The use of polluted water to irrigate is an increasing problem in the developing world. Lebanon is a case in point, with heavily polluted irrigation waters, particularly in the Litani River Basin. This study evaluated the potential health risks of irrigating vegetables (radishes, parsley, onions, and lettuce) using three water sources (groundwater, river water, and treated wastewater) and three irrigation methods (drip, sprinkler, and surface) over two growing seasons in 2019 and 2020. Water, crop, and soil samples were analyzed for physicochemical parameters, pathogens, and metals (Cu, Cd, Ni, Cr, and Zn). In addition, the bioaccumulation factor, estimated dietary intakes, health risk index, and target hazard quotients were calculated to assess the health risk associated with metal contamination. The study showed that, for water with less than 2 log E. coli CFU/100 mL, no pathogens (Escherichia coli, salmonella, parasite eggs) were detected in irrigated vegetables, irrespective of the irrigation method. With over 2 log E. coli CFU/100 mL in the water, 8.33% of the sprinkler-and surface-irrigated vegetables, and 2.78% of the drip-irrigated root crops (radishes and onions), showed some degree of parasitic contamination. E. coli appeared only on root crops when irrigated with water having over 3 log CFU/100 mL. The concentrations of most metals were significantly lower than the safe limits of the FAO/WHO of the Food Standards Programme Codex, except for zinc and chromium. The trends in the bioaccumulation factor and the estimated dietary intakes of metals were in the order of Cu < Cd < Ni < Cr < Zn. The target hazard quotient values for all metals were lower than 1.0. Under trial conditions, the adoption of drip irrigation with water with less than 3 log E. coli CFU/100 mL proved to be safe, even for vegetables consumed raw, except for root crops such as onions and radishes that should not be irrigated with water having over 2 log E. coli CFU/100 mL. Treated wastewater had no adverse effect on vegetable quality compared to vegetables irrigated with other water sources. These results support efforts to update the Lebanese standards for water reuse in agriculture; standards proposed in 2011 by the FAO, and currently being reviewed by the Lebanese Institution of Standards. This research will inform a sustainable water management policy aimed at protecting the Litani River watershed by monitoring water quality.
Most of Southern Mediterranean water courses suffer from numerous types of pollution. This study presents a comprehensive performance assessment of a pilot CW system for removing various contaminants from the Litani River, Lebanon. The physico‐chemical, pathogens and trace metal parameters were analyzed for river water as well as for the wetland effluent. Results revealed that the average removal efficiencies were 87.01% for COD, 64.99% for BOD5, 86.18% for TSS, 43.11% for NO3N, 34.82% for NH4N, 55.07% for PO4P and 73.05% for K. The removal efficiency of faecal coliforms was around 99.84%. Influent and effluent heavy metal pollution (Cu, Pb, As and Ni) concentrations greatly exceeded the range of the environmental limit values due to industrial emissions in river water. CWs seem to be a promising green technology for Lebanon for the reduction of bacterial contamination. Further studies are required to improve treatment modules for different pollutants, including metals.
In this paper, we propose to estimate the moisture of vineyard soils from digital photography using machine learning methods. Two nonlinear regression models are implemented: a multilayer perceptron (MLP) and a support vector regression (SVR). Pixels coded with RGB colour model extracted from soil digital images along with the associated known soil moisture levels are used to train both models in order to predict moisture content from newly acquired images. The study is conducted on samples of six soil types collected from Chateau Kefraya terroirs in Lebanon. Both methods succeeded in forecasting moisture giving high correlation values between the measured moisture and the predicted moisture when tested on unknown data. However, the method based on SVR outperformed the one based on MLP yielding Pearson correlation coefficient values ranging from 0.89 to 0.99. Moreover, it is a simple and noninvasive method that can be adopted easily to detect vineyards soil moisture.
This study investigated the effect of different water quality regimes [Freshwater (FW), treated wastewater (TW) and alternating FW and TW (FW‐TW)] on drip‐irrigated table grape yield, quality and microbial contamination. Water and soil samples were analysed. In addition, grape samples were harvested for quantitative and qualitative evaluation. The results showed that the plants irrigated with TW and those irrigated with alternating FW and TW gave 19.57 and 14.95% higher marketable yield, respectively, than plants irrigated with FW. Total soluble sugars, total titratable acidity and sweetness ranged, respectively, between 18.43–20.13, 0.69–0.81% and 21.52–29.19, and were within the desirable levels for table grape harvest. In addition, there was no significant difference in terms of total phenols and mineral composition of berries, leaves, peduncle and pedicels. Finally, table grapes did not present any bacterial contamination which confirm the importance of the adopted irrigation regime for a safe wastewater reuse in agriculture.
In the Bekaa Valley of Lebanon, the availability of freshwater is limited and therefore farmers must start using alternative water sources such as treated wastewater for irrigating crops. The present study is of great importance, since it provides evidence of some on-farm options that farmers can adopt when irrigating with treated effluent, in order to minimize the health risks. Eggplant was grown under two water quality regimes (Freshwater (FW) and treated wastewater (TW)) and two agronomic practices (no mulch (N_Mu) and use of plastic mulch (Mu)). Treatments were arranged in a split plot design with four replicates. Water quality regime was the main plot factor, while agronomic practices were the subplot factors. Water quality, soil, the marketable yield and other parameters were measured. Fruit samples were evaluated for bacterial contamination. The drip line performance was monitored. The study results revealed that the treatment with treated effluent gave more fruits.m-2, yield and mean fruit weight than the treatment using fresh water irrigation, with an increase of 3.98%, 10.74% and 5.63%, respectively. In addition, the use of mulch (Mu) resulted in an increase in yield (24.23%) and number of fruits (14.11%). Concerning the emitters’ performance and sensitivity to clogging, discharge reduction rate (Rd = 6.75%) for drippers delivering TW was lower than the admissible value of 20% discharge variation, indicating that the quality of water has little effect on emitter performance. Concerning bacterial contamination of fruits, irrigation with treated wastewater showed no contamination in terms of fecal streptococci, salmonella or E. coli. However, the fruits were contaminated with fecal coliforms that were present at a concentration less than 200 CFU.100 g-1. Following the World Health Organization Guidelines, pathogens could be reduced through post treatment health-protection control measures such as drip irrigation, product washing, disinfection and produce peeling
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