Resource Recovery from Wastewater

Short Commentary

Austin Environ Sci. 2017; 2(3): 1024.

Resource Recovery from Wastewater

Gude VG*

Associate Professor, Department of Civil & Environmental Engineering, Mississippi State University, United States of America

*Corresponding author: Veera Gnaneswar Gude, Associate Professor, Department of Civil & Environmental Engineering, Mississippi State University, United States of America

Received: August 03, 2017; Accepted: August 31, 2017; Published: September 08, 2017


The fundamental objective of designing a wastewater treatment plant is to return the surface waters in pristine conditions so as not to harm the receiving water bodies. Wastewater treatment plants play an important role in protecting our environment. Current wastewater treatment plants are mainly predominant in aeration based technology known as “activated sludge” process which has been proven to be a robust and reliable technology over the last century treating a variety of wastewater streams originating from various sectors [1,2]. The activated sludge process requires oxygen as a key ingredient to remove the biologically degradable organic matter in wastewater. Air supply to meet this oxygen requirement is also the key contributor for energy and operating costs in the process. Approximately, fifty percent of operating costs are associated with pumping oxygen into the activated sludge reactor [3].

Aeration based treatment technology was developed in times of the greatest need to protect surface water sources. This became the predominant technology when there were no significant concerns for the lack of energy sources. In recent decades, due to population growth and rapid industrialization and associated energy consumption, the need for developing more energy and resource-efficient technologies has become apparent [2]. Resource-efficient technology means that not only energy consumption should be minimized rather it should be recovered along with other valuable resources including nutrients, nitrogen and phosphorous. Water, itself, is the most valuable resource that can be recovered from these operations [3]. Considering the global challenges for water, energy and nutrients and food supplies, it is important to consider a paradigm shift in understanding and therefore redesigning our wastewater treatment systems.

Wastewater treatment system design and operations should now look beyond achieving environmental protection through reduction approach which is simply removing biodegradable and nutrient sources, often considered problematic for various reasons. However, these sources can be recovered or put to beneficial use in a recovery approach if appropriate technologies can be developed (see Figure 1). Wastewater contains up to ten times more energy than it is required to treat it [4]. This energy is present in the form of organic and inorganic “contaminants” and thermal gradient. In aerobic processes, about 40% of the organic waste is embedded into new biomass called sludge and 50% is converted into carbon dioxide through microbial metabolism which is released into environment and not considered an environmental emission by the United States Environmental Protection Agency and the remaining is considered non-biodegradable. About 1500 tons of carbon dioxide is released for every 1000 tons of wastewater is treated [3]. In reality, these emissions can be considered a significant contribution to man-made pollution when all the wastewater treatment plants around world are combined. Therefore, alternative technologies that diminish environmental emissions should be developed. These technologies should address energy, nutrient and water related issues intertwined with wastewater treatment.

Citation: Gude VG. Resource Recovery from Wastewater. Austin Environ Sci. 2017; 2(3): 1024.