沼气工程高效稳定运行技术现状及展望

总结分析了沼气工程相关技术现状和技术需求,并对其未来发展进行了展望。我国的原料收贮和预处理技术亟待升级,仍需大量的科研投入以研发关键的核心技术装备。实现沼气工程运行情况的有效监测和及时预警,以及开发合适的微量元素添加剂和功能微生物菌剂对推动我国沼气工程的高效稳定运行具有重要意义。试验并研发新型膜材料和对常规材料的共混与改性处理是提高沼气膜分离提纯能力的主要手段。沼液的资源化利用技术是摆脱沼气工程可持续发展瓶颈的关键。结合沼气工程产业发展需求,充分论证技术瓶颈,合理配置科技资源,加大科技攻关投入,实现自主化技术研发、标准化工程设计、工厂化装备制造、模块化安装建设以及专业化安装调试等标准化集成,同时创新沼气工程技术的应用模式能更好地推动沼气工程技术的发展。     

Manure-based biogas fermentation residues – Friend or foe of soil fertility?

Anaerobic digestion of organic residues has the potential to significantly contribute to a shift from fossil to renewable energy. The by-product, anaerobic slurry, does have properties that are different from the undigested material. There are concerns of soil organic matter depletion in soils, enhanced greenhouse gas and odour emissions, and pathogen spread upon production and use of biogas slurries as fertilizer. However, considering the pros and cons, anaerobic digestion of residues does have positive effects for the climate, the environment and for the farmer, compared to the use of undigested matter.     

Effects of individual and combined use of bio-fumigation-derived products on the viability of Verticillium dahliae microsclerotia in soil

Verticillium dahliae is the causal agent of strawberry wilt. A microencapsulated terpene product containing cineole, camphor and borneol, digestate from anaerobic digestion, and BioFence™ derived from a mustard-based defatted seedmeal were tested for their suppressive activity against V. dahliae. First, naturally infested soil was amended with microencapsulated terpene, lavender waste pellet and BioFence™ (pellet) in a laboratory test to assess the efficacy against V. dahliae. Next, mini-field-plot experiments were conducted to evaluate the efficacy of individual and combined use of terpene, BioFence™ (liquid) and digestate against V. dahliae; sterile distilled water treatment and untreated control were also included. In the laboratory test, all treatments significantly reduced V. dahliae densities, with the control efficacy ranging from 27% (BioFence™) to 69% (lavender waste pellet). Although the lowest (1×) rate of terpene treatment resulted in a much lower control efficacy (35%) than the other two higher rates (3× – 55%; 9× – 53%), these differences were not statistically significant. In the field mini-plot trials, all treatments led to significant reductions in the V. dahliae density, with the efficacy ranging from 50% (digestate) to 78% (combined three-product treatment), irrespective of the initial wilt level. There were no significant differences in all comparisons of pairwise treatments except between digestate and combined three-product treatment. For the combined two or three-product treatments, the observed efficacy was significantly less than the expected efficacy on the assumption of Bliss independence. Furthermore, there were no significant differences between the observed efficacy of combined treatments and the best single component product efficacy. Although the observed efficacy for the combined three-product treatment was consistently higher than the best single component across replicate plots, such a difference was not statistically significant. The results indicate the value of these alternative treatments in practice but these are not likely to reduce V. dahliae inoculum sufficiently to eliminate the risk of strawberry wilt and question the value of combined treatments.