Executive Summary : | Waste-water treatment is a crucial process for reusing or disposing of untreated water safely to the environment. Untreated water from large building complexes, including college hostels, residential complexes, and hospitals, contains kitchen waste, bio-waste, and detergents. When discharged into the environment, it can deteriorate ground water quality and inland fresh water resources, leading to improper hygienic conditions for living beings and adverse conditions for aquatic plants and animals. Water-treatment is a non-profitable investment, and the primary factors determining treated water quality are biochemical oxygen demand (BOD) and ammonium ion concentration. To control these factors, controlled air flow and optimal residence time are needed. A database of BOD and ammonium ion concentrations in natural freshwater will be developed by analyzing samples from different sources. A multi-variable dynamic mathematical model will be developed using data-driven frequency domain technique, controlling BOD by controlling dissolved oxygen and Ammonium ion concentration directly. A robust controller based on pre-compensated multi-variable quantitative feedback theory will be designed to meet performance specifications at minimal control effort. The controller will be implemented in an Arduino Uno platform to control electro-pneumatic valves to inject airflow and determine the flow of return activated sludge and optimal residence time. The project will be implemented as a case study at Hostel 9 of NIT Silchar, with 1000 students and an average monthly water consumption of 900 KL. This project may also be customized as a technology solution for building complex stakeholders, potentially offering research publications, patents, and PhD thesis outcomes. |