The main reason is that this experiment was conducted during my being in University of Florida, USA as a visiting scholar. Worse more, the soil can not be brought to China. Indeed, in this study, the analysis of biomass and microorganism of the soil samples is essential. But I did not do that. My visiting time is only one year. At the end, I had no time to complete and analysis the microbial community and biomass of the soil samples. But in the further study of the NP isomers in reclaimed water soil, this should be taken into account.
I strongly recommend the authors to analysis the biomass of the soil samples.