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This study experimentally investigates the integration of a flat plate solar collector and a condensation chamber into a basin solar still. Three prototypes were designed and constructed for evaluation: a basin solar still coupled to both a solar collector and a condensation chamber, a basin coupled with a solar collector, and a simple basin solar still as a reference. The experiments, conducted from July 24 to 28, 2016, at the UDES site in Bouismail, Algeria, used seawater from the Fouka region. Solar radiation emerged as the primary influencer on the solar desalination system, with active solar stills, particularly those equipped with a flat plate collector, showing significant temperature increases. Daily cumulative production analysis revealed the condensation chamber as a significant contributor, representing 58% of total production. Incorporating a flat plate collector resulted in a 110% increase in daily production compared to the conventional solar still. Simultaneously incorporating both the flat plate collector and the condensation chamber showcased an impressive 176% increase in daily production. Daily production quantified at 5.9 kg/m2 for the active with a condensation chamber, 4.5 kg/m2 for the active solar still, and 2.1 kg/m2 for the simple solar still. Economic analysis indicated that the active solar still with the condensation chamber enables more cost‐effective freshwater production than the active solar still alone. Water analyses demonstrated the efficiency of solar distillation, converting high‐salinity saltwater (31.4%) into exceptionally pure distillate (0.00%). [ABSTRACT FROM AUTHOR]

In this study, porous activated carbon was produced from coffee waste and used as an effective adsorbent for the removal of humic acid (HA) from seawater and methyl orange (MO) dye from aqueous solutions. Phosphoric acid H3PO4 was used as an activating agent for the chemical activation of these agricultural wastes. The characterization of the activated carbon obtained using a scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscopy analysis, X-ray diffraction (XRD) and the Brunauer–Emmett–Teller (BET) method revealed that the activated carbon products exhibited high porosity and the formation of various functional groups. The effects of different parameters were examined using batch adsorption experiments, such as the adsorbent masses, pH, initial pollutant concentration and contact time. The results show that the performance increased with an increased adsorbent mass (up to 0.25 g/L) and decreased initial concentration of the adsorbent tested. On the other hand, this study clearly showed that the adsorption efficiency of the MO on the raw spent coffee grounds (SCGs) waste was around 43%, while no removal was observed for the humic acid. The experiments demonstrated that the activated carbon synthesized from the used coffee grounds (the efficiency was compared with commercial activated carbon (CAC) with a difference of 13%) was a promising alternative to commercially available adsorbents for the removal of humic acid from seawater. To understand and elucidate the adsorption mechanism, various isothermal and kinetic models were studied. The adsorption capacity was analyzed by fitting experimental data to these models. The experimental data for methyl orange dyes were analyzed using Langmuir and Freundlich isothermal models. The Freundlich isotherm model provided a superior fit to the equilibrium data, as indicated by a higher correlation coefficient (R2) than that of the Langmuir model. The maximum adsorption was observed at pH 3. The Freundlich adsorption capacity was found to be 333 mg/g adsorbent. The PAC showed a high adsorption capacity for the MO and HA. The PAC showed the highest adsorption capacities for the HA and MO compared with the other adsorbents used (SCGs and CAC) and would be a good material to increase the adsorption efficiency for humic acid removal in the seawater pretreatment process. In addition, the prepared AC BET surface area was 520.40 m2/g, suggesting a high adsorption capacity. This makes the material potentially suitable for various applications that require a high surface area. These results indicate that high-quality sustainable activated carbon can be efficiently produced from coffee waste, making it suitable for a wide range of adsorbent applications targeting various pollutants. [ABSTRACT FROM AUTHOR]

The main objective of this work has been to carry out the synthesis of composite membranes from carboxymethyl cellulose (CMC)/polysulfone (PSf) by the crosslinking of glutaraldehyde (GA) or lactic acid (LA), using the nonsolvent induced phase separation (NIPS) method. The effects of different parameters, such as the type and degree of crosslinking, the immersion method, and the coating procedure, including the thermal treatment have been studied. The prepared membranes were analyzed in terms of water absorption and flux, as well as their efficiency in retaining salt ions from synthetic waters rich in mono/divalent salts and real seawater samples. The optimized membrane containing 2% by weight of CMC and 2% of lactic acid as crosslinking agent, coagulated by immersion for 10 min, represented a rejection efficiency of 97.3%, 88.3% and 34% for the solutions of MgSO4, CaCO4 and NaCl, respectively. The optimal membrane recorded a pure water flux of 127.37 L/m²h, under a low transmembrane pressure of 10 bars, and permeability of 26 L/m² h bars. The membrane flux recovery rate was greater than 94%, indicating satisfactory resistance to fouling. [ABSTRACT FROM AUTHOR]

The purpose of this study is to optimize the operating conditions in batch mode using Box‐Behnken Design (BBD), for the coagulation‐flocculation line sizing prior the sand filter in the pilot scale. Three coagulants were employed to achieve a high turbidity removal with a low concentration of residual metals. The results showed that the best turbidity removal was obtained with FeCl3. Using BBD (15 experiments), the optimal parameters were: coagulant dose = 5.5 mg FeCl3/L, slow stirring time = 33 min and slow stirring velocity = 45 rpm, in these conditions, the turbidity removal reached 94.89% and the residual iron concentration was 0.449 mg/L. Regarding the model fit, the obtained R2 values were 99.67% for turbidity removal and 99.47% for residual iron concentration. The optimum conditions obtained from this study could be scaled up and applied to desalination plants. BBD approach is of great interest because it allows the prediction of the response value without performing experiments. [ABSTRACT FROM AUTHOR]