ISSN:1093-4529    

DOI:10.1080/10934520009377032

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Integrated stormwater management is based on the natural processes in the water cycle and the criteria for sustainable development. The aim of this paper was to investigate which integrated stormwater system components might be suitable in cold climate regions. The evaluation was based on literature reviews and studies made in Luleå, Northern Sweden. It was found that porous pavement, grassed waterways (swales, ditches), wet pond, and percolation basin were themost suitableintegrated stormwater system components in cold regions whereas dry basin, stormwater infiltration surfaces, and stormwater reuse seemed to be theless suitable. Polluted snow may be treated at a central (large‐scale) snow deposit; cleaner snow may be placed in many local snow depots.

ISSN:1093-4529    

DOI:10.1080/10934520009377033

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In Sweden there is a growing interest for sustainable storm water management. In many cities full scale facilities are being constructed and investigated. Examples of such facilities are storm water ponds, wetlands, open ditches, infiltration and percolation basins, and different treatment devices as settling tanks, lamella separators and others. In the paper examples of different solutions are given. Results from some investigations are presented and the advantages and disadvantages of different methods is discussed. Criteria for sustainability of storm water facilities are suggested.

ISSN:1093-4529    

DOI:10.1080/10934520009377034

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Presence of ammonium nitrogen in small urban rivers in Japan due to domestic sewage inflow can lead to eutrophication of receiving lakes and can cause toxicity in aquatic systems, thus, emphasizing the need for direct purification of river waters until sewage treatment is provided. In this study, nitrification of small, polluted urban rivers in areas without centralized sewage works was experimentally examined using zeolite coated nonwovens (ZCN). NH4‐N adsorption by ZCN could be described by Freundlich adsorption isotherm withkand1/nvalues to be 0.28 and 1.17, respectively. The capacity of nonwovens to retain nitrifying activated sludge was determined to be 208 g‐MLSS/m2and the effluent from the nitrifying reactor packed with nonwovens was free of SS. The effectiveness of the zeolite coating on nonwovens was verified through two months of continuous nitrification treatment and it was found that the reactor packed with ZCN showed stable treatment at about 90% removal while the reactor packed with only nonwovens showed large fluctuations. The maximum allowable NH4‐N loading rate for 90 % removal of NH4‐N was determined to be 50 mg/L/d. Experimental results illustrated that this system was also capable of reducing TOC from 10 mg/L to less than 2 mg/L indicating that efficient simultaneous removal of TOC and NH4‐N is possible with ZCN. A protocol for culturing nitrifying microorganisms on nonwovens was also established.

ISSN:1093-4529    

DOI:10.1080/10934520009377035

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

An eleven year old constructed wetland system for storm water treatment at Stammersdorf near Vienna has to be redesigned. The small sand trap and the usage of loamy material as substrate for the main layer of the reed bed led to a rapid clogging of the system and to a very limited elimination rate. To obtain data for parameters (catchment hydrology, loading rates) for the new design, online measurements at the inlet of the system of water flow and some physical parameters were undertaken as well as sampling and analysis of the inlet water (TSS, TOC, NH4‐N). The new design includes two parallel ditches (each 1380 m3) which are a combination of settling and retention ponds. The regulated outlet of the ditches is now treated in the main treatment zone which is a horizontal subsurface flow constructed wetland (1500 m2) with coarse sand (1/4 mm) as main layer. The final structure is a polishing pond (800 m2) after which the effluent is recharged into the groundwater.

ISSN:1093-4529    

DOI:10.1080/10934520009377036

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The City of Toronto has built a stormwater management system, the Etobicoke Stormwater Management Facility (ESWMF), along the Lake Ontario shoreline. The Facility represents an innovative stormwater management solution that integrates two previously separate water quality improvement technologies ‐stormwater wetlands and flow balancing systems. The facility, besides improving water quality, will provide aesthetic, recreational and educational benefits. A conceptual plan to retrofit a wetland component within the ESWMF using three wetland design options is presented. The application of this ecotechnology at other stormwater discharges along the Toronto waterfront is discussed. The paper concludes with a review of the policy implications.

ISSN:1093-4529    

DOI:10.1080/10934520009377037

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Constructed wetlands provide good removals of BOD, COD, suspended solids, heavy metals, and pathogens from wastewaters being treated in them. However, although they are widely used in cold climates, winter operability often presents problems, and they normally only remove part of nitrogen and phosphorus nutrients in wastewaters being treated in them. What is needed was a new type of constructed wetland which removes nutrients as well as it does other contaminants, which operates better in cold weather, and which is able to handle especially difficult‐to‐treat wastewaters.

ISSN:1093-4529    

DOI:10.1080/10934520009377038

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Shell sand is a natural carbonatic material mainly produced by shells, snails and coral alga(Lithotaminion sp.). At some shallow coastal sites shell sand deposits are 5–10 m deep. One million tons of shell sand are harvested annually from Norway's coastline, mainly used as a liming product. Preliminary investigations indicate that shell sand has chemical and physical properties suitable for filter material in constructed wetlands and wastewater filters. Investigation of filtration properties show that shell sand has a high phosphorus sorption capacity, a variable hydraulic conductivity (60–2000 m/day), a high porosity (30–50%) and a relatively low bulk density (0.7 to 1 g/cm3). Column experiments with wastewater showed that shell sand removed phosphorus and organic matter (TOC) efficiently. Complete nitrification was achieved at high hydraulic loading (10 cm/day).

ISSN:1093-4529    

DOI:10.1080/10934520009377039

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

While constructed wetlands can be a cost‐effective method for reducing the export of P from agricultural ecosystems, removal rates vary widely. The objective of this research was to evaluate substrates that could consistently improve P treatment in these wetlands. We built eight 55 m2subsurface wetland cells on an 800‐head dairy farm in Newark, NY, USA, to test alternative substrates for removing soluble P from dairy barnyard runoff. The four media were (1) a fine loamy, mixed, mesic Glossic Hapludalf, (2) crushed limestone, (3) Norlite, lightweight coarse aggregates of fired shale, and (4) wollastonite (calcium metasilicate) mining tailings. Based on this research, we recommend Norlite for P removal in agricultural ecosystems. The native soil retained more soluble P but could not sustain subsurface flow. Wollastonite tailings warrant further research. They adsorbed 2 mg P/g in the laboratory but performed less well in the field, probably because of preferential flow.

ISSN:1093-4529    

DOI:10.1080/10934520009377040

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Fagernes, the only constructed wetland for wastewater treatment in the north of Norway, is located in the municipality of Lenvik. Despite the challenges presented by a cold climate the wetland has been operating well, and chemical and microbiological analyses shows that treatment efficiencies are high. This is particularly the case for COD and phosphorus. Total treatment efficiency for Tot‐N was very high (78%) in comparison with Haugstein, a similar wetland system in southern Norway. In Fagernes, a vertical flow pre‐treatment filter with light‐weight aggregates (Filtralite) aerates the wastewater, stimulates nitrification and binds phosphorus. Both horizontal subsurface flow wetlands (with sand and with light‐weight aggregates) have high phosphorous removal rates.

ISSN:1093-4529    

DOI:10.1080/10934520009377041

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor