Study On The Purification And Remediation Mechanism Of Indoor Aromatic Plants For Formaldehyde Pollution

Formaldehyde,as the number one“killer”for indoor pollution,poses a serious threat to human health.Adopting a green and cost-effective approach to improving indoor air quality is an integral aspect of the Healthy China initiative.Indoor aromatic plants have the capacity to release beneficial volatile organic compounds（BVOCs）that promote physical and mental well-being.These plants possess bactericidal and health-enhancing properties,particularly concerning indoor formaldehyde.Furthermore,plants offer high aesthetic value and environmental friendliness,striking a balance between ecological and economic benefits.Consequently,they represent an effective way to purify and remediate indoor formaldehyde pollution.At present,most of the relevant research at home and abroad focuses on the purification ability and resistance of indoor foliage plants to formaldehyde,leaving a need for further exploration of aromatic plants’purification and restoration mechanisms.The study of the purification and restoration mechanism of indoor aromatic plants aims to provide theoretical support for the screening of aromatic plants that can effectively purify and remediate indoor chemical pollution in the future.This study selected three common indoor aromatherapy plants,namely Gardenia Jasminoides,Jasminum Sambac,and Aglaia Odorata as research objects.The study employed a randomized area group design,establishing three different formaldehyde concentrations:1.00mg·m^-3,2.00 mg·m^-3,and 3.00 mg·m^-3.Formaldehyde conditions were simulated using a closed smoke method to assess the purification rate of plants at various concentrations,the purification capacity per unit leaf area,and the effects on physiological and biochemical indicators.By utilizing the average belonging to the function value method,the study comprehensively analyzed the purification and resistance abilities of the three plants,with the goal of identifying plants with strong adaptability.Additionally,correlation and principal component analyses were conducted on the selected plants to explain the mechanism underlying the purification and remediation of formaldehyde by indoor aromatic plantsThe research findings are as follows:1.Purification of formaldehyde by indoor aromatic plants（1）Indoor aromatic plants exhibited a significant purification effect on formaldehyde pollution.The purification rate and amount of formaldehyde varied significantly depending on plant species,formaldehyde concentration,and their interaction.Formaldehyde concentration had a more pronounced impact on the purification effects.（2）The concentration of formaldehyde was negatively correlated with the purification rate of the plant,and the decrease was increased.Conversely,it was positively correlated with the purification amount per unit of leaf area,and the increase was reduced.（3）Through comprehensive analysis using the average belonging to the functional value,it was concluded that Jasminum Sambac exhibited the strongest purification ability among the three indoor aromatic plants.2.Resistance of indoor aromatic plants to formaldehyde（1）The degree of damage to the three plants under formaldehyde pollution stress increased progressively with the severity of the stress.Among them,Aglaia Odorata exhibited a level of damage categorized as grade I,indicating the mildest injury and the strongest resistance.（2）The changes in plant indicators were also affected by plant species and formaldehyde concentrations at the same time.Under the same formaldehyde concentration,different plants exhibited variations in the content（activity）and rate of change of various indicators.Similarly,under different concentrations of formaldehyde,the same plant displayed variations in the content（activity）and rate of change of various indicators.The generation rate of superoxide anion(O₂^·-),the levels of malondialdehyde（MDA）and proline（Pro）,as well as the activities of peroxidase（POD）and ascorbate peroxidase（APX）,were significantly affected by formaldehyde concentration.Conversely,the content of chlorophyll（Chl）,soluble protein（SP）,and the activity of superoxide dismutase（SOD）exhibited more significant variations influenced by the plant species.（3）There were significant or highly significant differences observed among plant species and various indicators.The changes in indicators varied under different concentrations,and there were significant differences between the plants.The Chl content of the three plants decreased compared to the control group and gradually decreased with an increase in formaldehyde stress concentration.The generation rate of O2.-increased compared to the control group,while the levels of MDA,SP,and Pro increased.The activities of POD,SOD,and APX also increased and showed an increasing trend with an increase in formaldehyde stress concentration.（4）Through comprehensive analysis using the average membership function,it was determined that Aglaia odorata exhibited the strongest resistance among the three indoor aromatic plants.3.Purification and Remediation Mechanism of Indoor Aromatic PlantsCorrelation analysis of various indicators of Aglaia odorata in response to formaldehyde pollution stress showed significant or highly significant correlations for all indicators except the correlation between Chl content and purification amount,as well as MDA content and purification amount.Principal component analysis was conducted to identify important indicators for the purification and remediation of formaldehyde pollution by Aglaia odorata.These indicators included purification amount,purification rate,Pro content,SP content,Chl content,and APX activity.The principal component score of 45.97 was established as a reference value for evaluating the purification and remediation ability of indoor aromatic plants with similar indicators in environments with comparable pollution levels.The purification and remediation of formaldehyde by plants result from a complex interplay of substances within their bodies.When subjected to formaldehyde pollution stress,indoor aromatic plants experience an acceleration in the generation rate of reactive oxygen species,particularly the O₂^·-.This leads to the peroxidation of membrane lipids and an increase MDA content,thereby exacerbating membrane lipid peroxidation and causing damage to the plant’s photosynthetic and respiratory systems.Consequently,Chl content decreases.In response,the plants activate their purification and remediation mechanism,which involves an elevation in the activities of POD,APX,and SOD.Additionally,the contents of SP and Pro increase,facilitating the remediation of the biomembrane system and metabolic processes,and ultimately maintaining the integrity of cell structure.