Techno-economic assessment of a hybrid forward osmosis and membrane distillation system for agricultural water recovery

Enhancing water desalination efficiency through integrated photovoltaic thermal systems with phase change materials

This study investigates the effectiveness of chemically modified composite phase change materials in photovoltaic thermal solar energy systems and hybrid desalination systems in two municipalities, comparing their efficacy using different draw solutions for thorough comparison. The effect of non-composite Paraffin PCMs, Paraffin/CNTs Composite PCMs, and Nitrogen-doped graphene Composite PCMs on system efficiency over 96 h is investigated. The simulation under natural conditions looks at two scenarios: brackish water desalination in Irbid with tetraethylammonium bromide and seawater desalination in Aqaba with sodium chloride as a draw solution. When evaluated after 96 h of operation, non-composite Paraffin PCMs produced the most desalinated water compared to the two chemically modified materials, with 909.45 L and 760.43 L in the Irbid and Aqaba scenarios, respectively. In contrast, using Nitrogen-doped graphene Composite PCMs material produced the most desalinated water during night hours when compared to non-composite Paraffin PCMs; the difference was 37.36 L and 37.77 L in the Irbid and Aqaba scenarios, respectively. Electrically, using Nitrogen-doped graphene Composite PCMs material resulted in a significant improvement; the difference between using non-composite Paraffin PCMs and Nitrogen-doped graphene Composite PCMs material was 119.17 W/the first day of operation in Irbid and 107.16 W/the first day of operation in Aqaba. In the Irbid scenario, the difference in evaporation efficiency and specific thermal energy consumption at 4 a.m. between Nitrogen-doped graphene Composite PCMs and non-composite Paraffin PCMs was 6.26% and 334.47 kWh/m3, respectively. In contrast, it was 7.12% and 439.57 kWh/m3 in the Aqaba scenario, with Nitrogen-doped graphene Composite PCMs being the best option.

Techno-economic assessment of a novel algal-membrane system versus conventional wastewater treatment and advanced potable reuse processes: Part II

This study developed a comprehensive techno-economic assessment (TEA) framework to evaluate an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) in comparison with a conventional potable water reuse system (i.e., the benchmark system). The TEA study aims to estimate the levelized costs of water of individual units and integrated processes including secondary wastewater treatment, advanced water purification for potable reuse, and sludge treatment. This would provide decision-makers valuable information regarding the capital and operational costs of the innovative main system versus a typical potable water reuse treatment train, along with possible routes of cost optimization and improvements for the design of full-scale facilities. The main system consists of (i) a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water reuse and hydrothermal liquefaction (HTL) to produce bioenergy and subsequent nutrients extraction from the harvested algal biomass. The benchmark system includes (ii) an advanced water purification facility (AWPF) that consists of a conventional activated sludge biological treatment (CAS), microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), with anaerobic digestion for sludge treatment. Capital expenditures (CAPEX) and operational expenditures (OPEX) were calculated for each unit of both systems (i.e., sub-systems). Based on a 76% overall water recovery designed for the benchmark system, the water cost was estimated at $2.03/m³. The highest costs in the benchmark system were found on the CAS and the anaerobic digester, with the UV-AOP combined with GAC for hydrogen peroxide (H₂O₂) quenching as the driving factor in the increased costs of the system. The cost of the main system, based on an overall 88% water recovery, was estimated to be $1.97/m³, with costs mostly driven by the FO and SWRO membranes. With further cost reduction and optimization for FO membranes such as membrane cost, water recovery, and flux, the main system can provide a much more economically viable alternative in its application than a typical benchmark system.

Crumpled Globule-Heterotextured Polyamide Membrane Interlayered with Protein-Polyphenol Nanoaggregates for Enhanced Forward Osmosis Performance

Surface modulation of polyamide structures and the development of nanochanneled membranes with excellent water transport properties are crucial for the separation performance enhancement of thin-film composite membranes. Here, we demonstrate the fabrication of a modular nanochannel-integrated polyamide network on a nanoporous interlayer membrane comprising Mxene-reinforced protein-polyphenol nanoaggregates. The research indicates that the confined growth of the polyamide matrix inside this hydrophilic sub-10 nm nanochannel nanoporous intermediate layer stiffened the interfacial channels, leading to the formation of a polyamide layer with a spatial distribution of a network of unique 3D crumpled globule-like nanostructures. The high specific surface area of such a morphology bestowed the membrane with increased filtration area while facilitating the nanofluidic transport of water molecules through the nanochanneled membrane structure, leading to enhanced water flux of up to 26.6 L m^-2 h^-1 (active layer facing the feed solution) and 41.0 L m^-2 h^-1 (active layer facing the draw solution) using 1.0 M NaCl as the draw solution. The membrane equally exhibited good treatment for organic solvent forward osmosis filtration and typical seawater desalination. Moreover, the hierarchical nanostructures induced antimicrobial activity by effectively reducing the biofilm formation of Gram-negative Escherichia coli bacteria. This work provides significant insights into the interfacial engineering and compatibility of the nanomaterials and the polymers in interlayer mixed-matrix membranes, which are environmentally sustainable and cost-effective for the fabrication of advanced forward osmosis membranes for water purification and osmotic energy applications.

Techno-economic assessment of decentralized polishing schemes for municipal water reclamation and reuse in the industrial sector in costal semiarid regions: The case of Barcelona (Spain)

This study demonstrates the techno-economic reliability of an innovative fit-for-use treatment train to boost municipal reclaimed water reuse fore industrial uses in the Barcelona Metropolitan Area (BMA). The relatively high conductivity (2090 μS/cm) and hardness (454 mg/L) of reclaimed water in the BMA (e.g. Water Reclamation Plant (WRP) of El Baix Llobregat, Barcelona, Spain), together with the restrictive water quality demands in industrial uses, claims for the implementation of advanced reclamation schemes based on desalination technologies such as reverse osmosis (RO). The study assesses the benefits of two potential pre-treatments of the RO stage: (i) ultrafiltration (UF) or (ii) an innovative high-performance nano-structured polymeric adsorbent (CNM); in which a permeability decline of 5% was observed when CNM was used as a pre-treatment, while a stable permeability of RO was found when was fed by the UF effluent. On the other hand, generic cost curves have been calculated for the technologies evaluated and were applied to estimate capital and operational expenditures (CAPEX and OPEX) for the scale-up in three different industrial sites (e.g., chemical, waste management and electro-coating industries). The economic assessment indicates that the use of municipal reclaimed water is economically competitive in front of the use of tap water in the BMA, providing savings between 0.13 and 0.52 €/m³ for the waste management industry and between 0.49 and 0.98 €/m³ for the electrocoating industry. On the other hand, the use of groundwater in one of the industrial sites and its relatively low cost implied that, although it is necessary a RO, the current cost of water is significantly lower.