Development and Evaluation of BOD DO Model for River Ghataprabha near Mudhol (India), using QUAL2K

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1 I.J. Engneerng and Manufacturng, 2015, 1, Publshed Onlne March 2015 n MECS ( DOI: /jem Avalable onlne at Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K P. B. Kalburg a, R. N. Shareefa a, U. B. Deshannavar b,* a Cvl Engneerng Department, Basaveshwar Engneerng College, Bagalkot,587101, INDIA b Department of Chemcal Engneerng, KLE DR. M. S. Sheshgr College of Engneerng & Technology, Belgaum, , Karnataka, INDIA Abstract The present study nvolves the applcaton of a water qualty model QUAL2K for developng the BOD-DO model and evaluaton of the results for a 50 km stretch of rver Ghataprabha near Mudhol town of Bagalkot dstrct, Karnataka. QUAL2K s a modelng framework for smulatng rver and stream water qualty. Arc-GIS technque s used to obtan some hydro-geometrc data of the rver for nput to model QUAL2K. For calbraton and valdaton of the model, the BOD and DO values were montored at sx dfferent locatons. The calbrated model was valdated to predct water qualty usng a dfferent set of data under dfferent condtons. The performance of the model was evaluated usng statstcs based on Standard errors (SE), Normalzed Mean Errors (NME) and Mean Multplcatve errors (MME). The SE and MME values for BOD and DO durng calbraton are, 1.41 (1.12) and1.28 (0.90), respectvely. The values n the bracket show MME. Correspondng values for the valdaton are 1.27 (1.09) and 1.10 (0.96). These results show that the values predcted by the model are n close agreement wth measured values. Index Terms: Water qualty modelng, QUAL2K, Rver polluton, Rver Ghataprabha, Calbraton Publshed by MECS Publsher. Selecton and/or peer revew under responsblty of the Research Assocaton of Modern Educaton and Computer Scence. 1. Introducton In Inda, dsposal of domestc sewage from ctes and towns s the bggest source of polluton of surface water bodes whch cause depleton of oxygen n water bodes. Accordng to WHO estmate, about 80% of polluton n developng countres lke Inda s caused by domestc wastes (Bhuvaneswaran & Rajeswar, 1999). The unchecked urban growth across the country combned wth poor government oversght means the problem s only gettng worse gradually and the mantenance of the qualty of rver water wll be a severe problem n the years to come. * Correspondng author. Tel.: E-mal address: deshannavar@gmal.com

2 16 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K Mathematcal models can be used to predct the changes n ambent water qualty due to changes n dscharges of waste water. They are typcally used to establsh prortes for reducton of exstng waste water dscharges or to predct the mpacts of a proposed new dscharge. Wth the use of mathematcal models and modern computer tools t has become an easy technque to study the dynamcs of the rver system. The scentfc actvty of modelng has the capablty to delver customzed solutons through dentfyng a varety of arrangements. Ths n turn offers nexhaustble opportuntes of ntegraton, analyss and evaluaton of complex water qualty problems, whch wll ultmately gude the planners, polcy makers and decson makers to take quck steps to mtgate polluton problems and manage the water systems n a more scentfc and comprehensve manner. Rver Ghataprabha, durng ts flow through Bagalkot dstrct n Karnataka state, receves untreated domestc waste from Mudhol town and other vllages located on the bank of ths rver causng a serous threat to ts water qualty. Ths rver s a prmary source of drnkng water to the people of many towns and vllages located on the bank of ths rver. Consderng the mplcatons of water polluton on human and aquatc health, the effectve management of ths polluted segment of the rver s of prme mportance. QUAL2K (erson 2.04) s a modelng framework for smulatng rver and stream water qualty developed by Chapra, et al., (2005). It s ntended to represent a modernzed verson of the QUAL2E (or Q2E) model (Brown & Barnwell, 1987). Model s mplemented wthn the Mcrosoft Wndows envronment. Numercal computatons are programmed n Fortran 90. Excel s used as the graphcal user nterface. All nterface operatons are programmed n the Mcrosoft Offce macro language: sual Basc for Applcatons (BA). The present study nvolves the calbraton, valdaton and performance evaluaton of a water qualty model QUAL2K. In ths paper, a bref summary of the study area, descrpton and mplementaton of QUAL2K model s provded n Secton 2. Secton 3 analyses the nput data of the model. aldaton and performance evaluaton of the model are dscussed n Secton 4. Some conclusons are drawn n Secton Materals And Methods 2.1. Study area and database Mudhol town, a Taluka headquarter of Bagalkot dstrct of Karnataka state s located n the western part of Bagalkot dstrct at a dstance of 74 km. It les between 16 o - 06` to 16 o -26` north lattude and 75 o - 02` to 75 o - 28` east longtude. It s on the left bank of the Ghataprabha Rver and receves untreated domestc waste from Mudhol town and other vllages located on the bank of ths rver. Populaton of Mudhol town s about 1.0 lakh (censes of 2011). Other vllages stuated on the bank of ths stretch of the rver are Dhavaleshwar, Chnchalkhand and Budan havng a populaton of 10000, 4000 and 7500, respectvely. There s no sewage treatment faclty for the Mudhol town and all the other vllages. Domestc wastes from all these places are dscharged drectly nto Ghataprabha Rver wthout any pror treatment. The rver water s used for bathng, swmmng, washng of the clothes, cattle and vehcles at all the above sad places. All these human actvtes contrbute sgnfcantly towards the polluton of the rver. The major non pont sources of polluton are excess run off from agrcultural and urban areas. The pont sources are the domestc waste from Mudhol town and other vllages located on the bank of the rver. The map of the stretch of rver Ghataprabha selected for the present study s shown n Fg. 1.

