhabitants, gold and other precious metals worth millions of dollars can be mined every year, and used in the local industry.

This approach fits into a broader idea known as "Circular economy" – the idea that different actions and processes in society can feed each other in beneficial ways. Simply put: waste is what we have when we don't have enough imagination.

less is more

A very desirable place to start reducing waste is leaking water pipes. It is typical that between 10% and 40% of the water in the city is lost in the pipes. It's a huge waste. And since the city invests energy in purifying the water and running pumps to pump it out, the leaks also waste energy.

The energy consumption itself is incredibly wasteful. More than half of the energy consumed in cities is emitted as wasted heat from chimneys, car exhausts, heating and air conditioning installations, and electrical appliances. Improving the energy efficiency of all this equipment will reduce the amount of energy we have to generate, distribute, or remove from the environment.

Garbage is another source of waste that needs to be reduced. In the US, about two kilograms of solid waste are generated per person per day. Despite efforts to recycle some of the waste, use it to produce compost (dashonat), or burn it, a little more than half of it is still dumped in landfill sites. Using less packaging materials is a possible way to reduce the volume the garbage and at the same time enjoy additional benefits.For example, large store chains such as Walmart have found that as a result of reducing the amount of packaging materials they need less trucks to transport the goods and create more space to display them on the shelves.

Thrown food is a sad problem in itself. Although in many parts of the world hunger or food shortages prevail, in America a quarter to half of the food that is suitable for eating is thrown away. Huge amounts of energy, land and water are necessary to grow food, produce it, store it, prepare it, cook it and get rid of it when it is thrown in the trash, so wasted food is a significant damage. Food waste prevention initiatives such as the advertising campaign I Value Food In the US, and similar initiatives that have emerged in the UK, are the first steps towards solving this serious problem.

Waste that serves us

After reducing the amount of waste produced by the cities, they must use the waste from one urban process as a resource in other processes. Today this is still a rare approach, but there are interesting projects that are starting to implement it, such as the system established in Zurich to produce energy from garbage by burning it in a clean process. Some of these systems, for example the one operating in Palm Beach, Florida, capture more than 95% of the metals in the oily ash left after burning the garbage to transfer them to beneficial use. Rural communities such as Yunde in Germany produce biogas from cattle and pig manure. The amount of gas produced provides energy to a significant part of the residents' homes, as gas for heating or in the form of electricity. My group of researchers At the University of Austin in Texas, she showed that a cement plant in New Braunfels can burn fuel tablets made of non-recyclable plastic instead of using coal, thereby avoiding carbon dioxide emissions and the damages associated with coal mining.

Even from the garbage that is thrown in landfill sites, you can benefit. Cities can capture the methane gas that rises from the rotting garbage, and the captured gas can be used to run generators and generate electricity. Vancouver's landfill sites capture the methane emitted from the garbage, and the heat generated by burning it is used to heat nearby greenhouses where tomatoes are grown. Obviously, this is better than simply flaring the gas or letting it escape into the atmosphere, since methane is a potent greenhouse gas that traps more heat than an equal amount of carbon dioxide.

But this is not a complete solution, because some of the gas still leaks into the environment. Because of this, Vancouver, which has taken on the obligation to be the greenest city in the world, has begun to distribute to residents separate containers for normal garbage and organic waste (food scraps, branches and garden clippings). The municipality expects the residents to use them properly and sends inspectors to make sure that the garbage that is removed by the collection services has been separated as required. From the organic waste, the city produces methane and solids that can be used to fertilize the soil. These solutions solve several problems at the same time: they save expenses on energy, which would otherwise have to be bought from external sources, they reduce the need for expensive landfill sites, and they prevent unnecessary use of land and the damage caused to it in the process; And in addition - they are useful for agriculture.

The city of Austin uses sludge produced from municipal sewage in a similar way. The sludge is transferred toAnaerobic digestion facilities for biogas production. The city sells the gas or uses it at its production site as a source of heat. The city turns the remaining solids into a sought-after fertilizer called Dillo Dirt (after the armadillo living in the area). The city makes money from the sale of the fertilizer, and this revenue covers part of the wastewater treatment costs. The practice of creating home compost is indeed becoming more common among residents, and it is a definitely desirable trend, but when it is done incorrectly, the result is actually increased methane emissions. In Austin, it makes more sense for residents to use trash compactors to grind scraps and flush that waste down the drain to allow the industrial collection means at the city's wastewater treatment plant to do the composter's job more efficiently.

