At present,main sludge disposal manners of China contain landfill,composting,natural drying and incineration. A large number of sludge does not obtain standardized processing,which directly causes"secondary pollu...At present,main sludge disposal manners of China contain landfill,composting,natural drying and incineration. A large number of sludge does not obtain standardized processing,which directly causes"secondary pollution"and seriously threatens eco-environment. Therefore,how to rationally treat municipal sludge is one of problems that need urgent solution at present. In this paper,current mainstream pretreatment technique of municipal sludge and backend disposal technique are explored,and mainstream backend disposal technique is introduced. Moreover,key problems in municipal sludge disposal field are analyzed,which has certain reference significance for further understanding the current development of municipal sludge disposal field in China.展开更多
Oily cold rolling mill （CRM） sludge is one of metallurgical industry solid wastes. The recycle of these wastes can not only protect the environment but also permit their reutilization. In this research, a new proces...Oily cold rolling mill （CRM） sludge is one of metallurgical industry solid wastes. The recycle of these wastes can not only protect the environment but also permit their reutilization. In this research, a new process of ＂hydrometallurgical treatment ＋ hydrothermal synthesis＂ was investigated for the combined recovery of iron and organic materials from oily CRM sludge. Hydrometallurgical treatment, mainly including acid leaching, centrifugal separation, neutralization reaction, oxidizing, and preparation of hydrothermal reaction precursor, was first utilized for processing the sludge. Then, micaceous iron oxide （MIO） pigment powders were prepared through hydrothermal reaction of the obtained precursor in alkaline media. The separated organic materials can be used for fuel or chemical feedstock. The quality of the prepared MIO pigments is in accordance with the standards of MIO pigments for paints （ISO 10601-2007）. This clean, effective, and economical technology offers a new way to recycle oily CRM sludge.展开更多
In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi-continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease ...In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi-continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl = 15 g/L; in the three NaCl conditions, biodegradability of tested dyestuffs followed the following order: NaCl = 0 g/L>NaCl = 30 g/L>NaCl = 15 g/L.展开更多
Sludge quality is a critical factor influencing the economic and environmental performance of treatment and disposal processes.In many regions,sludge is typically characterized by a low organic matter content.Conseque...Sludge quality is a critical factor influencing the economic and environmental performance of treatment and disposal processes.In many regions,sludge is typically characterized by a low organic matter content.Consequently,the selection of sludge treatment and disposal routes should be tailored to the specific characteristics of sludge in each region,considering its dual attributes of“resource”and“pollution”,and aiming to maximize environmental,economic,and social benefits.Using the current sludge treatment and disposal situation in Wuhan,China,this study conducted a quantitative assessment of carbon emissions,environmental risks,and economic benefits associated with several existing treatment and disposal routes from a life cycle perspective.The results suggest that for sludge characteristics with low organic matter content,co-incineration in coal-fired power plants or cement production processes is the most favorable option.Specifically,when the organic matter content of the sludge falls below approximately 40%,cement production is deemed the preferred process,whereas co-incineration with coal is favored when the organic matter content exceeds 40%but is less than 50%.Owing to the relatively low organic matter and nutrient contents of sludge,optimization of existing anaerobic digestion and aerobic composting processes can be achieved through collaborative treatment with other solid wastes.Moreover,the prevailing carbon trading prices in the Chinese carbon market are relatively low and do not significantly impact the selection of current sludge treatment processes.This study aids in the development of sustainable management strategies for sludge characterized by low resource and pollution attributes in the future.展开更多
In China,over 1.43×10^(7)tons of dewatered sewage sludge,with 80%water content,were generated from wastewater treatment plants in 2007.About 60%of the COD removed during the wastewater treatment process becomes c...In China,over 1.43×10^(7)tons of dewatered sewage sludge,with 80%water content,were generated from wastewater treatment plants in 2007.About 60%of the COD removed during the wastewater treatment process becomes concentrated as sludge.Traditional disposal methods used by municipal solid waste treatment facilities,such as landfills,composting,or incineration,are unsuitable for sludge disposal because of its high water content.Disposal of sludge has therefore become a major focus of current environmental protection policies.The present status of sludge treatment and disposal methodology is introduced in this paper.Decreasing the energy consumption of sludge dewatering from 80%to 50%has been a key issue for safe and economic sludge disposal.In an analysis of sludge water distribution,thermal drying and hydrothermal conditioning processes are compared.Although thermal drying could result in an almost dry sludge,the energy consumption needed for this process is extremely high.In comparison,hydrothermal technology could achieve dewatered sewage sludge with a 50%–60%water content,which is suitable for composting,incineration,or landfill.The energy consumption of hydrothermal technology is lower than that required for thermal drying.展开更多
文摘At present,main sludge disposal manners of China contain landfill,composting,natural drying and incineration. A large number of sludge does not obtain standardized processing,which directly causes"secondary pollution"and seriously threatens eco-environment. Therefore,how to rationally treat municipal sludge is one of problems that need urgent solution at present. In this paper,current mainstream pretreatment technique of municipal sludge and backend disposal technique are explored,and mainstream backend disposal technique is introduced. Moreover,key problems in municipal sludge disposal field are analyzed,which has certain reference significance for further understanding the current development of municipal sludge disposal field in China.
