Suchergebnisse

Abstract
Under the framework of Water-Energy-Food Nexus, this study investigates the integration of solar-powered desalination with aquaculture and agriculture production systems to grow crops. Brackish water desalination is performed using reverse osmosis (RO), the permeate is directed to an aquaculture unit, and the fish effluent is used as irrigation water for crops. The experiment followed a split-plot design with three main variants: a full irrigation schedule for the basil plants with fish effluents as fertilizers, irrigation as fertigation with chemical fertilizers, and a mixed treatment of effluents and chemical fertilizers at 50% application each. Each treatment was further sprayed with or without foliar nutrient application. RO results gave a permeate recovery of 22%, and a salt rejection of 98.7%. In the aquaculture unit, tilapia harvest weight was 0.458 kg with a survival rate of 97.7% and harvest yield of 25 kg/ m3 of water. Effluent treatment exhibited the highest branching and plant height irrespective of the cut number, reaching 17.7 branches and 62-cm height. The effluent treatment under foliar application recorded the highest fresh and dry weights of basil with 14.7 ton/ha and 4.7 ton/ha, respectively. Effluent irrigation plus foliar application recorded basil yield of 5 kg/m3 effluent water. The dominant essential oil elements were linalool (55.5–61.6%), tau.-cadinol (5.3–8.3%), eucalyptol (5.4–7.7%), eugenol (2–6.8%), and (Z,E)-.alpha.-farnesene (3–5.2%). The study is among the very few integrated systems and, in particular, the current study is the first-time investigation of an integrated desalination, aquaculture, and agriculture production using renewable energy. Therefore, results suggest that integrating desalination, aquaculture, and agriculture could be a potential solution for the global water, energy, and food challenges.

AbstractFreshwater scarcity, salinity, and poor soil fertility are the major challenges affecting both food and feed productions in arid and semi-arid regions of the world. Utilization of brackish water in the production of saline-tolerant fish and valuable field crops under an integrated system is promising in the maximization of yield per crop. The aim of this study, therefore, was to (1) assess the effect of saline aquaculture wastewater on the growth, yield, forage quality, and nutritive composition of sorghum seeds and (2) assess the effect of different water qualities on the survival, growth performance, and health status of Pangasianodon hypophthalmus. The experiment was conducted in a randomized completely block design of four salinity treatments with three replicates, i.e., control (freshwater mixed with inorganic fertilizers), 5000 ppm, 10,000 ppm, and 15,000 ppm. Our results indicated that although the control exhibited the highest growth (plant height, leaf number, internode number, leaf area, and soil–plant analysis development), grain, and forage yield, no significant differences were noted among the treatments. Likewise, no significant difference in the grain nutrient composition was noted among all the treatments. Assessment of the forage quality revealed improved crude protein content in the control compared to the saline treatments. However, no significant differences in the leaves and stalks fiber fractions were noted among all the treatments. Furthermore, rumen fermentation in terms of in vitro digestibility indicated no significant differences in the in vitro digestible dry matter, digestible organic matter, metabolic energy, net energy, microbial protein, short-chain fatty acids, and total dissolved nutrients among the treatments. However, rearing P. hypophthalmus in water salinities exceeding 10,000 ppm reduced the growth performance and health status of fish. Therefore, the integration of sorghum and P. hypophthalmus production in water salinities not exceeding 5000 ppm is a viable alternative to maximize brackish water productivity in freshwater-scarce regions.

AbstractThis study investigated the potential of utilizing both the draw and feed solutions resulting from fertilizer drawn forward osmosis for hydroponic crop cultivation. Synthetic brackish groundwater of 2500 ppm was used as the feed solution, whereas commercial hydroponic nutrients, sourced from a local supplier, were utilized as a draw solution. This study also investigated the potential of integrating nanofiltration with forward osmosis, but supplementing the water necessary for further dilution of draw solutions through nanofiltration. Two crops were selected, i.e., cherry tomatoes and spinach grown at different water salinities, for their economic values. The cherry tomatoes were grown in Deep Water Culture hydroponic systems, while the spinach was grown in Nutrient Film Technique systems. If this application is deemed feasible, it allows for providing a method to grow two different crops in areas associated with non-arable land and brackish groundwater. During desalination, it was observed that there were two groups of flux readings, the first with an average flux of 7 to 9 l/m2/h, and the other with an average flux of 4 to 6 l/m2/h. This was due to using the same draw solution twice; once to concentrate the feed solution to 5000 ppm, and then once more to concentrate the feed solution to 3500 ppm. It was found that while the 3500 ppm cherry tomatoes tables had the highest yield and highest number of tomatoes throughout the plants lifetime, tomatoes from freshwater tables on average weighed more by about 19%, while, on average, 5000 ppm tomatoes weighed less than 3500 ppm tomatoes by 10%. The results of the spinach demonstrated that while both control and experiment groups yielded similar number of leaves, the average yield per plant for the experiment group was higher than the control group (by 25%).