Great opportunities also lie in the heat emitted into the environment. It is not easy to exploit it because it is difficult to convert low temperatures into electricity. NASA has indeed developed thermoelectric generators designed to do this in its spacecraft, but it is an expensive and inefficient technology. Even so, there are those who are developing advanced materials that will be able to convert heat into electricity more efficiently in the future. You can start using the hot waste water that flows from washing machines, Sinks and showers in Sandvika, a suburb of Oslo, are installed along the municipal sewage pipes Large heat exchangers that collect heat used to heat dozens of nearby buildings or to defrost sidewalks and roads; while in the summer, the operation of heat pumps allows this infrastructure to be used to cool those buildings. Vancouver liked the idea so much that the city decided to do something similar, and used wastewater to heat hundreds of buildings. and the Olympic Village.

The implementation of this idea goes even further in the industrial park Kalundborg Symbiosis in Denmark. Kalundborg is a leading example of closing energy circles. The park includes seven companies and municipal facilities - mainly electricity, water, sewage and solid waste facilities - which are interconnected so that each facility in the park uses by-products of other facilities. Cables, ducts and pipes carry steam, gas, electricity, water and waste materials back and forth to improve overall efficiency and reduce the total amount of waste materials, including the amount of carbon dioxide emitted into the environment. For example, the wastewater from the oil refinery flows to the power plant, where it is used to clean and stabilize the ash produced by burning coal. The refinery also flows the steam generated in it to the factory of the pharmaceutical company Novo Nordisk, which uses the heat to produce about half of the world's insulin supply using bacteria and yeast (see box). The entire park looks like a living industrial organism, and the emission of pollutants in it has remained stable or even decreased despite its economic growth.

decisions according to the data

Can cities around the world build solutions like in Kalundborg Symbiosis on a larger scale? Yes, but only if they become smart cities. The flexibility of an industrial park is made possible thanks to the fact that there are only a few parties and decision makers. But in the city there are many people and organizations that individually, every day, make decisions concerning energy, water and waste. In order for their decisions to be made in coordination, a cultural change is necessary that will include a transition to cooperation based on smart technologies. "Smart cities" will rely on the networking of the entire space with sensors and cheap computing, plus machine learning and artificial intelligence. This combination will make it possible to identify areas of inefficiency and adapt activities to changing conditions while automatically activating different types of equipment, which will reduce the amount of waste and operating costs.

Fortunately, making cities smart is a tempting goal for planners who want to increase population density without reducing quality of life. In India, for example, the Prime Minister, Narendra Modi, announced his intention to transform 100 small and medium-sized local authorities into smart cities as a possible solution to the serious problems of overcrowding and public health that the country suffers from.
The term "smart cities" implies that most cities are stupid, and this accusation seems true because it seems as if local authorities dealing with large amounts of waste are acting blindly. The National Science Foundation in the US recently launched a major research initiative called "Smart & Connected Communities" in order to improve the use of data. This name implies, by the way, that intelligence alone is not enough: a network of connections between systems and people is also important .

Smart cities are highly dependent on large amounts of data collected from an extensive network of sensors, and on advanced algorithms that make it possible to extract insights from the data, based on which decisions can be made. Data networks are necessary to transmit these data analyzes to equipment all over the city. It makes sense to start implementing this by deploying smart measuring devices that will follow with a high degree of accuracy, around the clock, the use of electricity, natural gas and water in residential homes and by industrial equipment. Sensors for monitoring traffic on the roads, monitoring air quality and detecting leaks are also expected to be integrated into the picture. The Pecan Street ConsortiumBaustin is collecting data from hundreds of homes to learn how access to that data can help consumers change their behavior in ways that will reduce home consumption and save them costs. Cities like Phoenix and military bases like Fort Carson in Colorado have pledged to become self-sufficient as consumers of energy and water, and to zero out the balance of waste they produce. Achieving these ambitious goals will require the integration of a great deal of data.

