Investigation of the effects of fillers on various envornmental parameters in planted systems

There has been a significant population shift from rural areas to cities in the last century. The movement of people living in rural areas to cities has rapidly increased the demand for new buildings and cities have grown significantly. This situation has led to a decrease in green areas, defined as concretion, in cities, and important problems have begun to emerge in terms of the natural environment and human health. The formation of heat islands in cities, decrease in biodiversity, pollution of water resources and city noise can be listed as the most important of these problems. In recent years, important studies have been carried out to develop a solution to this situation. The focus of these studies, which are based on the basic idea of creating sustainable cities and living spaces, is to increase green areas in cities. One of the best solutions developed to increase green areas in cities is the widespread use of green wall and roof systems. Green wall and roof systems can basically be explained as planning plants as part of the architectural design and growing them on building walls, roofs or interiors. These systems are frequently used in today's architectural designs because they make a significant aesthetic contribution to architectural designs. However, studies on green wall systems in recent years reveal that these systems, in addition to being an aesthetic element in architectural design, can make much more important contributions to buildings and cities. Studies on the subject have shown that green wall systems reduce air pollution, capture greenhouse gases that cause global warming, reduce heat islands in cities, increase biodiversity, contribute to sound and heat insulation in buildings, reduce the amount of energy used especially for cooling purposes, harvest rainwater and gray water It is reported that it has a significant potential in many areas such as purification. Especially in these days when climate change is being combated on a global scale and intense efforts are being made to create carbon neutral cities, it is very important to use the potential of green wall systems in this field. That is why, in many countries, in order to accelerate sustainable city transformation, significant support is given for the installation of green wall systems in new or existing buildings. However, green wall systems require maintaining a complex application such as plant cultivation as a part of architectural design. Considering that plant cultivation is a complex task even in gardens and fields where it is conventionally practiced, the difficulty of successfully carrying out this process in systems mounted on building walls and above the ground can be better understood. In order for plants to survive healthily in the green wall system, many factors important for plant development such as irrigation, meeting plant nutrient needs, and combating diseases and pests must be taken into consideration and optimized with engineering applications. In addition, even if ideal conditions for plant growth are created, the green wall system must also meet the aesthetic goals foreseen in the architectural design of the building. One of the most important needs for green wall systems to meet the desired aesthetic criteria and to achieve healthy plant growth is the plant growing media to be used. Essentially, growing plants in green wall systems is similar to growing potted ornamental plants. However, the growing media to be used in green wall systems are required to have additional qualities compared to those used in potted ornamental plant cultivation. These qualities can be listed as being light enough not to put too much load on the building, having a high water retention capacity so that it does not require too much irrigation, and being free of plant diseases. To meet these qualities, a good solution is to use growing media consisting of a mixture of different organic and inorganic materials. The need for organic materials in growing media mixtures to be used in green wall applications can be met from organic wastes of agricultural origin. This method both reduces the cost of the growing media and provides an economical and ecological disposal alternative for organic waste of agricultural origin. In this study, which was carried out based on this idea, growing media for green wall systems were prepared using agricultural wastes and some inorganic materials, which are abundant in our country, and the effects of these growing media on plant growth, heat and sound insulation in green walls were examined. For this purpose, peat, which is frequently used in green wall applications, and hazelnut husk, one of the organic wastes of agricultural origin, were selected as the main mixture materials, and growing media were prepared by mixing rice hull and perlite in the ratio of 12.5%, 25% and 50% by volume to these main materials (P: 100% peat, H: 100% hazelnut husk, PH1: 87.5% peat+12.5% hazelnut husk, PH2: 75% peat+25% hazelnut husk, PH3: 50% peat+50% hazelnut husk, PR1: 87.5% peat+ 12.5% rice hull, PR2: 75% peat+25% rice hull, PR3: 50% peat+50% rice hull, PPE1: 87.5% peat+12.5% perlite, PPE2: 75% peat+25% perlite, PPE3 : 50% peat + 50% perlite, HR1: 87.5% hazelnut husk + 12.5% rice hull, HR2: 75% hazelnut husk + 25% rice hull, HR3: 50% hazelnut husk + 50% rice