Brahim Arhoun

A significant municipal solid waste is managed by disposition in a landfill. This kind of management system makes producing leachate with toxic characteristics

Landfilling municipal waste is the most common way to manage waste in the world. An important problem associated with landfills is the production of leachates. Landfill leachate is heterogeneous wastewater and often possesses potential pollution with high concentrations of organic and inorganic contaminants. The generated leachate must be appropriately collected and treated before being discharged into the environment. Several technologies have been used for leachate treatment which can be classified as biological, chemical, and physical processes. Among physical processes, membrane separation including microfiltration, ultrafiltration, nanofiltration, and reverse osmosis has been used for landfill leachate treatment. However, single-membrane processes are not very effective unless they are combined with biological and physicochemical treatment processes. This is because membrane separation presents two main drawbacks: membrane concentrates (MCs) and fouling. Here, we briefly review the main processes currently used for MC treatment. Finally, the fouling membrane is also discussed.

The anaerobic digestion of pig slurry samples collected from different points of a farm and raw pig slurry pretreated by centrifugation and decantation was first studied. The specific methane production of raw pig slurry and after centrifugation and decantation pretreatment was 158, 24 and 42.34 L kgVS⁻¹, respectively. Second, the anaerobic digestion of the mixture of raw pig slurry and decanted solid fraction at different organic loading rate (1.364–3.41 gVS·L⁻¹·d⁻¹) results in a specific methane production of 249 ± 37·L kgVS ⁻¹. The concentration of ammonium ion in the digester increased to 2500 mg L⁻¹ without inhibition. Lastly, the co‐digestion of pear waste and raw pig slurry was also analysed, which enhanced the specific methane production (243 L kgVS⁻¹). This work deals with the integral management of pig slurry and points out the possibility of revalorization of other wastes in the same digester.

Electrodialytic remediation has been widely applied to the recovery of different contaminants from numerous solid matrices, solving emerging issues of environmental concern. Results and conclusions reported in studies about real contaminated matrices are summarized in this work. The influence of pH value on the treatment effectiveness has been widely proved, highlighting the phenomenon of ‘water splitting’ in the membrane surface. This dissociation of water molecules is related to the ‘limiting current’ which it is desirable to exceed at the anion exchange membrane in order to produce the entering of protons toward the solid matrix. Other important parameters for the optimization of the technique, such as the current density and the liquid/solid ratio, are also discussed through the revision of studies using real solid matrices.This work also focuses on the pioneer proposal of electrokinetic technologies for the recycling of lithium ion batteries, considering the relevance of waste properties in the design and optimization of the technique. From a thorough literature revision, it could be concluded that further experimental results are needed to allow an optimal application of the technique to the rising problem of residues from batteries. The main aim of this work is to take the first steps in the recovery of valuable metals such as Li and Co from spent batteries, incorporating principles of green chemistry. © 2019 Society of Chemical Industry

This study was undertaken to determine the possible changes in the digester yield and performance for the anaerobic co-digestion under mesophilic conditions of strawberry residues (SRs) together with pig manure (PM). The first part of this paper deals with the digestion of SR as a single substrate. For organic loading rates (OLRs) of 4.4 (g L⁻¹ d⁻¹) or less, the experimental specific biogas and methane productions are 0.588 and 0.231 L g⁻¹, respectively. When higher OLRs (5.5 g L⁻¹ d⁻¹) are used the digester fails due to acidification. In the second part, the co-digestion of both residues is explored using a wide variety of SR:PM ratios and OLRs of 5.5 g L⁻¹ d⁻¹ with good stability. Therefore, it is demonstrated that co-digestion allows the improvement of the treatment capacity as compared with SR as a single residue. The methane and biogas productions increase as the SR:PM ratio increases. It may be concluded that, when a digester works with a certain OLR, the performance for co-digestion is always better than for single substrates because the presence of PM provides a better stability and the presence of SR improves the biogas and methane production.