Improved transportation may give city dwellers the first opportunity to tangibly prove the benefits of a smart city - due to the reduction of time wastage. Reducing the environmental footprint of transportation means using clean fuel, improving the efficiency of transportation means, shortening travel distances and durations, transporting more passengers at once and reducing the number of trips. When people live near their workplaces, they can walk, ride a bike, or use public transportation. Studies have shown that building protected bicycle lanes results in a dramatic increase in the use of bicycles, and since bicycles take up little space compared to cars, their use can reduce road congestion.

In a city where cars are not driven, the space and time wasted on parking will also be freed up. Giving up the private cars that are currently parked next to homes and workplaces in favor of shared or autonomous cars that do not stop driving will allow for a radical reduction in the number of parking spaces, and the wasted space that will be freed up by this will further reduce the problem of road congestion. Researchers at the Center for Transportation Research at the University of Texas at Austin have shown through advanced modeling that shared autonomous vehicles can significantly reduce the number of cars needed in the city, as well as pollutant emissions, even though the total distance traveled in the city will increase slightly - because these vehicles will not stop moving. The passengers themselves, instead of wasting their time driving, will be able to read e-mail, make phone calls or take care of other matters, and this work can have an economic value that will contribute to reducing the length of time you were at the workplace and allow them to get home earlier in the evening.

Instead of sending garbage to a landfill, it can be burned to generate electricity. Sewage funnels allow gold and other metals to be mined for use in local industry.

Smarter infrastructure is undoubtedly the key to solving basic problems such as leaks from water pipes. Detecting leaks can be simple if measuring devices that will be scattered throughout the water system will follow the flow of water and show exactly the location and extent of leaks. Researchers in Birmingham, England have developed a system with tiny pressure sensors that use little energy and perform frequent tests to detect leaks in water networks. This is a real improvement over the old method: waiting for someone to call and complain that a jet of water is coming from the road. It is possible that in the future we will also send smart robots that will travel along the pipes and fix such problems.

Sensitive and efficient sensors will also allow us to find and predict natural gas leaks, and repair them before accidents occur. Gas leaks are not only a waste of a precious resource and damage to the environment, but also a danger, the results of which sometimes reach the headlines when explosions occur in urban areas with outdated infrastructure.

It is difficult to know where smart cities will emerge and are aware of the opportunities inherent in the wise use of waste. I believe that plausible candidates are cities in the Midwest of the US with a million or more residents and in urgent need of renewal due to the dismal economic situation they have been in for several decades. Indianapolis is a possible candidate, in part because it needs to rebuild the water systems , sewage and sewage due to poor decisions made a century ago. The city has invested in the development of its business district and is on the rise. Pittsburgh is trying to become a city that is identified with Chimneys for the city identified with knowledge and ideas, and it takes advantage of its existing assets for this - a vibrant urban core, local pride, leadership that looks to the future led by the mayor, William Peduto, the importance of Carnegie Mellon University, and other centers of innovation. Columbus, the capital of the state of Ohio and a neighboring place of an important university, is another place where you can expect innovative experiments to transform the Smart City Columbus recently received a $40 million grant from the US Department of Transportation to develop a new approach to mobility.

From here to there

It will not be easy to transform wasteful cities into cities that reduce their waste and use what is left. Besides the combined investment of the US federal government in research and development, government bodies at all levels will need to develop practical policies. Unfortunately, recently the budgets allocated to research and development have decreased, and it is possible that the Trump administration will decrease them even more.

The investment must be made in a wise way from a social point of view as well. Studies have shown that research and development in the context of smart cities has so far focused on technology more than the needs of the residents. Poor implementation of the solutions will mean that the benefits of the smart city will only serve those who already enjoy access to the Internet and advanced technologies, which will further increase the technological gap, in addition to other socio-economic gaps.

Local authorities must help residents become smarter residents, as each person makes decisions about resources every time they buy a product or flip an electrical switch. That is why access to education and information is extremely important. Connecting residents also requires cooperation and positive interactions between neighbors. Parks, playgrounds, public spaces, schools and religious and community centers - all these were at the center of the planning of prosperous cities hundreds of years ago. As our cities become more modern and smarter, our need for such old-world basics may increase to keep us cohesive as communities.