Decolourization of Acid Orange 7 Dye from Aqueous Solution by Adsorption on NaOH Treated Eggshells in Continuous Fixed Bed Reactor Application using Response Surface Methodology: Optimization by Box–Behnken Design.

NaOH Treated Eggshells   (TES) was investigated for the removal of Acide Orange 7 (AO7) from aqueous solution using the continuous method was modeled by response surface methodology (RSM) and was optimized using Box–Behnken design (BBD) . Fixed bed adsorption has become a frequently used in wastewater treatment processes. Various low cost adsorbents have been studied for their applicability in treatment of different types of effluents.  In this work, the intention of the study was to explore the efficacy and feasibility for azo dye, AO7 adsorption onto fixed bed column of TES. The effect of operating parameters such as flow rate, initial dye concentration, and bed height were exploited in this study. The studies confirmed that the breakthrough curves were dependent on flow rate, initial dye concentration solution of AO7 and bed depth.The precision of the equation obtained by Box–Behnken design (BBD) utility for modeling and optimization by response surface methodology RSM was confirmed by the analysis of variance (ANOVA) and calculation of correlation coefficient relating the predicted and the experimental values of removal of dye. The results revealed a good agreement between the predicted values, as obtained by the model, and the experimental values for AO7. The optimum conditions proposed by Box–Behnken design (BBD) to reach the maximum dye removal through adsorption process. Under the optimum conditions, the removal efficiency of AO7 were 89.89%.The application of response surface methodology in order to optimize using Box–Behnken design (BBD) . The research on modeling adsorption by RSM has been highly developed and The TES was shown to be suitable adsorbent for adsorption of AO7 using fixed-bed adsorption column

Fixed Bed Column Study for Removal of Textile Effluent Acid Orange 7 by NaOH Treated Eggshells and Amberlite FPA-98 as Efficient Adsorbents Using Response Surface Methodology.

In this study, we investigated the adsorption of Methylene blue (MB) dye on prepared activated carbons from eggshells treated with NaOH (TES) and eggshells Without Treatment (NTES)  as a new and potential biosorbent. Biosorption capacities and rates of different kinds of treated bioadsorbent for Removal of MB dye from aqueous solutions were compared under laboratory conditions as a function of initial dye concentration, temperature and pH . The extent of dye removal increased with increasing in the initial concentration of the dye ,increased with increase in contact time and the initial pH of the solution and also decreased with increasing in temperature of the adsorbent. Adsorption data were modeled using the Freundlich and Langmuir to fit experimental equilibrium data at different solution temperatures and the isotherm parameters were calculated in order to describe the biosorption process;  Langmuir model was found suitable for describing the biosorption of the dye by all the bioadsorbent. Among the two  adsorbents , TES exhibited the highest dye uptake capacity (Q0 =200 mg/g) at 20°C. A Comparison of different kinetic models parameters was evaluated for the pseudo-first-order and the pseudo-second-order model on the removal of MB. The results indicated that the dye uptake process followed the pseudo-second-order kinetics for each dye–adsorbent system. The thermodynamic parameters were evaluated; The negative values of ΔH° and ΔG° indicated respectively that the adsorption of MB onto TES and NTES was exothermic and spontaneous process, concerning  ΔS° which is also negative, it have showed that disorder in the interface system decreases during the adsorption process. In summary, the results have established good potentiality for the TES and NTES particles to be employed as  a low cost  sorbent for the removal of colour and dyes from wastewater.

Enhanced exergy analysis of a full-scale brackish water reverse osmosis desalination plant

Brackish water desalination by reverse osmosis membranes is energy-driven process. With the purpose of improving the energy performance of such unit a full-scale BWRO desalination plant located in Canary Island (Spain) has been working under intermittent operating conditions for 14 years was assessed with conventional and enhanced (exogenous and endogenous/avoidable and unavoidable exergy destructions) exergy analysis. The exergies across the major components of the plant are calculated. The conventional exergy analysis reveals that, largest irreversibilities were identified in the RO system (membrane modules), the high pressure pump and the feed pump which amounts to about 64.28%, 40.84% and 38.48% respectively. Results of advanced exergy analyses shows that 70.61%, 92.94% and 7.83% of the total exergy destruction in the high pressure pump, feed pump and the RO system respectively are avoidable. Moreover, the highest endogenous avoidable exergy destruction rate was determined owing to the feed and high pressure pumps. Using these findings, instructions were proposed to ensure optimal effectiveness of the RO system and to improve the exergy destruction in the pumps currently in use.91,7949,501Q1Q1SCI

TREATEMENT OF OLIVE MILL WASTEWATER USING ELECTROCOAGULATION PROCESS

 Olives mill waste water resulting from the extraction of olive oil are the major problem of olive growing because of their polluting power (rich in organic and mineral matter) and their acid pH. The aim of this study is to treat these margins electrochemically in an aluminum electrode reactor, in order to oxidize the organic matter, discolour the margins, neutralize the pH and consequently reduce the pollutant power of this product. After this study, it was found that the increase in electrolysis time and the intensity of the current significantly improved the treatment. However, simultaneous energy consumption and electrodes were observed. The results of these analyzes showed that thirty-fold diluted margins are effluents at acid pH (5.02), Conductivity (14.89).The evolution of the physicochemical parameters during the electrocoagulation (EC) treatment shows that under the conditions of an electrolysis time of 3 h and a current intensity of 3A (corresponds to 416 A.m-2), the discoloration Of the margins diluted ten times is between 91%, the reduction of the lost mass of the electrodes is 0.55 kg.m-3 and the reduction of the COD is 50%.  These optimal operational levels allow a good degradation of the effects of margins.  The results have established good potentiality for the electrocoagulation to be used as  a method for the removal of phenol from wastewater

Treatment of olive mill wastewater using electrocoagulation process

The aim of this study is to treat olives mill wastewater (OMWW) electrochemically in an aluminum electrode reactor, in order to oxidize the organic matter, discolour the reject, neutralize the pH and consequently reduce the pollutant power of this wastewater. It was found that the increase in electrolysis time and the intensity of the current significantly improved the treatment performance. However, simultaneous energy consumption and electrodes were observed. The results of these analyses showed that thirty‐fold diluted margins are acid (pH 5.02) and high electricly conductive (Conductivity 14.89 ms/cm). The evolution of the physicochemical parameters during the electrocoagulation (EC) treatment shows that under the conditions of an electrolysis time of 3 h and a current intensity of 3A (corresponds to 416 A/m2), the discoloration of the margins diluted ten times is arround 91 %. The reduction of the lost mass of the electrodes is 0.55 kg/m3 and the reduction of the chemical oxygen demand (COD) is 50%. These optimal operational levels allow a good treatment performance. The results have established good potentiality of the EC as an efficient method for discoloration of OMWW and the reduction of COD

Purification of industrial wet phosphoric acid solution by sulfide precipitation process: performance analysis, kinetic modeling, and solid characterization

National audienc

Dénitrification des eaux souterraines saumâtres par procédés électrochimiques

National audienc