Li Ruinan, Zhang Lu
College of Forestry, Beijing Forestry University, Beijing 100083, PR China.
College of Forestry, Beijing Forestry University, Beijing 100083, PR China.
Sci Total Environ. 2022 Jun 20;826:154166. doi: 10.1016/j.scitotenv.2022.154166. Epub 2022 Feb 25.
Composting is currently the best way to dispose of green waste (GW), which contains lignocellulose and other refractory substances that can prolong composting time. Although the natural degradation of litter involves photodegradation, few studies have considered the effects of photodegradation on GW composting. The current research investigated the influence of radiation with different spectral wavelengths (light-transmitting films were used to filter sunlight) on composting efficiency. Among six treatments that differed in the spectral wavelength of radiation, a no-UV-A treatment (the radiation between 320 nm and 380 nm was blocked by light-transmitting film) produced the best-quality compost product in only 34 days. Compared to the control (the full spectrum of light), the no-UV-A treatment increased total porosity, humus coefficient, optimal particle-size, and germination index by 10%, 2%, 3%, and 9%, respectively; increased available phosphorus, available potassium, and nitrate nitrogen by 21%, 17%, and 21%, respectively; decreased electrical conductivity, residual organic matter, and ammonium nitrogen by 9%, 13%, and 14%, respectively; and increased dehydrogenase, cellulase, and laccase activity by 76%, 66%, and 23%, respectively. These results indicated that the no-UV-A treatment resulted in the most complete degradation of lignocelluloses, the best nutrient properties, and the highest level of microbial activity in the GW compost. In addition, the bulk density, water-holding capacity, total porosity, void ratio, particle-size distribution, and coarseness index of the compost product were the closest to ideal ranges with the no-UV-A treatment and indicated that the no-UV-A compost product had the best granular structure in support of aeration, water drainage, and water retention. In a phytotoxicity assay, the compost produced by the no-UV-A treatment had the highest root length, seed germination rate, and germination index, indicating that the compost product was non-phytotoxic, mature, and suitable for use in agriculture and forestry.
堆肥是目前处理绿色废弃物（GW）的最佳方式，绿色废弃物含有木质纤维素和其他难降解物质，会延长堆肥时间。尽管枯枝落叶的自然降解涉及光降解，但很少有研究考虑光降解对绿色废弃物堆肥的影响。当前研究调查了不同光谱波长的辐射（使用透光薄膜过滤阳光）对堆肥效率的影响。在六种辐射光谱波长不同的处理中，无UV - A处理（320纳米至380纳米之间的辐射被透光薄膜阻挡）仅在34天内就产生了质量最好的堆肥产品。与对照（全光谱光）相比，无UV - A处理使总孔隙率、腐殖系数、最佳粒径和发芽指数分别提高了10%、2%、3%和9%；有效磷、有效钾和硝态氮分别增加了21%、17%和21%；电导率、残留有机物和铵态氮分别降低了9%、13%和14%；脱氢酶、纤维素酶和漆酶活性分别提高了76%、66%和23%。这些结果表明，无UV - A处理导致绿色废弃物堆肥中木质纤维素的降解最彻底，养分特性最佳，微生物活性水平最高。此外，无UV - A处理的堆肥产品的容重、持水能力、总孔隙率、孔隙比、粒径分布和粗度指数最接近理想范围，表明无UV - A堆肥产品具有最佳的颗粒结构，有利于通气、排水和保水。在植物毒性测定中，无UV - A处理产生的堆肥具有最高的根长、种子发芽率和发芽指数，表明该堆肥产品无植物毒性、成熟且适合用于农业和林业。
