Study On The Processing Of Domestic Organic Wastes Using The Solar-Assisted System Coupled Biofortification

Generation of domestic solid waste increases with the accelerated economic development and the rapid raising standards of living, which have led to a big pressure on the capacity of the environment to absorb wastes. Researches on waste management and recycling are essential for the protection of the natural environment in China. This study carried out experiments to characterize the composting process of domestic organic waste in a solar-assisted bioreactor, to explore factors influencing the reduction behaviors of different compositions in organic wastes, to isolate efficient organic wastes composting microbial inocula, and to optimize force aeration and leachate recycling systems. The main results obtained listed as follows:(1) Solar-assisted bioreactor is able to reduce organic waste effectively. The reducing amount of the volume reached 73.61% and the loss in substance dry matter was 41%. All the pH, C/N, organic matter content and total nutrient of the final compost product collected at day 42 were reached the basic requirements for its agricultural use.(2) The water loss of waste had the largest positive correlation with the total substance reduction (P<0.05). The decrease in the total weight of the fresh substances was primarily attributed to the water loss in all treatments. The composting temperature associated highly with the reduction of the total fresh substance and the water loss, while waste reduction occurred mainly in the thermophilic composting period. Exogenous microbial inocula and force aeration enhanced the carbon consumption during the early stage (0-13d) of composting. The different microorganisms population is a cause for the variation of waste reduction in treatments. Bacteria and actinomycete tend to increase the consumption of carbon and hydrogen.(3) All commercial microbial inocula used in this work under the experimental conditions had no obvious promotion on composting temperature. However, the reduction efficiency of wastes increased by 17% by using " Shui Gu-xin " inoculum with an inoculation proportion of 0.5%, Furthermore, we noted the newly constructed inocula EMI performed better than " Shui Gu-xin" inoculum. EMI was able to increase both composting temperature and substance reduction under the following experimental condition:the force aeration at the rate of 2.5 L/min, continuous force aeration within 5 days and then uncontinues force aeration (start 5 min stop 15 min).(4) In this experiment, force aeration at the rate of 2.5 L/min presented a greatest waste treatment than other treatments with a 6 days’thermophilic composting having temperature above 50℃ and 72.04% of substance reduction. Among different types of force aeration, the force aeration type with no force aeration within 2 days and then uncontinues force aeration (start 5 min stop 15 min) had a best reduction effect, presenting a reduction percentage of 64.55% and a 56.26% of dry matter loss.The frequency of leachate recycling was also optimized. A recycling interval of 6 days had a maximum dry matter loss of 51.81%. Overall, the optimal waste treatment in the solar-assissted reactor was:the force aeration at the rate of 2.5 L/min the force aeration type with no force aeration within 2 days and then uncontinues force aeration (start 5 min stop 15 min) and a recycling interval of 6 days.