hull, HPE1: 87% .5 hazelnut husk + 12.5% perlite, HPE2: 75% hazelnut husk + 25% perlite, HPE3: 50% hazelnut husk + 50% perlite). Peat and perlite suitable for agricultural use are commercial products and were purchased. Hazelnut husk and rice hull were provided after the harvesting process, and the hazelnut husk was passed through the shredding machine. No pretreatment was applied to the rice hull. All growing media mixtures were prepared as 50 liters. The physical and chemical properties of all prepared growing media were determined using standard methods and analysis methods applied in scientific studies, and the results obtained were compared with the desired values in ideal plant growing media. Model buildings were built so that the green wall system could be installed and its effects on heat and sound insulation could be tested in identical environments. Concrete boards measuring 125 cm x 125 cm x 125 cm and 2 cm thick were used in the construction of the model buildings. Insulation was applied to the floors and roofs of the model buildings, which are areas outside the green wall systems, with 5 cm thick carbon-reinforced styrofoam. Green wall systems were mounted on all four facades of the model building, leaving a 3 cm gap from the wall surface. The green wall system consists of plastic pots and drip irrigation systems attached at a certain angle on a steel cage woven from 5 mm thick wires. The pots in the green wall system were filled with growing media prepared before planting, and thuja (Thuja plicata) and boxwood (Buxus sempervirens L.) plants, selected to represent needle and flat-leaved plants, were planted. The plants were watered regularly with tap water. The success of the prepared growing media in growing plants was determined by the image processing method, which is a unique method for this study. For this purpose, digital images were taken from the green wall in the months of April, May, June, July, August and September, which constitute the plant growth period, and from these images, using the imageJ program, thuja (Thuja plicata) and boxwood (Buxus sempervirens L.) plants were formed on the green Wall plant area has been calculated. In order to determine the effects of the green wall system on thermal insulation, a green wall system was installed and temperature measurement sensors were placed in empty model buildings without a green wall system and temperature measurements were taken. Temperature measurements were carried out at 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00. In addition, measurements were taken in all months between April and September, which is the growing period, and the effects of the change in plant area on heat insulation were observed. In order to better understand the effects of green wall systems on thermal insulation, thermal imaging was also carried out in addition to temperature measurements. Within the scope of the study, the effects of green wall applications on sound insulation were determined by measuring the sound produced (in the third octave bands) according to UNE-EN ISO 10140-2 standards in model buildings with and without green wall systems and calculating the frequency-dependent sound reduction index from the difference. In the study, frequencies of 0.125 kHz, 0.250 kHz, 0.500 kHz, 1.000 kHz and 2.000 kHz were used to determine the effects of different frequencies. All analyzes and measurements carried out within the scope of the study were made in three replicates and the results were presented as means. All results were analyzed statistically by ANOVA and LSD tests using computer software. In the examination of the physical properties of the growing media, hazelnut husk (H) (0.28 g/cm3) was found to have the highest volume weight, and rice hull (R) (0.11 g/cm3) had the lowest volume weight. The volumetric weights of peat (P) and perlite (PE) are 0.21 g/cm3 and 0.15 g/cm3, respectively. Increasing the rice husk ratio in mixtures significantly reduces the volume weight of the growing media. The volume weights of PR3 and HR3 applications, which have the highest rice hull ratio (50%), are 0.15 g/cm3 and 0.18 g/cm3, respectively. The bulk density of all growing media examined was within the desired limit for ideal growing media. In general, the porosity of the growing medium increases with decreasing bulk weight. Although the bulk weight of perlite is lower than rice husk, its porosity (94.39% V/V) was found to be high. This is due to the microporous structure of perlite. Hazelnut husk (81.43% V/V) has the lowest porosity value. For this reason, the porosity values of HR1 (82.41% V/V) and HPE1 (82.4% V/V) applications containing 87.5% hazelnut hull are lower than other applications. Increasing the ratio of perlite and rice hull in the growing media increased the porosity values. The water retention capacities of the growing media components peat (770.38 mg/l) and hazelnut husk (619.29 mg/l) were significantly higher than rice hull (114.88 mg/l) and perlite (229.26 mg/l). was found high. The water retention capacity of HR3 (566.95 mg/l) containing 50% hazelnut husk and 50% rice hull and HPE3 (580.51 mg/l) containing 50% hazelnut husk and 50% perlite is well below the ideal value range. In the examination of the chemical properties of the growing media, all pH values measured in the growing media were within the desired range for ornamental plants, while all electrical conductivity