Review and Reflection on the Development Process of Soil Environmental Quality Standards in China

In this paper,the development process of the construction of soil environmental quality standards in China is reviewed,and the construction situation of soil environmental quality standards in typical developed countries is introduced.According to characteristics of soil environment and practice of soil environment management in China,the relevant suggestions are discussed,thereby further perfecting construction work of soil environmental quality standards in China.

Insights into the mechanism of multiple Cu-doped Co Fe_(2)O_(4)nanocatalyst activated peroxymonosulfate for efficient degradation of Rhodamine B

The multiple metal catalyst as a promising nanomaterial has shown excellent activity in the peroxymonosulfate(PMS)activation for pollutant degradation.However,the role of special sites and in-depth understanding of the PMS activation mechanism are not fully studied.In this study,a Cu-doped CoFe_(2)O_(4)nanocatalyst(0.5CCF)was synthesized by a sol-gel and calcination method,and used for PMS activation to remove Rhodamine B(RhB).The results showed that the Cu doping obviously enhanced the catalytic performance of CoFe_(2)O_(4),with 99.70%of RhB removed by 0.5CCF while 74.91%in the CoFe_(2)O_(4)within 15 min.Based on the X-ray photoelectron spectroscopy and electrochemical analysis,this could be ascribed to the more low valence of Co and Fe species generated on the 0.5CCF and faster electron transfers occurred in the 0.5CCF due to the Cu doping.In addition,Cu doping could provide more reaction sites for the 0.5CCF to activate PMS for RhB removal.The metal species and the surface hydroxyl were the reaction sites of PMS activation,and the surface hydroxyl played an important role in surface-bound reactive species generation.During the PMS activation,the Cu not only activated PMS to produce reactive oxygen species(ROS),but also regenerated Co^(2+)and Fe^(2+)to accelerate the PMS activation.The non-radical of ^(1)O_(2)was the main ROS with a 99.35%of contribution rate,and the SO_(5)^(·–)self-reaction was its major source.This study provides a new insight to enhance the PMS activation performance of multiple metal catalysts by Cu doping in wastewater treatment.