Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 130 STUDY ON UTILIZING OF INDUSTRIAL – AGRICULTURAL WASTE IN THE BUILDING CONSTRUCTION INDUSTRY Vu Hai Yen Department of Environment and Biotechnology, Ho Chi Minh City University of Technology TÓM TẮT Việt Nam có những lợi thế về sản xuất nông nghiệp. Hằng năm lƣợng phế thải dƣ thừa trong quá trình chế biến các sản phẩm nông sản, thực phẩm rất lớn. Với việc sản xuất đƣợc hơn 38,5 triệu tấn lúa trong năm 2009, chỉ riêng rơm, rạ, vỏ trấu thải ra trong quá trình thu hoạch, xay xát thành hạt gạo đã có khối lƣợng cả chục triệu tấn. Tuy nhiên, so với tiềm năng dồi dào của nguồn phụ, phế thải trong nông nghiệp hiện nay thì những công trình nghiên cứu, ứng dụng còn rất khiêm tốn. Lƣợng vỏ trấu, rơm rạ, xơ dừa, mùn cƣa thải đƣợc tận dụng không nhiều, phần xả thải ra các kênh rạch, sông ngòi chiếm tỷ lệ khá cao. Bên cạnh đó, một ngành công nghiệp cũng rất đáng lƣu ý về chất thải đó là ngành công nghiệp giấy. Công nghệ sản xuất giấy là một công nghệ tiêu thụ nhiều nƣớc. Tùy thuộc vào công nghệ và sản phẩm, lƣợng nƣớc cần thiết để sản xuất một tấn giấy dao động khoảng 200-500 m 3 . Nƣớc sử dụng trong quá trình rửa nguyên liệu, nấu ăn, làm sạch, xeo giấy và sản xuất hơi nƣớc. Trong bùn thải rất khó xử lý bởi thành phần đa dạng và phức tạp, hầu hết chứa cellulose và lignin, thành phần rất bền vững và khó bị phân hủy. Vì vậy, để tận dụng bùn làm vật liệu xây dựng cũng là một sự quan tâm nghiên cứu đáng kể. Nghiên cứu này sử dụng từ các vật liệu là phế phẩm công – nông nghiệp nhƣ vỏ trấu, xơ dừa và bùn từ hệ thống xử lý nƣớc thải nhà máy giấy để trộn với xi măng, cát và nƣớc (tỷ lệ pha trộn 1 phần xi măng: 3 cát phần: ½ phần nƣớc) để sản xuất vữa. Mẫu đƣợc pha trộn vào hỗn hợp tỷ lệ các thành phần khác nhau để thay thế chức năng của các chất phụ gia nhƣ chất kết dính xi măng, bao gồm 4 nghiệm thức 5, 10, 15, 20% của xi măng bằng phế thải. Trộn mẫu vữa vào khuôn 40x40x160 mm, sau đó các khuôn đƣợc đặt trong nƣớc ở nhiệt độ 27 ± 2 0 C trong 28 ngày. Sau đó mẫu đƣợc đƣa đo độ bền nén, độ bền uốn, lực cắt và độ hấp thụ nƣớc. Kết quả cho thấy các mẫu vữa đƣợc trộn với tỷ lệ phế phẩm thay thế 10 - 15% xi măng, đạt tiêu chuẩn về độ bền nén, uốn, lực cắt và độ thấm nƣớc. Đây là một kết quả tích cực trong việc tái chế và sử dụng chất thải để sản xuất vật liệu hữu ích để tiết kiệm nguồn lực, phát triển theo định hƣớng - sinh thái công nghiệp. Từ khóa: vỏ trấu, xơ dừa, bùn thải giấy, phụ gia, vật liệu xây dựng INTRODUCTION Vietnam has advantages in agricultural production. Annual amount of excess waste in the processing of agricultural products, food is great. With the production of more than 38.5 million tons of rice in 2009, only straw, rice husk waste during harvesting, the rice mill had tens of millions of tons of mass. However, compared with abundant potential sources of secondary, agricultural waste, the current study, the application is still modest. The amount of rice hulls, rice straw, coconut fiber, sawdust could be used without much waste, the waste discharged into the canals, rivers and a high proportion, causing environmental pollution. Therefore, the utilization of this waste material to be useful not only meant for recycling, but also sustainable development, conserving resources and limiting climate change. In addition, some types of industrial waste and pollution also need to be processed. Technology of paper production is one of the polluting technology in the creation of large sludge treatment difficult. Sludge with a high cellulose and lignin, create more suspended solids, black, odor, foam, high BOD and COD very difficult to handle. Paper recycling is a necessity, however, the reverse of this action is generated sludge including sludge in the process of inking and finally the waste must be buried into the ground. Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 131 Currently, there are many directions for recycling of industrial wastes - is agriculture, such as combustion boiler, as fertilizer In particular, this waste for recycling as construction materials is also a considerable flow direction mind. This experiment was conducted with three subjects: rice hulls, coconut fiber and sludge from wastewater treatment systems for the paper industry of building materials. The aim of the project not only aims to make use of waste products - agriculture, but also save natural resources, sustainable development RESEARCH OBJECTIVE AND CONTENT Research objective This study aims to be making sample from mixing mortar to build models of agricultural waste products including rice husk, coconut fiber and sludge from wastewater treatment system of the paper mill with cement, sand and water. Research The experiment included the following: - Handling pre - determine the composition, physical and chemical properties of waste samples. - Determine the composition and properties of mixed materials: cement, sand and water - Mixing cement, sand, water and paper sludge under different treatments with mortar model for certification includes cement, sand and water. - Determining the physical properties of cement mortar mixed paper sludge: density, water permeability, compressive strength, bending strength with the traditional cement mortar. RESEARCH METHODS Determining the composition and preliminary treatment of waste product Before performing experiments, have been identified: The origin arise, the primary features of the sample or faulty products (size, color, smell, humidity, ) Rice husk taken from Duc Hoa District of Long An Province. After removing the husks in the dry state, foam, lightweight, and many impurities such as straw, hotel, land, gravel Coconut from Hoc Mon District, Ho Chi Minh City. Sludge from the sedimentation tanks of the Binh An paper factory. (a) (b) (c) Figure 1 The original agricultural-industrial waste a) Rice husk ; b) Coconut coir ; c) Paper mill sludge The samples were separated out impurities. Mud was deposited samples and dehydration. Sample drying temperature 105 0 C until constant weight. Crushed sample and sieve samples through 0.25 mm sieve size. For rice husk and coconut fiber samples are heated at a temperature of 950 0 C to remove carbon in the sample composition. Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 132 (a) (b) Figure 2. The agricultural – industrial waste after preparation a) Rice husk ; b) Coconut coir Determination of physical and chemical properties of waste The waste samples after pretreatment were measured indicators physical chemistry. + Physical properties: density, moisture content, specific surface area, components nuts + Chemical properties: activity level, calcium absorption, the composition of organic / inorganic / ash of the material. Using experiments to determine the physical and chemical properties of waste Experiment type Criteria Sieves experiment TCXDVN311-2004 Determine the physical and chemical properties Calcium absorption TCXDVN311-2004 TCVN 3735-1982 Water properties determination Mixed water is domestic water. Mixed water is determined some parameters: pH, TDS, TSS, Cl - , SO 3 2- , CO 3 2- . Cement properties determination Cement use is multi-standard cement of Holcim Vietnam company. This cement meets the demand of TCXDVN311-2004 standard. Sand properties determination ISO Sand must comply with the provisions of gradation and moisture content. The materialsand mix available for each plastic bag with 1350g  5g weight used for packaging not affect the strength test results. The experiment uses standard sand was distributed by Ha Tien 1 Cement Company. (a) (b) (c) Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 133 (d) (e) (f) Figure 3. Materials and tools. a) Paper mill slude, b) Sludge quantity, c) Cement quantity, d) Standard sand, e) Sand quantity, f) Water quantity. Mortar mixing preparation (TCVN 6016-1995, ISO 679-89) Prepare 4 samples including mortar mix of materials: cement, sample waste, sand, water, waste