Preliminary Studies on ZiBOC- A Potential Eco-friendly Wood Preservative
S Tripathi, J K Bagga, V K Jain
Over the past decade, the wood processing industry has been increasingly involved in strategies to minimize the environmental impacts of treated wood. One sign of this is the dramatic increase in the use of preservatives based on inorganic metal oxides, which fix in wood. Among such preservatives the most common is chromated-copper-arsenate. In Ascu chromium and arsenic both are carcinogenic thus in the present study a new and fixed composition of three chemicals (Copper sulphate, Zinc chloride and Sodium borate) has been used to develop an environment friendly preservative. The formulation is amorphous and water insoluble and dissolved with the help of co-solvents. Fixation study of ZiBOC in Chir and Poplar exhibited only 23.6, 13.1 and 12.1 % leachability of Copper, Zinc and Boron in Chir and 53.5, 6.5 and 5 % leachability of respective metals in Poplar. Efficient fixation of Zinc, Boron in both the species and Copper in Chir was achieved.
Efficacy against Polyporous versicolar (PV) and Poria monticola (PM) a white and brown rot fungus respectively showed that 0.50% concentration of salt (3.13 kg/m3) protected Poplar completely against both the fungus as compared to control whereas PV caused 18% and PM caused 52.1% weight loss in control samples. In Chir, 0.2%(1.39 kg/m3) and 0.1% (0.68 kg/m3) concentration of salt protected blocks completely against PM and PV respectively as compared to control (54 and 11.4% weight loss caused by PM and PV). Accelerated field test after three months of installation reveals full protection of both the species against termite & fungus. Scanning electron micrograph revealed the difference of parent individual salts with the derived product. Thus, study is directed to develop synergistic biocidal compositions that combine a copper salt and inorganic biocide, removing arsenic and chromium, giving fourth generation of preservatives.
Keywords: Co-biocide; eco-friendly preservative; leaching; scanning electron microscope