Long-Term Tritium Transport through Field-Scale Compacted Soil Liner

The use of hydraulic barriers in sanitary landfills has become an impeccable means of protecting the groundwater system from leachate. A question to be asked is, can these barriers continue to impede the migration of leachate over a long period? This paper investigates the phenomenon of leachate migration in compacted laterite soil used as liner in sanitary landfills. An experiment was carried out using laterite soil compacted at optimum moisture content using Standard Proctor energy. Leachate was poured on the compacted soil in an acrylic column and its migration was monitored using Digital Image Technique (DIT). The DIT capture photographic images at successive intervals of time which were fed through an image processing code to convert them to hue-saturation-intensity (HSI) format with the help of Surfer and Matlab computer softwares. Subsequently, PetraSim computer software was applied to predict the velocity behavior. The predicted velocity value shows that the laterite soil is compatible with the leachate and can be used as soil liner. The outcome of this study would enable designers to use non-destructive method to monitor and predict leachate migration in compacted soil liners to simulates leachate migration in waste containment applications.

Download Full-text

Field-scale variability of soil test phosphorus and other nutrients in grasslands under long-term agricultural managements

Soil Research ◽

10.1071/sr13027 ◽

2013 ◽

Vol 51 (6) ◽

pp. 503 ◽

Cited By ~ 10

Author(s):

Weijun Fu ◽

Keli Zhao ◽

Peikun Jiang ◽

Zhengqian Ye ◽

Hubert Tunney ◽

...

Keyword(s):

Soil Nutrients ◽

Poultry Litter ◽

Soil Nutrient ◽

Statistical Correlation ◽

Soil Test ◽

Field Scale ◽

The North ◽

Positive Correlations ◽

Soil Test Phosphorus

Field-scale variation of soil nutrients in grassland is becoming important because of the use of soil-nutrient information as a basis for policies such as the recently introduced EU Nitrates Directive. This study investigates the field-scale variability of soil-test phosphorus (STP) and other nutrients in two grasslands with a long-term history of poultry litter application. Two fields (field 1 for silage and field 2 for grazing pasture) were selected, and soil samples were collected based on 12 m by 12 m (field 1) and 15 m by 15 m (field 2) grids. Data were analysed using conventional statistics, geostatistics, and a geographic information system (GIS). In field 1, STP values ranged from 12.4 to 90 mg L–1 (average 38.5 mg L–1). In field 2, STP values ranged from 4.3 to 130.0 mg L–1 (average 21.4 mg L–1). Attention should be paid to long-term poultry application, as the average STP values in both fields were much greater than the recommended agronomic optimum STP status in Ireland of 8 mg L–1. Coefficient of variation values of soil nutrients in field 2 were much higher than those in field 1. Log-transformation and Box–Cox transformation were applied to achieve normality. Statistically significant (P < 0.01), positive correlations between P and other nutrients were found in both fields. Exponential and spherical models were fitted to the experimental variograms of STP in fields 1 and 2, respectively. Compared with the counterparts in field 1, soil nutrients in field 2 had larger ‘nugget-to-sill’ values, revealing that sheep grazing could weaken the spatial auto-correlation of soil nutrients. A grid of 60 m by 60 m was recommended for soil sampling in grassland, based on this study. High STP concentrations in field 1 were in the north-eastern side, which was related to uneven poultry litter application. Strong spatial similarity of low STP, magnesium, and pH values in their spatial distribution were found in field 2, confirming their strong statistical correlation.

Download Full-text

Soil enzyme kinetics indicate ecotoxicity of long-term arsenic pollution in the soil at field scale

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2020.110215 ◽

2020 ◽

Vol 191 ◽

pp. 110215 ◽

Cited By ~ 1

Author(s):

Ziquan Wang ◽

Haixia Tian ◽

Mei Lei ◽

Mallavarapu Megharaj ◽

Xiangping Tan ◽

...

Keyword(s):

Enzyme Kinetics ◽

Soil Enzyme ◽

Field Scale ◽

Arsenic Pollution

Download Full-text

Physical properties of soils under intensive agricultural management

Scientia Agricola ◽

10.1590/s0103-90162005000200012 ◽

2005 ◽

Vol 62 (2) ◽

pp. 165-172 ◽

Cited By ~ 8

Author(s):

Jorge Luís Nascimento Soares ◽

Carlos Roberto Espindola ◽

Walcylene Lacerda Matos Pereira

Keyword(s):

Soil Structure ◽

Sequence Variation ◽

Soil Bulk Density ◽

Saccharum Officinarum ◽

Management Systems ◽

Vertical Profiles ◽

Compacted Soil ◽

Physical Attributes ◽

Lower Slope

Pedologic alterations after long-term sugar cane (Saccharum officinarum) cropping cycles under traditional soil management systems were studied on a farm in Bariri, SP, Brazil. A toposequence was established to evaluate the effects of the soil position in the relief in changing soil physical attributes. Morphological field descriptions and laboratory analyses were carried out on vertical profiles of the upper, middle and lower thirds of a Typic Haplorthox slope. Soil bulk density and macroporosity changed along the toposequence reflecting on soil hydrodynamics, especially in the lower slope parts. At sites with high clay levels, empty spaces were filled forming block shaped structures together with the micro-aggregate structure. The intensive cultivation induced the greatest soil structure alterations, even at the deepest layers. The study pointed out the importance of performing detailed morphological observations in vertical profiles, due to the great variation on pedological attributes over short distances. Compacted soil sections were observed side-by-side with desaggregated mottles in the same soil profile. This fact evidenced that both vertical (in each profile) and horizontal gradients (along a toposequence) need to be considered in studies of time sequence variation of pedological parameters.

Download Full-text