International Journal of Advance Engineering and Research Development STORMWATER MANAGEMENT USING BIORETENTION TECHNOLOGY

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1 Scientific Journal of Impact Factor (SJIF): 5.71 International Journal of Advance Engineering and Research Development Volume 5, Issue 04, April e-issn (O): p-issn (P): STORMWATER MANAGEMENT USING BIORETENTION TECHNOLOGY Fayiz K. 1, Shafeeba K.P. 2, Sree Lakshmi K.S. 3, Chaithanya 4, Nihala Kallankunnan 5, Nusrath Beegam 6, Sreechithra P B.Tech students, Department of Civil Engineering, Cochin College of Engineering and Technology, Valanchery, Kerala 7 Assistant professor, Department of Civil Engineering, Cochin College of Engineering and Technology, Valanchery, Kerala Abstract Bioretention systems are constructed to manage storm water runoff by moderating peak flow and reducing downstream pollution loads. Bioretention systems are generally soil plant based systems which typically include a filter media above a drainage layer. They are often either lined with a geo fabric to support infiltration or with an impermeable membrane to prevent infiltration and / or to allow storm water harvesting and reuse. Bioretention systems are known to treat a range of storm water pollutants, through physical, chemical and biological process such as mechanical filtering, sedimentation, adsorption and plant and microbial uptake. Tests were under taken to determine the levels of contaminant and heavy metals build up that occurred in filter media. Tests for that suspended solids, total phosphorous and total nitrogen are to be done for determine the level of contaminants. Keywords-water harvesting, sustainable, filter media, soil plant based system, etc. I. INTRODUCTION Stormwater is water that originates during precipitation events such as rainfall, snowmelt, and hailstorms. The precipitation that washes off of driveways, parking lots, roads, yards, rooftops, and other hard surfaces doesn t soak into the ground and becomes surface runoff. As the runoff flows over the land or impervious surfaces, such as paved roads, parking lots, and rooftops, it accumulates chemicals, sediment, debris, and other pollutants that can negatively impact water quality when the runoff is untreated.. Consequently, stormwater management in urban areas has become a priority for those responsible for planning and construction of new developments, and maintenance of existing storm water infrastructure. Bioretention systems are generally soil-plant based systems which typically consist of a filter medium (usually sandy), underlain by a gravel drainage. They are often either lined with a geo-fabric to support infiltration, or with an impermeable membrane to prevent infiltration and/or to allow stormwater harvesting and reuse. Bioretention systems are known to treat a range of stormwater pollutants through physical, chemical and biological processes such as mechanical filtering, sedimentation, adsorption, and plant and microbial uptake. However, the long-term pollution removal performance, particularly of heavy metals, remains largely unknown. It is generally accepted that the filter media used in bioretention systems has a finite life span, after which time it should be replaced. Bioretention systems are designed to drain within 24 hours, which allows a broad range of plants, including native sedges and rushes to be used. Fig.1. schematic diagram of a bioretention system different than a typical rain garden is the under drain present underneath the center of the garden, usually made of a four inch perforated PVC pipe. Typically, a bioretention under drain cross-section will be 18 to 24 inches deep and 1 to 2 feet wide, running at least 90 percent of the garden s length (DeBusk and Wynn 2011). This placement and sizing allows for ample system drainage while reducing the amount of soil plants must grow through. Valves can be installed on the under drain to help control drainage flow, which is especially important to minimize stresses to new plants established roots. Having a way to adjust the system drainage rate is beneficial as plant health and seasons change. Having a regulation valve in place also makes maintenance and repair activities easier and allows for infiltration performance testing. The soil of a bioretention system base is critical for infiltration and water storage, so the soil must be conditioned before planting. This involves loosening at least six inches of the soil from the garden surface and then tilling a four inch later of organic compost. Bioretention systems incorporate a unique soil mix made up of 20 to 30 percent topsoil, 20 to 30 percent compost and 50 percent sand (Davis et al. 2006). The mixture helps reduce the likelihood of nutrient leaching occurring as water flows through the under drain (Wu and Sansalone 2013). The under drain will be nestled in washed aggregate bedding to prevent system clogging. Plant selection is the final component of a bioretention system. It s important to choose plants that have both aesthetic appeal and a functional landscape role. We must take environmental conditions, rooting depth, drought tolerance, All rights Reserved 1687

