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Article
Publication date: 1 December 2005

John L. Daniels, Raghuram Cherukuri, Helene A. Hilger, James D. Oliver and Shi Bin

The purpose of this paper is to evaluate the influence of a mixture of nutrient solution, bacteria and biofilm on the consolidation, unconfined compression and desiccation…

Abstract

Purpose

The purpose of this paper is to evaluate the influence of a mixture of nutrient solution, bacteria and biofilm on the consolidation, unconfined compression and desiccation characteristics of two soils that could be used in waste containment applications.

Design/methodology/approach

Experimental work was conducted to investigate the influence of biofilm on the desiccation, strength and consolidation characteristics of two barrier soils. The soils were evaluated with water alone and with a biofilm solution composed of nutrients, bacteria and exopolymeric substances (EPS). These solutions were mixed with a locally available clay (“red bull tallow” (RBT)) as well as a mix of 65 percent sand and 35 percent bentonite (65‐35 Mix).

Findings

Reductions in strength and increases in ductility are observed with biofilm amendment for two soil types. The shear strength was reduced from 413 to 313 kPa and from 198 to 179 kPa for RBT and 65‐35 Mix, respectively. Desiccation tests reveal an increase in moisture retention for early time increments in amended specimens, while both increases and decreases are noted after extended drying. Increases in the rate of consolidation and modest decreases in the compression and swell index were observed. In particular, the consolidation coefficient was increased from 0.036 to 0.064 cm2/min and from 0.060 to 0.093 cm2/min for RBT and 65‐35 Mix, respectively.

Practical implications

These results are useful in establishing the broader impacts of using biofilm as an additive to increase the performance (e.g. reduce hydraulic conductivity and increase resistance to crack formation) of barrier materials in waste containment applications. Moreover, the data provide insight into the geotechnical implications of biofilm‐producing methanotrophic activity that occurs naturally in the covers of municipal solid waste landfills.

Originality/value

Very little research has been published on the influence of biofilm on the behavior of barrier materials in general, and on geotechnical properties in particular. This paper is unique in making the connection between methanotrophic activity, soil modification and barrier material performance.

Details

Management of Environmental Quality: An International Journal, vol. 16 no. 6
Type: Research Article
ISSN: 1477-7835

Keywords

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Article
Publication date: 24 May 2013

Helene Slagstad and Helge Brattebø

The paper aims to discuss how life cycle assessment can be used in the early stage planning phase of new settlements.

Abstract

Purpose

The paper aims to discuss how life cycle assessment can be used in the early stage planning phase of new settlements.

Design/methodology/approach

By applying the life cycle methodology on the waste, water and wastewater system of a new carbon‐neutral settlement under planning in Norway, the authors discuss the pros and cons with applying this methodology in an early planning phase.

Findings

The LCA methodology enabled the authors to compare suggestions from interdisciplinary planning teams, relate them to the existing systems in Trondheim and provide quantitative results back to the decision‐makers, in this case the municipality. The environmental benefits of implementing alternative solutions in the waste, water and wastewater systems were found to be small.

Research limitations/implications

Data availability and uncertainty can be limitations in the early planning phase.

Practical implications

By applying this methodology, the life cycle environmental impact of different solutions can be assessed at an early planning stage.

Originality/value

Even if life cycle assessment has been used for years in the research community, there is too little experience with applying the methodology in the early planning phase of new projects. This paper discuss how life cycle assessment can be used to compare suggestions from interdisciplinary planning teams, relate them to existing systems and provide quantitative results back to the decision‐makers.

Details

Smart and Sustainable Built Environment, vol. 2 no. 1
Type: Research Article
ISSN: 2046-6099

Keywords

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