基金financially supported by the National Key Technology R&D Program of China (Nos.2012BAC02B01,2012BAC12B05,2011BAE13B07,and 2011BAC10B02)the National High-Tech Research and Development Program of China (No.2012AA063202)+2 种基金the National Natural Science Foundation of China (Nos.51174247 and 51004011)the Science and Technology Program of Guangdong Province,China (No.2010A030200003)the Ph.D. Programs Foundation of the Ministry of Education of China (No.2010000612003)
文摘Oily cold rolling mill （CRM） sludge is one of metallurgical industry solid wastes. The recycle of these wastes can not only protect the environment but also permit their reutilization. In this research, a new process of ＂hydrometallurgical treatment ＋ hydrothermal synthesis＂ was investigated for the combined recovery of iron and organic materials from oily CRM sludge. Hydrometallurgical treatment, mainly including acid leaching, centrifugal separation, neutralization reaction, oxidizing, and preparation of hydrothermal reaction precursor, was first utilized for processing the sludge. Then, micaceous iron oxide （MIO） pigment powders were prepared through hydrothermal reaction of the obtained precursor in alkaline media. The separated organic materials can be used for fuel or chemical feedstock. The quality of the prepared MIO pigments is in accordance with the standards of MIO pigments for paints （ISO 10601-2007）. This clean, effective, and economical technology offers a new way to recycle oily CRM sludge.
文摘In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi-continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl = 15 g/L; in the three NaCl conditions, biodegradability of tested dyestuffs followed the following order: NaCl = 0 g/L>NaCl = 30 g/L>NaCl = 15 g/L.
基金supported by the Technical Service Foundation,China University of Geosciences(Wuhan)(No.122-KH2360504).
文摘Sludge quality is a critical factor influencing the economic and environmental performance of treatment and disposal processes.In many regions,sludge is typically characterized by a low organic matter content.Consequently,the selection of sludge treatment and disposal routes should be tailored to the specific characteristics of sludge in each region,considering its dual attributes of“resource”and“pollution”,and aiming to maximize environmental,economic,and social benefits.Using the current sludge treatment and disposal situation in Wuhan,China,this study conducted a quantitative assessment of carbon emissions,environmental risks,and economic benefits associated with several existing treatment and disposal routes from a life cycle perspective.The results suggest that for sludge characteristics with low organic matter content,co-incineration in coal-fired power plants or cement production processes is the most favorable option.Specifically,when the organic matter content of the sludge falls below approximately 40%,cement production is deemed the preferred process,whereas co-incineration with coal is favored when the organic matter content exceeds 40%but is less than 50%.Owing to the relatively low organic matter and nutrient contents of sludge,optimization of existing anaerobic digestion and aerobic composting processes can be achieved through collaborative treatment with other solid wastes.Moreover,the prevailing carbon trading prices in the Chinese carbon market are relatively low and do not significantly impact the selection of current sludge treatment processes.This study aids in the development of sustainable management strategies for sludge characterized by low resource and pollution attributes in the future.
基金the National High Technology Research and Development Program of China(Grant No.2006AA06Z384).
文摘In China,over 1.43×10^(7)tons of dewatered sewage sludge,with 80%water content,were generated from wastewater treatment plants in 2007.About 60%of the COD removed during the wastewater treatment process becomes concentrated as sludge.Traditional disposal methods used by municipal solid waste treatment facilities,such as landfills,composting,or incineration,are unsuitable for sludge disposal because of its high water content.Disposal of sludge has therefore become a major focus of current environmental protection policies.The present status of sludge treatment and disposal methodology is introduced in this paper.Decreasing the energy consumption of sludge dewatering from 80%to 50%has been a key issue for safe and economic sludge disposal.In an analysis of sludge water distribution,thermal drying and hydrothermal conditioning processes are compared.Although thermal drying could result in an almost dry sludge,the energy consumption needed for this process is extremely high.In comparison,hydrothermal technology could achieve dewatered sewage sludge with a 50%–60%water content,which is suitable for composting,incineration,or landfill.The energy consumption of hydrothermal technology is lower than that required for thermal drying.
