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Ion exchange represents one of the most promising processes for ammonium recovery from municipal wastewater (MWW). However, most previous studies on ammonium ion exchange did not optimize the process or evaluate its robustness under real operational conditions. This experimental study aimed at (i) developing a procedure for the selection of a sorbent for selective ammonium removal/recovery from MWW, (ii) validating the procedure by applying it to several sorbents, (iii) performing a preliminary optimization and robustness assessment of ammonium removal/recovery with the selected sorbent. The application of the procedure to natural and synthetic zeolites and a cation exchange resin confirmed that batch isotherm tests need to be integrated by continuous-flow tests. The selected sorbent, a natural mixture of Chabazite and Phillipsite, resulted in high performances in terms of cation exchange capacity (33 mgN gdry resin-1), ammonium operating capacity (5.2 mgN gdry resin-1), ammonium recovery yield (78-91%) and selectivity towards ammonium. The process performances resulted stable during 7 adsorption/desorption cycles conducted with MWW treatment plant effluents in a 60-cm column. The switch to a highly saline effluent produced in a hotspot of seawater intrusion did not determine significant changes in performances. Contact time was reduced to 6 min without any decrease in performances. Potassium – well tolerated by crops – was selected as the regenerating agent, in the perspective to produce a desorbed product to be re-used as fertilizer. The study shows that Chabazite/Phillipsite has a high capacity to recover ammonium from MWW in a circular economy approach.

Adsorption represents one of the most promising process for phosphorous (P) removal and recovery from municipal wastewater, but questions about its long-term stability remain. The goals of this work were (i) to assess changes in morphology and adsorption performances of hybrid anion exchanger (HAIX) LayneRT after 2.5 years of operation in a 10 m3 d-1 demonstration plant fed with secondary-treated municipal wastewater, (ii) to optimize the LayneRT regeneration procedure, and (iii) to evaluate the suitability of the ion exchange model to describe P adsorption on LayneRT. LayneRT is composed of hydrated ferric nanoparticles dispersed in a strong base anion exchange resin. Batch and continuous flow adsorption/desorption tests were conducted with the resin used for 2.5 years, regenerated with two alternative solutions: NaOH, reactivating mainly the iron nanoparticles active sites, and NaOH + NaCl, also regenerating the active sites of the ion exchange media. The physicochemical characterization by Scanning Electron Microscope indicated that regeneration by NaOH significantly reduced the deterioration of the resin surface, even after 59 adsorption/desorption cycles. Lab-scale continuous flow tests showed that the resin regenerated with either solution featured P adsorption performances very close to that of the virgin resin. The isotherm tests showed that P adsorption by LayneRT was effectively simulated with the ion exchange model. This study confirms that LayneRT is a durable, resistant and promising media for P recovery from wastewater.

When contaminants possess an intrinsic economic value, their removal from the waste and their recovery as a marketable product, does not only reduce the environmental footprint of the waste disposal, but also provides a revenue-generating opportunity. This is the case of the two wastewater (WW) investigated in the current study: olive-mill wastewater (OMWW) containing high content of phenolic compounds (PC) and municipal wastewater (MWW) which is today considered the most potential new source of phosphorus (P). In terms of WW valorisation adsorption-based technologies result an extremely attractive solution since the pollutant values can be recovered along with their removal from the effluents. In the first part of the current work a procedure for the selection of the optimal adsorbent for PC-recovery from actual OMWW was proposed and applied to compare 4 neutral resins (Amberlite XAD16N, Optipore SD-2, Amberlite FPX66, Amberlite XAD761) and one ion-exchange resin (Amberlite IRA958Cl), by means of batch and continuous-flow tests. Moreover, anaerobic digestion tests were conducted on both raw and dephenolized OMWW to drive the development of a cost-effective and integrated biorefinery process aimed at producing a directly reusable irrigation-quality water. The second part of the thesis focused on P-recovery from MWW. This study represents one of the really first attempt to place an adsorption-based process within an existing sewage works to remove and recover P from secondary effluent MWW. The process was investigated through a pilot-scale plant, treating 10m3d-1 of WW and characterized by 35L of the commercially available hybrid ion exchange resin HAIX LayneRT. The investigated system went successfully through 66 adsorption/desorption cycles proving the potential of the novel conduction method proposed, based on the multiple usage of the regenerant solution through consecutive adsorption/desorption cycles. Moreover lab-scale trials were performed to investigate the

To achieve a water‐secure world, water management should be approached from a multidimensional and integrative perspective, addressing the water‐related issues of health, household supply, economics, the environment, and resilience to water‐related and climate change hazards. Although water security has significantly improved since 2000 in Africa, there are still vast inequalities in access to water suitable in terms of quantity and quality, especially in rural areas. To achieve water‐related sustainable development of African economies, a broad scope of innovative technological and management solutions is required, involving governments, research institutions, private sector parties, and civil society. This special series, composed of 8 papers, illustrates a selection of the most relevant results achieved by the 7 research projects selected and financed by the European Union under 2 dedicated Horizon 2020 calls in 2015: Water‐5b‐2015 “A coordination platform” and Water‐5c‐2015 “Development of water supply and sanitation technology, systems and tools, and/or methodologies.” The innovations presented in this special series include both technological advancements and water management approaches, given that the development of water‐related technologies in developing countries needs to be integrated into water management strategies and economic instruments. This special series aims to help policy makers take informed decisions on how to implement innovative approaches to increase water security in African countries.

