1009650247015 Course

1009650247015
Course: PTD Environmental Services and Management
Module: A3309C Environmental Operations Project
Title: Reduction of the Municipal Solid Waste in The Shipyard
Date: 10th October 2018

Student Id No.: 18058822
Name: Rasmi Binte Abdul Karim

ABSTRACT
Shipyards today are faced with a changing workplace that requires the more efficient use of materials and waste minimization 1. The approach to this project was defining, identifying and presenting a waste management system in the shipyard. Developing an effective strategy in both waste source reduction and recycling techniques.
The development phases of the project as follows:
Survey the company to identify the waste generated in the shipyard
Assigning the waste stream of interest
Identifying waste minimization techniques being used by the shipyards – locally and international
Technical, economic and environmental regulatory analysis was adopted in evaluating the options for waste minimization
TABLE CONTENTS
ABSTRACT ……………………….…………………………………….……………….…. (00)
LIST OF FIGURES ……………………………………………………………………….…. (00)
LIST OF TABLES ……………………………………………………………………….…. (00)
INTRODUCTION ………………………………………………………………………….…. (00)
Background …………………………………………………………………..………. (00)
Objectives of The Study ………………………………………………………….…. (00)
SHIPYARD WASTE ……………………………………….…………………………….…. (00)
Waste stream ……………………………………………………………………….…. (00)
Ferrous ……………………………………………..……………………….…. (00)
Non-Ferrous ………………………………….…………………………….…. (00)
Electrical Waste ……..…………………………………………………….…. (00)
Hazardous Waste ………………………………………………………….…. (00)
Spent Abrasive Grits …….……………………………………………….…. (00)
Miscellaneous …………….……………………………………………….…. (00)
Recycling Methods in The Shipyard ….………………………………………..…. (00)
DATA COLLECTION …………………………..………………………………………..…. (00)
Data Collection Methodology ……………..…………………………………….…. (00)
Survey Design ………………………………………….………………….…. (00)
Setting Up …………………………………………….…………………….…. (00)
Survey Execution ………………………………………………………….…. (00)
Data Analysis and Reporting …………………………………………….…. (00)
PROPOSAL …………………………………………………………………………………. (00)
Data Analysis ……………………………………………………………………….…. (00)
Classification of The Municipal Solid Waste ………………………….…. (00)
Solid Waste Generation …………………………….……………….…. (00)
Waste of Interest ……………………………………………………..…….…. (00)
Recycling of Spent Abrasive Blasting Media …………………….…. (00)
Introducing Alternative Abrasive Blasting Media ……………….…. (00)
Cost Analysis ………………………………………………………….…. (00)
Environmental Analysis …………………………….……………….…. (00)
CONCLUSION …………………………………………………………………..……….…. (00)
APPENDIX ………………..……………………………………………………..……….…. (00)
REFERENCES …………………………………………………………………..……….…. (00)
LIST OF FIGURES
Figure (1-1): Singapore waste generation rate 2.
Figure (2-1): Typical waste generated in the shipyard.

Figure (2-2): Lansink Ladder of the waste hierarchy.

Figure (3-1): Data collection methodology flow chart.
Figure (4-1): A typical shipyard waste composition.

Figure (4-2): Costing comparison of the abrasive blasting media.

Figure (4-3): Abrasive blasting media consumption rate.

LIST OF TABLES
Table (1-1): Pollutant emissions and waste in the shipyard.

Table (4-1): Properties of copper slag.

Table (4-2): Abrasive blasting media use in the shipyard.

INTRODUCTION
Background
Based on 2017, Singapore generated about 7,000,000 tonnes of waste per year and has achieved a recycling rate of 60%. However, it was reported that 76% of the overall recycling rate was the non-domestic waste 2 while the rest making its way to the incineration plant for energy recovery and landfill disposal. Mainly contributed by the constructions and demolition (C&D), commercial and industrial waste recycling as Singapore is a heavily industrialized nation. At the rate of Singapore’s disposal trends, Semakau landfill would be filled before it’s estimated lifespan.

