Saline Effluents Research Articles

Optimizing growth and yield of striped catfish (Pangasianodon hypophthalmus) and quinoa (Chenopodium quinoa) in a biosaline integrated aquaculture–agriculture systems

Soil salinity and freshwater scarcity are among the major global threats to sustainable development owing to their adverse impacts on agricultural productivity especially in arid and semi-arid regions. There is a need to find sustainable alternatives such as salt-tolerant crops and fish to improve people’s livelihoods in marginal areas. This study aimed to maximize the growth and yield of striped catfish (Pangasianodon hypophthalmus) and quinoa (Chenopodium quinoa) cultivated under a biosaline integrated aquaculture–agriculture system. The study was laid in a randomized completely block design of three saline effluent treatments under three replicates: 5000 ppm (T1), 10,000 ppm (T2), 15,000 ppm (T3), and control (T0). Agro-morphological and physiological attributes of quinoa were measured. The crop yield in biomass and mineral element composition was also studied. Additionally, fish growth performance parameters such as feed intake and efficiency, growth, and survival rate were also calculated. Our results indicated that irrigating quinoa with saline aquaculture effluents above 10,000 ppm enhanced the plant growth, yield, and nutrient content of seeds. Furthermore, rearing striped catfish in saline water reaching up to 15,000 ppm did not have adverse impacts on the growth and survival of fish. Overall, integrating catfish and quinoa production under a salinity regime of 10,000 ppm could be a potential solution to ensuring alternative food sources in marginal areas.

Synthesis of Responsive Membranes for Water Recovery through Desalination of Saline Industrial Effluents

Polysulfone (PSF) and smart polymers (SRPs)—including polyacrylic acid (AAc), poly N-isopropylacrylamide (NIPA), and sulfonated poly(1,4-phenylene ether-ether-sulfone) (SPEES)—were used in the synthesis of responsive membranes (PSF-SRP) for application in sustainable desalination processes involving food industry effluents for water recovery and recycling. With the inclusion of SRPs, PSF-SRP membranes showed different characteristics when compared to the PSF membrane. AAc caused fibers to occur in the surface structure, increasing the MWCO of the PSF membrane, whereas NIPA and SPEES diminished the MWCO, resulting in ultrafiltration and nanofiltration membranes. Furthermore, NIPA and SPEES provided high mechanical and thermal resistance when incorporated into the PSF membrane. The performance of the membranes also showed important changes. In comparison with only PSF, PSF-SPEES and PSF-NIPA increased the water flux and salt rejection percentage by 20–30%. In addition, the highest membrane fouling resistance was observed with PSF-NIPA, while PSF-AAc and PSF-NIPA-AAc presented the lowest resistances. Therefore, PSF-NIPA and PSF-SPEES resulted in membrane improvement, including stimuli-responsive properties, allowing for effective saline effluent treatment.

Process integration and techno-economic assessment of crystallization techniques for Na2SO4 and NaCl recovery from saline effluents

Saline effluents containing primarily sodium chloride (NaCl) and sodium sulfate (Na2SO4) are generated from common salt production, tannery CETPs, textiles industries, desalination rejects, etc. In this work, experimental studies have been conducted for parametric evaluation of crystallization techniques for selective isolation of Na2SO4 and NaCl from saline effluent. Three crystallization approaches, i.e., evaporation-crystallization, cooling-crystallization, and antisolvent-crystallization, are assessed through parametric studies. A representative saline solution generated from a salt refinery unit is considered for the study. Lab-scale experiments were performed to determine the optimum process conditions for each crystallization process, and their performance was evaluated by estimating the separation efficiency. Chemical, P-XRD, and TGA analyses were performed to characterize the product composition, purity, and hydration state. For selective Na2SO4 recovery, cooling crystallization, and antisolvent crystallization were found suitable over evaporation crystallization. Subsequently, integrated process variants for cooling crystallization and antisolvent crystallization-based separation were developed. A techno-economic assessment (TEA) was performed to compare integrated process variants for the recovery of salts (Na2SO4 and NaCl) and establish the prospective towards commercialization. The parametric evaluation and TEA shows that the combined crystallization technologies can be potential approach to recover added-value products from saline effluents promoting waste to wealth notion.

