Study of the Potential for Agricultural Reuse of Urban Wastewater with Membrane Bioreactor Technology in the Circular Economy Framework

Abstract

The growing demand for water by the population and industry, as well as water scarcity due to climate change, has created a need to reuse treated water for agricultural purposes. In this context, the European Union, through its Regulation (EU) 2020/741, establishes minimum requirements for wastewater reuse, specifying that reuse for agricultural purposes can help to promote the circular economy and reduce the need for fertiliser use by setting high-quality standards. The aim of this article is to study whether the treated water from a pilot plant with membrane bioreactor technology operating with real urban wastewater from the city of Granada (Spain) satisfies the quality standards required for its reuse for agricultural purposes, as well as assessing the use of other resources produced during wastewater treatment, such as biogas and biostabilised sludge. This plant works in four cycles of operation at two different hydraulic retention times (6 and 12 h) and different concentrations of mixed liquor (2429–6696 mg/L). The pilot plant consists of a membrane bioreactor where there are four ultrafiltration membranes working in continuous operation and a sludge treatment line working in discontinuous mode. Subsequently, a tertiary treatment of advanced oxidation process was applied to the treated water for a time of 30 min, with different concentrations of oxidant. The results showed that the effluent has sufficient quality to be used in agriculture, complying with the characteristics established in the European legislation. Furthermore, the biostabilised sludge and biogas can be potentially reusable.

Performance of a Double-Filter-Medium Tandem Membrane Bioreactor with Low Operating Costs in Domestic Wastewater Treatment

“…The DT-MBR is composed of the aeration tank, air supply pipe, aeration head, filter cloth assembly, peristaltic pump, and UUF. The aeration tank is a stainless-steel cuboid with a length, width, and height of 840 mm, 720 mm, and 1700 mm, respectively, and an effective volume of 0.8 m 3 . The aeration head is a disc-shaped microporous membrane made of ethylene-propylene-diene monomer (EPDM) rubber with a diameter of 215 mm, and the released bubble is 0.9-1.0 mm in diameter.…”

“…The membrane bioreactor (MBR) has many advantages, including strong biodegradation ability, good and stable effluent quality, less residual sludge, and a small footprint [1][2][3]. It has been widely used in wastewater treatment around the world.…”

Kinetic Effects of Ciprofloxacin, Carbamazepine, and Bisphenol on Biomass in Membrane Bioreactor System at Low Temperatures to Treat Urban Wastewater

“…Pharmaceuticals may induce a variety of physiological changes, which can be reversible or not, in non-target aquatic organisms [4]. They can reach the aquatic environment via a high number of routes, such as discharge of both raw and wastewater treated by municipal [5], hospital [6], and industrial wastewater treatment plants (WWTPs); sewer leakage [7]; landfill leachate [8]; or treated wastewater used for irrigating [9]. These compounds can be found in both raw influents and treated effluents of WWTPs, so they are of particular interest [10].…”

Effect of Pharmaceutical Compounds (Diclofenac, Ibuprofen, and Erythromycin) on the Heterotrophic Behaviors of Biomass of a Membrane Bioreactor to Treat Urban Wastewater

“…Membrane bioreactor (MBR) technology is being increasingly adopted by numerous nations due to its advantages in terms of a compact design, high quality of treated water, and simplified operational procedures [36]. It integrates biological treatment with membrane filtration to produce a clarified effluent [37,38]. In addition, membrane technology, which encompasses a number of characteristic separation processes, offers a more holistic solution and makes provisions for treatments that deal with both salinity effect and the particularity of various pollutant characteristics [39].…”