Sustainable strategy for municipal solid waste disposal in Hong Kong: current practices and future perspectives.

Hong Kong (HK) is confronted by increasing problems of solid waste disposal, as it is an overpopulated city with limited land resources. Currently, solid waste disposal mainly relies on three landfills located in the New Territories. However, the current waste treatment facilities and policies cannot appropriately control and manage increments of solid waste. The primary reason is the increased amount of municipal solid waste (MSW) caused by the growth of the population and the economy, with food waste accounting for the largest proportion of MSW in HK. The secondary reason is that the capacity of existing landfills will be exhausted in the near future as the level of waste generated continues to grow. To deal with these problems, in this paper, we propose five approaches with the aim of identifying the most sustainable strategy for efficient solid waste disposal in HK: a food waste recycling program; an MSW charging scheme; the implementation of incineration plants (i.e., waste to energy); black soldier fly bioconversion and a waste trading scheme; and black soldier fly bioconversion and a hybrid anaerobic digestion system. This is followed by a detailed demonstration of each approach, particularly focusing on the benefits, limitations, and implementation of each in the case of HK. The results of this study may shed light on how to effectively and sustainably manage the increasing amount of solid waste in HK.