In Vietnam, since domestic solid waste (DSW) has not been separated at-source, only about 20 – 30% of domestic waste generated is used for composting, and the rest, which is difficult for biodegradation, is dumped in landfills.
Nghiên cứu khoa học công nghệ APPLICATION OF THE PYROLYSIS PROCESS IN RECYCLING NON-BIODEGRADBLE ORGANIC COMPONENTS OF MUNICIPAL SOLID WASTE IN HOT-MIX ASPHALT CONCRETE Le Anh Kien* Abstract:In Vietnam, since domestic solid waste (DSW) has not been separated at-source, only about 20 – 30% of domestic waste generated is used for composting, and the rest, which is difficult for biodegradation, is dumped in landfills Aiming at reducing the amount of solid wastes landfilled and enhancing waste recycling and natural resources reserving, the research team of ITE and University Putra Malaysia (UPM) has carried out a research on applying pyrolysis process in recycling non-biodegradable organic components of DSW in hot-mix asphalt concrete Primary results indicated that with an appropriate pyrolyzing condition, the final pyrolyzed product has an asphalt content of about 15%, and bitumous ability that can be mixed with other aggregate to make asphalt concrete This saved about 10 – 15% in the amount of asphalt used in producing the asphalt concrete The asphalt concrete produced has characteristics that comply with Vietnamese standards by Ministry of Transport for materials used in road construction Keywords: Pyrolyis process, Non-biodegradble organic, Municipal solid waste, Hot-mix asphalt concrete INTRODUCTION About 5,000 ton of DSW is generated daily in HCMC The increasing amount of DSW generated is contributing to serious problems of air, soil, and water pollution There are still difficulties in treatment of solid waste in HCMC as well as in Vietnam In the near future, HCMC is going to implement some projects on using DSW for composting, in which the biodegradable organic components of DSW is used for producing compost However, since DSW is not yet at-source separated, only 20 – 30% of DSW can be used for composting About 70 – 80% of DSW remained (including both organic and inorganic components) containing organic components that is not biodegradable, has to be treated by landfilling [1, 2] Aiming at reducing the amount of waste landfilled as well as enhancing recycling solid waste and reserving natural resources, some research on recycling DSW has been carried out, mainly for recycling construction solid wastes and rubber and plastic in domestic wastes There was a research by Nguyen Minh Chau on recycling inorganic components of DSW from Cau Dien Solid Waste Treatment Plant in producing concrete Hoang Dai Company (Hai Phong) is producing an organic solvent, which can be used as fuel, from rubber and plastic There was another research by Mai Ngoc Tam on recycling nylon and other plastics (PET and PVC bottles, plastic boxed, sponge, etc…) in making board In Ho Chi Minh City, there are a number of agencies working on recycling rubber and plastic, however, there have not been any researchs converting the DSW to asphalt concrete yet In 2007, Akbulut, H and C Gürer presented a study of “Use of aggregates produced from marble quarry waste in asphalt pavements” The test results indicated that the physical properties of the aggregates were within specified limits and these waste materials could potentially be used as aggregates in light to medium trafficked asphalt pavement binder layers [3] Tạp chí Nghiên cứu KH&CN quân sự, Số 48, 04 - 2017 155 Hóa học & Kỹ thuật môi trường In another research, Bassani, M., E Santagata, et al had published "Use of vitrified bottom ashes of municipal solid waste incinerators in bituminous mixtures in substitution of natural sands" The investigation was carried out by considering performance related compaction, volumetric and mechanical properties, which were assessed in the laboratory by employing a number of different characterisation techniques [4] In 2013, Abbas, A R., U A Mannan, et al Presented the study of "Effect of recycled asphalt shingles on physical and chemical properties of virgin asphalt binders" The results in the laboratory showed that a virgin asphalt binder meeting the Superpave specifications for PG 58e To determine the asphalt content in the “material”, the “material” is steeped in the mixture of solvents for two hours, and then the liquid containing asphalt is filtered, distilled, and dried at 160oC to achieve a mixture of asphalt Physicochemical characteristics of the asphalt are measured at Universiti Putra Malaysia 2.3 Testing experiment for physicochemical characterstics of the asphalt concrete made from the “material” 2.3.1 Experimental Objectives The experiment measures physicomechanical characteristics of the asphalt concrete produced with different replacement percentages of