Effect of Irrigation with Secondary Treated Effluent on Essential Oil, Antioxidant Activity, and Phenolic Compounds in Oregano and Rosemary

Abstract

Shortage of water throughout the world dictates utilization of marginal water for irrigation. Treated urban wastewater is a common alternative water source for irrigation in arid and semiarid regions. In this study we aimed to evaluate the eff ect of irrigation with secondary-treated effl uent on plant development, essential oil yield, antioxidant activity and selected antioxidant phenolic compounds in two commercial cultivars of the aromatic species, oregano (Origanum vulgare L.) and rosemary (Rosmarinus offi cinalis L.). Th e applied treated effl uent contained higher levels of Na, Cl, HCO 3 -1 , P, K, NH 4 +1 , NO 3 -1 , Ca+Mg, B, Mn, and Fe than the local potable water used as control, and were characterized by higher values of electrical conductivity (EC), pH, and sodium absorption ratio (SAR). Since effl uent eff ects on plants can become apparent only following several years of exposure, the plants were exposed to the water treatments for 3 yr. Despite the diff erences in water quality, the effl uent did not aff ect yield quantity and quality in either crop. Plant morphological development, biomass production, percent dry leaves of the total biomass, quantity and composition of the essential oil produced, antioxidant activity, and contents of selected antioxidant-phenolic compounds were not aff ected by irrigation with treated effl uent compared with potable water. Our results demonstrate that both oregano and rosemary are suitable as industrial crops for essential oil and antioxidant production under irrigation with secondary-treated municipal effl uent because their yield quantity and quality were not aff ected.

Comparable levels of microbial contamination in soil and on tomato crops after drip irrigation with treated wastewater or potable water

“…S2B, p = 0.001) and increased during the growing season (from 1.2-5 ms cm −1 , R 2 = 0.13). This finding is similar to those reported by previous studies that applied TWW irrigation in Israel (Bernstein et al, 2009;Sacks and Bernstein, 2011). There was no effect of irrigation water or the interaction of time and irrigation water.…”

“…1 and 2, Table 2). The accumulation and persistence of fecally sourced microbes from WW in soil is one of the major concerns associated with WW irrigation (Bernstein et al, 2009), and has been shown to occur under simulated conditions (Bernstein et al, 2007;Monaghan and Hutchison, 2012;Ramirez et al, 2009). Yet in this study utilizing TWW under field conditions, no evidence for this phenomenon was found.…”

Influence of compost of sewage sludge and low-quality water on pesticide uptake by tomato plants grown in an iron mine soil

“…It contradicts however previous reports which showed either no effects, as in several aromatic plants (Bernstein et al 2009), or even indicated yield increases in various crops (Chakrabarti 1995;Al-Nakshabandi et al 1997;Marecos do Monte MHF 1998;Negahban-Azar et al 2013;Peña et al 2014). The development of tomato plants, a species with low salt tolerance (Cuartero and Fernández-Muñoz 1999), was probably impaired by irrigation with WW, which had higher salinity than DW, especially when the plants were further stressed by pesticide addition.…”

Potential drawbacks associated with agricultural irrigation with treated wastewaters from desalinated water origin and possible remedies

“…The relative contribution of each source to the sewage is site specific but it is probably safe to say that in the majority of cases, in mass terms, Na þ is by far the most dominant cation that is added to the sewage. The reports on sodium addition due to domestic or mixed domestic/industrial water use vary considerably: While some sources report the addition to be in the range 40 -70 mg L 21 (Pettygrove & Asano 1985; Tchobanoglous et al 2003) or lower (Mercado & Banin 1994), other sources report on an additional Na þ concentration of , 115 mg L 21 (Rebhun 1965;Bernstein et al 2009) and a recent paper reports on Na þ addition in the range 200 to 250 mg L 21 (Friedman et al 2007).…”