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The interaction of calix(4)arene derivative and its monomeric componebt, p-tert-butylphenoxy-4-pyridine, with metal cations is investigated in acetonitrile and methanol. A demonstration is provided which suggests that the thermodynamic data for the complexation of the monomeric component of the ligand and metal cations contribute significantly to the interpretation of systems involving cation-calixarene interactions in solutions.

This research is intended to study the possible transfer of the residual chemical contamination from treated wastewaters reused for irrigation purposes of Fragaria x ananassa strawberry (cv. Camarosa). Different sewages from urban, and mixed urban-textile origins treated according to different treatment trainswere used for the irrigation of strawberry in pots. Organic and inorganic chemical contamination indicators, i.e.: PCBs, including dioxin-like congeners, PAHs, and Cr(VI), were monitored along the whole agricultural production chain (wastewater treatment effluents, soil and crop). Robust analytical procedures were specifically developed for the determination of contaminants in the above-mentioned matrices with quantitation limits (MQLs) ranging from 1.3 (Phe) to 11.0 ng/L (PCB169) for wastewaters; from 3 (PCB180) to 10 μg/kg (BbFl) for soils; from 1.0 (Phe) to 10.9 μg/Kg (PCB169) for strawberries. For Cr(VI), limits were 0.15 μg/L (waters) and 0.018mg/kg (soils). These performances fully satisfy limits fixed by Italian or European regulations on maximum admitted concentration of pollutants in treated water intended for irrigation, in soils and crops. Even if selected PAHs and PCBs were detected in wastewaters (highest concentrations observed for phenanthrene, 429 μg/L, and PCB52, 110 μg/L) their presence was not observed in soils and in strawberries above the MQLs. On the contrary, chromium content in strawberries and soils irrigated with TWs suggested a possible transfer of the metal during irrigation, which however does not represent a hazardous situation for consumers since calculated daily intake does not exceed the Tolerable Daily Intake of 300 μg/kg b.w. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of salinity on the biomass behavior and its diversity in activated sludge process (ASP) treating the table olive processing wastewater (TOPW), and to evaluate ASP performances under increased TOPW concentration feeding, the numerical abundance, diversity and activity of the biomass, removal efficiencies of chemical oxygen demand (COD), phenolic compounds, nitrogen and phosphorus were evaluated. Results showed that biomass growth is very high and became faster according to an increase in the percentage of TOPW feeding and reached 5.2 gMLVSS l−1. The specific oxygen uptake rate (SOUR) analysis revealed that salinity up to 10 g l−1 provides an increase in biomass activity. SOUR reached a maximum of 20.3 gO2 gMLVSS−1 h−1. The increasing percentages of TOPW induce actually an evolution of microorganism's biodiversity; the microorganism communities were characterized by the abundance of halotolerant, Pseudomonas and Yeast genus that became the most abundant in the bioreactor as adaptation response against salinity. Furthermore, COD, phenolic compounds, nitrogen and phosphorus removal efficiencies attained 92.3%, 84.5%, 80% and 60%, respectively. A satisfactory release of extracellular polymeric substances is found to occur in the reactor with regard to increased saline TOPW, providing significant removal efficiencies and best settling of sludge. [ABSTRACT FROM AUTHOR]

This paper presents a site-specific study of solar drying of wastewater sludge in the region of Marrakesh in Morocco. During the course of the experiments, drying pans (DP) and solar greenhouse drying processes were studied in summer and winter seasons. To simulate the DP process, representative samples were dried in plastic cylindrical plates in ambient conditions, near an Open Greenhouse Sludge Dryer (OGSD) designed and constructed as a tunnel plant. Results showed that the dry solids' (DS) concentration of 80% was reached in only 32 h in summer and 57 h in winter by DP process. The OGSD reached the same concentration in 45 and 65 h in summer and winter, respectively. The important influence of wind speed had a greater effect than the temperature on drying rate. The sludge water evaporation caused a large volume reduction during DP and OGSD processes in both seasons. The removal of total and fecal coliforms during summer experiment was noticeably better in the OGSD, even for Clostridium perfringens. Based on the obtained results, the solar greenhouse drying was practical and beneficial to wastewater sludge management and can be recommended as an alternative to DP in arid climate zones generally, and in Marrakesh particularly. [ABSTRACT FROM AUTHOR]

The current work aims to study the biomass behaviour in a continuous mode activated sludge system (ASS) treating olive mill wastewater (OMWW) through an increasing OMWW food to microorganism ration (F/M). To this end, the biomass growth, the specific oxygen uptake rate (SOUR), microbial characterization, sludge volume index (SVI) as well as COD and phenolic compounds removal efficiencies were examined over time. Results showed a successful growth of the biomass that reached 6.79 gTSSl−1and 5.42 gVSSl−1. Its viability, its adaptability, and its good physiological activity were confirmed by the obtained result of SOUR with an average of 9.95 mgO2gVSS−1h−1, as well as aerobic microbial population characterization in terms of aerobic revivable bacteria at 22°C and 37°C, Pseudomonas sp., mould and yeast and total fungi. The concentration of these strains characterized by their ability to degrade effectively COD and phenolic compounds increased significantly (p< .05) over time. This demonstrated a great promptness in response to the increasing OMWW mass ratio. For all treatment steps, removal efficiencies were high and reached 95% of COD and 93% of phenolic compounds, also the flocs settleability shown by SVI measurement was optimal. [ABSTRACT FROM AUTHOR]