paper sludge which replaced 5, 10, 15, 20% cement. The rate of sample volume consists of a traditional mortar part cement, three parts sand and half the standard is water (ratio water / cement = 0.5). For each batch will include: 450g  2 g cement., 1350  5 g sand and 225g 1g water can make 3 samples. Batch quantity Cement, sand, water are at room temperature. Cement and sand should be balanced with an accuracy of  0.01 g. When adding water, 225ml tube automatic, accurate  1ml. Sample was mixed into the waste form under the following treatments: Sample Weight (g) Cement (g) Sand (g) Water (g) Waste (g) DC 450 1350 225 0 G-5 427,5 1350 225 22,5 G-10 405 1350 225 45 G-15 382,5 1350 225 67,5 G-20 360 1350 225 90 DC is the form for certification: samples only cement, sand and water, no waste. Form 4 G-5, G-10, G-15, G-20 left: using waste instead turn 5, 10, 15, 20% cement. For sample 0 (traditional ratio): The rate of water / cement = 0.5 Figure 4. Mortar mixers and molds of size 40 x 40 x 160 mm. Mixing Pour into blender and add cement. Run right and run the mixer at low speed, 30 seconds after adding sand slowly during 30 seconds. Turn the mixer and the machine runs at high speed, continue mixing for 30 seconds more. Stop mixer 90 seconds. Within the first 15 seconds using sticking plaster flying rubber rakes in the mortar, mortar and earthing bottom vegetation in the middle. Continue mixing at high speed for 60 seconds. Casting sample Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 134 Prismatic specimen size 40 x 40 x 160mm conducted after casting prepared mortar. Mold and hopper tightly sandwiched goals tie, use a small shovel properly, contact one or two times to the first spraying plaster molds for each compartment so that each compartment Stage 2 class. Then plaster the first impacted by the ballast 60. Pour more plaster Monday, smaller aircraft are used in mortar and plaster impacted by a further 60. Gently lift off the mold and remove the funnel into the semiconductor. Rid of excess mortar with a metal bar to create a tricked stucco surface. Maintenance of test samples Brushing off excess mortar on the edge of campus. This immediately put up the price of mold horizontally in moist air or room in the closet. Exposure to moisture to the surface of the mold. Mold not overlap. Each mold will be removed from its place at the appropriate time for removing the mold. After removing the mold samples are marked and packed in water in the reservoir proper. After sample preparation is finished, all samples were soaked in water temperature t = 27 ± 2 0 C in 28 days + 8 hour. For each mixing ratio, taking three samples. Results are calculated from the average value. Material is experienced 4 parameter: a) Compressive strength, b) Splitting tensile strength, c) Water absorption, d) Density. Density determination Using density flask. Density is determinated: In that:  a (g/cm 3 , T/m 3 ) is the mass of a unit volume material assumption materials in special status fully. The volume of the material is 40 x 40 x 160 mm = 256 000 mm 3 = 256 cm 3 . G: material weight (g) m 1 : the volume of material and in the same volume of water (g) m 2 : water volume in the same volume (g) Water absorption determination (TCVN 3113, 1997, BS 1881, Part 112: 1983, BSI, 1983a) Samples were dried in drying 24 hours, should determine the amount of C (kg). Then, samples were soaked in water during 24 hour. Sampling from the water, weight loss E (kg). Water absorption (%) = 100 EC x C  E: wet weight (kg) C: dried weight (kg) Compressive strength and splitting tensile strength determination Experiment Criteria Compressive strength TCVN 6016 - 1995, ISO 679 - 89 Splitting tensile strength TCVN 6016 - 1995, ISO 679 - 89  Determination of splitting tensile strength Place the prism model on the side of testing machines with a title on the title and knee roller axis perpendicular to the sample of titles knee. Set the vertical load by the load roller to