Investigation on manhole sludge in Can Tho City

Abstract

During the rainy season, Can Tho city frequently faces severe flooding on its streets. In this study, the investigation is carried out on 30 streets and 10 canals nearby the streets in the center of Can Tho city. The results indicate that the surveyed manholes contain a lot of sludge with an average volume percent of 39.29%. In the food service areas, the average volume percent of sludge in manholes is found more than 70%. In the concentrated residential areas, the amount of sludge is less, but still at a relatively high rate (over 50%). In addition, the results show that the studied canals in the inner city are polluted due to waste directly from the drainage system. These issues have an effect on the drainage capacity of the roads. Some discussion on sand also shows that the sand shortage has reached an alarming level, which is the main factor leading to slow progress of some road projects. The sand reserves in the Mekong Delta region decrease sharply and the scarcity of sand causes sand prices to skyrocket, which is a difficult problem for this area. The development of mobile sludge treatment technology to produce a replacement material suitable for levelling and fertilizer purposes can be a potential topic for future research.