The present paper aims to perform a screening of native plants growing in Kettara mine-Marrakech (Southern Morocco) for its phytoremediation. Plants and soil samples were collected and analyzed for Pb, Zn, Cu and Cd concentrations at several sites in the mine. The results showed that the soil in the vicinity of Kettara mine is deficient in major elements and contain toxic levels of metals. Spontaneously growing native plants were botanically identified and then classified into 21 species and 14 families. Significant difference was observed among the average concentrations of four heavy metals (Pb, Zn, Cu and Cd) in plants (p ≤ 0.05). Six plants of 21 species namelyHammada scoparia (Pomel) Iljin, Hirschfeldia incana (L.) Lagreze-Fossat, Lamarckia aurea (L.) Moench, Calendula algeriensis Boiss. & Reuter, Aizoon hispanicum L. and Melilotus sulcata Desf.were considered as the best-performing specimens due to their high ability to accumulate multiple metals in their shoots and roots without sustaining toxicity. This was confirmed by the transfer factors generally higher than 1. Using the most common criteria to classify the hyperaccumulator plants, these species can be classified as new accumulator plants of many heavy metals and be potentially used as remediation tools of metal-contaminated sites. [ABSTRACT FROM PUBLISHER]

Composite nanofibers containing polyacrylonitrile and natural clay particles were fabricated and investigated for the removal of Pb(II), Cu(II) and Zn(II) from aqueous solutions. The adsorption behavior of Pb(II), Cu(II) and Zn(II) can be well described by the Langmuir adsorption model and high loading capacities at pH 7 were obtained. The kinetics of the adsorption process showed that equilibrium was attained after 60 min and the experimental data followed a pseudo-first-order model. The nanocomposites were also tested for photocatalytic degradation of Monocrotophos pesticides in which high degradation efficiency (>90%) was obtained in less than 60 min. [ABSTRACT FROM AUTHOR]

In Morocco, few studies focus on hospital wastewaters. This study is among the first studies on this subject because of its paramount interest to show the necessity of treating these effluents before discharging. This study focuses on the characterization of wastewaters from the University Hospital Centre (Mohammed VI) in Marrakech. This hospital has medical and surgical missions with a capacity of 409 beds. Its water consumption is estimated to 425 m3/d at the rate of 1.04 m3/d/bed with a rate of 1.63–12.67 m3/h. To assess the pollution degree of effluents generated by the hospital, we started with a survey of the different products used in every department of the hospital followed by sampling of different types of wastewaters and their fate in this hospital. Then we conducted a physicochemical and biological characterization of the samples. The investigation revealed that the various hospital departments used several chemicals including detergents, disinfectants used frequently in hospitals. These products are mainly recommended in the cleaning and maintenance of premises and represent 70% of the whole used chemicals. Around 30% of the products are pre-disinfectants and sanitizers such as glutaraldehyde (at concentration 2%). The annual consumption of medicines and drugs within the studied hospital are anesthetics and β-blockers that represent 37% of the total consumed drugs in the studied hospital. Antibiotics, gastro-entero-hepatology, and anti-inflammatory drugs represent 14, 9, and 7%, respectively. Other drugs used for different therapeutic classes represent 33%. From the total reported cases of hospital infections, 29% are died. This shows the risk of potential pathogens load in the hospital effluents. The physicochemical characterization of the effluents of each service revealed that they are heavily loaded with organic matter: 2,641 mg/L of COD, 910 mg/L BOD5, and 1,490 mg/L TSS. These levels exceed far the levels recommended by the Moroccan discharge standards. Total phosphorus; orthophosphates and Kjeldahl Total Nitrogen are, respectively, in the range of 8.02 mgP/L, 3.55 mgP/L, and 197.14 mgN/L. The heavy metals content are low except for copper (2.84 mg/L) and iron (3.38 mg/L), which are very high. Bacteriological characterization shows that fecal coliforms reached 108 CFU/100 mL. These effluents also contain pathogens responsible for nosocomial infections. Among these pathogens,Pseudomonas aeruginosaandStaphylococcus aureusare detected with suspectedSalmonellaandVibrio. The COD/BOD5ratio is around 2.9, value indicating that the hospital effluents are biodegradables by selected strains. Furthermore, it is essential to apply an adequate treatment to this hospital wastewaters because of their bacterial load pathogenicity that may have an adverse impact on the health of the population and the risk of epidemic diseases spread. [ABSTRACT FROM PUBLISHER]

