Finding optimal recycling strategies of wood ash, composted sludge, paper biosolids and lime slurry for plantation forestry in Quebec

在魁北克，造纸厂和热电厂每年产生数千吨森林生物质燃烧产生的灰烬。在未来几年，随着对气候变化、油价上涨和能源安全的担忧，越来越多地使用森林生物质作为燃料，灰烬产量必然会增加。此外，自1978年通过废水处理法以来，魁北克在20世纪80年代至90年代期间建造了700多座废水处理厂。市政当局必须管理大约100万吨污水污泥(市政生物固体)的处置。 魁北克新政府关于林地可持续管理的法律于2013年生效，旨在加强15%至20%的林地的木材生产。另一方面，魁北克对工业和城市垃圾处理的环境法规越来越严格，导致处理成本大幅增加。立法方面的这些变化正在为森林业和市政当局创造机会之窗。灰烬、生物固体和堆肥后的城市污泥等残余物是已知的养分和有机物质来源，可用作森林土壤的改良剂，以提高森林生产力或恢复严重干扰的土壤。这种做法还可能产生碳信用，因为它们有利于土壤碳封存。 该提案旨在加强魁北克在利用工业和城市废物作为森林土壤改良剂方面的科学专门知识。该提案将一些已经或正在开发的独立试验重新组合在一起。他们的目标是评估木灰、纸张生物固体、石灰浆和氮肥在不同组合中的潜力，以纠正养分失衡，改善土壤质量和改善针叶树和杂交杨树人工林的生长。还利用新鲜和堆肥的城市污泥进行了土壤复垦研究。痕量金属和病原体对陆地和水生生态系统(地表水质量)健康的威胁的命运也将是这一大型项目的重点。

Thousands of tons of ash from forest biomass combustion are being produced each year in Quebec by paper mills and cogeneration power stations. In the coming years, ash production is bound to rise with the increasing use of forest biomass as a fuel in response to concerns over climate change, swelling oil prices, and energy security. Additionally, more than 700 wastewater treatment plants were built in Québec between the 1980s and 1990s following the adoption of a wastewater treatment law in 1978. Municipalities must manage the disposal of approximately one million tons of sewage sludge (municipal biosolids). The new Québec Government's law on the sustainable management of forested land, coming into effect in 2013, aims to intensify wood production on 15 to 20% of the forested land mass. On the other hand, Québec's environmental regulations for industrial and municipal waste disposal are becoming more stringent, resulting in large increases in disposal costs. These changes in legislation are creating a window of opportunities for forest industries and municipalities. Residual wastes such as ash, biosolids and composted municipal sludge are known sources of nutrients and organic matter and could be used as amendments for forest soils to increase forest productivity or to restore severely disturbed soils. Such practices could also give rise to carbon credits because they favor soil carbon sequestration. The proposal aims at strengthening Quebec's scientific expertise in the use of industrial and municipal wastes as forest soil amendments. The proposal regroups a number of independent trials that were or are currently being developed. They aim to assess the potential of wood ash, paper biosolids, lime slurry and N fertilizers in various combinations to correct nutrient imbalances and improve soil quality and growth of conifer and hybrid poplar plantations. A soil retoration study using fresh and composted municipal sludge is also conducted. The fate of trace metals and pathogens as a threat to the health of terrestrial and aquatic ecosystems (surface water quality) will also be a focus of this large project.