Olya Skulovich

A sensitive biomarker for the detection of aquatic contamination based on behavioral assays using zebrafish larvae.

An effective biological early warning system for the detection of water contamination should employ undemanding species that rapidly react to the presence of contaminants in their environment. The demonstrated reaction should be comprehensible and unambiguously evidential of the contamination event. This study utilized 96h post fertilization zebrafish larvae and tested their behavioral response to acute exposure to low concentrations of cadmium chloride (CdCl2) (5.0, 2.5, 1.25, 0.625mg/L) and permethrin (0.05, 0.029, 0.017, 0.01μg/L). We hypothesize that the number of larvae that show advanced trajectories in a group corresponds with water contamination, as the latter triggers avoidance behavior in the organisms. The proportion of advanced trajectories in the control and treated groups during the first minute of darkness was designated as a segregation parameter. It was parametrized and a threshold value was set using one CdCl2 trial and then applied to the remaining CdCl2 and permethrin replicates. For all cases, the method allowed distinguishing between the control and treated groups within two cycles of light: dark. The calculated parameter was statistically significantly different between the treated and control groups, except for the lowest CdCl2 concentration (0.625mg/L) in one replicate. This proof-of-concept study shows the potential of the proposed methodology for utilization as part of a multispecies biomonitoring system.

Piece‐wise mixed integer programming for optimal sizing of surge control devices in water distribution systems

Despite their potential catastrophic impact, transients are often ignored or presented ad hoc when designing water distribution systems. To address this problem, we introduce a new piece-wise function fitting model that is integrated with mixed integer programming to optimally place and size surge tanks for transient control. The key features of the algorithm are a model-driven discretization of the search space, a linear approximation nonsmooth system response surface to transients, and a mixed integer linear programming optimization. Results indicate that high quality solutions can be obtained within a reasonable number of function evaluations and demonstrate the computational effectiveness of the approach through two case studies. The work investigates one type of surge control devices (closed surge tank) for a specified set of transient events. The performance of the algorithm relies on the assumption that there exists a smooth relationship between the objective function and tank size. Results indicate the potential of the approach for the optimal surge control design in water systems.

Optimization of Surge Protection Devices in Water Distribution Systems

Flow disturbances occur frequently in water distribution systems. Both planned (the automatic stopping of pumps, hydrant flushing) and the accidental events (power outages, mechanical failures of pipes) generate transient conditions, which if maltreated can lead to serious consequences for water utilities and its consumers. Various devices need to be specified to insure safe and efficient operation of the system. Each device should be properly selected, located, and sized in account for system’s specifications (Ghidaoui et al. 2005). This study considers optimizing pumped network performance under several transient conditions by selecting location of surge protecting devices and their optimal design parameters using genetic algorithm (GA). The study shows that GA can be integrated with transient simulation for pressurized flow system. The obtained solutions provide efficient protection against low (including cavitation) and high pressure events.

Industry Effluent Disposal into Rivers: Coupled Multiobjective-Analytical Optimization Model

AbstractIn this work, a linear system theory approach produces an analytical solution of contaminant mass transport equations for its subsequent use in multiobjective optimization for optimal waste...

Battle of Water Networks DMAs: Multistage Design Approach

AbstractLooped water distribution system (WDS) repartitioning to district metering areas (DMAs) gained popularity as an effective technique to manage the system and detect and reduce system leakage...