In order to overcome the toxic effect of olive mill wastewater (OMWW) on biomass during biological treatment, this work will test OMWW biodegradation in a membrane bioreactor (MBR) using an acclimation procedure and will study its constraints. Special focus will be put on soluble microbial products (SMP) analysis in MBR and their impact on membrane fouling. The study was realized in an external ceramic ultrafiltration MBR which offers more flexibility than the other biological treatments (i.e. independence between both hydraulic and sludge retention time) and a smaller footprint. Fed with a mass ratio of 40% OMWW/60% glucose, MBR biomass showed efficient chemical oxygen demand and polyphenols removal rates of, respectively, 90 and 65% despite a low activity of 3.2 mgO2 gMLVSS−1 h−1due to the harsh and toxic environment. Moreover, HPLC analysis has showed a removal from the permeate of the major phenolic compounds including hydroxytyrosol, tyrosol, and caffeic acid. The monitoring of SMP concentrations has contributed to identify the presence of an environmental stress during OMWW input. Polysaccharide and protein are the main SMP fractions released with, respectively, 10 ± 0.1–20 ± 0.5 mg gMLVSS−1and 4 ± 0.01–8 ± 0.01 mg gMLVSS−1. These SMP and higher molecular weight compounds brought by OMWW were found to be partially responsible for the intensive membrane fouling obtained. The feasibility of biomass acclimation directly to OMWW composed of multi-phenolic compounds was proved in MBR and its constraints were discussed. Microfiltration membrane would be suggested to overcome the constraints observed when ultrafiltration membrane was used (150 kDa). [ABSTRACT FROM PUBLISHER]

This paper presents the performance and behavior of a multi-soil-layering (MSL) system to remove fecal contamination bacteria indicators and pathogens from domestic wastewater. The experimental setup was performed using a laboratory-scale MSL system (depth 30 × width 36 × height 65 cm). The MSL system was composed of soil mixture blocks (SMB) arranged in a brick-like pattern and surrounded by permeable gravel layers (PL). The SMB comprised sandy soil, charcoal, sawdust and metal iron at a dry weight ratio of 7:1:1:1. The hydraulic loading rate was 200 L m−2day−1. Bacteriological analyses comprised total bacterial count at 22 and 37°C, fecal coliforms, total coliforms,Escherichia coli, streptococci, intestinal enterococci and pathogenic bacteria:Clostridiumsp.,Staphylococcussp.,Pseudomonassp. andSalmonellasp. The best removal efficiency was achieved forStaphylococcussp. by 1.42 log unit, while the lowest removal efficiency was found forE. coliby 1.01 log unit. The mean removal efficiencies of total suspended solids (SS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorous (TP) were 93, 86, 81, 78 and 80%, respectively. Based on these results, the MSL system could efficiently remove organic matter, phosphorus and nitrogen. However, the performance to reduce bacterial indicators and pathogens was still moderate. [ABSTRACT FROM PUBLISHER]

• Use of a new tool to assess waste management systems through a stage concept. • Holistic approach can evaluate 54 waste related system sub-components. • Identification of Circular Economy potentials for the city of Marrakech (Morocco). • Applicability proofed for waste management systems of the Global South. • Derivation of 33 recommendations for action to make Marrakech more circular. Waste management is essential for the safety and wellbeing of any society; it also helps to tackle global problems, such as climate change and resource scarcity. To support the evolution of waste management systems (WMSs) towards a circular economy (CE), assessment methods are applied. This paper shows, using the case of Marrakech (Morocco), how a novel holistic approach called WMS development stage concept (WMS-DSC) is applied to assess WMSs and determine measures promoting a CE. The approach enables a simplified derivation of measures that are useful to municipal decision makers and consists of five stages; stage 1 is equal to a WMS lacking essential WM elements and stage 5 describes a functioning CE. The approach was specifically designed to be transferable to other Global South cities through the categorization into these universal stages. The results from the WMS-DSC show that components related to energy recovery and waste recycling are classified in stage 1. For the latter, a slight development towards stage 2 can be assumed due to the planned activities in Marrakech. The components "collection and transport" and "prevention and reuse" are mainly in stage 2. Nevertheless, the components "governance", "sector and market" and "waste disposal" are assigned to stages 2 and 3 with a stronger trend towards stage 4. The results show that in Marrakech and Morocco, CE is still in its infancy, and with this current state, it is hard to achieve. However, 33 measures were determined to improve the WMS of Marrakech and promote a CE. [ABSTRACT FROM AUTHOR]

The studied Fertilizer industry effluent contains high concentration of phosphorus in the range of 228-1025 mg L-1, It is discharged in the surrounding sea without any preliminary treatment. Therefore, it constitutes a source of pollution to the coastal environment. This effluent contains also an important fluoride concentration. This quantity of phosphorus could be used to produce phosphorus fertilizer. So, the objective of this study was (i) to minimize fluoride concentration in fertilizer industry effluent and (ii) to recover phosphates from this effluent into the form of struvite (magnesium ammonium phosphate). To force the formation of struvite, NH4+ ion was added by using ammonium chloride (NH4Cl). A preliminary study showed that fluorides were transferred into solid phase at pH 4. At this value of pH, the degree of fluoride recovery amounted to 95.62%. In the second stage, experiments were conducted to examine the effects of pH and N/P molar ratio on the removals of NH4+ and PO43- by forming struvite. The results show that the optimum pH value for struvite precipitation is in the range of pH 9-10, and the best phosphate and ammonium removal efficiency was observed to be 98 and 70.7%, respectively. Furthermore, it has been noted in the previous studies that phosphate and ammonium removal was affected by the amount of added ammonium and it was stated that 99.21% of total phosphate was removed when N/P molar ratio was 2 at pH 9. [ABSTRACT FROM AUTHOR]

