The present experiment aimed to observe the effects of sweet potato (SP) and green tea waste (GTW) utilization as feed on the performance, digestibility, meat quality, and blood character of Meishan pigs during the fattening period. Twelve castrated pigs were classified according to the following 3 groups of 4 pigs each:usual feed with corn (control group), corn substituted with SP feed (experimental group 1), and GTW added to the feed of experimental group 1, (experimental group 2). Fattening test was carried out when body weight was from 45 to 90 kg. Digestibility test was carried out two times during this period and blood was collected on the final day. Carcass character and meat quality were observed after slaughtering. GTW-added feed-decreased daily feed intake and weight gain significantly (P<0.05) and extended the feeding period by about 3 weeks. Digestibility of CP decreased significantly (P<0.05) with the addition of SP and GTW, but the digestibility of crude fiber oppositely increased. There was no significant difference in the results of carcass and blood characters. For loin meat color, the a* value and L* value for back fat increased with the addition of GTW. The value of C16:0 for experimental group 1 was higher than that of experimental group 2, and the value of C18:2 in experimental group 2 was significantly (P<0.05) the highest. The value of C18:3 increased significantly (P<0.05) with the addition of GTW. In conclusion, although GTW has low palatability and reduces feed intake and body weight gain, the addition of GTW prevents body fat deposition.

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We investigated the optimum condition for the recovery of phosphorus as struvite (magnesium ammonium phosphate) from activated sludge treated wastewater and evaluated the removal and recovery efficiencies of phosphorus through a crystallization reactor. A laboratory-scale test was performed in a MAP reactor, with a reactor volume of 33 liters and a processing capacity of 240 liters/day, by using artificial phosphorus water excluding variable factors such as solids from livestock wastewater. For the optimum condition, another laboratory-scale test and a full-scale test (reactor volume of 700 liters and processing capacity of 5 m³/day) were performed by using activated sludge treated wastewater. The results of the examination with artificial phosphorus water showed a remarkable growth of MAP crystals in the range of pH 8.5 to 8.6 and Mg/P ratio of 1.5, and a recovery rate of more than 70%. For the results of full-scale and laboratory-scale tests using activated sludge treated wastewater in a reactor condition of pH 8.5 to 8.6 and Mg/P ratio of 1.5, total and soluble phosphorus in the effluent decreased remarkably compared with the influent, and the removal rate was more than 80%. The recovery rate using the activated sludge treated water was approximately 60% and lower than that using artificial phosphorus water. The amount of recovered struvite in the full-scale test for 43 days was 37.1 kg and for particle sizes of more than 0.2 mm, which could be separated with solid-liquid separator, the amount was 18.2 kg and approximately 50%.

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