the opposite side of the prism load and increase speed gradually to 50 ± 10N / s until fracture model. Moisture needed for the half prism to try to bring stability when compressed. Using this formula: In which: F: load is placed between the sample broken prism, calculated by (N) l: distance between the knee is entitled, calculated (mm) b: the next section of the square prism, calculated in (mm)  Determination of compressive strength Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 135 Try half the strength of the prisms on the face side of mold exposure Place side of half prism into the middle of the plates with mismatch than ± 0.5 mm, and placed horizontally so that the end face of the prism protruding outside the plates, or cheek pressed about 10mm. Slowly with increasing load speed 2400 ± 200 N / s during the sample until destroyed. Using this formula: Fn : is the maximum load at sample destroyed, calculated as (N) A: section under compression, calculated by (mm 2 : 40 x 40 = a 600mm 2 ) RESEARCH RESULT AND DISCUSSION Material reviews Cement material particles are mixed wastes less material finer than grains of pure cement. Paper mill sludge samples are less smooth. (a) (b) (c) (d) Figure 5. Material structure. (a) Cement, (b) Paper mill sludge, (c) Rice husk, (d) Coconut coir Physical and chemical properties of material Due to high water absorption of waste, should the country be mixed into the mortar samples is higher than standard, so the ratio will be lower than normal grout material. Sample Density (kg/m 3 ) DC G-5 G-10 G-15 G-20 Rice husk 390 381 376 355 324 Coconut coir 390 389 382 377 375 Paper mill sludge 390 370 350 321 309 Rice husk samples have very high calcium absorption and can be completely used as additives for mortar, helps increase the durability and waterproof. Parameter Unit Sample Rice husk Coconut coir Paper mill sludge Moisture * % 7,8 15,1 8,8 Calcium absorption Mg 156,24 99,17 82,83 *: Moisture: in room pressure and temperature. Results showed that rice husk ash samples had very strong activity levels (mg CaO due to adsorption by 1 mg samples were greater than 150mg). Coconut fiber and paper sludge major Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 136 component of the cellulose so it is lime adsorption capacity at its average level. In addition, the moisture content of coconut fiber and paper sludge is also higher than rice husk. Water absorption More and more the amount of waste water absorption of the material increased. Sample Water absorption (%) DC G-5 G-10 G-15 G-20 Rice husk 5,12 6,15 7,23 9,11 10,24 Coconut coir 5,12 7,34 9,25 11,37 13,66 Paper mill sludge 5,12 8,31 11,56 14,34 18,78 Water uptake by the higher ash husk coir husk ash is very fine particles and light so the surface area of water absorbed by a large husk ash. Coconut ingredients and nuts and it also weighs more than rice husk ash, small surface area of water absorption so that the decrease. Physical properties of mixed material (TCVN 6290-1997) Figure 6. Sample G-10 and G-20 of rice husk after 28 days. Figure 7. Sample G-10 and G-20 of coconut coir after 28 days. Compressive strength After 28 days, increased compression ratio decreases when mixed waste increased. It is because water in the material increases, leading to reduced gravity. Splitting tensile strength Similar to compression, bending of the material decreases when increasing the percentage of mixed waste. It was found that when mixing a high percentage of waste increases the absorption of water reduces the adhesive properties, decreased strength. Sample Symbol Splitting tensile strength (kG/cm 2 ) Compressive strength (kG/cm 2 ) Compressive strength reduction (%) Rice husk DC 6,85 41,30 0 G-5 6,78 39,51 4,36 G-10 6,23 37,93 8,16 G-15 5,91 32,52 21,26 G-20 4,12 24,61 40,41 Coconut coir DC 6,85 41,30 0 G-5 6,21 31,24 24,36 G-10 5,87 25,27 37,77 G-15 5,11 22,15 46,37 G-20 4,22 16,91 59,05 Kỷ yếu hội nghị Khoa học Môi trường và Công nghệ sinh học