Minimising Nuisances by Covering Compact Sewage Treatment Plants

Abstract

Stringent effluent quality programs to limit wastewater discharges into receiving waters require extensive upgrading of conventional wastewater treatment plants. Large facilities built some decades ago are now often located in densely urbanised areas where land is unavailable. Since nitrogen and phophorus removal often require additional unit processes, innovative solutions have to be found to upgrade existing plants for nutrient removal. This paper shows large scale examples of compact technology and the additional upgrading flexibility provided. New facilities are implemented in sensitive neighborhoods by creative siting under sports stadiums, parks or buildings. In covered plants, air emission control becomes of primary importance. To reduce visual impacts and facilitate odour control, more and more underground treatment plants are constructed, allowing multiple use of plant surfaces. Several plants are illustrated in inner-city locations, avoiding infrastructure cost to pump sewage to remote sites. Most of the presented plants incorporate spacesaving settling facilities and high rate biological reactors to reduce the ‘footprints' of the installations and thus favour coverage. Parallel plates in primary setllers reduce the surface to about one tenth of conventional systems. Biocarbone aerated filters combine biodegradation with very high removal rates and retention of particles in one reactor, without additional clarification or filtration. Air treatment for large plant is mostly performed by chemical scrubbing, completely eliminating environmental nuisances. Performance results of both air and water treatment technology are given. Examples include recent sewage treatment plants on the French Mediterranean Coast. A physico-chemical treatment plant for 1 Million p.e. has operated since 1987 under a stadium in Marseille. In Monaco, the sewage treatment plant for 100 000 p.e.is located in the city center underneath a building of 3000 m2. Primary lamella settlers are followed by biological treatment on Biocarbone aerated filters and air is chemically deodourised. Similar technology is used in Antibes' 200 000 p.e. plant, integrated underneath a park close to the beach.

Phosphorus Removal from Wastewater Using Oven-Dried Alum Sludge

“…Filtration has been used either alone or in conjunction with a coagulation process as a means to remove phosphorus from wastewater [10,11]. High-rate sedimentation has also been attempted in some studies [12,13]. Among the various physical-chemical methods, coagulation with chemical precipitation and adsorption are the most common techniques being used for removing phosphorus.…”

Gaseous emissions from wastewater facilities

“…Controlled odor from a municpal wastewater treatment plant was controlled by enclosing the tanks and scrubbing emissions with hydrogen peroxide (Darman and France, 1992). Rogalla et al (1992) discussed the difficulty for wastewater treatment plants located in dense urban areas to upgrade in order to achieve nitrogen and phosphorus removal. Examples were given of constructing underground to enclose facilities and using chemical scrubbing to clean the waste gases.…”

“…In another review paper, chemical scrubbing using a nickel-based catalyst, and the latest developments in bioscrubbers, including the design, control, and long-term assessment of odor control installations were discussed (Valentin, 1993). VOC control strategies were reviewed by Ruddy and Carroll (1993), including information on process modification, equipment selection, and the control technologies thermal oxidation, catalytic oxidation, condensation, and carbon adsorption.…”

Le nouveau procédé Biostyr : l'azote et le phosphore traités à grande vitesse

“…Les visiteurs « éconscients » cherchent en vain les stations d'épuration le long de la côte d'Azur (Monaco, Antibes, Sanary Bandol, St-Tropez, La Ciotat, Toulon...) ou dans la région des Jeux Olympiques (Aime-La Plagne, Bourg-St-Maurice, Passy), non pas parce que ces lieux sensibles ne sont pas équipés de stations de traitement, mais parce que les ouvrages sont parfaitement dissimulés dans le paysage (5).…”