Treatment by agricultural by-products of Industrial effluents polluted with heavy metals

Due to the increasing concern about the environmental pollution problems, it is so important to perform a number of methods for removing hazardous heavy metals from industrial liquid wastes. Adsorption technique is the most effective and economical one. In the present study, two agricultural by-products namely; cottonseed and soybean hulls, resulting from the oil industry, have been used in the adsorption of thorium element from a wastewater effluent coming from different industries. The results obtained indicate that maximum removal of thorium from a prepared solution takes place at pH 5 where equilibrium was attained after 100 min; using an adsorbent dose of 3 and 3.5 g/L for cottonseed and soybean hulls, respectively. On the other hand, the obtained mathematical data together with the obtained adsorption kinetic parameters indicate that both of cottonseed and soybean hulls could be useful adsorbents for thorium removal from industrial liquid wastes, especially when the low cost, environmental issues and high availability of these materials are considered

Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

The use of Fenton’s reagent (Fe2+/H2O2) and Fenton-like reagents containing transition metals of Cu(II), Zn(II), Co(II) and Mn(II) for an alum sludge conditioning to improve its dewaterability was investigated in this study. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton’s reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time (CST) reduction efficiency of 47% can be achieved under test conditions of Fe2+/H2O2 = 20/125 mg/gDS (Dry Solids) and pH = 6.0. The observation of floc-like particles after Fenton’s reagent conditioning of alum sludge suggests that the mechanism of Fenton’s reagent conditioning was different with that of polymer conditioning. In spite of the less efficiency in CST reduction of Fenton’s reagent in alum sludge conditioning compared with that of polymer conditioning, is less than that of polymer conditioning. This study provided an example of proactive treatment engineering which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.Not applicabl

Engineered nanostructured ZnO for water remediation: operational parameters effect, Box–Behnken design optimization and kinetic determinations

Abstract The photocatalytic oxidation of methylene blue (MB) in aqueous media is explored using nanoscale ZnO nanoparticles (ZnO NPs) for maximal dye removal within the high-surface-area nanoparticle photocatalyst. The operating parameters such as illumination time, initial MB load, ZnO NP dose, solution flow rate and pH were examined. The experimental results revealed the alkaline pH (12.0) corresponding to the higher oxidation rate within only 20 min of reaction time; however, increasing the initial MB load decreased the reaction rate at the optimum circulation flow rate of 460 mL/min and ZnO NP dose of 0.4 g. Additionally, for providing maximum performance, the interaction between the most effective independent parameters (ZnO NP dose, flow rate, and initial pH) were explored using Box–Behnken experimental design based on the response surface methodology. The results showed a good fitness of the model (R 2 = 96.86%) with the experimental data. The optimum values were recorded after 20 min of reaction time with the values: 0.45 g/L for ZnO NP dose, 370 mL/min for flow rate and pH 11, showing a 94% maximum dye removal compared to 92% using manual optimization. Finally, the kinetic models were applied and the data were described by second-order kinetic model

Application of Box–Behnken factorial design for parameters optimization of basic dye removal using nano-hematite photo-Fenton tool

Abstract A huge amount of water is consumed in the textile industry, and the result is the production of a large amount of wastewater. The treatment of such wastewater significantly reduces the pollution load. Oxidation by nano-Fenton reactions (Fe3+/H2O2) is a reasonable and cost-efficient process for the remediation of harmful pollutants in wastewater. In the present study, nano-hematite was applied as a source of iron in Fenton’s reagent for methylene blue dye removal from wastewater. The effects of different parameters, presence of nano-hematite, hydrogen peroxide concentrations and pH, were optimized using the response surface methodology technique. A Box–Behnken design was applied, and the response (dye removal) was maximized. A maximal dye removal (81.6%) was attained when wastewater was treated at pH 2.5 in the presence of nano-hematite and hydrogen peroxide in the amounts of 41 and 388 mg/L, respectively. The model is well fitted and described using the second-order polynomial equation. Moreover, the model validation showed a 97% fit between the theoretical and experimental ones

