Wastes, treatment

Processing methods for wastes should be compatible with the requirements of the receiving facility and acceptable to the Regulatory Body. 

Provision shall be made for adequate and reliable illumination in support of inspection and/or physical protection of spent fuel storage areas. 

For wet storage in pools, the pool area shall be provided with the necessary illumination equipment. The design shall address any requirements for underwater lighting near work areas and provide for replacement of underwater lamps. 

Materials used in underwater lighting shall be compatible with the environment and, in particular, shall not undergo unacceptable corrosion or cause any unacceptable contamination of the pool water. 

The physical, chemical, and biological methods are used to treat the waste just after its generation. 

The physical methods are used to concentrate and reduce waste volume, and to separate the different phases of waste, whereas the chemical treatment method is used to convert hazardous waste into nonhazardous by-products. 

Biological treatment is carried out with the help of microbes and enzymes to achieve the same goal as with the chemical treatment, especially for organic waste. 

Although incineration is the main process used for waste disposal, it is costly. Other methods, whenever possible, are chosen as alternative ways, and are used in conjunction with the other vmit process. For example, a typical process sequence might be decantation, sedimentation, biodegradation, followed by sludge agitation, and finally land-filling. 

This chapter consists of four main parts (i) sources of wastes and wastewater in the Asian region (ii) treatment of both solid waste and wastewater (iii) recycling as an emerging area of waste minimization and (iv) remediation ofpollnted areas. 

We can not here discuss the whole spectrum of waste production and treatment in the Asian region. Only some fundamental principles will be discussed with rather arbitrary selection of waste generation system and waste treatment facilities. You can find more information from additional recommended books and websites of interest at the end of this chapter. 

Municipal Solid Waste Types of municipal solid waste 

In the Asian cities, municipal solid waste (MSW) is generated from residences, commerce, institutions, construction and demolition, cleaning services and treatment plants. Generation rates ofMSW vary from city to city and season to season. In most of the Asian cities, these rates range from less than 0.5 to 0.8 kg per capita per day. Some cities have higher generation rates of more than 1.0 kg per capita per day. 

5 Tot l quafiEiTy Hitih-jncome countries Mirfdte-income countries [f Low hc-ams countries 

Small amounts of ammonia are added when needed as the nitrogen source for the bacteria in industrial and municipal biological waste treatment systems. Other industrial plants use minor amounts of ammonia to neutralize acid in plant 

Ammonia is used as a process chemical in photographic copy machines57. 

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Also, instead of using two separators, a purge can be used (see Fig. 4.2c). Using a purge saves the cost of a separator but incurs raw materials losses and possibly waste treatment and disposal costs. 

As with safety, environmental considerations are usually left to a late stage in the design. However, like safety, early decisions often can lead to difficult environmental problems which later require complex solutions. Again, it is better to consider effluent problems as the design progresses in order to avoid complex waste treatment systems. 

The whole problem is best dealt with by not making the waste in the first place, i.e., waste minimization. If waste can be minimized at the source, this brings the dual benefit of reducing waste treatment costs and reducing raw materials costs. 

The capital cost of most aqueous waste treatment operations is proportional to the total flow of wastewater, and the operating cost increases with decreasing concentration for a given mass of contaminant to be removed. Thus, if two streams require different treatment operations, it makes no sense to mix them and treat both streams in both treatment operations. This will increase both capital and operating costs. Rather, the streams should be segregated and treated separately in a distributed effluent treatment system. Indeed, effective primary treatment might mean that some streams do not need biological treatment at all. 

Freeman, H. M., Standard Handbook of Hazardous Waste Treatment and Disposal, McGraw-Hill, New York, 1989. 

The purpose of chemical processes is not to make chemicals The purpose is to make money. However, the profit must he made as part of a sustainable industrial activity which retains the capacity of ecosystems to support industrial activity and life. This means that process waste must be taken to its practical and economic minimum. Relying on methods of waste treatment is usually not adequate, since waste treatment processes tend not so much to solve the waste problem but simply to move it from one place to another. Sustainable industrial activity also means that energy consumption must be taken to its practical and economic minimum. Chemical processes also must not present significant short-term or long-term hazards, either to the operating personnel or to the community. 

FREEMAN Standard Handbook of Hazardous Waste Treatment and Disposal... 

R. E. Hiachee, G. D. Sayles, and R. S. Keen, eds.. Biological Unit Processes for Hazardous Waste Treatment, BatteUe Press, Columbus, Ohio, 1995. 

R. F. Hickey and G. Smith, eds.. Biotechnology in Industrial Waste Treatment and Bioremediation, Lewis PubUshers, Boca Raton, Fla., 1996. 

In 1987, Toray Industries, Inc., announced the development of a new process for making aromatic nitriles which reportedly halved the production cost, reduced waste treatment requirements, and reduced production time by more than two-thirds, compared with the vapor-phase process used by most producers. The process iavolves the reaction of ben2oic acid (or substituted ben2oic acid) with urea at 220—240°C ia the presence of a metallic catalyst (78). 

The carboxylated units, ionized, decrease adsorption on subterranean substrates (23), ia proportion to the number of units, an important parameter ia petroleum recovery processes. In waste treatment processes cationic acrylamide comonomer units are often used (31) to iacrease adsorption and thereby flocculation of soHds ia wastewater (see Acrylamide POLYMERS Flocculating agents). The favorable and characteristics of acrylamide facilitate the... 

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