Impacts upon soil quality and plant growth of bamboo charcoal addition to composted sludge

In this research, the effects of bamboo charcoal on soil contaminant accumulation, soil fertility and plant growth were investigated. The results indicated that sludge composted with bamboo charcoal (BCS) significantly increased plant growth and decreased the mobility of Zn, Cu and polycyclic aromatic hydrocarbons (PAHs), compared with the composted sludge without bamboo charcoal (CS), with lower absorption and less accumulation of contaminants by the plants. Concentrations of Cu in turfgrass treated with CS were 11.7-23.4% higher than those of turfgrass treated with BCS. Concentrations of Zn in turfgrass treated with CS were 14.2-25.9% higher than those of turfgrass treated with BCS. The concentration of sigma 16PAHs (total contents of 16 PAHs that are listed by USEPA as priority pollutants for remediation based on their persistence and carcinogenic potential) in ryegrass grown in yellow loamy soil amended with CS was 680 microg kg(-1)) and was higher than that of ryegrass treated with BCS (only 439 microg kg(-1)). The biomass of fescue in BCS-treated soils increased by 13-16% compared with that of fescue in CS-treated soil. The biomass of ryegrass in BCS-treated soil was 20-27% higher than that in CS-treated soil. Chlorophyll content in turfgrass grown in CS-treated soil was lower than that in grass grown in BCS-treated soil. Compared with the control, chlorophyll contents in plants grown in soil with CS increased by about 13-22%, whereas those in plants grown in soil with BCS increased by about 20-32%.