Unraveling the molecular mechanisms of fish physiological response to freshwater salinization: A comparative multi-tissue transcriptomic study in a river polluted by potash mining

Freshwater salinization is an escalating global environmental issue that threatens freshwater biodiversity, including fish populations. This study aims to uncover the molecular basis of salinity physiological responses in a non-native minnow species (Phoxinus septimaniae x P. dragarum) exposed to saline effluents from potash mines in the Llobregat River, Barcelona, Spain. Employing high-throughput mRNA sequencing and differential gene expression analyses, brain, gills, and liver tissues collected from fish at two stations (upstream and downstream of saline effluent discharge) were examined. Salinization markedly influenced global gene expression profiles, with the brain exhibiting the most differentially expressed genes, emphasizing its unique sensitivity to salinity fluctuations. Pathway analyses revealed the expected enrichment of ion transport and osmoregulation pathways across all tissues. Furthermore, tissue-specific pathways associated with stress, reproduction, growth, immune responses, methylation, and neurological development were identified in the context of salinization. Rigorous validation of RNA-seq data through quantitative PCR (qPCR) underscored the robustness and consistency of our findings across platforms. This investigation unveils intricate molecular mechanisms steering salinity physiological response in non-native minnows confronting diverse environmental stressors. This comprehensive analysis sheds light on the underlying genetic and physiological mechanisms governing fish physiological response in salinity-stressed environments, offering essential knowledge for the conservation and management of freshwater ecosystems facing salinization.

Modelling reverse osmosis process and multiple effect evaporator process of common effluent treatment plant using artificial neural network

This paper presents the study on modeling the performance of Textile and Tannery Common Effluent Treatment Plant (CETP) using Artificial Neural Networks (ANN). The process of Reverse Osmosis (RO) Process and Multiple Effect Evaporator (MEE) process of CETP is modelled using ANNs. Two ANN models were developed to predict the performance of CETP dealing with highly saline effluents. Model-I (RO Model) predicts TDS Rejection (%) by taking pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Chemical Oxygen Demand (COD) of RO feed as input parameters thus providing estimate of salt concentration. Model-II (MEE Model) predicts Steam Output needed by taking pH, TDS, Feed flow as input parameters. Levenberg-Marquardt backpropagation (trainlm) algorithm was used as training function for creation of both of ANN models and Hyperbolic Tangent Sigmoid (tansig) was used as transfer function. Separate model validation has been performed to test the predictability of the model and at last prediction accuracy were analysed to show its efficiency in prediction.

Aerobic granulation and resource production under continuous and intermittent saline stress

Three sequential batch reactors (SBR) were operated to evaluate salt addition's impact on granulation, performance, and biopolymer production in aerobic granular sludge (AGS) systems. System R1 was fed without adding salt (control); system R2 operated with saline pulses, i.e., one cycle with salt (2.5 g NaCl/L) addition followed by another without salt; and R3 received continuous supplementation of 2.5 g NaCl/L. The results indicated that the reactors supplemented with salt presented higher concentrations of mixed liquor volatile suspended solids (MLVSS) and better settleability than R1, showing that osmotic pressure contributed to biomass growth, accelerated granulation, and improved physical characteristics. The faster granulation occurred in R2, thus proving the beneficial effects of intermittent salt addition through alternating pulses. Salt addition did not impair the simultaneous removal of carbon, nitrogen, and phosphorus. In fact, R2 showed better carbon removals. In conclusion, continuous or intermittent (pulsed) supplementation of 2.5 g NaCl/L did not lead to increased production of extracellular polymeric substances (EPS) and alginate-like exopolymers (ALE). This outcome could be attributed to the low saline concentration employed, a higher food-to-microorganism (F/M) ratio observed in R1, and possibly greater endogenous consumption of biopolymers in the famine period in R2 and R3 due to the greater solids retention time (SRT). Therefore, this study brings important results that contribute to a better understanding of the effect of salt in continuous dosing or in pulses as a selection pressure strategy to accelerate granulation, as well as the behavior of the AGS systems for saline effluents.

