Study On The Characteristics And Process Of Combined Anti-mold Treatment Based On Biocides And White-rot Fungi For Bamboo

Due to its high content of nutrients such as starch,protein,and fat,bamboo is prone to mold growth in high humidity environments,leading to a decrease in appearance and lifespan.Impregnated fungicides are currently the most common method used for mold prevention,but due to bamboo’s lack of lateral conductive tissue and poor permeability,the efficacy and stability of modified bamboo are limited.Therefore,this study focused on Phyllostachys edulis and investigated changes in bamboo structure,composition,and properties during the pre-treatment process with the white-rot fungus Trametes versicolor.A water-based organic compound fungicide with high efficacy and strong permeability was selected,and the process parameters for the white-rot fungus-fungicide combined treatment were optimized.This study developed a green and long-lasting mold-resistant modification technology for efficient utilization of bamboo resources,and its main conclusions are as follows:1.Determine the influence of white rot fungus pretreatment on the performance of bamboo.With the increase of pretreatment time,the permeability of bamboo improves,the content of starch and reducing sugar decreases significantly,the mechanical and anti-mold properties of bamboo remain unchanged,and the content of cellulose,hemicellulose and lignin in bamboo changes slightly.When the pretreatment reached 30 days,the water absorption rate of bamboo increased from 37%of untreated bamboo to 54%,and the degradation rates of starch and reducing sugar were 93%and 88%respectively.2.Screening of green and efficient organic fungicides.Based on the antibacterial activity and soaking prevention of mold results,the laboratory-produced DIB fungicide(isothiazolone and aminomethanesulfonyl derivatives)has excellent penetration,antibacterial activity,and anti-loss properties.After 1%DIB pressure impregnation treatment,the efficacy of modified bamboo against mold prevention reached 100%.After 336 hours of loss testing,the retention rate of key effective ingredients in modified bamboo was over 75%.This overcomes the disadvantage of water-based fungicides being easily lost,and therefore DIB was chosen as the fungicide for subsequent experiments.3.Optimize the process parameters of the joint treatment of white-rot fungi and fungicide,and conduct outdoor anti-mold tests.According to the analysis of the results of orthogonal experiments,the pre-treatment time of white-rot fungi is the main factor affecting the amount of drug loading and anti-mold efficiency of modified bamboo material with joint treatment,followed by impregnation pressure,and the influence of impregnation time is not significant.After 20 days of pre-treatment with white-rot fungi and DIB pressurized impregnation(concentration of 0.5%)joint anti-mold treatment,no mold growth was observed on the surface of modified bamboo material after the 28-day anti-mold test,and the anti-mold efficacy reached 100%.Optimal process conditions for the combined treatment of white rot fungi and fungicides were determined to be a pre-treatment time of 20 days,an impregnation pressure of 1.2 MPa,and an impregnation time of 1 hour.The results of an orthogonal experiment were validated by using bamboo strips of two different lengths(2500mm and 1000mm),showing that the water absorption rate of bamboo was increased from 60%in the group without white rot fungi pre-treatment to 72%～78%.Results of an outdoor anti-mold performance test showed that after a period of 90 days,the antifungal efficacy of modified bamboo treated only with fungicide had been somewhat improved compared to the untreated group,but there were still some fungal spots on the surface.The surface of bamboo wood modified by joint processing is free from fungal growth,and the efficiency of mold prevention and control reaches 100%,confirming the reliability of process optimization results.