values were found to be lower than the desired values for the ideal growing media. The highest measured electrical conductivity value is 482.78 µS/cm (HPE3). Low electrical conductivity values were considered as an advantage due to situations that increase EC, such as long-term watering of green walls and decomposition of dried leaves and branches in pots. In all growing media applications where perlite, an inorganic growing medium component, was used, the amount of organic matter decreased as the amount of perlite in the mixture increased. The lowest organic matter content among the growing media was found in the FPE3 application (50.74%). The highest values of nitrogen and potassium, which are the most important nutritional elements for plant development, are in hazelnut husk (N: 1.48%; K: 2442.67 mg/kg), while the highest value of phosphorus is in rice hull (P: 3231.26 mg/kg) was found. Additionally, peat has the highest Ca (2587.28 mg/kg) and Fe (192.39 mg/kg) content, rice hull has the highest Mg (1183.74 mg/kg) content, and hazelnut husk has the highest Cu (5.87) content. and Zn (36.35 mg/kg). The macro and micronutrient content of perlite, which is an inorganic growing media component, was found to be quite low. In the studies examining the plant area by image analysis, the highest plant area of the thuja plant was reached in the HR1 growing media. In the green wall system using this growing medium, the initial (April) plant area was calculated as 0.327 m2 and the end of the growing period (September) plant area was calculated as 0.962 m2. The smallest plant area increase in the green wall was determined in the HR3 application with an initial plant area of 0.343 m2 and a final plant area of 0.612 m2. Similar to the results obtained with thuja, the highest plant area was reached in the PH1 growing medium in green wall systems using boxwood. In the PH1 application, where the highest values were obtained, the initial plant area was 0.412 m2 and the final plant area was 0.594 m2. The lowest value (0.521 m2) was obtained in the HR3 application. The highest positive correlations between physical and chemical properties of growing media and plant area were water retention capacity (R2:0.86; p <0.001), organik matter (R2:0.76; p <0.001), Ca (R2:0.52; p <0.001), Fe (R2:0.63; p <0.001) and Mg (R2:0.57; p <0,05) were also found. As a general result, as the water holding capacity and organic matter content of the growing media decreases, plant growth is negatively affected and the green wall plant area decreases. In the study, in the temperature measurements made to determine the effects of the green wall system on thermal insulation, it was observed that as the plant area values increase, the thermal insulation values of green wall applications also increase. When the temperature differences between the green wall model building and the control application were examined, the highest temperature difference was recorded at 15:00 in August measurements in the green wall application where 100% peat was used as the arborvitae plant growing media (6.2 °C). In the PH1 application in August, the highest value was measured as 6.0 °C. Other high temperature difference values measured are 4.8 °C in the PR1 application and 5.1 °C in the PPE1 application. The highest temperature differences measured in green wall applications using boxwood plants were also recorded in August. 4.4 °C in P application, 4.1 °C in PH1 application and 4.2 °C in PPE1 application are the highest temperature difference values measured in this application. As a result of the measurements made to examine the sound insulation effects of green walls, sound reduction indexes were calculated and when the results were examined, it was seen that the highest sound reduction index values were calculated in the September measurements in both plant types used. For thuja, this value was calculated as 16 dB in the PPE1 application, and for boxwood plants, it was calculated as 14.9 dB in the P application. These two calculated values were measured when the source sound was set to 0.500 kHz frequency. Considering all the results obtained in the study, all the results obtained in the growing environments consisting of peat-hazelnut husk and peat+perlite mixtures showed that they can be an alternative growing environment for green wall systems, although the results decreased slightly with the increase in the ratio of hazelnut husk and perlite in the mixtures. The use of hazelnut husk, which is one of the organic wastes of agricultural origin and has no practical use yet, as a growing media component is important for the sustainable disposal method of this waste. In addition, it has been determined that the use of alternative growing media components in green wall systems is effective in increasing the benefits of green walls such as thermal insulation and sound insulation. In addition, the indirect monitoring technique used in determining the plant area in this study will allow this study to be carried out in a safe and cost-effective manner without damaging green wall plants and systems. The simple and rapid information obtained by this method will help us better understand the effects of different growing media on the expansion of green wall plant area. The results obtained in this study can be used to optimize green wall design to improve plant growth and overall system performance in urban areas.