The mining and metallurgical mines that were abandoned with their residues constitute a source of metal pollution affecting the quality of water resources and soil. It is the case of an abandoned mining site Assif El Mal drained by the Assif El Mal River. In fact, these waters are a source of consumption without any treatment by the local population either directly or through their storage in reservoirs. A spatial variation of physicochemical parameters is determined to follow and monitor the behavior of some metals (Pb, Zn, Cu, and Al), from the abandoned mining district, in water and sediment samples along the river till the reservoirs. Also, an assessment of metal contamination level and toxicity of water is studied using the sequential extraction procedure (BCR). The results showed that the metallic load in water exceeds standards for human consumption, especially in the vicinity of the mine and the storage tanks. These levels range from 0.3-17, 0.02-0.05, 0.3-2.8, 0.03-0.1, 2.6-5.1mg L1, respectively, for Al, Ni, Fe, Pb, and Zn. The potential toxicity of heavy metals in sediment is due to their mobile fraction exchangeable/acid soluble often high (averaging 41 Pb, 52 Zn, and 68% Fe). [ABSTRACT FROM AUTHOR]

A novel reduced graphene oxide (RGO) synthesis using Verbena officinalis as a green, reducing agent was out-reaching. RGO was encapsulated in sodium alginate (SA) by cross-linking (SA-RGO beads). SA-RGO beads have been used to treat olive mill wastewater (OMWW). This effluent is rich in phenolic compounds that inhibit biological degradation and are toxic at high concentrations. The newly prepared SA-RGO beads were characterized by scanning electron microscopy (SEM),energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), BET surface area analyzer, and Fourier transforms infrared spectroscopy (FTIR). In addition, the organic compounds of Verbena officinalis were determined by HPLC to reveal the reduction mechanism of graphene oxide (GO). Finally, batch and fixed-bed column adsorption tests were performed to assess the performance of SA-RGO beads. The kinetics, isotherm models and adsorption thermodynamics show that the pseudo-second-order and Freundlich best present phenol adsorption and the endothermic reaction. Thomas and Yoon-Nelson's models satisfactorily described fixed-bed column adsorption. The optimized adsorption parameters were 3.68 g L−1 of adsorbent dosage, pH of 4.0, adsorption time of 135 min, and temperature of 25 °C. The reusability of SA-RGO beads and regeneration experiments with HCl (0.5 M) were performed in fixed-bed reactors. The results showed a phenol adsorption capacity of 994 mg g−1 for an initial concentration of 4000 mg L−1. [Display omitted] [ABSTRACT FROM AUTHOR]

Eutrophication has led to the widespread occurrence of cyanobacterial blooms. Toxic cyanobacterial blooms with high concentrations of microcystins (MCs) have been identified in the Lalla Takerkoust reservoir in Morocco. The objective of this study was to evaluate the efficiency of the Multi-Soil-Layering (MSL) ecotechnology in removing natural cyanobacterial blooms from the lake. Two MSL pilots were used in rectangular glass tanks (60 × 10 × 70 cm). They consisted of permeable layers (PLs) made of pozzolan and a soil mixture layer (SML) containing local soil, ferrous metal, charcoal and sawdust. The main difference between the two systems was the type of local soil used: sandy soil for MSL1 and clayey soil for MSL2. Both MSL pilots effectively reduced cyanobacterial cell concentrations in the treated water to very low levels (0.09 and 0.001 cells/mL). MSL1 showed a gradual improvement in MC removal from 52 % to 99 %, while MSL2 started higher at 90 % but dropped to 54% before reaching 86%. Both MSL systems significantly reduced organic matter levels (97.2 % for MSL1 and 95.8 % for MSL2). Both MSLs were shown to be effective in removing cyanobacteria, MCs, and organic matter with comparable performance. [Display omitted] • Cyanobacterial cell removal by Multi-Soil-Layering (MSL) ranged from 99 % to 100 % • Greater degradation capacity of MC-LR in MSL1 (sandy soil) and MSL2 (clay soil) • MC-YR variant was most persistent in substrate of both MSL systems • qPCR detected degrading bacteria in both MSL systems • MSL1 had significant abundance of mlrA gene copies and degrading bacteria [ABSTRACT FROM AUTHOR]