Mine Wastewater Effect on the Aquatic Diversity and the Ecological Status of the Watercourses in Southern Poland

Coal mining activity contributes to energy security and employment occupation, but is associated with environmental deterioration. Coal combustion leads to GHG emissions, while coal mining results in the generation of saline effluents. These effluents are discharged in inland surface waters, applying significant pressure on their quality, with a negative impact on aquatic life and the economy of a region. This study includes water samples that were analyzed in order to investigate the organic compounds, heavy metals, and other physicochemical parameters. Biological monitoring was done according to the Water Framework Directive methodology. The results from an aquatic area in Southern Poland, which indirectly receives coal mine effluents, indicate elevated salinity with excessive chlorides, sulfates, and sodium ions. The water quality of another non-polluted aquatic area was also assessed to examine the impact of indirect coal mine wastewater discharge on this area. The high salinity levels hinder the use of river water for drinking, agricultural, or industrial purposes. The results obtained show high pressure on the ecological status of streams and rivers that receive mine effluents, and on the density and diversity of aquatic invertebrates. This pressure is clearly visible in the structure of benthic communities and in invertebrate diversity. It also contributes to the appearance of invasive species and increasing water salinity. Limiting discharges of mine water transporting large loads of saline substances would reduce the negative impact on the quality of river waters and biological life.

A loose polyethersulfone hybrid nanofiltration membrane incorporated with polyethyleneimine-decorated silica nanoparticles for highly-efficient dye/salt separation

Loose nanofiltration (LNF) is a newly-developing technology for desalting dye-containing saline effluents, but suffers from membrane materials with low permeance and poor dye/salt separation selectivity. Herein, a hybrid polyethersulfone (PES) LNF membrane for dye/salt separation was prepared via a nonsolvent-induced phase inversion method, which was carried out using polyethyleneimine (PEI)-modified silica nanoparticles as a dopant. This design not only featured a hybrid PES LNF membrane with high porosity and small mean pore size, but also partially neutralized its charge and enhanced its hydrophilicity. Hybrid PES LNF membrane from a 21-wt% PES solution with 3-wt% PEI-decorated silica nanoparticles addition was demonstrated to achieve high water permeance (92.0 L m−2 h−1 bar−1) and dyes retention ratio (98.4 % for Congo Red, 98.8 % for Nile Blue A, and 95.1 % for Methyl Blue) accompanied with fully-pass for various salts (Na2SO4, NaCl, MgCl2 and CaCl2). In addition, the hybrid membrane exerted excellent resistances to strong acidic, oxidative and hot water (90 °C) environments and exhibited a pH-sensitive permeability. Multicycle test revealed that the hybrid membrane had high permeance recovery ratio (>92.8 %) and maintained its high dye retention and complete salt permeation even after 10 cycles, manifesting its outstanding fouling resistance and recyclability. Besides, the hybrid membrane repelled 92.6 % of dyes from a simulated wastewater consisting of multiple industry-applied direct dyes and salts after 12 h consecutive test, but allow 100 % of mixed salts passing through the membrane, proving its practical applicability to industrial dyeing wastewater. This study provided a simple and economically feasible route to high-performance LNF membrane production for dye/salt separation, thus popularizing LNF process in dyeing wastewater treatment, organic products purification, and resource recovery.

Resource recovery and phytoremediation of fish-processing effluents using halophyte plants

The reuse of saline effluents from the fishing industry is an appealing alternative for halophyte cultivation. The objectives of this study were to compare the growth of Atriplex lampa in hydroponics using fish-processing effluents (E) versus a control solution (Co), and to assess its potential for effluent phytoremediation. No significant differences between treatments were detected in the (fresh and dry) weight of the plants, shoots, and roots, or in the concentrations of total chlorophylls and carotenoids. Total N in leaves, stems and roots was lower in E than in Co (p < 0.05), likely due to the minor availability of inorganic N in the fish-processing effluent compared to the control. Conversely, the nutrient efficiency ratio (NER) for N was higher (p < 0.01) in plants from E than in Co, indicating an increased efficiency with which plants exposed to fish-processing effluent convert N resources into dry mass. Hydroponic cultivation reduced the effluent electrical conductivity (EC, 29.6 %), Biochemical Oxygen Demand (BOD5, 93.7 %), Chemical Oxygen Demand (COD, 73.2 %), NH4+ concentration (63 %), and odor. The successful integration of A. lampa cultivation, a fodder plant used for ecological restoration of degraded drylands, with hydroponics, offered a valuable model for reusing and remediating fish-processing effluents.