năm 2011 137 - The ratio of waste ceme nt clinker phases to increase the proportion and magnitude decreases. Mixing mortar samples from the husks down 4.36 to 40.41%, coconut fiber mortar samples decreased from 24.36 to 59.05%, paper sludge mortar samples decreased from 14.21 to 41.43%. Because of the mixed waste into cement, it will react with hydrated lime from the lime and the water free of the mineral calcium silicate minerals are calculated to create sticky, slightly soluble or insoluble. Content of rice husk / coir / paper mill sludge will make the intensity and mix of waste reduction depends on many factors such as mineral composition, activity level, waste processing technology, the intensity of to produce cement. - Based on actual data can be seen that the strength of cement mortar produced from mixed waste is greatly reduced intensity compared with traditional mortar samples. With such intensity, only 10 samples% husks and paper sludge samples of 5% is standard. The other samples have not reached the quality standard, so difficult that can be used for construction for the bearing structures that can only be used for construction of the wall or walls. The volume of mixed cement mortar samples and reducing waste than traditional models 100% mortar cement, so when put into execution, it contributes significantly reduce the volume of work. CONCLUSION The experiment is still continuing. Nevertheless, through the survey is the first step could see the positive signal from the process. The initial research results are as follows: - - Samples of mixed waste to replace 5, 10, 15, 20% as cement ratio and compressive strength of cement mortar significantly reduced from 4.36 to 40.41% for husk, from 24.36 to 59, 05% of coconut fiber, 14.21 to 41.43% for paper sludge. However, this model still allows standard. - Strength of cement mortar made from mixed waste is greatly reduced intensity compared with traditional plaster models. With such intensity can not be used for construction for the bearing structures that can only be used for wall construction or walls. Sample volume of cement mortar mixed paper and sludge samples decreased more than 100% traditional mortar cement, so when put into execution, it contributes significantly reduce the volume of work. RECOMMENDATION In the coming time, the research will continue to perform to perfection. Subsequent research, the subject will perform a number of studies follows: - Continue studies utilize sludge from wastewater treatment systems of paper machines making concrete. - The study utilizes a number of agricultural residue / additives to industrial activity in the construction materials. REFERENCES B. Ahmadi, W. Al-Khaja Utilization of paper waste sludge in the building construction industry, Department of Civil and Architectural Engineering, University of Bahrain, P.O. Box 32038, Bahrain, 2000. Hoang Thi Hanh, Experiment of Building material, Ho Chi Minh City University, 2008. Nguyen Xuan Hoang, Nguyen Bao Van, Tran Thanh Tuan, Pham Cam Nam, Study to use diatomite making additives in building material, Da Nang University, 2008. Vu Hai Yen, Study using agricultural waste to produce building material, Ho Chi Minh City University of Technology, 2010. Paper mill sludge DC 6,85 41,30 0 G-5 6,71 35,43 14,21 G-10 6,12 31,22 23,68 G-15 5,94 29,35 28,93 G-20 4,52 24,19 41,43 Criteria (TCVN 6260-1997) 14 . nghệ sinh học năm 2011 130 STUDY ON UTILIZING OF INDUSTRIAL – AGRICULTURAL WASTE IN THE BUILDING CONSTRUCTION INDUSTRY Vu Hai Yen Department of Environment and Biotechnology, Ho Chi Minh. limiting climate change. In addition, some types of industrial waste and pollution also need to be processed. Technology of paper production is one of the polluting technology in the creation of. million tons of rice in 2009, only straw, rice husk waste during harvesting, the rice mill had tens of millions of tons of mass. However, compared with abundant potential sources of secondary, agricultural