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Water treatment for human uses is a vital asset to economic development. This article focuses on a combination of physical, biological, and chemical processes. Methods of water treatment require concrete or steel base structures, rendering them heavy, costly, and time-consuming to establish. Water treatment systems should be economically viable and practicable in design for developing societies; hence, structural builds should be simplified. Novel structures, a series of polyethylene cyclonic ponds for water treatment, were built and tested. Tanks were equipped with a settled material central outlet, water side outlet, and a pump shower system that enabled sludge removal without mechanical intervention. A freely flowing vortex was produced, aerated, given a biological treatment, and finally mixed with a chemical treatment step. Test establishment of the batch system enabled improvement in water quality, with removal performance as follows: TSS (total suspended solids) = 98%, UV254 absorbance = 50%, DOC (dissolved organic carbon) = 56%, and turbidity=95%. The batch system builds of the current study required short construction time and were economically priced. Cyclonic ponds are suited to diverse usage. The value may be felt in the improvement of water quality for human consumption, utility, and ecosystem services to counter the extensive pollution caused by oil and gas extraction and other industries.

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.

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.

Phytoremediation with aquatic plants is a new, effective and inexpensive method for improving water quality and wastewater. In this study, Nickel removal by the aquatic plant, coontail (Ceratophyllum demersum L.), native hydrophyte of most of Iran's rivers, was reviewed after optimum growing pH nomination, within 14 days cultivation in contaminated Hoagland nutrient solution, at the four different concentration of nickel (0, 1, 2, 4, and 6 mg L -1 ). With daily analysis of nickel concentration in cultivation solution and also initial and final concentration of this element in plant, nickel phytoextraction potential evaluated, and nickel biological effects on coontail grows with biomass production was studied. Maximum removal efficiency was 50% calculated from 6 mg L -1 metal concentration. Maximum bioconcentration factor and maximum uptake index calculated from 6 mg L -1 metal concentration were 338.65 and 5.05 mg, respectively. Maximum (3.6 g/day) and minimum (1.27 g/day) biomass production index caused from 0 mg L -1 and 6 mg L -1 of pollutant concentrations. Based on the results, nickel phytoremediation of industrial wastewater by coontail is applicable.