Figure (1-1): Singapore waste generation rate 2.
Shipbuilding is one of the heavy metal industries with several hazardous material exposures. Average volume of wastes and pollution is being released during shipbuilding processes such as metal works, surface treatment operations, outfitting, ship maintenance and repair activities which poses a major risk on the human health and safety as well as adverse effects on the environment.
The typical pollutant emissions and specific wastes in the shipyard from the construction processes:

Table (1-1): Pollutant emissions and waste in the shipyard.

Objectives of The Study
Surface preparation through blasting process in shipbuilding industry is marked as a major source in the generation of waste. During blasting, the environment in the vicinity is polluted by the fine dust of the abrasive blasting media causing air emissions of toxic metals. Each year, its estimated about 300,000 tonnes are used for abrasive blasting in the shipyard 3. Shipyards have relied on hazardous waste landfill disposal and treatment for its abrasive blasting media disposal due to the abrasive containing relatively high metal contains. This approach is commonly known as ‘end of pipe’ waste management.
Therefore, solutions must be found to reduce the amount of waste generated and to limit their negative effects on the environment by improving the recyclable of abrasive blasting media to get the maximum usage before requiring for disposal.
SHIPYARD WASTE
Shipyard waste – solid waste causes storage problems primarily because of the large quantities. Therefore, sorting of waste is the crucial step in recycling as separation at source will prevent the waste being mixed with other wastes and increases the number of materials suitable for recycling.
Waste stream

Figure (2-1): A typical waste generated in the shipyard.

Ferrous
Steel is the most monetary valuable materials in shipbuilding industry mainly the construction of the ship structural. It includes all forms of iron and steel alloys.
Non-Ferrous
Materials that contain either no iron or only significant amount of alloy. Such examples are copper tubing used in the heating, ventilation and air conditioning systems. Aluminium cable ladders for routing electrical cables and aluminium framings that are used as furnishing supports.
Electrical Waste
Sources from the marine electrical cables insulated with PVC and copper cores. It is valuable and is usually sent back to the vendor for recycling purposes.
Hazardous Waste
Sludges from the liquid waste such as washed water, oily water from bilges and tank cleanings. Possibly contain heavy metal that requires engaging National Environmental Agency’s licensed contractors for disposal of sludge.
Spent Abrasive Grit
It is mandatory for the surface preparation before painting process in new shipbuilding or for the removal of the old paint from the surface of old vessels. The particulate emissions are contaminated by blasting abrasives and paint chips during surface preparation processes and might contain toxic metals concerning the production area, off-site and surrounding surface waters when blown off-site. Blasting process in shipyards could be marked as one of the most significant sources of waste.

Miscellaneous
Main sources from the outfit installations such as furniture that is made of marine plywood and insulation materials purpose of acoustic and fire prevention. These wastes are usually sent back to the vendors for recycling purpose.

Recycling Methods in The Shipyard

Figure (2-2): Lansink Ladder of the waste hierarchy.

The shipyard recycling methods are grouped according to the ladder of Lansink as shown in figure (2-2). Upper step is the most preferred waste option for the shipyard and the environment but in most cases, it is virtually impossible to be eliminated completely. Next down the ladder, when elimination is not possible, reduction in volume is preferable. Third, reuse of materials is preferred. For example, the balance steel plates could be transferred to another project instead of placing new orders. Waste may be recycled onsite but if it is not economically feasible and possible, the waste is sent to an off-site recycling facility in most of the cases in the shipyard by selling the material to scrap company for recycling. The next step down the ladder after recycling is not feasible, the waste undergoes chemical and physical methods of treating hazardous waste generated by the shipyard so that smaller volume can be sent off for disposal. Such processes include separation and concentration technology; and detoxification of waste 4. Last step of the ladder where materials are dumped as an end stage. This applies to material which of no useful application is available, and of which are hazardous to incinerate.

DATA COLLECTION
Data Collection Methodology

Figure (3-1): Data collection methodology flow chart.

The figure above shows the flow chart methods used to collect the analyse data for this project. The data were collected in two phases.

