The increase of the global population and the requirement of food production and agricultural development, combined with a lack of water resources, have led to human attention being drawn to unconventional water sources, including saline water and wastewater. Most unconventional water treatment methods are not cost-effective; however, researchers have become interested in the phytoremediation method due to its cost-efficient and eco-friendly removal of many pollutants in recent years. Research showed that due to its unique characteristics, vetiver grass can be useful in phytoremediation. In the current review, research on vetiver-based phytoremediation of unconventional water, especially wastewater, was reviewed. The vetiver-reduced contaminants in wastewater can be related to the interactions between (1) the root-released oxygen into the rhizosphere; (2) the root-based uptake of nutrients from the wastewater; (3) the existence of an appropriate surface area for the attached microbial growth; as well as (4) the root-exuded organic carbon.

The main aim of this study was to develop an index to determine groundwater drought. Then, as a case study, for the sustainable use of groundwater, the optimum cropping pattern was determined in full compliance with the drought conditions in a plain. The newly presented index, known as the groundwater recharge drought index (GRDI), was determined based on the values of recharge in different zones in the plain. The GRDI for different zones within the region was calculated using the data covering 30 years (1980–2010). Based on this index, groundwater drought was found to occur frequently in these regions since 1981. According to the obtained results, the developed index, as compared with other indices, had several basic features including the ability to predict drought in groundwater, consideration of the possible effects of basin characteristics on groundwater drought, the capability of using different methods and models to calculate the GRDI, and separation of the human effects on the hydrological...

In this paper, the application of a stable immobilized cetyltrimethylammonium bromide (cationic surfactant) and laundry detergent (anionic surfactant) on the surface of a biological origin support (ostrich bone waste) was reported as the novel bio-adsorbents for the removal of Pb(II) and Hg(II) ions from aqueous solution. The synthesized bio-materials were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Brunnauer–Emmett–Teller, SEM-EDX, thermal gravimetric, and point of zero charge. The removal efficiency of the bio-adsorbent was investigated as a function of contact time, pH, initial ion concentration, temperature, adsorbent dosage, and chemical modification process. Equilibrium, kinetics, and thermodynamic studies were also performed for design and evaluate the bio-adsorbents in removing Pb(II) and Hg(II) ions from aqueous solution. The modified ostrich bone with anionic surfactant indicated remarkable capability to remove Pb(II) and Hg(II) ions from aqueous solution. The results showed that the majority of Pb (91.9%) and Hg (87.7%) ions were removed within the first 0–60 min contact with the B-Detergent bio-adsorbent. Langmuir–Freundlich isotherm type model satisfactorily described the Pb(II) and Hg(II) experimental data. The adsorption process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model.