To prevent environmental pollution caused by leakage of leachate from waste landfill, vinyl acetate-ethylene (VAE) resin is applied to liner and cover materials to improve their performance. Styrene, styrene butadiene rubber, and VAE are widely used as polymer resins that have excellent water resistance and durability. Further, VAE resin is known to have additional advantages such as adhesion to nonpolar materials and resistance to saponification as a copolymer. In this study, the effect of VAE content on the properties of liner and cover materials was studied. The water and air content ratios, bending and compressive strengths, water absorption ratio, and coefficient of permeability of these materials were measured. The liner and cover materials with 4 wt% VAE showed good properties.

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring 30×17×17 cm, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

At present research on mining backfill materials is being carried out to prevent ground subsidence and breaking by underground cavern of exhausted mines. However, backfill materials can cause secondary environmental issues such as ground pollution. To solve these issues, liner and cover materials are constructed before backfill materials constructed, to inhibit toxic substances form moving to the surroundings. Liner and cover materials, however, should have an accelerating performance after construction and when the accelerating performance is degraded, the work efficiency can be lowered, and the construction cost can be increased, by many rebound content. Therefore, this study develops mining liner and cover materials, and evaluates their accelerating performance and physical properties of liner and cover materials by types and content of accelerating agent. In case of aluminate accelerating agent, it is mixed with more than 5% of liner and cover materials(binder/ratio); thus an accelerating performance satisfying Korean Industrial Standards(KS) occurs, and in case of alkali-free accelerating agent, when it is mixed with more than 7%(binder/ratio), accelerating performance satisfying KS occurs. The more the accelerating agent capacity increases, the more compressive strength decreases. In addition, it is confirmed that compressive strength of aluminate accelerating agent is more degraded than compressive strength of the alkali-free accelerating agent. It is also confirmed that drying shrinkage stability of the alkali-free accelerating agent is better than the drying shrinkage stability of the aluminate accelerating agent.

1. 각 시험구에서 재배 2년째 시기별 에너지작물의 초장을 조사한 결과, 하수슬러지 고화물을 처리한 시험구에서의 에너지작물 중 거대 1호의 생육이 가장 우수하였으며 원지반토에서는 생육이 미비하였다. 2. 원지반토의 거대 1호 초장은 재배 1년차 97 cm에서 2년차 229 cm로 141% 증가하여 성장폭이 하수슬러지 고화물을 처리한 두 시험구의 거대 1호에 비해 우수하였다. 3. 각 시험구의 토양 pH는 하수슬러지 고화물을 처리한 후 2년이 경과하여도 일정하게 pH 7.2~8.4의 수준을 유지하고 있었다. 원지반토의 염농도는 하수슬러지 고화물을 처리한 두 시험구에 비해 월등히 높은 것으로 나타났으며 원지반토의 평균 염농도(0.27%)는 1년차의 염분 농도(0.31%)와 비교하여 조금 감소한 것으로 나타났다. 4. 원지반토의 평균 치환성 나트륨(Ex. Na) 함량은 8.99 cmol+kg1으로 하수슬러지 고화물 혼합구의 평균치(0.7 cmol+kg1)에 비해 약 12배 높았으며, 하수슬러지 고화물을 처리한 두 시험구에 비해 월등히 높았다. 5. 하수슬러지 고화물 처리 후 에너지작물 재배 1년차와 2년차 동일시기(5월, 11월)의 토양 유기물 함량은 1년차에 비해 2년차 증가하였음을 알 수 있었고, 특히 하수슬러지 고화물 복토구의 유기물 함량의 증가폭이 가장 우수하였다. 6. 간척지 토양에 하수슬러지 고화물 처리는 토양 무기양분의 공급, 염류의 상향이동 완충 효과, 작토층 및 근권확대로 인한 지하경의 정상적인 번식이 이루어져 원지반토에 비해 에너지작물 생육이 우수하여 하수슬러지 고화물처리는 토양복토재로써 간척지 토양의 화학성 및 물리성 개선에 효과적이었음이 확인되었다.