Performance Evaluation of Two-Stage Electrokinetic Washing as Soil Remediation Method for Lead Removal using Different Wash Solutions

The study explores the application of a two-stage electrokinetic washing system on remediation of lead (Pb) contaminated soil. The process involved an initial soil washing, followed by an electrokinetic process. The use of electrokinetic process in soil washing not only provided additional driving force for transporting the desorbed Pb away from the soil but also reduced the high usage of wash solution. In this study, the effect of NaNO3, HNO3, citric acid and EDTA as wash solutions on two-stage electrokinetic washing system were evaluated. The results revealed that a two-stage electrokinetic washing process enhanced Pb removal efficiency by 2.52-9.08% and 4.98-20.45% in comparison to a normal electrokinetic process and normal washing process, respectively. Low pH and adequate current were the most important criteria in the removal process as they provided superior desorption and transport properties. The effect of chelating by EDTA was less dominant as it delayed the removal process by forming a transport loop in anode region between Pb ion and complexes. HNO3 was not suitable as wash solution in electrokinetic washing in spite of offering highest removal efficiency as it caused pH fluctuation in the cathode chamber, corroded graphite anode and showed high power consumption. In contrast, citric acid not only yielded high Pb removal efficiency with low power consumption but also maintained a low soil: solution ratio of 1 g: <1 mL, stable pH and electrode integrity. Possible transport mechanisms for Pb under each wash solution are also discussed in this work.

Developing management capability within a horizontal supply chain in performance measurement deployment and evolution: A Dynamic Capabilities and Goal Theory perspective

Complex collaboration in rapidly changing business environments create challenges for management capability in Utility Horizontal Supply Chains (UHSCs) involving the deploying and evolving of performance measures. The aim of the study is twofold. First, there is a need to explore how management capability can be developed and used to deploy and evolve Performance Measurement (PM), both across a UHSC and within its constituent organisations, drawing upon a theoretical nexus of Dynamic Capability (DC) theory and complementary Goal Theory. Second, to make a contribution to knowledge by empirically building theory using these constructs to show the management motivations and behaviours within PM-based DCs. The methodology uses an interpretive theory building, multiple case based approach (n=3) as part of a USHC. The data collection methods include, interviews (n=54), focus groups (n=10), document analysis and participant observation (reflective learning logs) over a five-year period giving longitudinal data. The empirical findings lead to the development of a conceptual framework showing that management capabilities in driving PM deployment and evolution can be represented as multilevel renewal and incremental Dynamic Capabilities, which can be further understood in terms of motivation and behaviour by Goal-Theoretic constructs. In addition three interrelated cross cutting themes of management capabilities in consensus building, goal setting and resource change were identified. These management capabilities require carefully planned development and nurturing within the UHSC.