Biological nitrogen removal characteristics and mechanisms of a novel salt-tolerant strain Vibrio sp. LV-Q1 and its application capacity for high-salinity nitrogen-containing wastewater treatment

High concentration of salts in wastewater can adversely affects the metabolic activities and growth of microorganisms, resulting in reduced efficiency of biological nitrogen removal. Screening high-efficiency heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria with salt tolerance is important for the wastewater treatment. In this study, a novel salt-tolerant strain LV-Q1 capable of HN-AD was isolated and identified as Vibrio sp. This strain demonstrates a salinity tolerance range of 0–8 %. Notably, strain LV-Q1 exhibited exceptional nitrogen removal efficiencies (at initial concentrations of 100 mg/L), achieving 97.97 % for NH4+-N, 100 % for NO3--N, and approximately 100 % for mixed nitrogen (NH4+-N and NO3--N) at a salinity of 5 %. Optimal ammonium removal parameters for LV-Q1 were established. The nitrogen removal pathway of LV-Q1 primarily involves direct assimilation of ammonium and its conversion into N2 through HN-AD. Analysis of the salt tolerance mechanism revealed LV-Q1's ability to equilibrate osmotic pressure through the accumulation of amino acids and betaine, production of antioxidative enzymes or extracellular protein, and utilization of its quorum sensing (QS) properties to withstand high-salinity environments. The strain LV-Q1 exhibited strong resistance to salinity shock in bioaugmentation within a moving bed biofilm reactor (MBBR), markedly enhancing nitrogen and carbon removal performance with an improved removal efficiency of 26.74 % and 10.15 % averagely at the end of the reaction at a salinity of 5 %. Moreover, Vibrio sp. LV-Q1 successfully proliferated and dominated, and its relative abundance gradually increased to 59.81 %. This study contributes new insights and resources for the treatment of nitrogen in saline effluents.

Treatment of highly saline effluents laden with organic pollutants using ceramic ultrafiltration membranes and application to leachate treatment

The aim of this study is to assess the efficacy of three ultrafiltration ceramic membranes with distinct porosities (20, 50, and 100 nm) in treating highly charged effluents and their potential application in leachate treatment. In the initial phase, Response Surface Methodology (RSM) was employed using a solution containing NaCl (TDS = 20 g/L) and glucose (mass concentration (Cm) = 10 g/L). The investigation focused on operational parameters, specifically Circulation velocity (CV) and volumetric concentration factor (VCF). The responses considered encompass permeate flux (PF) and retention (R). In the subsequent phase, as part of a practical application, leachate was subjected to treatment, and the fouling mechanisms specific to each membrane were identified. The Hermia model was employed, distinguishing between four fouling modes: cake formation, intermediate blocking, pore constriction, and complete blocking. The results demonstrate that, during the treatment of the synthetic solution, VCF has a more significant influence on both responses compared to CV. Furthermore, CV impacts the critical flux of the three membranes, without affecting the retention of suspended matter (SS). When treating the leachate, removal efficiencies of 55%, 51%, and 47% for COD and 36%, 33%, and 29% for SS were achieved for membranes with porosities of 20 nm, 50 nm, and 100 nm, respectively. Modeling the flux over time showed that fouling of these three UF membranes is superficial, and the main fouling mechanism is cake formation.

Acclimation of microbial communities to low and moderate salinities in anaerobic digestion

In recent years anaerobic digestion (AD) has been investigated as suitable biotechnology to treat wastewater at elevated salinities. However, when starting up AD reactors with inocula that are not adapted to salinity, low concentrations of sodium (Na+) in the influent can already cause disintegration of microbial aggregates and wash-out. This study investigated biomass acclimation to 5 g Na+/L of two different non-adapted inocula in two lab-scale hybrid expanded granular sludge bed (EGSB)-anaerobic filter (AF) reactors fed with synthetic wastewater. After an initial biomass disintegration, new aggregates were formed relatively fast (i.e., after 95 days of operation), indicating microbial community adaptation. The newly formed microbial aggregates accumulated Na+ at the expense of calcium (Ca2+), but this did not hamper biomass retention or process performance. The hybrid reactor configuration, including a pumice stone filter in the upper section, and the low up-flow velocities applied, were key features for retaining the biomass within the system. This reactor configuration can be easily applied and represents a low-cost alternative for acclimating biomass to saline effluents, even in existing digesters. When the acclimated biomass was transferred from EGSB to an up-flow anaerobic sludge blanket (UASB) reactor configuration also fed with saline synthetic wastewater, more dense aggregates in the form of granules were obtained. The performances of the UASB inoculated with the acclimated biomass were comparable to another reactor seeded with saline-adapted granular sludge from a full-scale plant. Regardless of the inoculum origin, a defined core microbiome of Bacteria (Thermovirga, Bacteroidetes vadinHA17, Blvii28 wastewater-sludge group, Mesotoga, and Synergistaceae) and Archaea (Methanosaeta and Methanobacterium) was detected, highlighting the importance of these microbial groups in developing halotolerance and maintaining AD process stability.