• Microcystin-degrading bacteria as a solution for removal of microcystins. • Mechanisms of action employed by microcystin-degrading bacteria. • Role of microcystin production in the survival of Microcystis cells. • Multi-soil-layering systems and microcystin-degrading bacteria in water treatment. • Interaction of microcystin-degrading bacteria with sediment particles. Microcystins (MCs) constitute a significant threat to human and environmental health, urging the development of effective removal methods for these toxins. In this review, we explore the potential of MC-degrading bacteria as a solution for the removal of MCs from water. The review insights into the mechanisms of action employed by these bacteria, elucidating their ability to degrade and thus remove MCs. After, the review points out the influence of the structural conformation of MCs on their removal, particularly their stability at different water depths within different water bodies. Then, we review the crucial role played by the production of MCs in ensuring the survival and safeguarding of the enzymatic activities of Microcystis cells. This justifies the need for developing effective and sustainable methods for removing MCs from aquatic ecosystems, given their critical ecological function and potential toxicity to humans and animals. Thereafter, challenges and limitations associated with using MC-degrading bacteria in water treatment are discussed, emphasizing the need for further research to optimize the selection of bacterial strains used for MCs biodegradation. The interaction of MCs-degrading bacteria with sediment particles is also crucial for their toxin removal potential and its efficiency. By presenting critical information, this review is a valuable resource for researchers, policymakers, and stakeholders involved in developing sustainable and practical approaches to remove MCs. Our review highlights the potential of various applications of MC-degrading bacteria, including multi-soil-layering (MSL) technologies. It emphasizes the need for ongoing research to optimize the utilization of MC-degrading bacteria in water treatment, ultimately ensuring the safety and quality of water sources. Moreover, this review highlights the value of bibliometric analyses in revealing research gaps and trends, providing detailed insights for further investigations. Specifically, we discuss the importance of employing advanced genomics, especially combining various OMICS approaches to identify and optimize the potential of MCs-degrading bacteria. [Display omitted] [ABSTRACT FROM AUTHOR]

• MCs in isolate are approximately 7 times lower than natural blooms from which it was isolated. • Investigating cyanobacterial dynamics and microcystin transfer from reservoirs to farms. • Identification of key cyanobacteria species: Microcystis (toxin producer) and Synechoccus (non-toxic). • Conducting a comprehensive investigation employing Landsat imagery, molecular analysis, and HPLC/LM/MS toxin assessment. • Gaining insights from NDVI analysis: revealing 30-year cyanobacterial proliferation patterns, depth variations, and distance-driven toxin dynamics. Cyanobacterial harmful algal blooms (CyanoHABs) threaten public health and freshwater ecosystems worldwide. In this study, our main goal was to explore the dynamics of cyanobacterial blooms and how microcystins (MCs) move from the Lalla Takerkoust reservoir to the nearby farms. We used Landsat imagery, molecular analysis, collecting and analyzing physicochemical data, and assessing toxins using HPLC. Our investigation identified two cyanobacterial species responsible for the blooms: Microcystis sp. and Synechococcus sp. Our Microcystis strain produced three MC variants (MC-RR, MC-YR, and MC-LR), with MC-RR exhibiting the highest concentrations in dissolved and intracellular toxins. In contrast, our Synechococcus strain did not produce any detectable toxins. To validate our Normalized Difference Vegetation Index (NDVI) results, we utilized limnological data, including algal cell counts, and quantified MCs in freeze-dried Microcystis bloom samples collected from the reservoir. Our study revealed patterns and trends in cyanobacterial proliferation in the reservoir over 30 years and presented a historical map of the area of cyanobacterial infestation using the NDVI method. The study found that MC-LR accumulates near the water surface due to the buoyancy of Microcystis. The maximum concentration of MC-LR in the reservoir water was 160 µg L−1. In contrast, 4 km downstream of the reservoir, the concentration decreased by a factor of 5.39 to 29.63 µgL−1, indicating a decrease in MC-LR concentration with increasing distance from the bloom source. Similarly, the MC-YR concentration decreased by a factor of 2.98 for the same distance. Interestingly, the MC distribution varied with depth, with MC-LR dominating at the water surface and MC-YR at the reservoir outlet at a water depth of 10 m. Our findings highlight the impact of nutrient concentrations, environmental factors, and transfer processes on bloom dynamics and MC distribution. We emphasize the need for effective management strategies to minimize toxin transfer and ensure public health and safety. [Display omitted] [ABSTRACT FROM AUTHOR]

