How to control the infections on contaminated water

October 31, 2019
October 31, 2019 admin

New trends in water management at Hospitals

The control of infections on contaminated water is rarely spoken of when it comes to sizing or refurbishing existing units. For wastewater, it is always about the connection of domestic sewage networks in municipal collectors or any eventual sewage treatment. Little more being said about the theme throughout the projects and during the lifetime of the units.

However, we forget the most critical of the control of infections on contaminated water. We think of contaminated solid waste, sterilization areas, blocks, clean rooms, clean areas, but we never talk about contaminated, dangerous waters. With a very high risk of infection, these waters result from block activities, morgue, from laboratories, infectious services in public and private hospitals of all kinds. Clinics also generates in analytical laboratories and research laboratories, blood banks, autopsy rooms, criminal investigation laboratories, and funeral societies.

All these waters go to the same discharge point. The overwhelming majority of hospitals have no sewerage networks. There are many facilities around the world that neither public sewerage nor wastewater facilities have. This is a serious public health problem because the water runs out of the drainage pipes and nobody sees them! The problem is not supposed to be in the hospital.

The European Commission has been addressing this problem. Mainly as a result of the registration of death events by municipal wastewater treatment plants, the causes are attributed to uncontrolled contamination from contaminated domestic sewage. By the time the effluent reaches the municipal wastewater, much domestic sewage is already mixed. We cannot require every house to separate and disinfect its sewage. The attention must be focused on the entities that can contribute to this phenomenon. Namely hospitals, clinics, laboratories, funeral homes, also the units dedicated to the veterinary sector. The same problems are in the control of infections on contaminated water.

Contaminated waters treatment inside and outside the units

It is urgent to promote means and systems that prevent potentially contaminated sewage from being released into the public sewage system. We have to think from origin to arrival at the wastewater treatment plant. These potentially contaminated waters can generate ruptures, can contaminate pipes, pumps, and valves that need human intervention, can have chronic leaks, and in all these situations. We will be spilling and releasing into the environment and surroundings, without any control, all potential types of infections generated by known and unknown pathogens. Every day, under our feet, these waters flow. All technical personnel is responsible for the well-being of hospital users. Like the general population, when outside the hospital. At any time, they will handle water, piping, pumps, valves, and access to all types. Compartments through which contaminated or potentially contaminated water circulated.

We must also realize that the wastewater treatment plant does not solve this problem at all. This potential infectious load, in the form of bacteria and viruses, will find, upon arrival at the wastewater treatment plant all the conditions to proliferate and interact with the entire microorganism community that is part of the facility and created in there to treat water. In a wastewater treatment plant, we control pH, food, aeration, and nutrients. The goal is to create the best conditions for the proliferation of strains, that allow digesting and consuming the organic matter we send in the sewers. It is certainly not these conditions that will negatively affect the life and survival of pathogenic strains for humans.

Therefore, sending the water to the wastewater treatment plant or having one or an EPTAR (pre-treatment station) in the health facility does not solve the problem. It must exist, but always at a stage before and/or after the elimination of the contamination problem.



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The use of Advanced Oxidation Processes (AOP)

There are practices in some units of separation and segregation of these waters, and especially when resulting from laboratory activity. There is the practice of separation of radioactive waters for separate treatment, but in the case of potentially contaminated and bio-hazardous wastewater, current practices are expensive or complex.

Thermal disinfection requires large equipment, large energy consumption and has complex and risky handling, with huge investment. Chemical disinfection by the addition of sodium hypochlorite (bleach) solutions has chemical hazards, chemical manipulation and is in the process of being banned in the European Union. The problem is the negative effect on downstream WWTP and the formation of carcinogenic complexes resulting from chlorine formation amines. The practice of segregating, accumulating, transporting and treating these contaminated waters inside and outside the hospital combines all the risks inherent in handling accumulation deposits. The transportation of these waters on public roads for hundreds of kilometers is a real issue, not to mention the enormous cost for the institutions.

Therefore, the solution involves in situ treatment, taking advantage of new disinfection and sterilization technologies. These, small, portable, mobile units, without pressure or temperature, for centralized installation or in the places where these waters are generated, avoiding major adaptation work at existing networks. The use of advanced oxidation processes using ozone is proven on a scientific way. Produced on the equipment itself, complemented by other oxidation technologies. It can eliminate all risk of microbial contamination (bacteria), allowing these waters to be discharged into the sewage system. Together, with the others and to be treated by traditional waterways without any risk to the environment, surrounding or distant, nor to system technicians and operators, that promote these treatments. The additional capacity of ozone as a disinfectant agent compared to other chemical agents is also emphasized.

A serious public health problem

There is a technical and scientific difficulty in measuring this efficiency, only surpassed by the scientifically and statistically representative validation of the technology by an independent and internationally recognized entity in the area, using real tests, in a real environment and with strains created and controlled for this purpose, in a voluntary process by the manufacturer, unique in the world.

A serious public health problem is solved, cleanly, quickly, cheaply, practically, without risks, without consumables, without energy consumption. Numerous examples already exist around the world, in Europe and beyond, including in countries considered “less developed”.

Experience shows us the payback times of these investments. When compared to the costs of alternative chemical and/or thermal methods. When compared to the costs of segregation, contextualization, transportation, and external treatment. They’re extremely short, even immediate, given that the volumes generated are somewhat consistent (100 liters per bed). The operating costs of the mentioned systems are extremely low, around 0.50 € per tonne of disinfected or sterilized water.

Changes in practices and mindsets are always slower than technological developments, but we are faced with an issue that cannot be overlooked, otherwise, we have a serious problem at hand that was not merely avoided by inertia or ineptitude than those who had the power to decide to do so. The social responsibility is very large. No one will want it, certainly.

How to intervene in the control of infections

Whenever the status quo is to be changed in any area or sector, a set of obstacles is raised, but these have been foreseen for this technology on the control of infections on contaminated water.
When we intend to install the technology in existing hospital units, the solution can be broken down into small, point-to-point treatment units. It eliminates the problem immediately at the point of generation. Without requiring complex network alteration work, with much higher investments and equipment concerned.

Units can be placed in laboratories, in the morgue, down the drainage of infected, with very slight interventions on the discharge lines at their starting point, to integrate the system power and their discharge from the treated waters. In laboratories, they can even be installed under the benches, integrated with the aesthetics and organization of the laboratory. It creates no new obstacle to circulation or the moving of required treatment elements.

How to proceed in new projects 

If the installation is designed in the design phase of new units, it allows the treatments’ centralization, using separative networks from the points of generation of these waters. The teamwork with designers and architects allows perfect integration of the solutions in the technical structures of the new building, without creating constraints of any kind and allowing, of course, an optimization of the sizing and daily operation. Consideration should always be given, in larger units, to the inclusion of contaminated effluent collection tanks upstream of the treatment unit to regulate flow rates, avoiding peak flow operation, which substantially reduces sizing. hydraulic unit.

This is clearly the most critical area today which deserves our attention in water management in health systems. Others must also draw our attention, especially by addressing the issues of economic and environmental sustainability of hospitals.
To reduce operating costs and compatibility with local and national environmental rules and legislation, we must bear in mind that other sewage generated in this sector must also be the focus of attention and review of mindsets.

Canteen and kitchen effluents (contaminated with grease)

We can perfectly take the wastewater generated in the canteens and restoration of a hospital. Treat it and reuse it for the toilets, watering of green spaces or washing of soil. Naturally dependent on the cost of mains water at each location, his solution is already adopted in hospital-related units.  Operational profitability issues are critical, but that should be copied, from a benchmarking perspective, by healthcare unit administrations. They are sustainable, profitable and safe.

Failure to comply with the legal limits of contamination for discharge into the public sewage system is systematic in the water resulting from hospital restoration. Due to the inefficiency of the usual “fat separators”, creates legal and institutional problems. It also generates social inconveniences, bad smells, disturbances, and blockages in the discharge networks. It generates conflicts, concern and a source of distraction for those responsible for managing the institution. These problems can be completely eliminated by adopting more advanced technical treatment solutions.

The possibility of recovery and reuse creates the economic and environmental case for decision making. They are easy, compact solutions that can be deployed without affecting existing networks. Without requiring major changes or interventions in current infrastructures. They only need awareness and decision for who you are, allowing you to solve problems and save resources, lacking in other areas.

Examples of successful installations

Coachin Hospital, Paris
The largest maternity hospital in Europe, specialized in infectious diseases in pregnant, treats infected and contagious pregnant women. It generates substantial amounts of potentially contaminated effluents from toilets and operating rooms, with above-normal public health risks. The solution was to install a 500 liters/ cycle batch model with a 500 liters integrated lung tank. A fully automatic system, fulfilling a specification that requires a chemical treatment system with pH modulation inactivation. A great improvement for the control of infections on contaminated water.


The control of infections on contaminated water


Institut Pasteur, Lille
Created by Louis Pasteur in 1894, the Institut Pasteur is a recognized private foundation. Its research and research laboratories generate effluents contaminated with pharmaceuticals, various chemicals, and biological compounds. Thus, a wastewater treatment solution was necessary for the control of infections on contaminated water. The solution involved the installation of a discontinuous 50 liters/ cycle system specifically for mounting under laboratory benches. It is fully automatic chemical treatment system for inactivation by pH modulation, with final activated carbon filtration.


The control of infections on contaminated water


Domestic global hospital effluent 

This same logic of treatment and reuse can be applied to the hospital’s global domestic sewage. We have to look at the hospital as a mini-city. Technologies are already tried and tested and it´s not difficult nor complicated to apply them. Water reuse is the theme today and will always be the theme for the future. We no longer discuss sewage treatment. The discussion is on water reuse, which assumes pre-treatment that ensures conditions for reuse.

Household wastewater treatment technologies are many and varied and can be chosen based on several features. Available space, treatment objectives, available budget, greater or lesser automation is desired. The objective is to ensure complete treatment, allowing the incorporation of these waters into final recovery systems.

Some systems can be installed under the floors, integrated into the differences of relief dimensions of the surrounding land. No visual impact or occupation of space above ground. Others can be installed in the roofs, integrated into the architecture of buildings and spaces. Basically, we can have “friendly”, efficient and economical solutions, without much engineering effort. There are already tried and proven solutions in similar situations.

Radioactive Effluents

The wastewater coming from Nuclear Medicine and Oncology services delivers radioactive effluents, that capture the attention of designers and engineers. These effluents have different characteristics and requirements, and therefore, need to be separated, requiring different dimension solutions. Oncology always generates larger solutions, but it demands requirements on construction techniques to protect against possible surrounding radiation. Depending on existing radioisotopes, these systems should be fully automated with decay control algorithms.

The availability of spaces in areas farther from the circulation of people facilitates the processes. It ensures the integrity of lower-cost solutions, like the example below from CUF Hospital, at Porto.


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