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In many areas, wastewater feeds water bodies, which leads to it being non-usable for agricultural and other uses. Phytoremediation is a scientific approach which cleans contaminated waters, demanding large areas for application. Vertical agriculture is a new method to compact plant cultures. This study investigates vertical wastewater phytoremediation (VWP). Twenty vetiver grasses were planted in a hydroponic vertical agriculture system. Wastewater flowed into the system in four different flow rates, 60, 80, 100, and 160 l day−1 and water purity was assessed in order to measure the remediation ability of the VWP. Results showed a reduction in biochemical oxygen demand (BOD5 and NO3− concentrations and an increase of electrical conductivity (EC) and dissolved oxygen (DO) in the outlet. Maximum and minimum (BOD5) reduction percentage (78.47% and 67.36%) and NO3− removal percentage (90.53% and 36.41%) occurred in flow rates 60 and 160 l day−1, respectively. With the increase of wastewater flow rate, phytoremediation performance decreased, but the performance of VWP with vetiver grass was efficient enough to enable wastewater remediation. Scaling up VWP with Vetiver and related competitive plant species holds promise for wastewater remediation for both human and ecosystem services.

COVID-19 (coronavirus disease) is a global pandemic that started in China in 2019 and has negatively affected all economic sectors of the world, including agriculture. However, according to estimates in different countries, agriculture has suffered less than other sectors such as construction, industry and tourism, so agricultural development can be a good option to compensate for the economic damage caused to other sectors. The quality of available water and soil resources for agricultural development is not only limited, but is also decreasing incrementally, so the use of saline and unconventional soil and water resources is inevitable. Biosaline agriculture or haloculture is a system in which highly saline water and soil resources are used sustainably for the economic production of agricultural crops. It seems that in the current situation of the world (with COVID-19's impact on agriculture on the one hand and the quantitative and qualitative decline of freshwater and soil on the other), haloculture with a re-reading of territorial capabilities has good potential to provide a part of human food supply. In this review article, the potential of haloculture to offset the adverse impacts of the pandemic is analyzed from five perspectives: increasing the area under cultivation, using unconventional water, stabilizing dust centers, increasing the body's immune resistance, and reducing losses in agribusiness due to the coronavirus. Overall, haloculture is an essential system, which COVID-19 has accelerated in the agricultural sector., Graphical abstract Image 1

The aim of the present study was investigation of two aquatic plants efficiency, duckweed Lemna gibba (floating-leaved hydrophyte) and coontail Ceratophyllum demersum L. (free-floating hydrophyte) on Cd and Ni removal from synthetic aqueous. Both aquatic plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of each of the contaminants tested (0, 1, 2, 4 and 6 mg L −1 ) in a completely randomized design with three replications. Plants dry matter production as well as heavy metals and nutrient tissue concentrations were measured at the end of the experiment. The results showed that increasing heavy metal concentrations in nutrient solution caused a decrease in both plants biomasses. L. gibba reduced the contamination level which was up to 91% for Cd and 50% for Ni. In addition, the efficiency of C. demersum was 82.01% for Cd and 52.5% for Ni. L. gibba uptake both heavy metals (5.07 mg for Ni and 9.70 mg for Cd) but C. demersum accumulated both heavy metals (4.5 mg for Ni and 3.87 mg for Cd) less and slower for Cd removal but a little more and faster for Ni than the other plant. The Ni and Cd BCF values for L. gibba ranged between 270.19 to 638.95 and 942.79 to 5093.27, respectively; and for C. demersum ranged between 104.16 to 200 and 75 to 707.92, respectively. The high efficiency of L. gibba and C. demersum in Cd and Ni removal from synthetic medium makes it a proper treatment method.