Microcystins (MCs) pose a significant threat to human health and the environment due to their persistence and toxicity as potent cyanobacterial toxins. Effective biodegradation strategies are required for their removal and detoxification. In this study, bacterioplankton were isolated from eutrophic reservoir water used for crop irrigation and tested for their ability to degrade MCs. These bacteria are hydrologically transported from the contaminated reservoir to downstream farms where they are able to grow under the favorable conditions provided by a multi-soil-layering (MSL) system, a low-cost and locally applicable ecotechnology for the removal and detoxification of MCs. These bacteria enhance the ability of the MSL to remove MCs by forming biofilms within the MSL system. The bacterial strains were then sequenced and their partial 16S rRNA was compared to the reference strains in the NCBI database. The effectiveness of the MSL system in the removal of MCs from water was evaluated. The MSL utilizes a layered soil matrix that promotes microbial growth and physicochemical interactions that enable the removal of various contaminants. The mechanisms of MC removal in the MSL were evaluated by studying the physicochemical properties of the system substrate before and after treatment using X-ray fluorescence, zeta potential, and scanning electron microscopy (SEM) analyses. The microbial functional groups, including ammonifying and denitrifying bacteria, were also investigated in the MSL soil matrices before and after treatment. The results showed that seven bacterial strains exhibited high MC degradation capabilities, with MC degradation performance exceeding 97%. These isolated bacterial strains had a nucleotide identity score of 100% and an E value of 0.0 compared to reference strains. The MSL showed a 99% removal rate for MC-LR and MC-YR, as well as significant reductions in other pollutants, including COD (60%), BOD5 (60%), chlorophyll-a (96%), pheophytin (70%), organic nitrogen (80%), and nitrites (90%). After treatment, there was a statistically significant increase in the total bacterial count, as well as ammonifying and denitrifying bacteria, in the MSL soil matrices compared to their state before treatment. SEM analyses revealed the formation of dense biofilm microbiota, indicating additional biological processes besides adsorption for MC reduction. Overall, the MSL provides a low-cost alternative for the removal of MCs and cyanobacteria with minimal resource requirements and maintenance. It offers a promising solution for mitigating toxic cyanobacterial blooms, ensuring safe agricultural water reuse. [Display omitted] • Effective biodegradation strategies for cyanotoxin removal have been investigated. • Bacterioplankton efficiently removes microcystins in the MSL system (>97%). • MSL soil composition, HRT, and surface charge significantly influence MCs removal. • Biofilm matrix is a major physical barrier that entraps MCs in the MSL through EPS. • MSL is a promising environmentally friendly solution for mitigating cyanoHABs [ABSTRACT FROM AUTHOR]

The depletion of water resources has gained global attention, particularly in arid climates, where there is growing interest in reusing treated wastewater for irrigation. This study focuses on the impact of irrigating treated wastewater using a hybrid multi-soil-layering (MSL) technology on soil physicochemical properties and the agro-physiological characteristics of maize (Zea mays) cultivated in Morocco, a region characterized by arid conditions. To achieve this research goals, three plots were cultivated with Zea mays and subjected to irrigation with water of varying qualities: raw wastewater (RWW), treated wastewater (TWW), and well water (WW). This experiment ran for five months, covering one crop season. The physicochemical and microbiological parameters in the soil and water were investigated, and the agro-physiological characteristics of the maize crops were assessed. The findings revealed significant differences in physicochemical and microbial parameters within both water and soil, as well as in the physiological responses of the maize crop, among the three water treatments. TWW's quality met the permissible limits for direct wastewater discharge, as prescribed by Moroccan norms, making it suitable for potential irrigation reuse. Moreover, the higher content of key elements (Na, K, Ca, and Mg) in WW indicated that TWW was more suitable for irrigation. Zea mays irrigated with RWW and TWW exhibited a higher accumulation of protein and sugar content compared to WW irrigation. Furthermore, the biomass parameters, including root, aerial, and grain dry weight, showed a positive effect on Zea mays irrigated with RWW and TWW compared to WW. Total chlorophyll content, on the other hand, was highest in plants irrigated with WW, followed by TWW. Plants irrigated with RWW produced the highest amounts of nitrogen, phosphorus, and potassium. Conversely, plants irrigated with WW had a higher content of Ca, Na, and Mg. TWW yielded medium concentrations of N, P, K, Ca, Mg, and Na compared to RWW and WW, attributed to the nutrients provided by irrigation with TWW using the hybrid MSL technology. In conclusion, aside from their use as irrigation water, treated wastewater emerges as a valuable source of plant nutrients and soil fertilizers. They offer significant nutritive value, enhancing plant growth, reducing the need for additional fertilizer application, lowering mineral fertilization costs, and increasing the productivity of infertile soils. This highlights the potential of treated wastewater to improve agricultural sustainability in arid regions like Morocco. [Display omitted] • Effects of RWW, TWW, and WW water irrigation on soil and Zea mays were investigated. • TWW by MSL improves maize's biochemistry, agrophysiology, and productivity. • WW irrigation improves the prevalence of total chlorophyll content in maize. • TWW and WW irrigation had a positive impact on the crop biochemical parameters. • TWW has a beneficial effect on soil fertility and physicochemical characteristics. [ABSTRACT FROM AUTHOR]

