Wyniki wyszukiwania - BazTech

1

The status and plan for municipal wastewater treatment in China

Yuwen Z., Xingpo L., Xiaoying Z.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

311-318

EN

The article consists of three segments: (1) the status of municipal wastewater treatment plant (WWTP) in China; (2) the current situation and the future development of urban treatment processes; (3) municipal sewage treatment program during the tenth "five year plan". China has commenced treating sewage since 1970, initially using the stabilization ponds. From the completion of the first wastewater treatment plant (1984) to 2000, 427 WWTPs were finished in china, including 282 secondary treatment plants. Meanwhile, the ratio of wastewater treatment reached 34.2 percent, approximately 15 percent of secondary treatment in particular. However, less town build wastewater treatment infrastructures in China. Eighty percent of the municipal WWTPs in China treated sewage employing activated sludge process, while others used primary treatment, enhanced primary treatment, the stabilization ponds, land treatment methods, etc. Ordinary aeration methods were adopted before 1980's, while AB process, the oxidation ditch, various styles of SBR, were frequently used after 1980's. With the increasingly focus on water environmental quality, national sewage comprehensive emission standards (revised: GB8978-1996) established stringent requirement, so the newly constructed WWTPs have to take de-nitrogen & de-phosphorus into consideration. Hence, many improved processes were developed and put into practice. In the presented paper, the recent innovation and the future trend of treatment processes were also involved. |According to the outline of the tenth national "five-year plan", the ratio of sanitary sewage treatment must reach 45 percent until 2005, in particular go up to 60 percent for large cities with more than 500,000 persons. During the tenth "five year plan" (2000-2005), 5 key projects related to water protection will be carried on execration, with a total investment of 684 billion RMB.

2

Status and planning layout of Beijing municipal wastewater treatment plants

Yuwen Z., Xiaoying Z., Xingpo L.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

319-325

EN

The status and planning layout of Beijing Municipal wastewater treatment plants are described, and the survey of several major wastewater treatment plants in Beijing is also showed here. In the past decade, the wastewater treatment in Beijing has developed rapidly. The capacity of wastewater treatment plants was up to 1,480,000 m3/d and the ratio of municipal wastewater treatment was near 50% in 2002. It is predicted that the ratio of wastewater treatment will be more than 85% in 2005. According to the overall plan of Beijing, 15 wastewater treatment plants will be in operation in 2008, At that time, the capacity of these 15 plants will be up to 3,160,000 m3/d. This will play a very important role in the alleviation of water pollution in Beijing. Beijing is a city lacking in water resource. The reuse of wastewater is an effective way to solve water crisis in Beijing. In the past decade, many attempts have been made in wastewater reuse, and certain achievements and valuable experience have been gained. At present, the capacity of wastewater reuse project in Gaobeidian wastewater treatment plant is 300,000 m3/d, and 60,000 m3/d in Jiuxianqiao plant. Among the 15 wastewater treatment plants, two plants are intended to treat wastewater for reuse. The reuse ratio is predicted to be 50% in 2008. This is very important to protect water resource and realize the sustainable development of water resource.

3

Status and countermeasures of sewage sludge treatment and disposal in Beijing

Xiaoying Z., Yuwen Z., Hongying R.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

511-517

EN

The problem of sewage sludge treatment and disposal is becoming more and more serious with the rapid development of sewage treatment in Beijing. In this paper, the status and problems of Beijing sewage sludge treatment and disposal are analyzed, and the components of sludge are also analyzed. At present, a sewage sludge treatment and disposal center is in operation in Beijing, treating and disposing the sludge from the 5 existing wastewater treatment plants in Beijing. It is an achievement, but also has certain problems which are needed to be solved for the safety use of sludge. The analysis of sludge components shows that there are rich plant nutrients and organics in the sludge, and also a large number of pathogenic microorganisms which needed to be killed. The concentrations of certain kinds of heavy metals exceed the Chinese standards of sludge for agricultural purpose. So it is very important to adopt rational and effective treatment processes to make sludge harmless before it is used for agricultural purpose or other purposes. The countermeasures probed here include: establish relative standards concerning sewage sludge treatment and disposal, study techniques of sludge volume reduction and thermal drying, study the utilization of sludge as resources, establish sewage sludge treatment and disposal center and improve the sewage sludge treatment and disposal processes.

4

Effects of pretreatment of dye wastewater using iron filings filtration and H2O2

Ruixia H., Peng L., Yuwen Z., Shuiyuan C.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

277-282

EN

China is the largest country in the world in production and exportation of dye. The wastewater from dye producing process is a serious source of pollution in natural water resources. Its ingredients are very complex and harmful to the environment. Most of the ingredients are man-made synthetic chemical materials that are very difficult to biodegrade, which makes bio-treatment methods inefficient. At present, there are no satisfactory methods for the treatment of the wastewater. This paper reports the result of pre-treating the dye wastewater by an Iron Filings Filter (IFF) + H2O2. Micro electrolysis action takes place with the IFF and produces Fe2+ ions, which form the Fenton oxidation reagent with added H2O2 in the influent. This can break and change the long-chains and link structures of the dye molecules or pollutants into biodegradable materials so that this wastewater may be further treated easily by biological methods. When only using the Iron Filings Filter (IFF), the BODs/COD value of the effluent increased by 0.2-0.3 more than that of the original wastewater at pH4 and hydro-remain time (HRT) 8 min. When 30%H2O2 was added to the influent at a rate of 8%o, the biodegradation of this wastewater was greatly improved so that bio-treatment is shown to be more efficient by using both IFF and H2O2.