2 habitat value into consideration as well. Native and adapted plants are the best option to meet those criteria because they require little maintenance or water resources once established. They have deep roots and are well adapted to drought conditions while not becoming an invasive species. The use of native and adapted plants will help to enhance biodiversity and pollinator habitat quality. Fig.1: Schematic Diagram of a Bioretention Cell Bioretention basins are typically associated within small areas of land with residential usage or with parking lots where the islands become visually pleasing stormwater treatment centers. Excessive storm water is normally diverted to stormwater drains once the basin s ponding area is full. II. PREVIOUS RESEARCH Hem Nalini Morzaria-Luna. et.al (2004); Bioretention systems are one option for direct stormwater infiltration. These systems consist of a depression over porous soil, covered with mulch and planted with variety of vegetation. Bioretention was originally designed to minimize surface water runoff volume, but increasingly it is being used to improve ground water quality. Bioretention is recommended as a structural best management practice. In particular, rain gardens have attracted attention because they are aesthetically pleasing, simple to build and can very effective when infiltration is focused to maximize recharge. A rain garden is a landscaped garden on a small shallow depression that receives the runoff form one house hold or lot through layers of mulch and porous soil. K M DeBusk, T M Wynn (2011); The bioretention cell was successful in reducing flow volumes and peak flow rates leaving the parking lot, as well as reducing the total mass of sediment, total nitrogen and total phosphorus leaving the site. The bioretention cell achieved cumulative mass removals of greater than 99% for suspended sediment, total nitrogen and total phosphorus, significantly reducing inflow pollutant loads. Study results indicated the BMP effectiveness at reducing storm water volume, peak runoff rates and pollutant. On the basis of the results of this study, bioretention is highly recommended as a method of treating urban storm water. Abubakar Ismail, Zaharaddeen Baffa Baba (2015); Filtration is one of the most important operations in the water purification process, through screening and sedimentation remove a large proportion of suspended matter. Basically the process of filtration consists of passing the water through a bed of sand, or other suitable medium at low speed. Results of the foregoing research have indicated that, local sand can be used as a filter media, since the effective size of the sand was found to be 0.22 mm and uniformity coefficient is by passing of raw water through the filter media there is considerable reduction of turbidity and coli form with insignificant changes in ph. The usual media size/effective size of 0.15 mm 0.35 mm and uniformity coefficient between should always be use. This is because carefully graded media performed better in terms of turbidity and coli form removal. Norshafa Elyza Muha, Lariyah Mohd Sidek(2015); Urban planners, engineers and local authority are looking into the best solution to create a more sustainable environment, namely through stormwater management to protect the environmental values of urban areas and their surroundings. Bioretention system is made of an excavated basin or landscape depressions consisting of plants, ponding area and mulch layer, several layers of plantings soil and under drain. Primarily results indicated that bioretention system have the ability to remove TSS, TP, TN and turbidity significantly. Additional monitoring and analysis will be made for the long term performance in terms of water quality and hydrological aspects. Peter Nichols, Terry Lucke (2016); Bioretention systems are generally soil-plant based systems that typically consist of a filter medium, underlain by a gravel drainage layer. Bioretention systems may be lined with geofabric to allow infiltration or include an impermeable liner to assist in stormwater capture and reuse. Bioretention systems treat stormwater via a range of chemical, physical and biological processes. Depending on the precise filter media used in the basin design, bioretention basins have previously been known to be occasional exporters of pollution, particularly particulate-bound phosphorous. This study found that bioretention basins reduced TP loads in all tests, although the removal performance was found to be most effective during the higher pollution concentration tests. The test results showed that the basins exported both TSS and TN, while TP was found to show a modest pollution removal performance All rights Reserved 1688

3 III. MATERIALS AND METHODOLOGY A. Methodolgy Stormwater management using bioretention technology is in the system of purification of storm water and other purpose using the water. Different stages in the bioretention system includes the collection of stormwater and then this water testing before passing through bio-retention cell such as PH Value, alkalinity, hardness, total suspended solids (TTS), Total Nitrogen (TN), Total phosphorus (TP), Biological oxygen demand (BOD), Dissolved oxygen (DO),Chloride and Nitrogen are tested. Then choose the site for construction of bioretention cell. After that bioretention cell is to be constructed as per the test result. Then the water to be treated is passing through the cell and the water after passing through bioretention cell is again tested. At last compare the results for getting the result. B. Raw Materials Tank In bioretention technology for treatment of stormwater, a concrete masonry used under the ground for filling the filter media layers. But in our project, we are used a tank made with glass of depth of 1m for filling the filter media layers. Glass tank is considered for the easiness to see the process undertaken in the filter media layers. Fig.2 shows tank constructed using glass tank. Each layers provided in the tank is clearly seen through the tank glass. Fig 2. Tank Constructed Using Glass The depth of tank is taken as 1m as per the test results of water before passing through the bioretention cell. The test results include very less impurities and so the average depth for each layers were provided. That is the depth for each layer are 0.2m depth for drainage layer, 0.1m for transition layer, 0.5m for filter media and 0.2m for top soil and mulch. Some plants also provided at the top of the soil such as Alovera, Vetiver. Impermeable Geomembrane Liner For no-infiltration sections, install a 30 mil (minimum) PVC geo-membrane liner, on the bottom and sides of the basin, extending up at least to the top of the underdrain layer. Fig.3 Geotextile membrane. Provide at least 9 inches (12 inches if possible) of cover over the membrane where it is attached to the wall to protect the membrane from UV deterioration. Fig 3. Geo textile membrane Drainage Pipe The pipe placed below the tank used to collect the treated water. Two or more pipes are used on the basis of size of the tank. We are mostly choosing the PVC pipe. Underdrain piping beneath the soil planting bed and sand layer must be perforated. All joints must be secure and watertight. The underdrain piping must connect to a downstream storm sewer manhole, catch basin, channel, swale or ground surface at location that is not subjected to blockage by debris or sediment and is readily accessible for inspection and maintenance. Fig. 4. shows Drainage Pipe. Fig 4. Drainage All rights Reserved 1689

4 Drainage Layer The drainage layer collects treated water at the bottom of the system and conveys it to the under drain pipes. Drainage layer material is to be clean, fine gravel. Here we are providing a drainage layer with 0.2m deep (i.e. 20% of total depth). Fig 5. shows the Gravel. It must have sufficient thickness to provide a minimum thickness of 3 inches of gravel above and below the pipes. It should consist of 0.5 to 1.5 inch clean broken stone or pea gravel. The perforation in the under drain pipes should be small enough that the layer cannot fall into the pipe. Fig 5. Gravel Transition layer The transition layer prevents filter media from washing into the drainage layer. Transition layer material shall be a clean, well-graded sand material containing <2% fines. To