In-situ purification island structure and the construction method thereof

An in-situ purification island structure, characterized in that the structure comprises an upstream purification island main body (1) located on the upstream of a river and a downstream purification island main body (2) located on the downstream of the river;

• said upstream purification island main body (1) comprises a first base backfill layer (11), a first lower layer (12), a first hydrophobic layer (13), a first water permeable layer (14), and a first upper layer (15);
• the first base backfill layer (11) is set on a river bed and an upper part of the first base backfill layer (11) is parallel to a horizontal plane of the river's water level;
• the first lower layer (12) is located on the upper part of the first base backfill layer (11);
• the first hydrophobic layer (13) is located on an upper part of the first lower layer (12);
• the first water permeable layer (14) is covering an upper part of the first hydrophobic layer (13);
• the first upper layer (15) is located on an upper part of the first water permeable layer (14);
• a plurality of first ecological bags (111) are set around a surface of the first base backfill layer (11);
• the first lower layer (12) has a central opening defining a lower layer backfill transitional zone (121);
• the first hydrophobic layer (13) has a central opening defining a hydrophobic layer backfill transitional zone (131);
• the first water permeable layer (14) has a central opening defining a water permeable layer backfill transitional zone (141);
• the upper part of the first base backfill layer (11) passes through the lower layer backfill transitional zone (121), the hydrophobic layer backfill transitional zone (131) and the water permeable layer backfill transitional zone (141) successively, and extends to an area between the first water permeable layer (14) and the first upper layer (15) so as to form a first base backfill layer peak (112);
• the first upper layer (15) has a surface paved with a first protecting layer (151);
• a peak protective layer (1121) is formed on top of the first base backfill layer peak (112) within a central opening formed in the first upper layer (15) and the first protecting layer (151);
• the downstream purification island main body (2) comprises a second base backfill layer (21), a second lower layer (22), a second hydrophobic layer (23), a second water permeable layer (24), and a second upper layer (25);
• the second base backfill layer (21) is set on the river bed and an upper of the second base backfill layer (21) is parallel to the horizontal plane of the river's water level;
• the second lower layer (22) is located on an upper part of the second base backfill layer (21);
• the second hydrophobic layer (23) is located on an upper part of the second lower layer (22);
• the second water permeable layer (24) is covering an upper part of the second hydrophobic layer (23);
• the second upper layer (25) is located on an upper part of the second water permeable layer (24);
• a plurality of second ecological bags (211) are set around a surface of the second base backfill layer (21);
• a center area between the second water permeable layer (24) and the second upper layer (25) is formed with a second base backfill layer peak (212);
• the second upper layer (25) has a surface paved with a second protecting layer (251).