Review of the characteristics and graded utilisation of coal gasification slag

The characteristics of the energy structure of rich coal,less oil and less gas,coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal,have brought opportunities for coal chemical industry.However,with the large-scale popularisation of coal gasification technology,the production and resulting storage of coal gasification slag continue to increase,which not only result in serious environmental pollution and a waste of terrestrial resources,but also seriously affect the sustainable development of coal chemical enterprises.Hence,the treatment of coal gasification slag is extremely important.In this paper,the production,composition,morphology,particle size structure and water holding characteristics of coal gasification slag are introduced,and the methods of carbon ash separation of gasification slag,both domestically and abroad,are summarised.In addition,the paper also summarises the research progress on gasification slag in building materials,ecological restoration,residual carbon utilisation and other high-value utilisation,and ultimately puts forward the idea of the comprehensive utilisation of gasification slag.For large-scale consumption to solve the environmental problems of enterprises and achieve high-value utilisation to increase the economic benefits of enterprises,it is urgent to zealously design a reasonable and comprehensive utilisation technologies with simple operational processes,strong adaptability and economic benefits.

Effect of seasonal thermal stress on oxidative status,immune response and stress hormones of lactating dairy cows

This study aimed to assess the impact of seasonal thermal stress on oxidative stress,immune response,and stress hormones of lactating dairy cows in subtropical regions with different levels of temperature-humidity index(THI).A total of 32 healthy lactating Holstein dairy cows experienced 4 seasons(8 cows/season).The physiological parameters were categorized into low THI(LTHI,THI=42.97±0.95)in winter,moderate THI(MTHI,THI=61.84±0.42)in spring and autumn,and high THI period(HTHI,THI=86.09±0.23)in summer.The blood samples were collected twice in each season to measure oxidative stress,inflammatory and hormonal parameters.Our results showed THI had a positive cor-relation with the rectal temperature(R2=0.821,P<0.001)and respiratory rate(R2=0.816,P<0.001).Dry matter intake,milk yield and fat percentage also significantly differed among groups(P<0.05).Compared with the MTHI group,the LTHI group exhibited a significant increase in malondialdehyde(MDA)level(P<0.001),and the HTHI group displayed a significant increase in levels of cortisol,interleukin(IL)-10,IL-1βand tumor necrosis factor-α(P<0.001).Opposite changes in serum endotoxin and immunoglobulin G levels were observed with the increasing THI(P<0.001).LTHI notably increased the triiodothyronine level,although the thyroxine level was reduced by LTHI and HTHI compared with the MTHI group.In conclusion,LTHI and HTHI conditions may induce different degrees of oxidative stress,inflammation response,and stress hormone imbalances on lactating dairy cows,therefore envi-ronmental management is necessary for the health of dairy cows in extreme weather conditions.