In order to remove as many of your perplexities as possible, we have decided to gather together some of the FAQs most frequently encountered during our journey.

Retention, resistance and maintenance

What debris can rotating devices handle?

The River Cleaning barrier intercepts more than 90%, on average, of the debris found in the surface water (0-35 cm below the water level). The size spectrum of the intercepted debris is 2 – 70 cm. The materials recovered usually vary depending on the area, but the most frequent, in addition to organic debris, are plastic objects such as bottles, foodcontainers and packaging.

What happens when large-sized debris is in the water? (e.g., branches, logs)

In the case of large debris such as branches or logs, you can choose the desired system response: thanks to the object recognition function  you can choose to lift and lower the system remotely to allow that debris through. Let us not forget that logs and branches are nourishment for the ecosystem! Should you want to retain the object (for instance, if there is plastic litter together with the branches), the system will detect the operational blockage and send a signal for removal.

How does the system behave in unfavorable environmental conditions?

The River Cleaning system is specifically designed to offer little surface area and, therefore, resistance to the force of water, using it to enhance performances instead. Consequently, the structure is also able to withstand stronger currents. During particularly violent floods, the barrier can be lifted from the water temporarily and put back in actionwhen conditions are more favorable.

What kind of maintenance does it require?

The system is designed to carry out regular cleaning cycles independently, including the removal of large debris. If there are persistent faults that require extraordinary maintenance, these will be limited to individual rotating units, which can be easily replaced or repaired.

Installation and operation

How are the devices kept in place?

The devices can be anchored underwater or with an overhead structure, depending on the installation and site requirements. In the first case, each buoy is anchored with a cable to a supporting structure at the bottom of the riverbed or higher up on the banks. In the second case, the overhead structure acts as a truss and keeps all the devices on the axis.

How are water level and currents affecting the correct alignment?

A simple counterweight attached to the devices is sufficient for watercourses with fairly homogeneous conditions over the year and level variations of no more than twice the minimum water level. While the devices tend to float, the weight pulls down vertically and counteracts the horizontal movement induced by the current, thus ensuring the correct alignment. When conditions do not permit this setup, it is necessary to equip the cable with an automatic winding conditioned to the buoyancy of the water. On the contrary, in the system anchored from above alignment is always guaranteed by the rigidity of the structure.

How does the system let vessels pass?

In the underwater anchored system, small boats can pass because the boat moves the buoy modules, which then align themselves again. In the case of a waterway where larger boats or vessels pass through, the best solution is a rail, allowing the temporary opening of the entire system. In the system with emerged anchorage, on the other hand, hinges can be placed in the structure that allow the opening of specific sections of the barrier.

How is the system energetically self-sufficient?

In its basic application and provided that water is moving, River Cleaning harnesses the power of water to operate. It can generate electricity through the rotating motion and store it in a battery pack. This electricity is used to power specific parts of the system remotely. Should there be additional components such as a conveyor belt for automatic extraction of waste, solar panels would be added to maintain energy consumption neutrality.

Is there a standardized version of River Cleaning?

When it comes to river pollution, we cannot afford to install a system that risks being inefficient or sub-optimal. That is precisely the reason we refer to ‘one river, one solution’: customizing the system is not just a question of size, but also of functionality and level of automation. Working on a river means fitting into a place’s institutional, social and industrial tissue. That is why, just as it is possible to choose options for a car, it is our job to know each customer’s needs and study the best solution.

Waste collection and collection

What does the collection point look like?

In its simplest version, the collection point consists of a conduit-like piece of the structure at the end of the series of rotating buoys. The piece is anchored but able to float and extends down below the water surface, deep enough to catch debris in the system’s area of effect, approximately 40 cm below the water level. A net is attached to the collection duct and, once filled, can be easily unhooked and emptied. If it is required by the customer and the location allows it, it is possible to install an automated conveyor belt instead of the net to take the waste directly out of thewater.

How is waste collection handled?

Waste pick-up requires prior arrangement with the waste management authority and/or company in the area or municipality. Once the system is in place, no special operations are required. We make the necessary contacts and organize the waste collection partners on site.