An advanced oxidation process of combining cobalt and peracetic acid (Co/PAA) was developed to degrade sulfamethoxazole (SMX) in this study. The formed acetylperoxy radical (CH3CO3 •) through the activation of PAA by Co (Co2+) was the dominant radical responsible for SMX degradation, and acetoxyl radical (CH3CO2 •) might also have played a role. The efficient redox cycle of Co3+/Co2+ allows good removal efficiency of SMX even at quite low dosage of Co (<1 μM). The presence of H2O2 in the Co/PAA process has a negative effect on the degradation of SMX due to the competition for reactive radicals. The SMX degradation in the Co/PAA process is pH dependent, and the optimum reaction pH is near-neutral. Humic acid and HCO3 – can inhibit SMX degradation in the Co/PAA process, while the presence of Cl– plays a little role in the degradation of SMX in this system. Although transformation products of SMX in the Co/PAA system show higher acute toxicity, the low Co dose and SMX concentration in aquatic solution can efficiently weaken the acute toxicity. After reaction in the Co/PAA process, numerous carbon sources that could be provided for bacteria and algae growth can be produced, suggesting that the proposed Co/PAA process has good potential when combined with the biotreatment processes.
AimsTo evaluate current status of prostate cancer incidence and mortality worldwide, and compare the global trends of incidence and mortality in the past two decades and in the most recent period.MethodsData on the incidence and mortality of prostate cancer for 174 countries in 2020 were obtained from the GLOBOCAN 2020 database, and associations with the human development index (HDI) were evaluated. Data for trend analyses in 89 countries from 2000 to 2019 were retrieved from the Global Burden of Disease 2019 platform. Age standardized incidence rate (ASIR) and mortality rate (ASMR) were calculated by using the Segi's population. The average annual percent changes (AAPC) of ASIRs and ASMRs were evaluated by joinpoint regression analysis.ResultsA total of 1 414 259 new cases of prostate cancer and 375 304 related deaths were reported in 2020 globally. HDI was positively correlated with ASIRs (P < 0.001) and negatively correlated with ASMRs (P < 0.001). In the past two decades, ASIRs have been increasing in 65 countries, stable in 15 countries and decreasing in 9 countries, and ASMRs have been increasing in 19 countries, stable in 25 countries and decreasing in 45 countries, respectively. In the most recent period, 44 countries have increasing ASIRs, and 32 countries have decreasing ASMRs, respectively. For instance, in the United States of America, the AAPC of ASIRs significantly decreased by 0.62% and ASMRs significantly decreased by 1.22% from 2000 to 2019, while the AAPC from 2015 to 2019 significantly increased by 0.49% for ASIRs and significantly increased by 0.48% for ASMRs.ConclusionThe magnitude of increasing incidence and decreasing mortality of prostate cancer is attenuated in the recent period. Further study is needed to analyze the absolute effect of risk factors, PSA screening and treatment.
China 93 1.2 Production of textile industry pollution Textile Printing and dyeing processes include pre-treatment, dyeing and printing, finishing. The main pollutants are organic matters which come from the pre-treatment process of pulp, cotton gum, cellulose, hemicellulose and alkali, as well as additives and dyes using in dyeing and printing processes. Pre-treatment wastewater accounts for about 45% of the total, and dyeing/printing process wastewater accounts for about 50%~55%, while finishing process produces little. In China, chemical fiber accounts for about 69% of total in which polyester fibers accounts for more than 80%. Cotton accounts for 80% of the natural fiber production. Therefore, the dyeing wastewater analysis of production and pollution is based on these two fibers. Pre-treatment of cotton includes desizing and scouring. The main pollutants are the impurities in the cotton, cotton gum, hemicellulose and the slurry, alkali in weaving process. The current average COD concentration in the pre-treatment is 3000 mg/L. The main pollutants in dyeing/printing are auxiliaries and the residual dyes. The average concentration of COD is 1000 mg/L and the total average concentration is 2000 mg/L after mixing. Pre-treatment of polyester fibers mainly involves in the reduction with alkali. The so-called reduction is treating the polyester fabric with 8% of sodium hydroxide at 90 C for about 45 minutes. Some polyester fabrics will peel off and decompose into terephthalic acid and ethylene glycol so that a thin polyester fabric will have the feel of silk. This process can be divided into continuous and batch type. Taking the batch type as an example, the concentration of COD is up to 20000 mg/L-60000 mg/L. The wastewater from reduction process may account for only 5% of the volume of wastewater, while COD accounts for 60% or more in the conventional dyeing and finishing business. The chroma is one pollutant of the wastewater which causes a lot of concerns. In the dyeing process, the average dyeing rate is more than 90%. It means that the residual dyeing rate in finishing wastewater is about 10%, which is the main reason of contamination. According to the different dyes and process, the chroma is 200 to 500 times higher than before. pH is another factor of the dyeing wastewater. Before the printing and the dyeing process, pH is another factor ,the pH of dyeing wastewater remains between 10 to 11 when treated by alkali at high temperature around 90C in the process of desizing, scouring and mercerization. Polyester base reduction process mainly uses sodium hydroxide, and the total pH is also 10 to 11. Therefore, most dyeing water is alkaline and the first process is to adjust the pH value of the textile dyeing wastewater. The total nitrogen and ammonia nitrogen come from dyes and raw materials, which is not very high, about 10 mg/L. But the urea is needed while using batik techniques. Its total nitrogen is 300 mg/L, which is hard to treat. The phosphorus in the wastewater comes from the phosphor detergents. Cons...
Chemical oxidation using peracetic acid (PAA) can be enhanced by activation with the formation of reactive species such as organic radicals (R−O • ) and HO • . Thermal activation is an alternative way for PAA activation, which was first applied to degrade micropollutants in this study. PAA is easily decomposed by heat via both radical and nonradical pathways. Our experimental results suggest that a series of reactive species including R−O • , HO • , and 1 O 2 can be produced through the thermal decomposition of PAA. Sulfamethoxazole (SMX), a typical sulfa drug, can be effectively removed by the thermoactivated PAA process under conditions of neutral pH. R−O • including CH 3 C(O)O • and CH 3 C(O)OO • has been shown to play a primary role in the degradation of SMX followed by direct PAA oxidation in the thermoactivated PAA process. Both higher temperature (60 °C) and higher PAA dose benefit SMX degradation, while coexisting H 2 O 2 inhibits SMX degradation in the thermoactivated PAA process. With a variation of solution pH, conditions near a neutral value show the best performance of this process in SMX degradation. Based on the identified intermediates, transformation of SMX was proposed to undergo oxidation of the amine group and oxidative coupling reactions. This study definitively illustrates the PAA decomposition pathways at high temperature in aquatic solution and addresses the possibility of the thermoactivated PAA process for contaminant destruction, demonstrating this process to be a feasible advanced oxidation process.
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