SIDE-BY-SIDE COMPARISON OF FOUR DIFFERENT MEMBRANE BIOREACTOR TECHNOLOGIES IN HAWAII

A side-by-side pilot study of five different membrane bioreactors (MBRs) is being conducted at the Honouliuli Wastewater Treatment Plant in Honolulu, Hawaii. The study is testing the MBRs on three different waste streams and examining performance and operational issues including pretreatment needs, effluent water quality, sludge characteristics, power and chemical usage, ease of operation, control complexity, cleaning and maintenance requirements, equipment durability, compatibility for retrofitting, scalability, technical support an spare parts availability, company experience and warranties, and life-cycle costs. All of the MBR systems have produced excellent quality water suitable for water recycling. Comparisons with existing recycled waters produced using sand filtration in Hawaii have indicated that MBR permeate is much better quality. Differences have been observed in the degree of complexity of MBR equipment, required amount of operator attention, membrane cleaning frequency, and power requirements.