RESUMO
We previously reported a sustainable food waste management approach to produce an acceptable organic liquid fertiliser for recycling food waste called "FoodLift." This study follows our previous work to evaluate the macronutrients and cation concentrations in harvested structural parts of lettuce, cucumber, and cherry tomatoes produced using food waste-derived liquid fertiliser (FoodLift) and compare them against commercial liquid fertiliser (CLF) under hydroponic conditions. N and P concentrations in the structural parts of lettuce and the fruit and plant structural parts of cucumber appear to be similar between FoodLift and CLF (p > 0.05), with significantly different N concentrations in the various parts of cherry tomato plants (p < 0.05). For lettuce, N and P content varied from 50 to 260 g/kg and 11 to 88 g/kg, respectively. For cucumber and cherry tomato plants, N and P concentrations ranged from 1 to 36 g/kg and 4 to 33 g/kg, respectively. FoodLift was not effective as a nutrient source for growing cherry tomatoes. Moreover, the cation (K, Ca, and Mg) concentrations appear to significantly differ between FoodLift and CLF grown plants (p < 0.05). For example, for cucumber, Ca content varied from 2 to 18 g/kg for FoodLift grown plants while Ca in CLF-grown cucumber plants ranged from 2 to 28 g/kg. Overall, as suggested in our previous work, FoodLift has the potential to replace CLF in hydroponic systems for lettuce and cucumber. This will lead to sustainable food production, recycling of food waste to produce liquid fertiliser, and will promote a circular economy in nutrient management.
RESUMO
OBJECTIVE: To investigate whether a simulated He-O2 saturation dive to 65 msw would affect oxidative balance in humans. METHODS: Seven divers participated in a simulated saturation dive to 0.75 MPa (65 msw). 24-h urine samples were collected twice before, twice during, and twice after the dive, then were analyzed for contents of superoxide dismutase (SOD), malondialdehyde (MDA), total amino acid (T-AA) and total anti-oxidant capacity (T-AOC). Meanwhile, total urine volume and body weight were measured. RESULTS: The content of T-AA was higher. (P < 0.05) than the base value in final decompression, but reverse to normal at one week after decompression. There were no changes in contents of SOD, MDA and T-AOC during and after the dive compared with their basic value. Total urine volume was lower (P < 0.05, vs basic value) at first day in chamber, then returned to normal. Body weight gradually increased after compression till the end of decompression (higher than basic value, P < 0.05). CONCLUSION: These data indicate that simulated saturation dive to 65 msw may not induce obvious oxidative damage, but it is necessary to monitor 24-h urine volume and oxidative sress by time in order to prevent from tissue injury.
