Study Of The Preparation Of Eco-concrete Incubated With Plant And Its Performance For Water Purification

With the increasing of public environmental consciousness, environmental friendly concrete is getting more and more attention. Ecological concrete (eco-concrete) is one of the main technologies to remedy water quality. Eco-concrete is a porous concrete, which can incubate microbes, plants as well as small animals. This combination may help for biodiversity, complexity of ecosystem and purification of water quality.This study developed an eco-concrete material which contained zeolite and excess sludge. The influences of void ratio and percentage of sludge to concrete of eco-concrete were investigated. Meanwhile, the performances of eco-concretes prepared under different conditions were examined.Results showed that void ratio had little influence on pH of eco-concrete leaching water, while excess sludge had greatly increased the pH to12. It was obvious that adding excess sludge and increasing the void ratio were beneficial for water purification, and the larger the void ratio of eco-concrete, the better water quality was obtained. In terms of water quality purification, the optimized fabrication parameters of eco-concrete were as follows:void ratio30%, the percentage of excess sludge15%, ratio of water to cement0.28, zeolite particle size20-30mm. With optimized eco-concrete, the total nitrogen (TN) removal rate reached68.0%, the total phosphorus (TP) removal rate was95.0%, and the removal rate of COD was as high as79.1%.In order to indentify the appropriate river bank protection plants, three plants of ryegrass, tall fescue, and clover were investigated for their endurance to water immersion. The results showed that tall fescue and perennial ryegrass are more tolerant to flood than clover. Considering the fact that lower part of the river banks are usually immerged under water especially during the rainy season, tall fescue and perennial ryegrass are recommended to be planted at the lower part of river banks, while clover at the upper part. Results obtained from the study of the vegetation performance of the eco-concrete, indicated that garden soil was suitable for filling the interior space of eco-concrete, which supported the growth of perennial ryegrass and clover without external supplement of nutrients.