Agricultural applications of olive mill wastewater (OMW) represent a critical challenge, consistent with waste recycling and the trend towards a more sustainable pattern of agriculture. In this context, an integrated study on the agroecological applications of OMW from the ultrafiltration (UF) - nanofiltration (NF) process was carried out. This process generated three fractions: UF retentate and NF permeate, depleted in salts and phenolic compounds, were studied for their fertilization and irrigation potential, while NF retentate, enriched in these elements, was studied for its potential as a bioherbicide. The phytotoxicity of the NF retentate fraction on two crops (maize and flax) was evaluated on seedlings growth and chloroplast pigments content. In addition, the induced defense responses in maize and flax seedlings were investigated by measuring two parameters: the activity of the detoxification enzyme glutathione-S-transferase (GST) and the concentration of polyphenols, as a component of the antioxidant defense strategy in plants. Biomass, height, and chloroplast pigments content decreased progressively with increasing NF retentate concentration. Conversely, an increase in GST activity and polyphenol concentration was observed. These results highlighted the ability of OMW to induce an oxidative stress on maize and flax seedlings, triggering a defense response through GST and phenolic compounds. On the other hand, in vitro tests on the phytotoxicity of the NF retentate fraction on the common weed Sinapis arvensis were carried out. No germination was observed even with the lowest dilution applied, thus establishing the first data about the selectivity of potential OMW-derived bioherbicides. On the other hand, UF retentate and NF permeate treatments led to a significant increase in maize growth: these fractions could then be considered as a promising organic fertilizer for degraded agricultural soils, as well as an alternative water source for crops irrigation. [Display omitted] • Ultrafiltration -Nanofiltration of OMW provided valuable fractions. • The agricultural application of OMW fractions is an emerging weed control tool. • NF retentate is a novel selective bio-herbicide alternative to the phytosanitary product. • OMW fractions are an encouraging organic fertilizer/irrigation source for degraded agricultural soils. [ABSTRACT FROM AUTHOR]

Olive mill wastewater (OMWW) is an environmentally critical effluent, specifically due to its high content of phenolic compounds (PCs), which are hazardous due to their antimicrobial activities in water. However, their properties have good health effects at suitable doses. For the first time, the electrosorption of PCs from actual OMWW has been proposed for their possible recovery as value-added compounds, while decontaminating OMWW. A bio-sourced alginate-activated carbon (AC) fixed-bed electrode was prepared based on the reuse of olive pomace solid waste as powdered AC. At the optimal AC content (1% w/v), the internal ohmic drop voltage was lower (2.26 V) and the mass transport coefficient was higher (9.7 10−5 m s−1) along with the diffusivity (7.3 10−9 m2 s−1), which led to enhanced electrosorption rates. Afterward, an optimal electrode potential was obtained (−1.1 V vs. Ag/AgCl), while higher voltages led to faradaic reactions. Moreover, the adsorption capacity was lower (123 mg g−1) than that of electrosorption (170 mg g−1) and was even higher (307 mg g−1) with actual effluents. This was probably due to the influence of electromigration, which was confirmed by new models that could predict the electrosorption kinetics well considering mass transport and acid dissociation constants. [Display omitted] • Electrosorption of phenolic compounds with real olive mill effluents for the first time. • New model of phenol electrosorption kinetics including transport in transient regime. • Electro-migration was added to diffusion in electrosorption model of real effluent. • Mass transport was correlated with the activated carbon content in alginate beads. • Electrosorption occurred mainly within the beads and not at the electrode interface. [ABSTRACT FROM AUTHOR]

The annual production of wastewater from the olive table industry poses a serious problem owing to its high organic matter load, which is highly concentrated in phenolic compounds (PCs) and inorganic materials. This research used adsorption to recover PCs from table olive wastewater (TOWW). Activated carbon was employed as a novel adsorbent. The activated carbon was obtained from olive pomace (OP) and activated using a chemical agent (ZnCl 2 ). Fourier transform infrared spectroscopy analysis (FTIR), Brunauer-Emmett-Teller analysis (BET), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were applied to characterize the activated carbon sample. To optimize the biosorption conditions of PCs (adsorbent dose (A), temperature (B), and time (C)), a central composite design (CCD) model was used. An adsorption capacity was 1952.34 mg g -1 for optimal conditions with an activated carbon dose of 0.569 g L -1 , a temperature of 39 °C, and a contact time of 239 min. The pseudo-second-order and Langmuir models as kinetic and isothermal mathematical models were proved to be more appropriate for the interpretation of the adsorption phenomenon of PCs. PC recovery was performed in fixed-bed reactors. The results of the adsorption of PCs from TOWW by activated carbon could be an effective process at a low cost., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This paper evaluates the performance and potential of a full-scale hybrid multi-soil-layering (MSL) system for the treatment of domestic wastewater for landscape irrigation reuse. The system integrates a solar septic tank and sequential vertical flow MSL and horizontal flow MSL components with alternating layers of gravel and soil-based material. It operates at a hydraulic loading rate of 250 L/m 2 /day. Results show significant removal of pollutants and pathogens, including total suspended solids (TSS) (97%), chemical oxygen demand (COD) (88.57%), total phosphorus (TP) (79.93%), and total nitrogen (TN) (88.49%), along with significant reductions in fecal bacteria indicators (4.21 log for fecal coliforms and 3.90 log for fecal streptococci) and the pathogen Staphylococcus sp. (2.43 log). The principal component analysis confirms the effectiveness of the system in reducing the concentrations of NH 4 , COD, TP, PO 4 , fecal coliforms, fecal streptococci, and fecal staphylococci, thus supporting the reliability of the study. This work highlights the promising potential of the hybrid MSL technology for the treatment of domestic wastewater, especially in arid regions such as North Africa and the Middle East, to support efforts to protect the environment and facilitate the reuse of wastewater for landscape irrigation and agriculture., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

