[Water Purification Effect and Saline-alkali Tolerance Improvement Mechanism of in the Estuary Area].

The pollution load of nitrogen and phosphorus in pollutants entering the sea is high, which seriously affects the water quality of coastal water. It is necessary to strengthen land-sea coordination. However, affected by the seawater encroachment, the salt and alkali content of the water in the estuary area is high and the variation range is large, which leads to difficulty in plant growth.

[Heavy Metals Pollution in Topsoil from Dagang Industry Area and Its Ecological Risk Assessment].

Based on previous studies and field investigation of Dagang industry area in Tianjin, a total of 128 topsoil samples were collected, and contents of 10 heavy metals (As, Cd, Cr, Co, Cu, Pb, Ni, V, Zn and Hg) were determined. The geoaccumulation index and geostatistics were applied to examine the degree of contamination and spatial distribution of heavy metals in topsoil. The assessment on ecological risk of heavy metals was carried out using Hakanson's method, and the main resources of the heavy metals were analyzed as well.

[Effect of iron plaque on root surfaces on phosphorus uptake of two wetland plants].

In situ micro-suction cups were used to collect samples of soil solution with Arundo donax Linn and Typha latifolia from defined segments at rhizosphere in field. The experiment was conducted to elucidate the contribution of iron plaque while wetland plants were used to remove phosphorus. The reddish iron plaque was observed and measured on the surfaces of roots of Arundo donax Linn and Typha latifolia in the field, 20,170.