Answer

Environmental Management

Recurrent hazardous wastes are generated from the ongoing use of hazardous materials used in manufacturing or in service activities. Your company is the leading shop in the area for painting commercial trucks. Senior management wants to reduce the amount of hazardous waste that is generated by 30% in the next three years.  To do this, hazardous materials will need to be identified and switched out of the painting process. As the EHS manager for the facility, you are tasked with proposing a plan that accomplishes this goal. To construct the plan, (a) use external resources to identify the current waste profile for the paint process;

Having established the absence of resources that can identify current waste profile of the paint process, the organization will have to turn outside to borrow tools from other organizations.  What the organization needs is waste profile sheet.  This is a sheet that is provided by a waste generator facility.  In addition to their facility information, it will capture the transporter details.  Importantly it will have specific and precise information of the waste stream.  The waste stream describes the waste, the quantity and shipping details, the regulatory status – this will be dependent on the local regulatory authority, the hazardous, health and toxicity characteristics.  When this form is filled with care and comprehensively the profile of the waste generated from the paint making process will be easily and correctly identified.  Different jurisdiction might have different requirements, however a minimum set by a national body – the Environmental Protection Agency, ensures that there is a standard for all.

(b) Identify the material substitutions to use in the painting process;

In the painting process, material substitutions can be achieved by using water-based material in place of solvents and actively seeking substitutes for hazardous materials used for cleaning and processing with the aim of reducing if not eliminating the release of mercury and lead/chromate based bactericides and volatile organic compounds (VOCs) (Osemeahon and Maina, 2007).  This could and need to be supported by best practices that could include, spill management, management and reduction of rinse water and reduction in the rate of cleaning equipment.

(c) Estimate the new waste profile showing that the 30% reduction has been achieved.

The desired 30 percent reduction achieved will be manifest in a number of ways.  Reduction of cleaning needs, generation of rinse water and the discharge of wastewater could be achieved by having longer production runs, minimizing the mill passes while ensuring quality by using high speed mixers, employing manual or automatic wiper blades as a strategy of reducing pain residual in tanks, having solutions dedicated to specific tanks, among other measures.  Wastewater could be reduced and reused if the water washes and rinse solvents from water-based and solvent-based paints are collected for reuse in compatible batches.  To better manage spillage, dry absorbents have been known to offer excellent soak capabilities which should eliminate the need to wash spillages down the drain (Osemeahon and Maina, 2007).  These measures will attain more the desired 30 percent reduction in the waste profile.

You are an EHS manager of a specialty chemical company that makes chemical intermediates for the pharmaceutical industry to use in the production of medicines. The local permitting authority will soon require you to pre-treat your wastewater in an onsite biological treatment system prior to discharging the wastewater to the local municipal wastewater treatment facility. Select a biological system (lagoons, conventional treatment plants, sequencing batch reactors, anaerobic systems, etc.) to install and state three reasons why you selected it as your first choice. For each unit operation that you did not select, give the reasons why you choose not to use it.

Given the location of the specialty chemical company, the lagoon is the best option for pre-treating the wastewater on site.  The local authority prefers a biological treatment system and the lagoon is the oldest, simplest yet most effective biological system.  Despite its simplicity, the within a lagoon complex physical, chemical and biological processes are constantly taking place (Kalavrouziotis, 2011).  It is the systems most recommended in developing economies because of its low maintenance and mechanical simplicity.  A lagoon offers a variety of options from which to choose from which depend on the amount of air and degree of mixing being achieved on site.  A lagoon can either be an anaerobic or facultative – has both aerobic and anaerobic zones within the same system (Kalavrouziotis, 2011). 

Conventional wastewater treatment could be ideal for this case since it incorporates biological, chemical and physical operation and processes to eliminate organic matter, nutrients and solids from the waste.  Herein lays the chink of the system.  Since the waste will not have any solids or organic matter, it will be an expensive investment that will not be utilized effectively and efficiently.  Similarly, given the waste profile of the wastewater to be pretreated, the conventional treatment will not offer value for money (Kalavrouziotis, 2011).

Finally the Sequencing Batch Reactor (SBR) refers to a process that is operated under non-steady conditions and uses mainly activated sludge.  It is cheaper that the conventional continuous-flow method since all activities are performed in one tank – there is not movement.  The SBR offers user time flexibility as opposed to the space flexibility offered by lagoon and conventional systems (Kalavrouziotis, 2011).  Overall it is an expensive system to set up since majority of activities require unique combination of software and equipment.  This equipment will also require skilled operator to operate them which is another cost.