The first phase allows the classification of the waste at the source where data were collected over the period of 1 week of refuse sampling to:
Assess the composition of the waste stream.
Obtain qualitative and quantitative estimated of solid waste as part of the overall waste stream.
Develop the waste generation rates and the potential emissions from the shipyard.

The second phase provides more in-depth information related to the waste stream of interest. This enables to derive:
By conducting surveys in the shipyard to identify options for waste reduction through the hierarchy of waste management.

Evaluation of economic, regulatory and environmental analysis was adopted.

The results of such an analysis would provide for the knowledge and application of the best-integrated waste management solutions.

Survey Design
Survey for the total waste stream data.

The components of the waste of interest.

To justify if any seasonal variations to be included.

Setting Up
Sorting area for storing refuse where open skips were placed at the respective disposal areas – Blasting chamber, workshops, quaysides and slipway.
Survey Execution
Collection of the refuse sample into categories for municipal collection.
Duration sampling of 1 week.

Weighing the refuse conducted daily.

Data Analysis and Reporting
Compilation of the results from the survey into a database.

Total weights and determination of the composition percentage for each waste components.
PROPOSAL
Data Analysis
Classification of The Municipal Solid Waste
Solid Waste Generation

Figure (4-1): Typical shipyard waste composition.

As we can see from the above chart, the biggest contributor to the waste generated in the shipyard are steel scraps 31.95% and the spent abrasive blasting media 27.15%. The recycling rate of the steel is 98% 2, while abrasive blasting media preferable disposal method is landfill as it is a cheaper and easier option for the industry.
However, with the rate of Semakau Landfill reaching its capacity, landfill disposal may soon become prohibitively expensive or eliminated completely. Therefore, there is a need to study the effective way of reducing the waste.
Waste of Interest
Recycling of Spent Abrasive Blasting Media
Used copper slag from the blasting process is the biggest single source of waste generated from the shipyards in Singapore. Each year it is estimated 300,000 tonnes are used for abrasive blasting in Singapore 3 and with the amount of volume generated, not all abrasives are easy to recycle. Steps should be taken to implement processes that will improve the recyclable of abrasive blasting media to get the maximum usage before requiring for disposal.

Due to its favourable mechanical and excellent soundness characteristics, good abrasion resistance and good stability 5, the copper slag can be recycled to be used as a raw material for a new product such as aggregates for concrete. The greatest advantages of recycling copper slag, it does not consume valuable landfill space which can be reserved for the higher level of hazardous wastes and the cost of recycling is much lower than the cost of disposal.
Following are the typical properties of copper slag that enable it to be recycled as fine aggregates:

Table (4-1): Properties of copper slag.

Therefore, its suitability as approved replacement of up to 10% by mass of saved in the production of structural grade concrete and commonly used as eco-concrete production.
The recyclability of the copper slag is influenced by the physical and chemical characteristics. However, the flexibility in selecting and implementing recycling of abrasive blasting media is controlled by the regulatory agency Building and Construction Association (BCA) and the National Environmental Agency (NEA) as it is classified as hazardous waste due to the metal contamination. NEA regulation requires that a Toxicity Characteristics Leaching Procedure (TCLP) test to be performed in determining if the material is hazardous prior to being recycled as aggregates.
Introducing Alternative Abrasive Blasting Media
As mentioned in the previous section, due to the high breakdown rate of the copper slag, its life cycle is rather shorter and suitable for single use or reuse not more than twice. Even though it could be upcycled into raw material for a new product, the production of the waste will continue to increase.
Based on the hierarchy of waste management in section 2.2, the basic principle is that to avoid waste generation is far easier than to process it later.
Therefore, there is a need to find a solution of reducing the generation of waste through the introduction of alternative blasting media that have a higher reusable cycle.
right29591000The table below is the comparison summary chart of the alternative blasting media.
Table (4-2): Abrasive blasting media use in the shipyard.

