본 연구는 10년 이상 과채류를 재배하여 뿌리혹선충 피해가 많이 발생되었던 시설재배 토양에서 친환경적인 뿌리혹선충방제를 위하여 밀기울 토양환원처리 효과를 구명하였다. 토양소독처리후 뿌리혹선충의 밀도를 조사한 결과 시험전과 비교하여 모든 처리구에서 뿌리혹선충밀도가 감소하는 경향을 보였지만 특히 밀기울처리구에서는 높은 방제효과를 보였다. 처리후 90일경에도 밀기울처리구가 매우 낮게 유지되었으며 멜론의 생육도 가장 양호하였다. 수확기 멜론의 고사율을 조사한 결과 무처리구 65%인데 비해 밀기울처리구, 3%로 현저히 낮았으며 과실의 크기와 품질도 밀기울처리구가 우수하였다. 따라서 밀기울 토양환원처리는 뿌리혹선충 발생포장에 농약을 사용하지 않고 멜론을 1작기 동안 안전하게 재배할 수 있는 유망한 소독방법일 뿐만 아니라 멜론의 품질을 개선하는데 매우 효과적인 방법으로 생각되었다.

Since the membrane distillation (MD) has attached to anaerobic fermentation (AF) process, all suspended solid contents including acetogenic and methanogenic microorganism can be retained inside the system to expect the more effective degradation of organic matter under operational parameters of hydraulic retention time (HRT) and solid retention time (SRT). In this study, we only focused to monitor the carbohydrate and protein parameters inside the single AF compared to the AF coupled with MD. Synthetic high-strength wastewater was used as a substrate by using the composition of 99 g glucose/L, 34 g/l NH4HCO3, 60 g yeast extract/L, 3 g KH2PO4/L, and K2HPO4 g K2HPO4/L. HRT was 20 days with feed flowrate of 0.3 L/d. The steady state of single AF and the AF coupled with MD were monitored for 60 days and 30 days, respectively. The configuration of AF coupled with MD used the circulation rate of 1.5 L/min, cross flow velocity of 0.014 m/s, and temperature difference of 30℃. pH changed from 7.6 in the single AF to 8.2 in the AF coupled with MD. The wastewater quality was analyzed everyday according to total carbohydrate, soluble carbohydrate, total protein, and soluble protein in the influent and effluent of both reactors. The average removal of total and soluble carbohydrate in the single AF were 98.4% and 97%, respectively. The average removal of total carbohydrate in the AF coupled with MD was 98% (in the effluent AF) and the average rejection was 97.8% (in the effluent MD as permeate). The average removal of soluble carbohydrate in the AF coupled with MD was 95% (in the effluent AF) and the average rejection was 97.5% (in the effluent MD as permeate). For the single AF, the average increased of total protein was 86% while the average removal of soluble protein was 42%. The average total protein in the AF coupled with MD increased to 75.6% in AF and the average rejection was 99.7% in the effluent MD. Furthermore, the average soluble protein in the AF coupled with MD increased to 87.7% in AF and the average rejection was 97% in the effluent MD. After attaching MD to AF, the hydrolysis microbial biomass changed by reducing the concentration of total protein and increasing the concentration of soluble protein in the AF process. This effect warrants further investigation which associated with changes in the microbiology in the microbiology or physicochemical aspects.

This study was conducted to investigate the effects of different carbon sources on the anaerobic fermentation characteristics in the startup phase using the biochemical methane potential test. The treatments for this experiment were combinations of carbon sources (starch, cellulose, and xylan). Anaerobic fermentation was done at 37oC for 18 days with agitation and pH, ammonia nitrogen, volatile solids reduction, gas production, methane content, and methane production were investigated at 0, 1, 2, 3, 4, 5, 7, 9, 12, 15, and 18 days after incubation in triplicate. In the experiment, the pH was changed depending on the characteristics of the carbon source. The ammonia nitrogen concentration was the highest in the starch-treated group at 7, 12, and 15 days after incubation (P < 0.05). Cumulative volatile solids reduction was the highest in the cellulose-treated group at 18 day after incubation (P < 0.05) and cumulative gas production was higher in the cellulose-treated group than for other two treatments at 18 day after incubation (P < 0.05). Methane content was the lowest in the xylan-treated group at 18 days after incubation (P < 0.05). Cumulative methane production was higher in the xylan-and cellulose-treated group than in the starch-treated group at 18 days after incubation (P < 0.05). In this study, the carbon sources had significant effects on anaerobic fermentation characteristics; especially, the carbon source was shown to have a positive effect on the operation time and hydraulic retention time for the anaerobic digestion startup phage. Therefore, carbon sources should be considered systematically for efficient anaerobic digestion of organic waste.