Enhanced technology of phytoremediation

The enhanced technology of phytoremediation has the advantages of low treatment cost, good purification effect, low environmental risk and environmental aesthetics. However, some hyperaccumulators grow slowly and their biomass is generally low; the activity of heavy metals in the soil is very low; the roots of plants are distributed in the surface of the soil, and the remediation effect of deep soil is poor; the nutrients of the soil to be repaired are seriously insufficient. It is necessary to take a series of strengthening measures to improve the efficiency of phytoremediation. The strengthening technologies of phytoremediation include chemical strengthening, microbial strengthening, animal strengthening, carbon dioxide strengthening, agronomic and management measures strengthening, etc.

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Heavy Metals Accumulation and its Environmental Risk in Sediments of Xihe River, Shenyang City

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.414.250 ◽

2011 ◽

Vol 414 ◽

pp. 250-253 ◽

Cited By ~ 1

Author(s):

Ji Song Yang ◽

Xiao Jun Hu ◽

Xin Xin Li ◽

Hao Wu

Keyword(s):

Heavy Metals ◽

Environmental Risk ◽

Metal Accumulation ◽

Geoaccumulation Index ◽

River Sediments ◽

Heavy Metal Accumulation ◽

Deep Soil ◽

Shenyang City ◽

Heavy Metals Accumulation ◽

Accumulation Characteristics

Heavy metal accumulation in Xihe River sediments was studied, and also its potential environmental risk was evaluated using geoaccumulation index (Igeo). The results showed that mean concentrations of Hg, Cd, Zn, Pb, Ba, Bi, Sn and Sb were 2.73, 18.42, 1066.1, 128.8, 366.9, 7.76, 24.70 and 8.53 mg/kg, respectively. The values of examined heavy metals, except for Ba, were higher than the reference of deep soil. There were different accumulation characteristics for heavy metals at different river sections. Cadmium and Pb concentrations in sediment dropped from upper to lower reaches along river, but Ba was quite the reverse. The potential environmental risk of heavy metals in sediments was in order: Cd > Hg > Bi > Zn > Sb > Sn > Pb > Ba. The river was subjected to a higher potential risk by Hg, Cd, Zn and Bi, a medium-high risk by Sn and Sb, and a lower risk by Pb and Ba.

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Farmland heavy metals can migrate to deep soil at a regional scale: A case study on a wastewater-irrigated area in China

Environmental Pollution ◽

10.1016/j.envpol.2021.116977 ◽

2021 ◽

Vol 281 ◽

pp. 116977

Author(s):

Shushen Yang ◽

Wenzhao Feng ◽

Shiqin Wang ◽

Liang Chen ◽

Xin Zheng ◽

...

Keyword(s):

Heavy Metals ◽

Regional Scale ◽

Deep Soil ◽

Irrigated Area

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Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3309-2016 ◽

2016 ◽

Vol 20 (8) ◽

pp. 3309-3323 ◽

Cited By ~ 35

Author(s):

Xuening Fang ◽

Wenwu Zhao ◽

Lixin Wang ◽

Qiang Feng ◽

Jingyi Ding ◽

...

Keyword(s):

Soil Moisture ◽

Influencing Factors ◽

Loess Plateau ◽

Vegetation Restoration ◽

Native Vegetation ◽

Watershed Scale ◽

Vegetation Types ◽

Deep Soil ◽

Soil Layers ◽

Management Measures

Abstract. Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80–500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120–140 and 480–500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80–220 cm); (ii) a transition layer (220–400 cm); and (iii) a stable layer (400–500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially for the choice of vegetation types, planting zones, and proper human management measures.

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