Economic Analysis
Annual cost comparison of copper slag vs recycled steel grit:

Figure (4-2): Costing comparison of the abrasive blasting media.
The cost analysis illustrates that despite steel grit cost is twice as expensive as copper slag which is SGD 400 and SGD 220 respectively, it produced a saving cost of SGD69,360 that is 93% in total abrasive consumption annually. Unlike copper slag, steel grit having the high recyclability rate, thereby also reducing the disposal cost up to 96% from SGD 13,800 to SGD 5,160 annually. Making it much more cost-effective than other blasting media such as copper slag and garnets. The lowest cost of the blasting material does not always yield the lowest total cost.

Abrasive consumption rate:

Figure (4-3): Abrasive blasting media consumption rate.

Switching from traditional expendables mineral abrasive (copper and garnet) to a recyclable abrasive such as steel grit can reduce consumption rates by 70% – 90% due to steel grit ability to resist breaking and can be recycled up to 80 times before losing its effectiveness 6. This could be seen from the graph above; steel grit abrasive offers 96% waste reduction whereas garnet only achieving 76% with a cycle rate of 8 times. Steel grit may initially cost more, but the overall annual abrasive cost is dramatically decreased with proper recycling methods 7. See appendix B for calculations and details.

Environmental AnalysisDisposal of the large volumes of potentially hazardous spent blasting grit generated by the shipyards are becoming increasingly more difficult, costly and have created an environmental problem 1 such as particulate air emissions with abrasives and paint chips that can enter waterways if not properly contained. Whereas, steel grit usage has a minimal environmental impact as compared to most of the traditional media such as copper slag. Reduced in waste generation meant that lesser space taken up in the landfill and reduces production of hazardous leachate in the landfill.
CONCLUSION
Shipyards generate large quantities of waste, many options are available for reducing the pollution from the shipyard processes, most of them being source reduction methods. Reuse/recycling options have been evaluated in this project for the reduction of abrasive blasting media. Even though recycling into fine aggregates can be an effective and relatively inexpensive option for managing the hazardous waste compared to treatment or disposal, as long the regulatory requirements are met and satisfied the TCLP test prior to the usage for recycling. However, the consequences of the leaching of heavy metals into the soil that will impose future environmental issues should be taken into consideration. Therefore, steel grit is an economically and environmentally viable for the current practice of using disposal copper slag. The reasons being due to its durability and toughness that can be reused more than 80 times as a result significantly smaller volume of abrasive waste are generated for disposal. Thus, minimization of waste, improving cost, reduce air pollution and the safety of the workers.
APPENDIX
Appendix A – Singapore Domestic Waste Generation 2.

Appendix B – Singapore Waste Stream Recycling Rate 2017

Appendix C – Shipyard waste Generation and Composition.

Appendix D – Economic Analysis of The Abrasive Blasting Media.

REFERENCES
1 Keener, J., Coffer, A., Hitzrot, H. W., Hansen, L., ; Hamilton, A. (1993). Feasibility Study: Tank Blasting Using Recoverable Steel Grit. doi:10.21236/ada458692
2 Waste Statistics and Overall Recycling. (n.d.). Retrieved from https://www.nea.gov.sg/our-services/waste-management/waste-statistics-and-overall-recycling
3 Environmental Sustainability. (n.d.). Retrieved from https://www.sembmarine.com/sustainability/environment/
4 Buruiana, D. (n.d.). The Development of Integrated Waste Management Systems: Case Studies and their Analysis. Integrated Solid Waste Management, 33-83. doi: 10.1002/9780470999677.ch3
5 Salleh, S., Shaaban, M., Mahmud, H., Looi, K. T., ; Kang, J. (2014). Production of Bricks from Shipyard Repair and Maintenance Hazardous Waste. International Journal of Environmental Science and Development, 5(1), feb, 52-55.

6 Battelle, N. (1996). Technology Transfer report On Recycling Spent Sandblasting Grit Into Asphaltic Concrete. Naval Facilities Engineering Service Center, april.
7 Process, Price, Production, Reserves, and Application. (n.d.). Retrieved from http://www.oem.msu.edu/images/abrasive_blasting/