avoid of the filter media into the transition layer, the particle size of the sand should assessed to ensure it meets the bridging criteria.fig.6. shows the Coarse Sand Fig 6. Coarse Sand Sand The sand layer serves as a transition between the planting soil bed and the gravel layer and under drain pipes. It must have a thickness of 6 inches and consist of clean medium aggregates concrete sand. Fig.7. shows the sand passing through the 600 micron IS sieve and retained on the 300 micron sieves. We are providing 50% of the total height (0.5m deep). Fig 7. Sand Soil&Mulch The clay in the planting soil provides adsorption sites for hydrocarbon, heavy metals, nutrients and other pollutants. Fig. 8 shows the soil.stormwater storage is also provided by the voids in the planting soil. The stored water and nutrients in the water and soil are then available to the plants for uptake. The combination of top soil and mulch are 20% of total height. The organic or mulch layer also filters pollutants and provides an environment conducive to the growth of microorganisms, which degrade petroleum-based products and other organic material. This layer acts in a similar way to the leaf litter in a forest and prevents the erosion and drying of underlying soils. Planted ground cover reduces the potential for erosion as well, slightly more effectively than mulch. Wood mulch handles sediment build-up better than rock mulch; however, wood mulch floats and may clog the overflow depending on the configuration of the outlet or settle unevenly. Fig. 9 shows the All rights Reserved 1690

5 Fig 8. soil Fig 9. Mulch Plants The best surface cover for a rain garden is full vegetation. When using an impermeable liner, select plants with diffuse (or fibrous) root systems, not taproots. Taproots can damage the liner and/or under drain pipe. Use a cutoff wall to ensure that roots do not grow into the under drain or place trees and shrubs a conservative distance from the under drain. Fig.3.9 shows the vetiver plant, it is an ayurvedic plant. Its common name is vetiver Grass. Plant growth form is Shrub, Grass and Grass-like Plant having a maximum height of 1.5 m. This is used in the Landscape as Hedge, Screening, Accent Plant, Borders. The desirable plant features are Strong, deep roots for soil stabilization. It requires full sun and moderate water. It is having the capacity to remove nitrate at a percentage of 93 %. Fig 10. Vetiver (Chrysopogon Zizaniodes) Fig 11. Aloe Vera Fig.3.10 shows the Aloe Vera plant. This is a member of family Liliaceae and has medicinal properties. Aloe Vera growth parameters including leaf numbers, leaf length and fresh weight significantly increased in plants treated with nitrogen and phosphorus at the rate of 75 and kg/ha. Aloe Vera received nutrient solution containing highest amount of nitrogen, which adsorb both phosphorus and nitrogen in large amounts. IV. RESULT AND DISCUSSION Sl.no Parameters Unit Value before passing Value after passing through the cell through the cell Std limits 1 Turbidity NTU ph Nitrogen mg/l Hardness mg/l Dissolved oxygen mg/l Total phosphorus mg/l Alkalinity mg/l Acidity mg/l Biological oxygen demand mg/l Total suspended solids mg/l Chlorides mg/l Table 1. Result Comparison Some properties of test water are in the standard limit for the irrigation and domestic purpose, so that the properties are not considered for the analysis of results. Considerable changes in the results were identified in the properties All rights Reserved 1691

6 stormwater such that turbidity, total nitrogen, total hardness and total suspended solids. The results shows that the removal efficiency of turbidity, total nitrogen, total hardness and total suspended solids are 97%, 14.5%, 46.87% and 99% respectively. REFERENCES [1] Hem Nalini Morzaria-Luna et.al., Implementation of bio retention systems: a Wisconsin case study, Journal of the American water resource association (JAWRA), paper No.02126, 2004 [2] K.M DeBusk, and T.M Wynn, Storm-water bio retention for runoff quality and quantity Mitigation. Journal of Environmental Engineering, Vol. 137, No. 9, September 1, ASCE, ISSN / 2011/ , [3] M.P. Jones, Effect of Urban Storm water BMPs on Runoff Temperature in Trout Sensitive Regions International Conference on Urban Drainage, Edinburgh, Scotland, UK.2008 [4] Norshafa Elyza Muha and Lariyah Mohd Sidek, Bio retention system as storm water quality improvement mechanism. Scientific journal (SCIRJ), vol. III, issue II, February. ISSN , All rights Reserved 1692