Bio-Based Adsorption as Ecofriendly Method for Wastewater Decontamination: A Review.

Intense human activities have for years contributed to the pollution of the environment by many dangerous pollutants such as heavy metals, pesticides, or polycyclic aromatic hydrocarbons. There are many conventional methods used to control pollution, with practical and/or financial drawbacks. Therefore, in recent years, an innovative, easy-to-implement and inexpensive adsorption method has been developed to recover waste and clean up water from micropollutants.

Potential of using Alfa grass fibers (Stipa Tenacissima L.) to remove Pb, Cu, and Zn from an aqueous solution.

This study used alfa grass fibres as a natural low-cost adsorbent to remove lead, copper, and zinc ions from aqueous solutions. The adsorbent was characterized by FTIR, SEM, BET surface area, ATG, and XRD techniques. The effects of pH, contact time, initial metal concentration, and adsorbent dosage on the adsorption efficiency were evaluated in batch experiments.

Desorption of zinc, copper and lead ions from loaded flax fibres.

Biosorption is an efficient and cost-effective method for heavy metals' remediation. However, saturated biosorbents may pose a serious problem for the environment. Flax fibres have shown very good adsorption capacities to remove zinc, copper and lead ions from contaminated aqueous solutions.

Competitive and non-competitive zinc, copper and lead biosorption from aqueous solutions onto flax fibers.

Competitive and non-competitive batch experiments were conducted on flax fibers to study Zn, Cu, and Pb ions biosorption performance. Biosorption efficiency was dependent on contact time, pH, and biosorbent concentration. The results under competitive conditions were different from those obtained in non-competitive form.

Assessment of clogging of managed aquifer recharge in a semi-arid region.

To overcome water scarcity issues in arid and semi-arid regions, Managed Aquifer Recharge (MAR) remains a viable and suitable solution to manage and restore aquifers. However, clogging represents a major issue that can affect the durability and efficiency of MAR structures. The aim of this study was to evaluate the extent of clogging in MAR sites (Berrechid, Morocco).

Effect of natural geotextile on the cotransport of heavy metals (Cu, Pb, and Zn) and kaolinite particles.

A cotransport study of heavy metals and kaolinite particles in sand column with and without flax geotextiles was carried out. The objectives were to evaluate the potential role of kaolinite in heavy metals transfer and to analyse the influence of flax geotextiles on the transfer of these pollutants. The adsorption rates of heavy metals on the kaolinite particles were, respectively, 53%, 65% and 25% for copper, lead, and zinc.

Nonwoven flax fibres geotextiles effects on solute heavy metals transport in porous media.

Filtration tests were carried out in laboratory columns filled with crushed sand with and without flax geotextiles to study the transfer and retention of soluble heavy metals. Divalent cations of copper, zinc and lead were simultaneously and continuously injected in filtration columns. Results show that, when geotextiles discs are present the retention of metals in sand is favoured and retention profiles are modified.

Modeling of the transport and deposition of polydispersed particles: Effects of hydrodynamics and spatiotemporal evolution of the deposition rate.

A time-distance-dependent deposition model is built to investigate the effects of hydrodynamic forces on the transport and deposition of polydispersed particles and the evolution of deposition rates with time and distance. Straining and the heterogeneity of the particle population are considered to play important roles in the decreasing distribution of deposition rates. Numerical simulations were applied in a series of sand column experiments at different fluid velocities for three different porous media.

Modeling of retention and re-entrainment of mono- and poly-disperse particles: Effects of hydrodynamics, particle size and interplay of different-sized particles retention.

In this paper, numerical simulations of experimental data were performed with kinetic rate coefficients to characterize the retention and re-entrainment dynamics under different hydrodynamic conditions for monodisperse and polydisperse latex particles (3, 10, 16μm and the mixture). The results show that drastic increase in fluid velocity provokes hardly any remarkable decrease in retention in the presence of large energy barriers (>2000kT). Systematical increases in deposition and re-entrainment dynamic rates were observed with fluid velocity and/or particle size.

Porous media grain size distribution and hydrodynamic forces effects on transport and deposition of suspended particles.

The effects of porous media grain size distribution on the transport and deposition of polydisperse suspended particles under different flow velocities were investigated. Selected Kaolinite particles (2-30μm) and Fluorescein (dissolved tracer) were injected in the porous media by step input injection technique. Three sands filled columns were used: Fine sand, Coarse sand, and a third sand (Mixture) obtained by mixing the two last sands in equal weight proportion.

Experimental investigation on removal of suspended particles from water using flax fibre geotextiles.

Natural geotextiles are increasingly used in geotechnical applications such as bank protection and short-term soil reinforcement. This study aimed to highlight the behaviour of natural flax fibre geotextiles towards the retention of suspended particles (SP) present in urban runoff and often polluted. Indeed, it is well known that a large fraction of the heavy metals are often associated with the SP.