China’s territory is polluted at 13% and this percentage reaches 19% if we consider arable land – Italian land is polluted at 3% and 13% in the plains.
This data have been provided by the director of the Italian Ministry of the Environment Francesco La Camera and they show how much work there is to do to bring earth back to health – in particular rivers, lakes and dams, which concentrate the most of pollution in their bottom.
China issued two decrees to deal with the problem, allocating EUR 300 billions – 2000 billions of yuan – to decontaminate 3% by 2020. China aims to decontaminate 95% by 2030 investing a greater amount of money, still to be estimated.
In order to understand the huge effort required, it should be pointed out that Italy tackled the problem with government, regions and private companies, investing EUR 4,5 billions in the period between 2000 and 2014.
The decision of China’s government is a significant innovation from a methodological point of view. Generally, in European countries there are action plans for harbor dredging and remediation of earth, but also of dams and rivers. However, there isn’t a unique action plan and the problem has been moved from rivers to earth in a vicious circle.
Last month Italian companies presented themselves in Beijing and Shanghai (link), proposing a global solution for the question of remediation of bodies of water.
Traditional dredging creates much turbidity with grabbers, as they lift materials and spread all the pollutants trapped in the mud of the seabed. This situation produces a huge environmental disaster, with a great death toll of fishes and mussels (link). For instance, traditional dredging of rivers causes spread of materials in huge areas of the valley. As a consequence, the banks of the basin will be covered by silt and clay and they will be partially cleaned up only by the following river flood.
Furthermore, the grabber extracts not only muds but also much water, so that there will be double materials to free from pollution.
Another type of dredge is suction and flowing dredge (link) which causes less damage in the extracting stage but it increases tenfold the extracted material, as they are blended with 9 parts of water. If the polluted materials settle on earth there will consequences for years.
The link to the video that we provided above shows a suction and flowing dredge working in a non-polluted area. However, it brings a black and smelly mud out and it dirties the beach. This is the effect of the use of such a dredge, even if concerning non-polluted materials.
Up to now, in the absence of a strict regulation, it was easy to take the muds from the seabed and put them in the shore, so as to consent navigation. But now things have changed. China’s government, for instance, aims to reduce the surface of earth and water to be remediated – a surface equivalent to the whole of Italy. And here comes Decomar’s Limpidho dredge (link). I have often talked about Limpidho in my articles and I presented it in China last month, and it suddenly became a very current topic.
Limphido eco-dredging is based on a closed-circuit suction pump. It uses the water in the inner circuit of the pump to extract sediments. Water demolishes the mud pressed in the bottom and takes it into the treatment system, which separates polluted material (15%) from clean material (85%). Once it has drained the mud, it gets back to work to extract new sediments.
As a result, eco-dredging doesn’t create turbidity nor spread pollution in the extracting area. It only removes the muds, then there will be to treat just the polluted part of the muds. The remaining part, instead, will be recycled once it become clean sand or silt.
To summarize, here is what Chinese realized:
Dredging with grabbers spreads pollutants, creates turbidity in the ecosystem and the total polluted material of the seabed requires to be cleaned at 200%.
Dredging with flowing dredge requires the total polluted material of the seabed to be cleaned at 900%.
Eco-dredging with the Italian system Limpidho doesn’t create turbidity in the extracting process and the muds of the seabed require to be cleaned at 15%.
Furthermore, Decomar has reached an agreement with 6V, a company of the Trevi group. They have a treatment system for polluted muds and they want eco-dredging as a partner to create a team involved in reclamation.
In China we have been guests of honor of the biggest companies and we met excellences with whom eco-dredging could marry to solve big as well as small problems.
The cooperation between China and Italy can really give a global solution to the problem of remediation with enormous benefits for water, earth and the planet affected by pollution.
Eco-dredging system can perform the above-mentioned functions also from a watercraft. It seems to be the only solution for hydroelectric basins and lakes that have been filling up with muds for years (link). In fact, the bottom of the basin is very deep and the more deep the pump works, the more efficient it becomes.
If the basins in our country had been cleaned from mud in time, like Monti government suggested, now we would have a billion of m3 of water available, in the current situation of emergency for drought.
We will talk about the question of eco-dredging on the 13th of July at Ecofuturo festival (link Ecofuturo program 2017) with the participation of Davide Benedetti (Decomar), Ennio Rao (6V), Silvia Paparella (Ramtech), Giuliano Gabbani (UniFi), Giampiero Ravagnan (Ca’ Foscari) and many others. We will prove that, after the treatment of polluted muds with the method outlined above, there will be no need to wound the land again. The recovered and recycled materials will be enough for the construction industry and the beach nourishment in our country.