One step purification of active nisin by electrodialysis from a commercial product

Nisin is a natural antimicrobial peptide widely used in food and medical applications. Its use is hampered by its costly production process and complex further purification. Therefore, electrodialysis process was used, for the first time, to purify a commercial nisin solution, in comparison with a conventional multiple-step centrifugation approach. Electrodialysis was, in one purification step, as efficient as the centrifugation process for nisin desalination (demineralization rate of 95.6% vs 94.3–99.8% respectively) with a higher protein recovery yield (83.8% vs 12.5–42.1% respectively). Centrifugation at higher concentration allowed the purification of nisin with the highest specific activity for supernatants S2 (3653.8–7307.6 AU/mg of proteins) and S3 (2394.2–9577.3 AU/mg of proteins). In a circular economy scheme, since saline effluents produced during centrifugation and precipitation processes represent an ecological and economical hurdle regarding their disposal, the use of electrodialysis would be of interest, by reusing the salts and lowering or eliminating the production of by-products.

Exopolysaccharide Production from Marine-Derived Brevundimonas huaxiensis Obtained from Estremadura Spur Pockmarks Sediments Revealing Potential for Circular Economy.

Marine environments represent an enormous biodiversity reservoir due to their numerous different habitats, being abundant in microorganisms capable of producing biomolecules, namely exopolysaccharides (EPS), with unique physical characteristics and applications in a broad range of industrial sectors. From a total of 67 marine-derived bacteria obtained from marine sediments collected at depths of 200 to 350 m from the Estremadura Spur pockmarks field, off the coast of Continental Portugal, the Brevundimonas huaxiensis strain SPUR-41 was selected to be cultivated in a bioreactor with saline culture media and glucose as a carbon source. The bacterium exhibited the capacity to produce 1.83 g/L of EPS under saline conditions. SPUR-41 EPS was a heteropolysaccharide composed of mannose (62.55% mol), glucose (9.19% mol), rhamnose (19.41% mol), glucuronic acid (4.43% mol), galactose (2.53% mol), and galacturonic acid (1.89% mol). Moreover, SPUR-41 EPS also revealed acyl groups in its composition, namely acetyl, succinyl, and pyruvyl. This study revealed the importance of research on marine environments for the discovery of bacteria that produce new value-added biopolymers for pharmaceutical and other biotechnological applications, enabling us to potentially address saline effluent pollution via a sustainable circular economy.

The effect of application of effluent water on sage (Salvia officinalis L.) yield and quality in lysimeters

ABSTRACT Cultivation of medicinal plants with the irrigation of agricultural effluents might be of great importance to save fresh water resources, extend cultivation area and increase economic feasibility. We investigated the effects of saline fish farm effluent water, diluted and gypsum-supplemented effluent, and natural freshwater as a control irrigation in lysimeters. Beside plant growth parameters, macronutrient and sodium content and the amount and composition of essential oil of sage plants were measured. Significant differences among irrigation treatments were found in plant height, SPAD value and essential oil content. Seasonal variation was also observed on plant height, nutrient content of the leaves and the total essential oil content. The essential oil components characterised by the highest levels of availability were detected as α-thujone, camphor, ß-thujone, 1,8-cineol and ledol. Under effluent irrigation, the concentrations of - and ß-thujone increased slightly; only camphene, trans-sabinole and caryophyllene-oxide changed significantly. The other main components remained stable. Our analysis of the response of sage to the input of effluent provides a reasonable ground for recommending the utilisation of saline effluent water from intensive fish farming in sage production, thus preventing the wastage of valuable water resources.