In the Nile Delta region in Egypt, agriculture represents a crucial economic activity, and all the agricultural surface is irrigated with freshwater ultimately provided by the Nile river through a complex network of canals. Surface irrigation is widely applied, and the excess irrigation water, contaminated with fertilizers and pesticides, is collected by means of an intricate network of drainage water canals. However, several villages in Egypt are still suffering from low sanitation coverage and poor sanitary technology. Therefore, small drainage canals are often used to dispose untreated municipal wastewater (MWW) and industrial wastewater. The contaminated drainage canal water (DCW) is typically discharged in main drains, which eventually discharge in the Mediterranean sea. The treatment of drainage canal water potentially represents an important option for the Nile Delta, with the double purpose to produce water that can be reused for irrigation or for aquaculture and to reduce the pollutant load discharged in the Mediterranean. Thus, simple, low-tech, low-energy water treatment technologies are needed to treat drainage water up to irrigation-quality water. This dataset comprises the concentrations of key parameters measured in the inlet, outlet and in several intermediate sections of the NWRC pilot plant of drainage canal water treatment located near Lake Manzala, Egypt. The NWRC constructed wetland pilot project (250 m3/d) consists of a 500 m3 capacity sedimentation pond and 3 vegetated free water surface wetlands (20*10*1 m and 100 m3 capacity each) The 3 free water surface cells were designed to examine 3 new wetland types as follows: 1. Cascade Hybrid Constructed Wetland (CHCW): Consists of a 0.4-m deep FWS wetland on top of 0.4-m gravel bed subsurface wetland GBSW. A group of metal baffles were fixed at the entrance, exit and middle and inner parts to force water to flow through FWS and GBSW cells to create the maximum treatment paths. Reeds were transplant

In Agadir, a water-scarce Moroccan region, municipal and industrial wastewater is tertiary-treated to be reused in golf courses. Wastewater reuse has been constrained by severe emitter clogging that caused technical and financial problems. This study aimed to perform an in-depth characterization of the treated wastewater in relation to its susceptibility to cause clogging, and to assess the capacity of an aeration post-treatment to reduce the clogging potential. The post-treatment consisted in injecting different airflows (0-33 L/min/Lreactor) into the treated wastewater. The structural, morphological and elemental composition of the clogging matter collected in the irrigation pipeline was characterized using Scanning Electron Microscopy, Scanning Transmission Electron Microscopy, X-ray Diffraction and X-ray Energy Dispersive Spectroscopy. The 15-day aeration post-treatment at 16.5 L/min/Lreactor presented the best cost-benefit ratio. Organic matter was totally degraded. Calcium was reduced by 9%, bicarbonates by 54%. The analysis of the deposits induced by the aeration post-treatment revealed a relevant decrease of the major constituents of the clogging deposits found in the irrigation pipeline. The results show the effectiveness of post-aeration in biodegrading residual organic matter and precipitating several salts, thus reducing the clogging potential.

The goal of this study was to develop a mesophilic anaerobic co-digestion (co-AD) process of olive mill wastewater (OMW) and sewage sludge (SwS) from municipal wastewater treatment. Different volumetric OMW:SwS ratios up to 100% OMW were fed in continuous 1.7-L bioreactors. The reactors fed with raw OMW (rOMW) performed better than those fed with OMW dephenolized by adsorption (dOMW). At a 23-day hydraulic retention time (HRT) the best performances were obtained in the reactor fed with 25% rOMW, with a 105% increase in methane yield in comparison to the 100% SwS test. At a 40-day HRT, the reactor fed with 40% rOMW attained a 268 NLCH4/kgVS methane yield (144% increase in comparison to 100% SwS). These results prove the feasibility of co-digesting with SwS the entire OMW production in regions characterized by intense olive oil production, with a strong increase in methane production.

In the Nile Delta, a complex network of canals collects drainage water from surface-irrigated fields, but also municipal wastewater. The goal of this work was to assess the technical, environmental and financial feasibility of the upgrade of a drainage canal (DC) into either an in-stream constructed wetland (ICW) or a canalized facultative lagoon (CFL), in order to produce a water re-usable in agriculture according to the Egyptian law. The model-based design of the proposed technologies was derived from field experimental data for the ICW and laboratory data for the CFL. Both technologies, integrated by a sedimentation pond and a disinfection canal, led to the attainment of the water quality standards imposed by Egyptian Law 92/2013 for the reuse of drainage water. The life cycle assessment indicated that the proposed upgrade of an existing DC resulted in a decrease of environmental burden for the ICW, or in an environmental impact equal to 0.3% of that of a traditional activated sludge process for the CFL. The cost/benefit analysis (CBA) was based on the assumptions that (i) farmers currently irrigate a non-food crop (cotton) with the low quality drainage water present in the DC, and (ii) thanks to the upgrade to a ICW or CFL, farmers will irrigate a food crop characterized by a higher market price (rice). The CBA indicated that the DC upgrade to an ICW represents an attractive investment, as it leads to a financial rate of return > 10% over a wide range of cotton market prices. Conversely, the upgrade to a CFL is less attractive due to high investment costs. In conclusion, the upgrade of DCs to ICWs appears a promising option for the treatment of drainage canal water in the Nile Delta, thanks to the high pollutant removal performances, low cost and negligible environmental burden.