End of Pipe Treatment

Treat the effluent using incineration, biplogical digestion, etc. to a form suitable for discharge to the environment, called end-of -pipe treatment. 

The problem with relying on end-of-pipe treatment is that once waste has been created, it cannot be destroyed. The waste can be... 

The common practice in waste management is either to recycle waste or to treat and dispose of it at the end of a process. However, many end-of-pipe treatment processes simply transfer a waste, albeit sometimes in a different chemical form, from one environmental medium (i.e. air, land or water) to another often at high dilution. 

List several reasons why pollution prevention tends to be more cost-effective than end-of-pipe treatment. Be specific with some concrete examples. 

It should be emphasized, however, that pollution prevention techniques are, nevertheless, often more cost-effective than pollution reduction through end-of-pipe treatment technologies. A case study based on the Amoco/EPA joint study claimed that the same pollution reduction currently realized through end-of-pipe regulatory requirements at the Amoco facility could be achieved at 15% of the current costs using pollution prevention techniques. 

Make no mistake about it - air pollution abatement, especially based upon end-of-pipe treatment technologies is expensive. Not too long ago the prevailing attitude among industry stakeholders was that air pollution control was simply a part of the cost of doing business, and that add-on costs associated with compliance simply had to be passed on to the consumer s purchase price for products. With the intensity of international competition in the chemical and allied industries, this philosophy simply does not cut it anymore. 

Although it is generally thought of as typical end-of-pipe treatment technology, the maimer in which it can be applied enables it to be used in pollution prevention applications. Figure 9 shows an installation in a steel mill operation. 

Condensation scrubbing systems are a relatively new technology and are not yet generally commercially available. It may be argued that this is a pollution prevention type of technology since it replaces other approaches to controlling very fine PM, although the primary role is end-of-pipe treatment. 

Do you see the potential advantage of P2 over an end-of-pipe treatment option ... 

The most important aspect of this is that profits can be increased by either an increase in revenues or a decrease in expenses. Water treatment operations are by and large end-of-pipe treatment technologies, and hence from the standpoint industry applications that must treat water, the investments required increase expenditures and decrease profit. Municipal facilities view their roles differently, because their end-product is clean water which is saleable, plus they may have addon revenues when biosolids are developed and sold into local markets. There are different categories of revenues and expenses, and it is important to distinguish between them. 

End-of-pipe treatment refers to the application of chemical, biological, and physical processes to reduce the toxicity or volume of downstream waste. Treatment options include biological systems, chemical precipitation, flocculation, coagulation, and incineration as well as boilers and industrial furnaces (BIFs). 

Lack of global harmonization on regulation/ environmental policy Legislation - cost of end-of-pipe treatment... 

It should be noted that in all cases the size (and hence cost) of end-of-pipe treatment has a direct relationship to both the volume of effluent to be treated and the concentration of pollutants contained in the discharge. For example, the size of most physicochemical reactors (balancing, neutralizing, flocculation, sedimentation, flotation, oxidation, reduction, etc.) is determined by hydraulic factors such as surface loading rate and retention time. 

It is evident therefore that the reduction of emissions by action at source can have a significant impact on the size and hence the cost of an end-of-pipe treatment system. On this basis, it should be established practice in industry that no capital expenditure for end-of-pipe treatment should be made until all waste reduction opportunities have been exhausted. This has not often been the case, and many treatment plants have been built that are both larger and more complicated than is necessary. 

The UNIDO project Demonstration of Cleaner Production Techniques 11 demonstrates that the concept of preventing wastes at their source as opposed to end-of-pipe treatment is as applicable and profitable in developing countries as in developed countries. The experience gained as well as the demonstrations produced will be of great value in the promotion and implementation of a Cleaner Production Program. 

Many facilities in this industry use in-plant technology to reduce or eliminate the waste load, requiring end-of-pipe treatment and thereby improve the quality of the effluent discharge and reduce treatment costs. In-plant technology involves water reuse, process material conservation, reclamation of waste enamel, process modifications, material substitutions, improved rinse techniques, and good housekeeping practices.3-615... 

Option 3 treatment system for common metal wastes consists of the Option 2 end-of-pipe treatment system plus the addition of in-plant controls for lead and cadmium. In-plant controls would include evaporative recovery, ion exchange, and recovery rinses.16... 

Briefly expressed, the sustainable approach of the sewer process concept can be interpreted by changing wastewater management from an end-of-pipe treatment to a pipe and plant treatment. This is not the only way of approaching a sustainable solution for an urban wastewater system, however, it is a contribution. But, it is certainly true that the sewer process concept tends to put much more focus on the dry-weather performance of the sewer than is typically done. 

Traditionally, processes have used a single destruction technique, and this has historically been the case also for HYDECAT . Thus, nearly all installed processes treat the waste hypochlorite at the concentration it exits the scrubbing system down to concentrations suitable for discharge (Fig. 26.2). The key aspect in the re-evaluation described herein is to question the practices of firstly single technology and secondly end-of-pipe treatment the destruction of the hypochlorite exclusively in the blowdown stream from the scrubber. That is, it is questioned whether installation of a single treatment technique solely to process the effluent at its natural concentration from the scrubber loop is necessarily the best process option. This chapter will consider the two parts of the question paraphrased above sequentially. 

Economic analysis of designs at lower natural hypochlorite strengths equally show potential investment benefits. They are, however, much less significant than the batch and high concentration cases described above. While an economic case can be made for retrofitting an in-loop reactor to a system that already has an end-of-pipe treatment system based on payback, it is not always clear that this is a better option than an end-of-pipe hybrid system as described earlier in the chapter. For a particular system the optimum solution is often as much a function of the required expenditure on the heat exchangers as it is the relative cost of the reactor options. 

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