the “material” in order to determine the appropriate mixing ratio of the “material” in asphalt concrete 2.3.2 Equipment Facilities and equipments for the experiments were employed from University Putra Malaysia The machine is the Accu-Tek Touch 250 Automatic Compression Machine 110V/60Hz This machine is designed to meet the need for reliable and consistent concrete testing It is fully compliant to ASTM C39 and AASHTO T22 standards 2.3.3 Materials - Aggregate for the road surface application under 22 TCN 249-98 [8] - Bitumen type 60/70 - “Material” from pyrolyzing non-biodegradable organic component of DSW at 350oC in 30 minutes 2.3.4 Procedure The experiment procedure is followed the construction standard 22TCN 62-84 [9] Indicators to be determined are air void, stability, and deformability RESULTS ANDDISCUSSION 3.1 Result of determination of asphalt content and testification of asphalt physicocheical characteristic The asphalt content in the “material” makes up from 14 to 15% of the “material” weight Results of testing physicochemical characteristics of the asphalt extracted from the “material” are presented in Table Results of the experiment indicate that the dissolubility in CCl4 and the ignition point of the asphalt achieved from pyrolyzed “material” are equivalent to those of conventional bitumen currently used in producing asphalt concrete However, the density, the flexing temperature and the extension ability of the asphalt from the “material” is lower than those required for asphalt 60/70 158 L A Kien, “Application of the pyrolyis process… in hot-mix asphalt concrete.” Nghiên cứu khoa học công nghệ Table Physicochemical characteristics of asphalt 3.2 Result of testing experiment for physicochemical characterstics of the asphalt concrete made from the “material” Experiment results is presented in Table and Figure 2, 3, and The experiment results can be summarized as follows: - Stability: asphalt concrete samples has compactability strength varies from 5.5 to 16.1 kN; there are 12/18 samples are conformed to standards of stability (AASHTO-T22 or ASTM-C39) which specify a compactability strength 8 kN It is noted that the samples of asphalt concrete that meet standards for Marshall stability are those with replacement percentage of less than 15% - Deformability: the samples of asphalt concrete have deformability varies from 2.8 mm to 6.4 mm There are 6/18 samples that meet the standard for deformability 22 TCN 249-98 (4mm) It is noted that the asphalt concretes with replacement percentage of 10% meet 22 TCN 249-98 for deformability - Air void: the samples of asphalt concrete have the air voids varies from 14.1% to 27.3% There are 9/18 samples meet the standards for air void 22 TCN 249-98 (14 – 18%) It is noted that the asphalt concretes with replacement percentage of 10% meet 22 TCN 249-98 for air void Components Asphalt Conventional Sample from the bitumen height “material” % % (mm) 100 65.0 95 66.7 10 90 68.8 15 85 71.5 20 80 71.3 25 75 72.9 Construction standard 22TCN 249-98 Table Results of marshall experiment Experiment results Asphalt concrete Air void Deformability Stability density (g/cm3) % (mm) (kN) 2.3 14.4 2.8 16.1 2.3 15.5 4.0 13.8 2.2 17.2 5.1 12.1 2.1 18.2 5.1 11.4 2.0 22.5 6.3 7.5 1.9 25.8 6.4 5.5 14-18 4.0 8.0 Tạp chí Nghiên cứu KH&CN quân sự, Số 48, 04 - 2017 159 Hóa học & Kỹ thuật mơi trường Figure The stability of the asphalt concrete for different replacement percentages Figure The air void of the asphalt concrete for different replacement percentages Figure The deformability of the asphalt concrete for different replacement percentages There are some remarks from the testing results, as follows: - The increase of the replacement percentage result in the decrease of physicomechanical abilities (decrease in stability and deformability and increase in air void - Even though the asphalt concrete produced has high stability, its 160 L A Kien, “Application of the pyrolyis process… in hot-mix asphalt concrete.” Nghiên cứu khoa học công nghệ deformability is also relatively high, particularly when increasing proportion of the “material” Therefore, in order to assure the required physicomechanical characteristics of asphalt concrete, replacement percentage of the asphalt from “material” for conventional bitumen is recommended to be – 10% In conclusion, it is feasible to apply pyrolysis processes in recycling nonbiodegradable organic component of DSW in producing asphalt concrete for road construction, and the appropriate replacement percentage of asphalt from the “material” in the blend is determined to be 10 % CONCLUSIONS Pyrolyzing non-biodegradable organic components of DSW at an appropriate condition (350oC, 30 minutes), we achieve a material with high content of asphalt (15%) and bituminous ability that can be mixed with