Seminar Series

The Chemical and Biochemical Engineering Department Graduate Student Seminar series is a bi-weekly seminar taking place during the Fall and Winter terms. Each seminar features a different student presenters.

Fall 2026 - Winter 2027: Seminars will be held from 12:30 pm - 1:30 pm every second Thursday. The location will be announced. *Please bring Student Card for attendance*

Speakers to Present in Fall 2026

Sep. 24, 2026, 12:30 pm

Location: ACEB 1415

Title: Recovery of Iron and Aluminum from Calcined Water Treatment Sludge

Presenter: Salil Mathew

Supervisor(s): Dr. Madhumita Ray and Dr. Hassan Gomaa

 Abstract:

Drinking water-treatment sludge (DWTS) represents a potential secondary source of Fe and Al, although recovery strategies are commonly centered on acidification and are often evaluated primarily by metal solubilization. This study investigated Fe and Al recovery from calcined WTS across acidic, reducing, and complexing environments, while integrating solution-chemistry interpretation, operational optimization, reagent-normalized assessment, and subsequent reuse of the metal-containing leachates.

HCl effectively solubilized both metals, achieving approximately 70% Fe recovery and near-quantitative Al recovery at 5 M. Beyond acidification, dithionite-based treatment increased Fe solubilization to approximately 53%, while selected combinations with HCl further enhanced Fe and Al recovery. Response-surface optimization predicted 88.2% Fe recovery within the investigated domain and 73.6% when HCl and temperature were constrained to ≤1 M and ≤60 °C, respectively. Reagent-normalized comparisons further differentiated extraction pathways based on chemical requirements, recovery cost, and upstream carbon burden. Importantly, extraction chemistry also influenced subsequent reuse, including phosphate-removal performance. Overall, the work provides a broader basis for selecting Fe and Al recovery pathways from water-treatment sludge according to their intended reuse.