Comparative life-cycle assessment of water supply pipes made from bamboo vs. polyvinyl chloride

Abstract

Bamboo is one of earth's most plentiful natural materials and provides a high-quality alternative to many other raw materials. Utilizing bamboo can help to curtail global warming by decelerating the destruction of forests because it can be a good alternative to wood in its various applications. Bamboo winding composite pipe is a new developed product for water supply application. Life-cycle assessment is a tool used to evaluate the environmental impacts for the use of bamboo in pipes considering all stages of a water pipe's life from raw material extraction to the end of pipe life. In this study, the environmental impacts of polyvinyl chloride pipe and bamboo winding composite pipe were compared using SimaPro (Version 8.5) software. The results demonstrated that, all major indices of environmental impacts (except for the Eutrophication index) were significantly reduced by 1.1–488.8 times when bamboo winding composite pipes were used to replace polyvinyl chloride pipes for the water supply system. In addition, when the bamboo pipe was used to replace the polyvinyl chloride pipe, the cumulative energy demands were reduced by 3.40 times and the total environmental burdens (eco-indicator 99 points) were reduced by 7.19 times. The Building for Environmental and Economic Sustainability index (which is represented by equivalent CO2 uptake value in SimaPro software) was used to compare the different life cycle stages affecting environments. The results showed that the eq.CO2 index for the stage of production of bamboo winding composite pipe was 5.35 times of that of the stage of waste pipe disposal/degradation. In addition, the environmental impacts of six raw materials for the bamboo winding composite pipe (per functional unit), i.e., bamboo slivers, modified urea-formaldehyde resin, filling powder of walnut husk, Styrene E, cotton textile and bamboo fiber fabric, were compared using the eq.CO2 index. It was discovered that the urea-formaldehyde resin, Styrene E and cotton textile took the major parts affecting environment. The sensitivity analysis results indicated that the environmental impacts could be further reduced if 10% Styrene E and urea-formaldehyde was replaced with bamboo slivers. As a conclusion for this study, the major environmental impact indices were significantly reduced when the bamboo winding composite pipe was used to replace polyvinyl chloride pipe.