Production of biodegradable plastic from agricultural wastes

AbstractAgricultural residues management is considered to be a vital strategy in order to accomplish resource conservation and to maintain the quality of the environment. In recent years, biofibers have attracted increasing interest due to their wide applications in food packaging and in the biomedical sciences. These eco-friendly polymers reduce rapidly and replace the usage of the petroleum-based synthetic polymers due to their safety, low production costs, and biodegradability. This paper reports an efficient method for the production of the cellulose acetate biofiber from flax fibers and cotton linters. The used process satisfied a yield of 81% and 54% for flax fibers and cotton linters respectively (based on the weight of the cellulosic residue used). The structure of the produced bioplastic was confirmed by X-ray diffraction, FT-IR and gel permeation chromatography. Moreover, this new biopolymer is biodegradable and is not affected by acid or salt treatment but is alkali labile. A comparison test showed that the produced cellulose acetate was affected by acids to a lesser extent than polypropylene and polystyrene. Therefore, this new cellulose acetate bioplastics can be applied in both the food industry and medicine

Production of biodegradable plastic from agricultural wastes

Agricultural residues management is considered to be a vital strategy in order to accomplish resource conservation and to maintain the quality of the environment. In recent years, biofibers have attracted increasing interest due to their wide applications in food packaging and in the biomedical sciences. These eco-friendly polymers reduce rapidly and replace the usage of the petroleum-based synthetic polymers due to their safety, low production costs, and biodegradability. This paper reports an efficient method for the production of the cellulose acetate biofiber from flax fibers and cotton linters. The used process satisfied a yield of 81% and 54% for flax fibers and cotton linters respectively (based on the weight of the cellulosic residue used). The structure of the produced bioplastic was confirmed by X-ray diffraction, FT-IR and gel permeation chromatography. Moreover, this new biopolymer is biodegradable and is not affected by acid or salt treatment but is alkali labile. A comparison test showed that the produced cellulose acetate was affected by acids to a lesser extent than polypropylene and polystyrene. Therefore, this new cellulose acetate bioplastics can be applied in both the food industry and medicine. Keywords: Cotton linters, Flax fibers, Cellulose acetate, Preparation, Characterizatio

Photo-catalytic degradation of an oil-water emulsion using the photo-Fenton treatment process : effects and statistical optimization

The application of advanced oxidation processes (AOPs) to the treatment of an effluent contaminated with hydrocarbon oils was investigated. The AOPs conducted were Fe2+/H2O2 (Fenton’s reagent), Fe2+/H2O2/UV (Photo-Fenton’s reagent) and UV-photolysis. These technologies utilize the very strong oxidizing power of hydroxyl radicals to oxidize organic compounds to harmless end products such as CO2 and H2O. A synthetic wastewater generated by emulsifying diesel oil and water was used. This wastewater might simulate, for example, a waste resulting from a hydrocarbon oil spill, onto which detergent was sprayed. The experiments utilising the Photo-Fenton treatment method with an artificial UV source, coupled with Fenton’s reagent, suggest that the hydrocarbon oil is readily degradable, but that the emulsifying agent is much more resistant to degradation. The results showed that the COD (chemical oxygen demand) removal rate was affected by the Photo-Fenton parameters (Fe2+, H2O2 concentrations and the initial pH) of the aqueous solution. In addition, the applicability of the treatment method to a ‘real’ wastewater contaminated with hydrocarbon oil is demonstrated. The ‘real’ wastewater was sourced at a nearby car-wash facility located at a petroleum filling station and the experimental results demonstrate the effectiveness of the treatment method in this case. A statistical analysis of the experimental data using the Statistical Analysis System (SAS) and the response surface methodology (RSM) based on the experimental design was applied to optimize the Photo-Fenton parameters (concentrations of Fe2+, H2O2 and initial pH) and to maximize the COD removal rate (more than 70%).Not applicabl