3 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 17 Fg. 1. Descrpton of study area wth samplng locatons Fg. 2. Dgtal elevaton model (DEM) for Ghatrabha Rver Usng Arc-GIS

4 18 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 2.2. Remote sensng and GIS technque The hydraulc parameters lke longtudnal slope and elevaton of the study locaton from sea level etc., whch are requred for nput to model QUAL2K, the Dgtal Elevaton Model (DEM) and satellte mage was used. Ths model was created usng Arc-GIS and s shown n Fg Samplng and analyss Water samples at varous dstances from the selected stretch of the rver were collected at about 15 cm depth (to avod floatng materal) from three ponts across a locaton of the rver (1/3, 1/2 and 2/3) usng the dp and grab samplng method and stored n pre-cleaned polythene bottles. To measure the head water flow of the man rver, current meter was used to measure the velocty of the water at 0.6d (where d = depth of the water at any flow locaton) across the wdth of the rver and the levelng staff was used to measure the water depth. The dscharges from the pont sources were calculated usng the velocty and cross sectonal area. All the analyss was done usng standard methods gven n (APHA, 1998) Descrpton of the model QUAL2K s a rver and stream water qualty model and s modernzed verson of the QUAL2E. In the QUAL2K model the Rver s dvded nto several reaches whch represent stretches of rver that have constant hydraulc characterstcs (e.g., slope, bottom wdth, etc.). Each reach s dvded nto segments whch consttute the model s shortest parts of smulaton. A steady-state flow balance s mplemented for each model reach. The depth and velocty are calculated n one of three ways: wers, ratng curves, and Mannng equatons. The reaeraton coeffcent (at 20 o C) can be prescrbed on the Reach Worksheet. Multple loadngs and wthdrawals can be nput to any element. It allows specfyng many of the knetc parameters on a reach-specfc bass. For all but the bottom algae varables, a general mass balance for a consttuent n an element s wrtten as dc dt Q Q ' ' 1 out, 1 c 1 c c c 1 c c 1 c S (1) Q E E W where W = the external loadng of the consttuent to element [g/d or mg/d], and S = sources and snks of the consttuent due to reactons and mass transfer mechansms [g/m 3 /d or mg/m 3 /d] Implementaton of the model The data measured n the month of January 2014 were used for calbraton. The calbraton tme step was set at mnute to avod nstablty n the model. The soluton of ntegraton was done wth Euler s method. The model was run untl the system parameters were approprately adjusted and the reasonable agreement between model results and feld measurements were acheved. In order to test the ablty of the calbrated model to predct water qualty under dfferent condtons, the model was run usng a dfferent set of water qualty data taken n the month February 2014 for valdaton. 3. Input Data 3.1. Water qualty and flow data The water qualty and flow data measured for calbraton and valdaton of the model n the month of January and February 2014 s gven n Tables 1 and 2, respectvely.

5 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 19 Table 1. Some commonly used predctve re-aeraton equatons Dstance from upstream boundary, km Dscharge/ Wthdrawal 0.00 Head water (man rver) 0.28 Dhavelashwar waste 2.64 Mudhol abstract Temp. o C ph BOD DO Org-N NH 4-N NO 3-N Alkalnty Mudhol waste Chnchalkhand abstract 4.92 Chnchalkhand waste Budn abstract Budn waste Flow m 3 /s Table 2. The nput water qualty data for head water and pont source n the month of February 2014 Dstance from upstream boundary, km Dscharge/ Wthdrawal Temp. o C ph BOD DO Org-N NH 4-N NO 3-N Alkalnty Flow m 3 /s 0.00 Head water (man rver) 0.28 Dhavelashwar waste 2.64 Mudhol abstract 3.53 Mudhol waste Chnchalkhand abstract 4.92 Chnchalkhand waste 7.50 Budn abstract Budn waste System parameters The ranges of model rate parameters were obtaned from varous lteratures ncludng Envronmental Protecton Agency (EPA) gudance document (George et al., 1985), the model user manual (Pelleter & Chapra, 2005) and documentaton for the enhanced stream water qualty model QUAL2E, and QUAL2E UNCAS (Brown & Barnwell, 1987). 4. Results And Dscusson 4.1. Results of Calbraton and aldaton of the Model For calbraton and valdaton of the model, sx samplng ponts were selected n a 15 km reach between

6 20 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K Dhavaleshwar and Mudhol at varous dstances. The results of BOD and DO predcted by the model and the actual values measured n the laboratory for calbraton n the frst week of January are gven n Table 3 and represented graphcally n Fgs. 3 and 4. Smlarly, the results of valdaton carred out n the frst week of February are gven n Table 4 and represented graphcally n Fgs. 5 and 6. Table 3. Results of Calbraton n the month of January 2014 Sl.No. Dstance from upstream end, km Predcted BOD Measured Predcted DO Measured Fg. 3. Calbraton Results for BOD of Rver Ghataprabha Fg. 4. Calbraton Results for DO of Rver Ghataprabha

7 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 21 Table 4. Results of aldaton n the month of February 2014 Sl.No. Dstance from upstream end, km Predcted BOD Measured Predcted DO Measured Fg. 5. aldaton Results for BOD of Rver Ghataprabha Fg. 6. aldaton Results for DO of Rver Ghataprabha

8 22 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 4.2. Performance Evaluaton of the Model From the results obtaned for calbraton and valdaton, the performance of the model was evaluated usng statstcs based on dfferental or standard errors (SE), Normalzed mean error (NME) and mean multplcatve errors (MME). The background related to these parameters s avalable n Moog & Jrka (1998). The SE and NME whch are dfferental errors are determned usng the followng equatons. 1 2 K K 2 N p m SE (2) N NME N N 1 K p K K m m (3) where N = number of measurements; KP and KM are predcted and measured respectvely. The mean multplcatve error, MME, whch may provde a better bass for assessng the mpact of naccuraces n predctng modellng equatons, s defned as MME N 1 K ln K N p m exp (4) The SE, NME and MME values computed for both calbraton and valdaton are gven n Tables 5 and 6 and represented graphcally n Fgs. 7 and 8, respectvely. Table 5. Error values of BOD and DO for Calbraton of the Model Parameter SE MME NME BOD DO Table 6. Error values of BOD and DO for aldaton of the Model Parameter SE MME NME BOD DO

9 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 23 Fg. 7. SE and MME values for BOD durng Calbraton and aldaton Fg. 8. NME values for BOD and DO durng Calbraton and aldaton From the results t can be observed that the standard errors for BOD durng calbraton are and respectvely, and for DO, these values are and 0.648, respectvely. Thus t can be sad that the measured and predcted values are n close agreement wth each other both durng calbraton and valdaton. Smlarly, the values of MME also ndcate that the there was not much devaton n the predcted and measured values both durng calbraton and valdaton. However, the NME values for BOD were -3.8 and and the DO values were and durng calbraton and valdaton, respectvely. From the NME values t can be observed that, even though the values for BOD are n close agreement both durng calbraton and valdaton, the devaton n the values of DO durng calbraton was more than that durng valdaton of the model. Ths devaton may be due to some of the non pont sources of polluton lke the runoff from agrcultural felds and rural areas whch were not consdered n the model. Agrcultural actvtes were more durng the month of January than n the month of February. Also lot of sand mnng actvtes from the rver bed was takng place n the month of January. Due to these mnng actvtes deep pts were created n the rver, whch affect the rate of re-aeraton of oxygen from the atmosphere. Ths mght have also affected the level of measured values of DO from the predcted values. Over all, t can be sad that the measured values and the values predcted by the model for both BOD and DO were n satsfactory range of agreement wth each other except at few locatons.

10 24 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 5. Conclusons A stream water qualty model, QUAL2K, was calbrated and valdated n a 15 km stretch of the rver Ghataprabha from Dhavaleshwar to Mudhol durng the month of January and February 2014, respectvely. The results of calbraton and valdaton of the model for BOD and DO at sx montorng locatons showed that the values predcted by the model were n close agreement wth measured values except at few locatons. The performance of the model was evaluated usng statstcs based on Standard errors (SE), Normalzed Mean Errors (NME) and Mean Multplcatve errors (MME).The results of the evaluaton revealed that there s not much varaton n these values between calbraton and valdaton. The SE and MME values for BOD and DO durng calbraton are, 1.41 (1.12) and1.28 (0.90), respectvely. The values n the bracket show MME. Correspondng values for the valdaton are 1.27 (1.09) and 1.10 (0.96). From the observaton of error values t can be sad that the model can be appled to obtan the predcted values whch are practcally n reasonable agreement wth the measured values. References [1] Bhuvaneswaran NG, Rajeswar S. Water qualty of rver Adyar n Chenna cty-the Rver a Boon or Bane. Indan J Env Protecton 1999;19(6): [2] Chapra SC, Pelleter GJ, Tao H. QUAL2K: A Modelng Framework for Smulatng Rver and Stream Water Qualty, erson 2.04: Documentaton and Users Manual. Cvl and Envronmental Engneerng Dept., Tufts Unversty, Medford, MA; [3] Brown LC, Barnwell Jr TO. The enhanced stream water qualty models QUAL2E and QUAL2E-UNCAS: documentaton and user manual. EPA/600/3-7/007, USEPA, Envronmental Research Laboratory, Athens, GA, USA; [4] APHA. Standard Methods for the Examnaton of Water and Wastewater: 20th ed. Amercan Publc Health Assocaton, Washngton, DC; [5] George LB, Wllam BM, Donald BP, Carre LC, James RP, Gretchen LR, Kay MJ, Peter WHC, Steve AG, Charles EC. Rates, constants and knetc formulatons n surface water qualty modellng. 2nd ed. U.S. Envronmental Protecton Agency, EPA/600/3-85/040; [6] Pelleter GJ, Chapra SC. QUAL2KW theory and documentaton (erson 5.1), a Modelng Framework for Smulatng Rver and Stream Water Qualty; onlne: [7] Moog DB, Jrka DH. Analyss of reaeraton equatons usng mean multplcatve error. J. of the Env. Engg. Dvson, ASCE; Author(s) Profle Dr. P. B. Kalburg s Professor n Department of Cvl Engneerng at Basaveshwar Engneerng College, Bagalkot, Karnataka, Inda. He dd hs B.E. n Chemcal Engneerng, M.Tech. and Ph.D. n Envronmental Engneerng. He has 10 years of ndustral and 10 years of teachng experence.

11 Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K 25 Ms. R. N. Shareefa s Assstant Professor n Department of Cvl Engneerng at SECAB nsttute of Engneerng and Technology, Bjapur, Karnataka, Inda. She dd her B.E. n Botechnology, and M.Tech. n Envronmental Engneerng at Basaveshwar Engneerng College, Bagalkot. Dr. Umesh B. Deshannavar s Professor n Department of Chemcal Engneerng at KLE DR. M. S. Sheshgr College of Engneerng and Technology, Belgaum, Karnataka, Inda. He dd hs B. E. n Chemcal Engneerng, M.Tech. n Energy Systems Engneerng, and Ph.D. n Chemcal Engneerng at Unverst Teknolog PETRONAS, Malaysa. He has 13 years of teachng experence. How to cte ths paper: P. B. Kalburg, R. N. Shareefa, U. B. Deshannavar,"Development and Evaluaton of BOD DO Model for Rver Ghataprabha near Mudhol (Inda), usng QUAL2K", IJEM, vol.5, no.1, pp.15-25, 2015.DOI: /jem