The typology and classification of rivers are highly relevant concepts in the field of limnology and freshwater ecology. Water body typology systematically categorizes water bodies based on their natural attributes, while water body classification groups them based on specific criteria or purposes for management, regulatory, or administrative reasons. Both concepts play important roles in understanding and managing water resources effectively. This scientific article focuses on the ZAT River in Morocco as a model for studying low-flow and intermittent rivers. The objective is to develop an accurate model for the typology and classification of small, low-flow rivers into homogeneous classes based on natural and anthropogenic factors. The study also investigates the impact of human activities on altering the uniformity and reference nature of the water body. The typology of water bodies is carried out according to the European methodology specified in The European Commission's Water Framework Directive (WFD) in 2000. The classification of water bodies is conducted by assessing their chemical and biological quality using the weighted index (WI), the Iberian Biological Monitoring Working Group (IBMWP) index, and multivariate statistical methods such as principal component analysis (PCA) for confirming water quality assessment. The results indicate the possibility of dividing the basin into four water bodies. Water bodies show homogeneity in terms of chemical quality when human influence is minimal or during periods of high river flow. However, increased human influence and decreased river flows lead to heterogeneity in chemical quality, indicating an unstable state. This study is the first of its kind in arid and semi-arid intermittent rivers, where such an approach could be suggested to determine their typology and classification., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This present study depicts the successful employment of fixed-bed column for total chromium removal from tannery wastewater in dynamic mode using sodium alginate-powdered marble beads (SA-Marble) as adsorbent. The SA-Marble composite beads prepared were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Brunauer, Emmett and Teller (BET) method. The adsorption process performance of this bio-sorbent was examined in batches and columns for real effluent (tannery wastewater). After 90 min, the total chromium removal efficiency could be kept above 90% in the batch experiment. The adsorption kinetics fit better with the pseudo-second-order model, indicating the chemisorption process and the adsorption capacity of about 67.74 mg g -1 at 293 K (C0 = 7100 mg L -1 ) was obtained. Additionally, dynamic experiments indicate that the total chromium removal efficiency could be maintained above 90% after 120 min at 293 K and 60 min at 318 and 333 K; it's an endothermic but rapid process. The effects of two adsorption variables (Temperature and time) were investigated using central composite design (CCD), which is a subset of response surface methodology (total Cr, COD, sulfate, and total phosphorus percentage removal). This work paves a new avenue for synthesizing SA-Marble composite beads and provides an adsorption efficiency of total chromium removal from tannery wastewater., Competing Interests: Competing interestThe authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (© The Author(s), under exclusive licence to Tehran University of Medical Sciences 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Olive oil mill wastewater (OMWW) poses an undeniable environmental problem due to its high organic loads and phenolic compound (PC) content. This study determined the optimal conditions for preparing a new bio-sorbent from olive pomace (OP) and the adsorptive treatment of OMWW by this bio-sorbent. The activation reaction was performed with hydrogen peroxide. The results of the combination effect optimization of the three preparation variables, the activation temperature (°C) X 1 , the activation time (min) X 2 , and the impregnation ratio X 3 , are presented by the response surface methodology (RSM). The maximum adsorption capacity was obtained at an activation time of 240 min, a temperature of 80 °C, and a ratio equal to 6.2:1. The bio-sorbent was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffractometer (XRD). The adsorption process performance of this bio-sorbent was examined in batch (phenol solution) and fixed-bed columns (real effluent of OMWW). An adsorption capacity of 789.28 mg g -1 and 643.92 mg g -1 has been achieved for 4000 mg L -1 concentration of PCs, respectively, for batch and fixed-bed column essays. The adsorption isotherm and kinetics were consistent with the Langmuir and pseudo-second-order models. Therefore, the Thomas model best fits the fixed-bed column experimental data. The bio-sorbent gave a high desorption percentage of PCs, which was above 60% using HCl (0.1M)., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aims to evaluate and monitor the efficacy of a full-scale two-stage multi-soil-layering (TS-MSL) plant in removing fecal contamination from domestic wastewater. The TS-MSL plant under investigation consisted of two units in series, one with a vertical flow regime (VF-MSL) and the other with a horizontal flow regime (HF-MSL). Furthermore, this study attempts to see whether linear model (LM) and K-nearest neighbor (KNN) model can be used to predict total coliform (TC) removal in the TS-MSL system. For 24 months, the TS-MSL system was monitored, with bimonthly measurements recorded at the inlet and outlet of each compartment. Obtained results show removal of 85% of COD, 67% of TP, 27% of TN, and 3 log units of coliforms with good system stability. Thus, the effluent meets the Moroccan water quality code for reuse in the irrigation of green spaces. In addition, as compared to LM, the KNN model (R 2 = 0.988) may be considered as an effective method for predicting TC removal in the TS-MSL system. Finally, sensitivity analysis has shown that TC and dissolved oxygen level in the influent were the most influential parameters for predicting TC removal in the TS-MSL system., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)