Application of ecological engineering in landfill remediation

Ecological engineering is a new branch of engineering based on ecology that emerged in the 1960s from the growing need for more sustainable biological solutions to environmental problems. It is based on the design of natural ecosystems for the benefit of both nature and human society, and its techniques can be applied to a range of environmental problems, from the restoration of degraded ecosystems to the removal of pollutants. One of the major environmental problems worldwide is waste disposal in the form of landfills, with its various negative impacts on the environment, living beings and human health. Conventional landfill closure and remediation techniques have proven to be economically and energetically challenging and are not sufficiently effective in reducing leachate formation and removing pollutants. For this reason, this article presents several ecological engineering techniques that can be used in landfill remediation. Phytocapping is an alternative to conventional cover systems that uses plants to control and limit water infiltration into waste, leachate formation, stabilize landfills, control erosion, and reduce methane emissions. Phytoremediation is an environmentally friendly technology for soil remediation through natural processes, in two forms: phytoextraction and phytostabilization. Phytoextraction uses plants to extract and remove pollutants from waste and soil, while phytostabilization is used to immobilize pollutants in the root zone. Constructed wetlands, designed and constructed according to the principles of natural wetland ecosystems, can be used to clean leachate. Natural attenuation uses natural biological processes to mitigate pollution without taking specific action. All of these techniques are based on viable natural solutions that can reduce remediation costs and further maintenance of the landfill. Although they are increasingly being considered in developed countries, there are few examples of their application in landfill remediation in Croatia.