Abstract:The carbon stocks in Guangdong Province in 2002,2012,and 2022 were assessed by means of the In VEST model,and the temporal and spatial evolution patterns were explored.The driving forces of the spatial variation of carbon stocks were analyzed by using geographic detectors.The results reveal that:(1)The total carbon stock in Guangdong Province rose from 2002 to 2022,with the stock feature in spatial distribution of"high in the north and low in the south".Qingyuan City had the largest proportion of carbon stock,Zhanjiang City witnessed the greatest increase,and the cities with the greatest decrease were mainly distributed in the northern part of Guangdong.(2)Carbon stocks are affected by multiple factors,with natural factors playing a dominant role.The interactive effect between the slope and NDVI factors and other factors is the most prominent.The research findings can offer a reference basis for Guangdong Province to optimize the allocation of land and space and achieve the dual carbon target.

Abstract:The research found that the mechanism of Fe2+and zero-valent iron activating persulfate for sludge dewatering is:Fe2+generates strong oxidizing free radicals to destroy extracellular polymeric substances,significantly reducing the sludge moisture content and specific resistance.Zero-valent iron has excellent reducing properties and can be recovered and reused,which can further reduce the sludge dewatering treatment cost.In addition,by enhancing the adsorption action and improving the structure of the sludge,the dewatering effect can be further improved.After sludge was treated with iron-activated persulfate,the sludge CST reduction rate ranges from 49％to 92％,the specific resistance reduction rate ranges from 40％to 96％,and the sludge moisture content was reduced to between 64％and 78％,making sludge dewatering not only highly efficient but also more environmentally friendly.It has broad promotional value for actual engineering applications.