This study investigated the impact of a 12-week problem-based learning (PBL) intervention on three psychological constructs (motivation, locus of control and self-esteem) linked to learner autonomy. Results indicated that there was a significant increase in the students' intrinsic motivation (P<0.05) and a non-significant shift towards an internal locus of control after the intervention period. Students perceived the benefits of PBL to be the opportunity to work in teams and to consider a wider knowledge base. A short course of PBL was successful in developing learner autonomy and other key employability skills alongside the application of content knowledge.

Due to the increasing number of treatment plants facing stringent nutrient limits, a greater understanding of technologies capable of achieving ultra-low effluent total phosphorus (TP) concentrations is needed. The City of Coeur d'Alene is preparing to upgrade its wastewater treatment plant to meet a draft NPDES permit of 0.036 mg/L effluent TP. Previously tested in a small scale pilot in 2006, the tertiary membrane filter was selected as part of a two year intensive low phosphorus demonstration program. Results show that the TMF system reliably produced effluent quality of less than 0.036 mg/L TP on a monthly average basis.

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The City of Portland Bureau of Environmental Services (BES) is planning to implement a biogas use project to fully utilize biogas produced at the Columbia Boulevard Wastewater Treatment Plant (CBWTP). Five biogas use alternatives were evaluated to determine which would provide the largest return on investment and demonstrate the sustainability benefits. The alternatives included cogeneration to provide electricity and heat, renewable natural gas (RNG) for vehicle fuel, RNG for industrial customers, and use in biosolids dryers. Using HDR's Sustainable Return on Investment (SROI) methodology, each of the alternatives was evaluated to determine the Financial Return on Investment (FROI) and the SROI. For the SROI analysis a number of environmental and social costs and benefits were monetized in order to establish a comparison of the five alternatives. Financial, social, and environmental cost and benefits were modeled using software simulation to establish risk adjusted cost profiles.