ISSN:1093-4529    

DOI:10.1080/10934520009377069

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

China is facing serious water pollution problems. Only 15 % of the municipal wastewater is appropriately treated each year. A lack of funds is one major obstacle facing the construction of wastewater treatment plants. Conventional treatment technology such as activated sludge process has both relatively high capital and operational costs. An alternative to this dilemma is to develop and apply the technologies with lower costs or better performance. This paper reviewed the appropriate technologies for municipal wastewater treatment in China. Based on both research and engineering practice, four technologies, including natural purification systems, highly efficient anaerobic processes, advanced bio‐film reactors and membrane bioreactors were discussed in detail.

ISSN:1093-4529    

DOI:10.1080/10934520009377070

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A pilot‐scale membrane bioreactor was tested for its long‐term performance in domestic wastewater treatment. The treatment capacity was 5.5 m3/d. Over 300 days were maintained. The results demonstrated that a high‐quality effluent with COD<30 mg/L and NH3‐N<1 mg/L can be obtained. The bioreactor degraded 70% of the influent COD, while the membrane separation insured 90% of the total COD would be removed. The biomass morphology and the molecular weight distribution of the organic substances were also investigated. It was observed under a scanning electronic microscope (SEM) that sludge deposition, gel‐layer formation and microbial growth caused the membrane fouling. The membrane fouling can be under control through clear‐water washing, intensified aeration and NaClO solution in‐line cleaning.

ISSN:1093-4529    

DOI:10.1080/10934520009377071

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The specific strain,Flavobacterium sp. BX26, was examined to decolorize bromamine acid, which is an important intermediate for the synthesis of anthraquinone dyes. The results showed thatFlavobacterium sp. BX26 had a high capacity to decolorize bromamin acid within a relatively short time. The decolorization was an inductive process.Flavobacterium sp. BX26 cannot use bromamine acid for growth, but its metabolic intermediates were. It was found that the decolorizing process mainly took place outside the cells or the functional enzymes might be extracellular enzymes. Some factors including salinity, heavy metal ions, complexing agent like EDTA, and the lack of oxygen can seriously inhibit the decolorization process.

ISSN:1093-4529    

DOI:10.1080/10934520009377072

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

An innovative combination using a sequencing batch reactor (SBR) with iron filing filtration was developed for the treatment of dyeing wastewater. Iron filing filtration served as a pretreatment process to improve the biodegradability of wastewater. Thus the potential of a sequencing batch reactor can be better exerted to decompose toxic substances more efficiently. The experimental results demonstrated that 85% COD and over 90% BOD5and color can be removed when the influent COD ranged from 1000 mg/L to 1500 mg/L, BOD5from 200 mg/L to 400 mg/L and color from 200 to 800 times. The combination processes were specifically suited for the treatment of dyeing wastewater containing oxidative dyes.

ISSN:1093-4529    

DOI:10.1080/10934520009377073

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The combination of an activated sludge process with powdered activated carbon can enhance the process efficiency of wool‐dyeing wastewater treatment. In addition to decolorization by direct adsorption, the powered activated carbon can also support the growth of activated sludge as a medium. Thus the biomass of the activated sludge increased significantly. The experimental results demonstrated that the combination of the activated sludge with powdered activated carbon was able to effectively decolorize the wool‐dyeing wastewater. When the biomass content was 2 g/L, and powdered activated carbon content was 2g/L, the decolorization yield reached 86%. The synergistic mechanism was further explored.

ISSN:1093-4529    

DOI:10.1080/10934520009377074

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In this paper, anoxic/anaerobic/aerobic processes were developed to remove nitrogen and phosphorus from wastewater more efficiently. Laboratory experiments were conducted, and the results demonstrated that the innovative combined processes have a much higher efficiency in the removal of nitrogen and phosphorus than the commonly used anaerobic/anoxic/aerobic processes. The removal rates of nitrogen and phosphorus can be increased by about 50% on average. In addition, the new combination can also simplify the process operation of sludge cycles.

ISSN:1093-4529    

DOI:10.1080/10934520009377075

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In this paper, the performance of a well designed anaerobic baffled reactor (ABR) under shock load was tested with pentachlorophenolic sodium (PCP‐Na). The reactor tested had a capacity of 16.2 L and consisted of 5 compartments. Normal operation conditions included a COD of 1150 mg/L and a PCP‐Na of 1.5 mg/L. The shock load was generated using a PCP‐Na influent at 17.5 mg/L. The experimental results demonstrated that the ABR system was able to cope with the toxic shock load tested. The determined acetate and methane production indicated that acidogens and methanogens in the first two compartments might be inactivated, but its impacts on the other compartments were relatively light and could quickly recover.

ISSN:1093-4529    

DOI:10.1080/10934520009377076

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Four oxidation processes involved ozonation (O3), ultraviolet irradiation (UV), O3/UV and TiC2/UV to degrade mono‐ and tri‐chloroacetic acids present in drinking water were compared. The results showed that ozonation was relatively inefficient for the destruction of the chloroacetic acids tested. UV irradiation was much more efficient than ozonation. But the combination of UV with either O3or TiC>2powder did not make much difference. It was found that fiber‐TiO2/UV was the best combination of the four oxidation processes tested, especially in regards to the refractory tri‐chloroacetic acids. The T1O2fiber was highly practical because it is easily separated and recovered.

ISSN:1093-4529    

DOI:10.1080/10934520009377077

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The mutagenicity and acute toxicity of source water, water from five different treatment units as well as tap water from waterworks in Beijing were studied. The aim of this research was to examine the seasonal variation of water toxicity during water treatment processes, and to evaluate the effects of each treatment process. The results indicated the existence of frame shift mutagens in the source water in Beijing, but not base pair substitute mutagens. Prechlorination, coagulation and chlorination may cause mutagenic effects to increase, while coal‐sand filtration and granular activated carbon adsorption may remove most of the mutagens formed. Similar conclusions were drawn from the acute toxicity assay.

ISSN:1093-4529    

DOI:10.1080/10934520009377078

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor