ENVIRONMENTAL ENGINEERING

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1 NVIRONMNTAL NGINRING May 22-23, 2008 The 7 th International Conference Faculty of nvironmental ngineering Vilnius Gediminas Technical University Saulėtekio ave 11, LT Vilnius, Lithuania Phone: ; Fax.: ; ap2008@ap.vgtu.lt RMOVAL OF TOTAL PTROLUM HYDROCARBONS FROM INDUSTRIAL STORM WATR RUNOFF Vilmante Karlaviciene, Mindaugas Rimeika Vilnius Gediminas Technical University, Sauletekio av. 11, LT 10223, Vilnius, Lithuania -mail: vilmante.karlaviciene@ap.vgtu.lt; mindaugas.rimeika@ap.vgtu.lt Abstract. Industrial storm water related to industrial activities is one form of industrial waste discharge of increasing concern in many countries. The objective of this research was to evaluate the pollution of industrial storm water runoff (ISWR) focusing on the concentrations of suspended solids (SS) and total petroleum hydrocarbons (TPH) and to determine the suitability of the use of sand filter technology to remove TPH. The research started from the evaluation of ISWR pollution in six industrial areas (metal scrap processing industry, metal scrap collecting industry, storage area of municipal solid waste, storage area of building materials, stateowned enterprise of pubic transport, vehicle service area) and one industrial are of Vilnius city. Grab samples of ISWR were taken manually and analysed according to standard methods. The suitability of the use of sand filter technology to remove TPH was tested in lab-scale and pilot scale experiments. The results of investigation of removal efficiencies of filtration through the sand layer in lab-scale and pilot scale experiments showed that the calculated removal of TPH was higher than 94% or 63% and sufficient in both cases. According the obtained results the sand filter technology for the treatment of ISWR removing TPH and SS can be tested in a full scale experiment as a promising technology. Keywords: industrial storm water runoff, total petroleum hydrocarbons, suspended solids, sand filter technology, removal efficiency, gravel. 1. Introduction The literature review shows that storm water has been recognised as an important source of pollutants to receiving waters since the 1970 s. Among all investigated pollutants, the focus has been on Total Petroleum Hydrocarbons (TPH) and suspended solids (SS). Suspended solids have also been considered as the critical pollutant. Settling of suspended particles has been showed to be one of the most effective ways to treat storm water runoff. Pollutants that are attached to particles can be separated from the industrial storm water by sedimentation or filtration [1, 2, 3, 4]. Industrial Storm Water Runoff (ISWR) related to industrial activities is one form of industrial waste discharge of increasing concern in many countries. However, the characteristics of chemical composition of ISWR and their impact on receiving water bodies are not well understood [5]. Pollutant type, concentration, and long-term load may be expected to vary over the time and across locations with factors such as density of urban development, type of washed surfaces, and seasonality of precipitation [5]. Numerous different methods for storm water runoff treatment have been proposed during the years. Often the term best management practice (BMP) is used as a conception for all the different practices used to control pollution in storm water runoff. A storm water best management practice is a technique, measure or structural control that is used for a given set of conditions to manage the quantity and improve the quality of storm water runoff in the most cost-effective manner. The best and most suitable way to reduce the pollution load from ISWR is to decrease the pollution load on surfaces that are washed by the rain. However, such measures are hard to implement in certain industrial areas. Structural measures involve changes in the drainage system and demand construction work. These measures can be of two different kinds, either the end of pipe solution, where the treatment facility is constructed just 563

2 before the storm water enters the receiving body of water, or a more local solution where the aim is to decrease the amount of water that runs off from the industrial area. The use of sand filtration to improve water quality is not a new concept. Slow sand filtration has been used for decades to treat waste water, purify drinking water in many parts of the globe [5]. Some kind of sand filter can be applied to almost any development site. Use of sand filters is only limited by their cost and local maintenance capability. Sand filters are particularly suitable for smaller development sites where other storm water practices are often no practical [6]. Much still needs to be learned before the sand filters can be routinely and cost-effective applied in many countries Laboratory scale experiment The lab-scale experiment was designed according to the theory of engineering experimentations [14, 15]. The objective of the experiment was to evaluate the efficiency of the sand filter technology for the removal of TPH at four different inflow concentrations: 1 7 mgl -1, 7 20 mgl -1, mgl -1 and mgl -1. In laboratory scale experiment, real ISWR from metal scrap processing industry in Sweden was used. The principal scheme of the lab-scale experiment is show in Fig. 1. Filter media was submerged during the entire experiment. 2. Methodology The combination of treatment methods used for the removal of TPH and SS from ISWR mainly depends on the initial concentrations of these pollutants. The research started from the evaluation of ISWR pollution. The suitability of the use of sand filter technology to remove TPH was tested in lab-scale and pilot scale experiments. Chemical analyses were selected according to the requirements for the management of storm water runoff [7]. Grab samples of ISWR were taken manually and analysed according to Standard methods: TPH - ISO :2000 [8], SS - N 872:1996 [9]. Grab samples were selected for the research because they are the easiest and least costly samples to obtained valuation of ISWR pollution The investigation of ISWR pollution was conducted because of two main reasons. Firstly, differences in ISWR constituent characteristics among different types of industrial activities are poorly understood so the concentrations of TPH and SS were determined in six separate industrial territories of Lithuania and Sweden and one industrial area of Vilnius city. Secondly, the selection of the combination of treatment methods for the ISWR is limited by the lack of calculated values of pollutant concentration for certain industrial areas. The industrial areas for the research were selected according to the following criteria: the industrial activities are conducted in open areas, exposed to the storm water rainfall; the territories have relatively large and paved surfaces and because of the type of activities it is impossible to have it under the roof; the specificity of the activities allows to suspect that toxic substances can be released on the surfaces. Selection of industrial areas in Lithuania and Sweden based on the willing to check the ISWR pollution in two countries of different level of industrial development. ISWR was sampled according to [10, 11, 12, 13] Fig. 1. The principal scheme of the lab-scale model Pilot scale experiment The objective of the pilot scale experiment was to evaluate the efficiency of the sand filter technology with the large volumes of ISWR at the ISWR treatment plant of Vilnius city. Three parallel horizontal flow sand filters of 10 m length each were constructed for the experiment. These filters hade different grain size filter media. The distribution of grain size of used filter media is presented in Table 1. Three filters (10 m 0.5 m 0.4 m) were installed m under the soil layer and were isolated with polythene film. Before the sand filters the raw ISWR was accumulated in the sedimentation pond, where were favourable conditions for the equalisation of inflow concentrations and sedimentation of SS. Nine piezometers were installed to monitor the loss of pressure in the filters. 564

3 Table 1. The grain size distribution of three types of filter media used for the treatment of ISWR in pilot scale experiment. Filter media Sand (1-3 (2-8 (3-20 Sieved particles Diameter of particles ( > < Fig. 2. The scheme of the pilot plant experiment with the horizontal flow sand filter (length 10 m) for the removal of TPH. The scheme of the pilot plant experiment is shown in Fig. 2 and the characterisation of three types of horizontal flow sand filters is presented in Table 2.The duration of the experiment was five months. To evaluate the efficiency of three sand filters ISWR samples were taken from the end of sedimentation pond and at the outflow of each filter. Table 2. Characterisation of three types of horizontal flow sand filters for the removal of TPH designed for the pilot scale experiment. Filter media Sand (1-3 (2-8 (3-20 Grain size Porosity Coefficient of filtration Hydraulic load Retention time mm % cm/s m 3 /m 2 h h 0,3-5,0 27 0,015 0,2 0, ,25-10,0 31 0,75 0,7 2, ,5 20,0 36 2,18 1,5 4, Results Results of investigation of ISWR pollution are intended as a screening level determination and can be 565 used as addition information for the development of the preliminary storm water management plans for industrial areas [16].

4 In Table 3 the content of TPH and SS in ISWR are presented for seven different industrial areas. The concentrations of pollutants vary within the given range depending on local conditions such as types of used materials. Since, the grab samples only represent an instantaneous measurement of what is happening at that point in time and space the average, minimum and maximum concentrations are given in Table 3. The concentrations of pollutants in investigated industrial areas are very different from other industrial territories [17] and are higher when concentrations in receiving water bodies [18]. Table 3. Average, minimum and maximum concentrations of TPH, SS and ph at the inflow of local treatment of industrial storm water runoff units of seven investigated industrial areas in Sweden and Lithuania. Parameters Investigated industrial areas TPH (mgl -1 ) SS, (mgl -1 ) ph Average (min max) [number of samples] Average (min max) [number of samples] Average (min max) [number of samples] Metal scrap processing industry (Sweden) 38 ( ) [14] 4807 ( ) [14] 7.3 ( ) [52] Metal scrap collecting industry (Lithuania) 7.94 ( ) [55] 82 (1 966) [55] 7.58 ( ) [55] Storage area of municipal solid waste (Sweden) 7.5 (0.9 84) [25] 36 (2 634) [25] 7.7 ( ) [25] Storage area of building materials (Lithuania) 13 ( ) [123] 88 (1 1167) [123] 7.43 ( ) [123] State-owned enterprise of pubic transport (Lithuania) 24 ( ) [135] 71 ( ) [135] 7.58 ( ) [135] Vehicle service area (Lithuania) 14 ( ) [43] 161 (1 1970) [43] 7.37 ( ) [43] Industrial area of Vilnius city (Lithuania) 13 (0.7 44) [12] 270 (22 440) [12] 8.2 ( ) [12] The highest concentration of TPH and SS were in the ISWR of metal scrap processing industry and were up to 1821 mg L -1 for TPH and mg L -1 for SS respectively. The lowest concentration of TPH and SS were in the ISWR from the industrial area of Vilnius city and were up to 44 mg L -1 for TPH and 440 mg L -1 for SS respectively. The results of lab-scale experiment are presented in the Table 4. The efficiency of TPH removal was sufficient when the inflow concentration was fluctuating from 1 mgl -1 up to 45 mgl

5 Table 4. The efficiency of the removal of TPH treating the industrial storm water runoff from the Metal scrap processing plant, filtering storm water through the layer of sand during the lab-scale experiment. Concentration of TPH, (mgl -1 ) (v=0,01 mh -1 ) : 1 7 (mgl -1 ) : 7 20 (mgl -1 ) : (mgl -1 ) : (mgl -1 ) Average Min Max Number of samples The results of pilot scale experiment are shown in Table 5. The calculated removal efficiency for TPH and SS was 63-78%. Sufficient results were obtained even in case when the diameter of particles of tested filter media was the biggest ( Based on the above shown results, for the future studies it could be recommended not to test the sand (0.3 5 and gravel ( ) mm. Table 5. The average concentrations of TPH, SS at the inflow and outflow of three horizontal flow sand filter beds (length 10 m) with different grain size of sand and calculated removal efficiency during the pilot scale experiment. Parameter Sand (0.3-5 Removal efficiency, ( ( Sand (0.3-5 (1,25-10 (2,5-20 SS (mgl -1 ) TPH, (mg L -1 ) Conclusions The investigation of ISWR pollution showed that the concentrations of TPH and SS vary very much and depends on the type of industrial activity. Since the combination of treatment methods used for the removal of TPH and suspended solids (SS) from ISWR mainly depends on the initial concentrations of these pollutants the equalisation tank of pollutant load is needed. Results of lab-scale experiment from the pollutant removal efficiency calculation show TPH removal to a great extent at four different inflow concentrations of TPH. When the inflow concentration of TPH was 1 7 mgl -1 the average removal efficiency was 94%; 7 20 mgl -1 97% respectively. The efficiency removal was 98% when the concentrations of TPH in the inflow were mgl -1 and mgl -1. Based on the lab-scale results we can conclude that the sand filter technology can be successfully applied for the removal of TPH in range from 1 mgl -1 to 45 mgl -1 when the filtration speed of ISWR is 0.01mh -1. In lab-scale tested modification of sand filter technology can be consider as biological treatment unit due to the facts that the hydraulic loading is very low (the retention time is long, T = 24 h). Results of pilot scale experiment showed that the removal of TPH and SS was sufficient for all three tested types of filter media. When the grain size of filter media was mm, porosity 36%, the coefficient of filtration 2.2 cm/s, the hydraulic load m/h and the retention time h the removal efficiency of horizontal sand filter for TPH was 66% and for SS 78% respectively. When the grain size of filter media was mm the removal efficiency didn t increased and was 78% for SS, and 63% for TPH respectively. According to the obtained results of lab-scale and pilot scale experiments the sand filter technology for the treatment of ISWR removing TPH and SS can be tested in a full scale experiment as a promising technology.

6 References 1. Fujita S. Infiltration structures in Tokyo. Water Sience and Technology, Vol 30 (1), 1994, p Färm, C. Constructed gilters and detention ponds for metal reduction in storm water. Ph.D. thesis, Dept. of Public Technology, Mälardalen Univrsity, Västerås ISBN Bäckström M. Grassed swales for urban storm drainage. Ph.D. thesis. Luleå University of Technology, Sweden, ISSN Hwang S. H-M, Foster G-D. Characterization of Polycyclic Aromatic Hydrocarbons in Urban Stormwater Runoff Flowing into the Tidal Anacostia River, Washington, DC, USA. nvironmental Pollution, p. 140, 2006, p Duke L. D., Buffleben and the M. Bauersachs L. A. Pollutants in storm water runoff from metal planting facilities, Los Angeles, California. Waste Management, Vol.18, 1998, p Schueler T., R., Holand H., K. Developments in sand filter technology to treat storm water runoff. Article 105 from The Practice of Watershed Protection Techniques (2): Lithuanian PA: nvironmental Requirements for the Management of Storm Water Runoff. (2007) 8. ISO :2000: Water quality-determination of hydrocarbon oil index-part 2: Method using solvent extraction and gas chromatography N 872:1996. Water quality - Determination of suspended solids - Method by filtration through glass fibre filters ISO/IC 17025:2005 (2005): General requirements for the competence of testing and calibration laboratories. 11. ISO :2003 (2003): Water quality - Sampling - Part 3: Guidance on the preservation and handling of water samples 12. ISO :2006 (2006): Water quality - Sampling - Part 1: Guidance on the design of sampling programmes and sampling techniques. 13. PA (1992): NPDS Storm Water Sampling Guidance Document. 14. Schenck, H. Theories of engineering experimentation. Mc Grow-Hill book company. New Yourk, psl Mir: Maskva ). 15. Dixson, J.R. Design enginering: inventiveness, analysis and desicion making. Mc Grow-Hill book company. New Yourk, psl Stormwater Management in Industrial Facilities: An Integrated Approach. dgar J. Oubre, Robert M. Howe and J. David Keating, Jr. nvironmental Progress, Vol. 14, No Hogland, W., Marques, M. and Karlaviciene, V., Stormwater Runoff from Industrial Areas and Pollution Transport. In: Proceedings of the 1 st International Conference on Urban Drainage and Highway Runoff in Cold Climate, March 2003, Riksgränsen, Sweden, p. 18. Idzelis R-L, Greičiūtė K and Paliulis D (2006): Investigation and valuation of Surface Water Pollution with Heavy Metals and Oil Products in Kairiai Military Ground Territory. nviron ngg and Landscape Management, Vol XIV, No 4, p