Efluente salino de piscicultura como alternativa para irrigação de Croton blanchetianus (Euphorbiaceae)

ABSTRACT The use of saline effluents from fish farming in agricultural activities has been increasing, especially in semiarid regions. This study was to evaluate the use of saline effluents from fish farming for the irrigation of Croton blanchetianus and to analyze the physiological and biochemical responses. After the cuttings were planted, irrigation with the effluent began. Treatments included four salinity levels (control, 1.5, 2.5, 3.5 dS m-1). The control treatment was the supply water (0.56 dS m-1). The evaluated variables were growth, relative water content, dry biomass, and levels of proteins, proline, hydrogen peroxide, malondialdehyde, and photosynthetic pigments. Physiological and biochemical adjustments ensured the maintenance of relative water content and osmotic adjustment under saline conditions without increasing lipid peroxidation. The salinity levels did not affect C. blanchetianus, indicating the lack of saline stress. The fish farm effluents are rich in organic matter, from food, and excrement, which was beneficial for the development of C. blanchetianus. The reuse of saline effluents from fish farming for the irrigation of C. blanchetianus can be a viable environmental alternative, avoiding direct disposal into the environment.

Incorporating a viable Renewable-energy System towards Industrial Effluent Treatment &amp; Reuse: A Short Review

In many regions throughout the continent, industries and farms struggle with low-quality water supplies. They threaten environmental health and the safety of drinking and industrial waterways. The regeneration of industrial effluents is modeled in detail in this study. Solar stills are designed to emulate natural evaporation, purifying effluent from industrial processes. This approach is best suited for small, off-grid structures that produce their own power from renewable sources and have a salinity effluent stream. Effluent recycling is a useful process that benefits both commercial and agricultural endeavors. Renewable power solutions that use concentrated sun electricity are reviewed in this paper. This study develops and evaluates a solar concentration system based on a parabolic reflector for water recycling and reuse that makes use of air-condensed water, solar stills, and salt effluent. Desalinating industrial effluent using only renewable energy is the goal of this research. This technique relies on research on how solar panels and collectors may enhance solar still processing.

Influence of salt addition to stimulating biopolymers production in aerobic granular sludge systems

The influence of salt addition to stimulating biopolymers production in aerobic granular sludge (AGS) systems was evaluated. The control systems (R1: acetate and R2: propionate) initially obtained less accumulation of mixed liquor volatile suspended solids (MLVSS), indicating that the osmotic pressure in the salt-supplemented systems (R3: acetate and R4: propionate) contributed to biomass growth. However, the salt-supplemented systems collapsed between days 110 and 130 of operation. R3 and R4 showed better performance regarding nutrients removal due to the greater abundance of nitrifying and denitrifying bacteria and phosphate-accumulating organisms. Salt also contributed to the higher production of biopolymers such as alginate-like exopolymers (ALE) per gram of volatile suspended solids (VSS) (R1: 397 mgALE∙gVSS−1, R2: 140 mgALE∙gVSS−1, R3: 483 mgALE∙gVSS−1, R4: 311 mgALE∙gVSS−1). Amino acids like tyrosine and tryptophan were better identified in extracellular polymeric substances extract from salt-operated reactors. This study brings important results in the context of resource recovery by treating saline effluents.

Ammonium recovery from municipal wastewater by ion exchange: Development and application of a procedure for sorbent selection

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.

Evaluating the effects of chloride on the performance of microbial fuel cells for wastewater treatment

Up to 5% of wastewater generated worldwide is highly saline effluent. Microbial fuel cells (MFCs) have been considered as a promising saline wastewater treatment, which uses microorganisms to convert organic compounds into electrical energy. This study investigated lab-scale MFCs to evaluate the effect of chloride at different concentrations (0, 5, 10 and 20 g/l NaCl) on the performance of the MFC by examining its electrical generation and wastewater treatment efficiency. Increasing NaCl concentration led to a decrease in power generation with maximum power at 30, 18.7, 18.8, and 5.2 mW/m2 corresponding to 0, 5, 10, and 20 g/l of NaCl, respectively. The COD removal efficiency of the four treatments did not significantly vary (p&gt;0.05) and reached 65.9% to 78.7%. Acidovorax spp. was isolated from the treatment without NaCl while Pseudomonas citronellolis was isolated from the treatments containing 10 and 20 g/l NaCl. Pseudomonas citronellolis can be used as a potential inoculum for MFCs treating highly saline wastewater based on its high electrical generation ability (606.8 mW/m2) based on inoculation of this pure strain into the mini MFC.