ANALYSIS AND SIMULATION OF ENERGY USE AND COST AT A MUNICIPAL WASTEWATER TREATMENT PLANT

The cost of electricity, a major operating cost of municipal wastewater treatment plants, is related to influent flow rate, power price, and power load. With knowledge of inflow and price patterns, plant operators can manage processes to reduce electricity costs. Records of influent flow, power price, and load are evaluated for Blue Plains Advanced Wastewater Treatment Plant. Diurnal and seasonal trends are analyzed. Power usage is broken down among treatment processes. A simulation model of influent pumping, a large power user, is developed. It predicts pump discharge and power usage based on wet-well level. Individual pump characteristics are tested in the plant. The model accurately simulates plant inflow and power use for two pumping stations [R2 = 0.68, 0.93 (inflow), R2 =0.94, 0.91(power)]. Wet-well stage-storage relationship is estimated from data. Time-varying wet-well level is added to the model. A synthetic example demonstrates application in managing pumps to reduce electricity cost.

Substance Use and Academic Outcomes among High School Seniors: Examining the Influence of Emotional Academic Engagement

Substance use is prevalent among adolescents, with two-thirds trying alcohol and half trying an illicit drug by twelfth grade (Miech et al., 2015). Substance use is known to affect academic performance. This study utilized nationally representative data from the 2013 Monitoring the Future twelfth grade survey to examine the relationships between substance use, skipping school, grades, and academic engagement. One-quarter of respondents (26%) had never used a substance. The majority (67%) had used at least one substance during the past year. Substance use during their lifetime but not during the past year was uncommon (7%). Lifetime non-users were less likely than past-year users to skip school during the past month and to have low grades. Lifetime non-users also had greater academic self-efficacy and emotional academic engagement relative to past-year users. These findings underscore the importance of screening and intervention for substance use to promote academic achievement and adolescent wellbeing.

The Relation between Substance Use and Medication Adherence among HIV Positive Substance Users in Residential Treatment

Poor medication adherence is problematic among HIV positive, low-income African-American substance users. Substance use has been shown to be associated with poor medication adherence, though we do not know the mechanism that underlies this relationship. Lack of positive environmental rewards and the propensity to discount delayed rewards may be possible mechanisms to explain this relationship. Using baseline data from a randomized controlled trial, we examined the relationships between substance use and medication adherence, testing both environmental rewards and delay discounting as independent mediators. There was a main effect of substance use on adherence, such that high frequency of substance use predicted poor adherence. There was also a main effect of environmental rewards on adherence, such that a lack of environmental reinforcement predicted poor adherence. This study shed light on the processes that contribute to low adherence, namely substance use and lack of environmental contingencies, and suggests important targets for intervention.