Effects of treated papermaking wastewater on the biological properties and enzyme activities of salt-affected soil

The main purpose of the study was to investigate the effect of irrigation with treated papermaking wastewater on microbe and enzyme activity in different depths of salt-affected soil. The soil irrigated with wastewater showed an increase in the amount of bacteria, fungi and actinomycetes in each depth, especially in topsoil. The amounts of bacteria, fungi and actinomycetes increased significantly in topsoil by 70%, 200% and 246%, respectively, compared to non-irrigation topsoil. The activities of urease and hydrogen peroxidease showed an evident increase in middle-layer soil and showed the following trend: middle-layer soil>topsoil>subsoil.