aggregate to produce asphalt concrete; The asphalt extracted from the “materials” has physicochemical characteristics (ignition point,tensile strength, dissolubility in solvent, etc…) that equivalent to bitumen and can be used to replace conventional bitumen in producing asphalt concrete; The achieved “material” can replace by – 10% in aggregate and 10 – 15% in bitumen used in asphalt concrete The asphalt concrete produced conforms to technical standards by Ministry of Transport However, to assure a long-term stability for road surface, the asphalt concrete should first be used for rural roads or grade roads It is clearly from the experimental study that it is feasible to recycle nonbiodegradable organic components of DSW in road surface application This contributes to reducing the amount of solid wastes dumped in landfills, which in turn contribute to land and natural resources saving as well as reducing environmental pollution However, it is recommended to have follow-up research on reusing heat from pyrolyzing process as well as have a project of producing the “material” in pilot scale before mass production in practice Acknowledgement: The data for this study was collected from the research of Dr Nguyen Quoc Binh Thanks for analysis results that were carried out at the lab of Mr Zurina Zainal Abidin and Prof M Halim S Ismail in the Putra University, Malaysia REFERENCES [1] N Q Bình, "Applying pyrolysis for organic waste treatment in MSW", Hochiminh City for recycling material, 2006 [2] G A.-H.- AIT, "Training, management of MSW, South of Vietnam," 2005 [3] H Akbulut and C Gürer, "Use of aggregates produced from marble quarry waste in asphalt pavements," Building and Environment, vol 42, pp 19211930, 2007 [4] M Bassani, E Santagata, O Baglieri, M Ferraris, M Salvo, and A Ventrella, "Use of vitrified bottom ashes of municipal solid waste incinerators in Tạp chí Nghiên cứu KH&CN quân sự, Số 48, 04 - 2017 161 Hóa học & Kỹ thuật môi trường [5] [6] [7] [8] [9] bituminous mixtures in substitution of natural sands," Advances in Applied Ceramics, vol 108, pp 33-43, 2009/01/01 2009 A R Abbas, U A Mannan, and S Dessouky, "Effect of recycled asphalt shingles on physical and chemical properties of virgin asphalt binders," Construction and Building Materials, vol 45, pp 162-172, 2013 K H Moon, A C Falchetto, M Marasteanu, and M Turos, "Using recycled asphalt materials as an alternative material source in asphalt pavements," KSCE Journal of Civil Engineering, vol 18, pp 149-159, 2014 M Abukhettala, "Use of Recycled Materials in Road Construction," in Proceedings of the 2nd International Conference on Civil, Structural and Transportation Engineering (ICCSTE’16), Ottawa, Canada – May – 6, 2016 M o Transport, "Professional standard 22 TCN 249:98," 1998 M o Transport, "Professional standard 22 TCN 62: 84," 1984 TĨM TẮT ỨNG DỤNG Q TRÌNH NHIỆT PHÂN TRONG TÁI CHẾ THÀNH PHẦN HỮU CƠ KHÔNG PHÂN HUỶ SINH HỌC CỦA CHẤT THẢI RẮN ĐÔ THỊ TRONG BÊ TÔNG NHỰA TRỘN NĨNG Tại Việt Nam, chất thải rắn thị không phân loại nguồn, khoảng 20 đến 30% chất thải nội địa sử dụng cho việc ủ phân, phần lại khó phân huỷ sinh học chôn bãi chôn lấp rác Nhằm mục đích giảm lượng chất thải rắn chơn lấp tăng cường tái chế chất thải giữ gìn tài ngun mơi trường tự nhiên, nhóm ngun của Viện Nhiệt Đới Môi Trường Đại học Putra Malaysia thực nghiên cứu tính ứng dụng trình nhiệt phân tái chế thành phần hữu không phân huỷ sinh học chất thải rắn thị bê tơng nhựa trộn nóng Các kết quan trọng với điều kiện nhiệt phân thích hợp, sản phẩm nhiệt phân có hàm lượng nhựa khoảng 15% khả nhựa hoá trộn với chất kết tự khác để tạo bê tơng nhựa Điều tiết kiệm khoảng 10-15% lượng nhựa sử dụng sản xuất bê tơng nhựa Bê tơng nhựa sản xuất có đặc điểm phù hợp với tiêu chuẩn Việt Nam ban hành Bộ Giao Thông Vận Tải vật liệu sử dụng xây dựng đường giao thơng Từ khóa: Bê tơng nhựa, Khơng phân huỷ sinh học, Nhiệt phân, Chất thải đô thị Received date, 25th January 2017 Revised manuscript, 16th March 2017 Published on 28th April 2017 Address: Institute for Tropical Technology and Environment (ITE), Academy of Military Science and Technology * E-mail: leanhkien@vnn.vn 162 L A Kien, “Application of the pyrolyis process… in hot-mix asphalt concrete.” ... 58e To determine the asphalt content in the “material”, the “material” is steeped in the mixture of solvents for two hours, and then the liquid containing asphalt is filtered, distilled,... mơi trường In another research, Bassani, M., E Santagata, et al had published "Use of vitrified bottom ashes of municipal solid waste incinerators in bituminous mixtures in substitution of natural... The stability of the asphalt concrete for different replacement percentages Figure The air void of the asphalt concrete for different replacement percentages Figure The deformability of the asphalt