Design considerations, wastewater

The successful design of an industrial wastewater treatment system is a complex decision and often integrated into site and process specific considerations. The quantity of wastewater can be established from an overall water balance. The quality is determined from the process design. The wastewater treatment unit operations will vary as a function of discharge requirements, reuse considerations, and economic reviews. 

Design considerations for the limestone flume are discussed elsewhere.7 8 The flume is a 500 ft long vee-section channel filled with txH in. crushed limestone to a depth of about 3 in., designed to neutralize 2 gpm of pH 4.0 mine wastewater to pH 6.3. 

Awad, Y. M. and Abuzaid, N. S. (1997) Electrochemical treatment of phenolic wastewater Efficiency, design considerations and economic evaluation. J. Environ. Sd. Health A 32, 1393-1414. 

The required design considerations for PAC-activated sludge wastewater treatment systems are ... 

Bartels CR, Will M, Andes K, and long J, Design considerations for wastewater treatment by reverse osmosis. Water Science and Technology 2005, 51(6-7), 473-482. 

Design considerations in the joint treatment of dairy and domestic wastewaters are the high chlorine demand and the presence of surface-active agents. In addition, cheese production wastewaters are usually nitrogen deficient. Septicity should be a consideration in the design of any equalization or clarification facilities. 

This chapter provides a state-of-the-art review of HFMST including a general review of hollow fiber membrane contactors, operating principles, design consideration, commercial availability of hollow fiber membrane, and module for scale-up and large-scale studies. Application of HFMST in pharmaceutical, biotechnological, gas absorption and stripping, wastewater treatment, and few latest studies of metal ion extraction are described in detail. 

Processes for SS separation may fill three distinct functions in wastewater treatment, namely, pretreatment to protect subsequent processes and reduce their loadings to required levels, treatment to reduce effluent concentrations to required standards, and separation of solids to produce concentrated recycle streams required to maintain other processes. In the first two functions effluent quality is the prime consideration, but where the third function must be fulfilled along with one of the others, design attention must be given to conditions for both the separated solids (sludge) and the process effluent. 

A sewer network and any corresponding treatment have traditionally been separately designed and operated. Two different and separate functions have been dealt with the sewer system must collect and convey the wastewater to the treatment plant, and the treatment plant must reduce pollution load into the receiving water according to the quality standards set. Consequently, sewers are often just considered input systems at the boundaries where they are connected with wastewater treatment plants and overflow structures that discharge untreated wastewater into watercourses during rainfall. This traditional approach to sewer performance needs considerable improvement. 

Against this background, a sustainable and integrated dimension of wastewater management in sewer networks is needed. The safe and efficient collection and conveyance of wastewater to treatment and disposal are still main concerns. The consideration of sewer processes as an element in the design and operation of sewers will give anew dimension to the overall objective of sewer management and contribute to improved sustainability. Therefore, the technical systems must be considered holistically ... 

When designing sewer networks, particularly gravity sewers, reaeration is the major process that should be focused on to reduce sulfide formation and the formation of organic odorous substances (cf. Section 4.4). A number of hydraulic and systems characteristics can be managed to increase the reaeration rate and avoid or reduce sulfide-related problems. The hydraulic mean depth, the hydraulic radius, the wastewater flow velocity and the slope of the sewer pipe are, in this respect, important factors that are dealt with in Section 4.4. It should be stressed that it is not necessarily the objective to avoid sulfide formation (in the sewer biofilm), but the sulfide that occurs in the bulk water phase should be at a low concentration level. Therefore, the DO concentration in the bulk water phase should not be lower than about 0.2-0.5 g02 m-3, sufficiently high to oxidize sulfide before a considerable amount is emitted to the sewer atmosphere. 

Krofta, M. Wang, L.K. Design of Dissolved Air Flotation Systems for Industrial Pretreatment and Municipal Wastewater Treatment - Design and Energy Considerations, AIChE National Conference, Houston, TX, NTIS-PB83-232868, 1983, 30 p. 

The Kuhni contactor (Fig. 13e) has gained considerable commercial application in Europe. Its principal features are the use of a shrouded turbine impeller to promote radial discharge within the compartments and a variable hole arrangement to allow flexibility of design for different process applications. Kuhni extractors are used for extraction of petrochemicals and chemicals, phosphoric acid purification, as well as hydrometallurgical applications and wastewater treatment. Columns up to 16.5 ft in diameter have been constructed. 

UV germicide mechanisms are introduced. Basic principles of UV disinfection system design, installation, and operation considerations are presented. The concern about UV disinfection by-products is also discussed. In addition, the mechanisms of UV oxidation are addressed. Its applications on organic pollutants decomposing as an emerging water and wastewater treatment technology are discussed. 

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