Development of high load constructed wetlands for treatment of wastewater

Resum

Constructed wetlands (CWs) technology is an established green multi-purpose option for water management and wastewater (WW) treatment, with numerous effectively proven applications around the world and multiple environmental and economic advantages. Their adaptability and low operation and maintenance (O&M) requirements make them a sustainable and cost-effective choice for various WW treatment applications. CWs have been widely applied for over 50 years, initially for municipal wastewater and later for industrial and agricultural wastewater, livestock farm effluent, landfill leachate, and stormwater runoff. Industrial wastewater often requires pre-treatment due to its distinct composition. The introduction of oxygen in CWs, known as aerated CWs, enhances treatment efficiency, especially for nitrification and denitrification processes. These systems can be operated intermittently to improve total nitrogen removal. Aeration strategies can vary in intensity, making aerated CWs flexible and effective in removing nitrogen and organic matter. The primary objective of this thesis is to investigate and optimise various factors affecting WW treatment in aerated CWs, encompassing urban and industrial WW, with the aim of enhancing the design parameters and future implementation of these systems. Additionally, the thesis seeks to evaluate the feasibility of employing the hydrolitc upflow sludge blanket (HUSB) reactor followed by CWs configuration for treating diverse sources of WW, including urban, food industry, and winery WW, and to assess the impact of design and operational parameters on treatment efficiency. Research findings are intended to enhance the understanding of guidelines for CWs design, operation, and maintenance. Being carried out at outdoors pilot and full scale systems, the study spans several years and focuses on crucial factors such as unit performance, phosphorus removal, HUSB reactor for pre-treatment to prevent clogging risks in CWs, the influence of bed depth in aerated CWs, and treatment efficiency. This research holds significant relevance in improving the design of efficient and costeffective aerated CWs systems. It addresses the need for a better understanding of the internal processes involved in these systems and seeks to provide valuable performance data and information to guide the design and operation of aerated CWs.