Current research progress on carbon-sand filter process

In recent years, the problems of drinking water source pollution are constantly changing, and drinking water quality standards are also improved, which makes drinking water plants need to upgrade water treatment technology. The carbon-sand filter has many advantages such as small footprint, low capital and operating costs. As a dual-medium biofilter, carbon-sand filter has both strong adsorption performance of activated carbon and excellent retention function of quartz sand layer, at the same time, it can effectively remove organic matter and ammonia nitrogen in micro-polluted water depending on biological action. Therefore, it has been extensively studied and applied in recent years. However, there is still a lack of systematic summaries in this field. The influent conditions, filter material selection and operation scheme of carbon-sand filter have great influence on the system performance. It is worth to summarize the influencing factors of carbon sand filter, and find the synergistic effect of carbon-sand filter under multi-factor conditions, so as to solve the problems of filter material clog, poor backwashing effect and reduced compression of filter material service life. This article reviews the research progress of the carbon-sand filter process in terms of its working principle and function, filter media selection, parameter optimization, as well as problems and prospects in practical applications. The aim is to propose directions for subsequent research and further enhance the application prospects of the carbon-sand filter.