Volume: 09 Issue: 03 | Mar 2022 www.irjet.net ISSN: 2395 0072 2022, IRJET Impact Factor value: 7.529 9001:2008
JuanhongLiandXiwuLu(2017),designedaANF WDSRBC systemcombinedwithananoxicfilter(ANF)andafourstage waterdroppingself rotatingbiologicalcontactor(WDSRBC) as an option for post treatment. Total hydraulic retention timeusedwas8.8hrswitharefluxratioof1:1.Thesystem wasoperated160days.Thesystemhadgreaterperformance without the need for a mechanical aeration devices. The COD, ammonia and total nitrogen removal were 61.4% ± 4.3%, 86.1% ± 3.7%, and 54.5% ± 3.9% respectively. The system had great potential in the decentralized domestic wastewaterpost treatment.
Mahetab A. Mohamed1, Hanan A. Fouad2, Rehab M. ElHefny2
In order to make the sewage water of Zenin wastewater plantsuitableforuseinirrigationworks,thisresearchaims totreatwastewaterusingrotatingbiologicalcontactor(RBC) withbananaleavesasRBCmedia.
Jayamala and Nitin A. Deshpande (2016), used attach growthprocesswithRotatingBiologicalContactormodelto treat domestic sewage. Partially submerged Rotating BiologicalContactorshowedaremovalefficiencyforBODat a rotational speed of disc at 6rpm. The usage of Polyvinyl chloride and polyethylene material resulted in a thick biofilm(Microorganism) growthforeffectivetreatmentof sewage. Results also proves that Rotating Biological contactor is efficient, economical and effective in treating organicandinorganicwaste.
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1. INTRODUCTION
2Department of Sanitary and Environmental Engineering at Shoubra, Behna University, Benha, Egypt ***
Abstract The standard of freshwater water per capita globally per year is 1000 m3, various studies expected by year 2025 that freshwater per capita annually in Egypt will be under 600 m3 (Abd elKader and Abd elRassoul, 2010; World Bank, 1995). In Egypt, with the industrial development and population increases, it is expected that both industrial and domestic wastewater will be increased. Therefore, the recycling of those mentioned water sources should be considered as fundamental pillar of water resource policy, thus in this study, two identical stages of the RBCs systemwere used to treat wastewater after its primary treatment at Zenin wastewater treatment plant inGiza, Egypt. Different materials were used in the treatment process such as geotextile, (in two different forms), circular discs and discs in the form of gear, with 15 discs per RBC stage, a steel cylinder, a plastic bottle with sugarcane straw inside and finally a plastic bottle with banana leaves inside and this will be the main topic of this research. The rotation speed of 5 RPM was used, where it was found later that it gave the best results. The hydraulic retention time ranged between one, two, andthree up toseven days. It was found that the best results obtained at HRT of 3 days. Results showed that the removal rates of BOD, COD and TSS were almost 79.16%, 90.6% and 78.95% at 5RPM for banana leaves respectively.
Rotating biological contactor (RBC) is one way of wastewatertreatmentwaystobeinvolvedaftertheprimary treatment,whichis,inordertomakeitsuitableforirrigation purposes.Whileprimarytreatmentkeyaimistoeliminate all contaminants that may settle or float, also secondary treatmentisintendedtoeliminatethesolubleandcolloidal organicsthatresistprimarytreatmentandtoenablefurther eliminationofsuspendedsolids.Thoseremovalsareusually occurs by the use of processes of biological treatment. Therefore, wastewater biological treatment is of vital importanceforthehealthofourwater.
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International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056
1Civil Engineering Depertment, Eljazeera Higher Institute for Engineering & Technology, Cairo, Egypt
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Rotating Biological Contactor Wastewater Treatment Using Banana Leaves for Green Areas Irrigation
Key Words: Wastewater Treatment, Rotating Biological Contactor, Banana leaves, Geotextile, Steel Cylinder, SugarcaneStraw,GearShapedGeotextile.
A. H. GHAWI and J. KRIŠ (2009),showedthesignificanceof Organicloadingparameter.TheresultsprovesthattheCOD removalinrotatingbiologicalcontactorsystemsisafunction oftheorganicloadingrate.However,boththewastewater concentration and flow rate also influence the system’s efficiency,buttheirimpactcanbecombinedbytheeffectsof organic loading. In the system’s first stage Most of the removaloftheCODoccurs.Resultsalsoshowsthatathigher loadingshigherconcentrationsarenoted.
S.A. Mirbagheri et al (2016), investigated the denitrificationofTehran(Iran)oilrefinerygroundwaterin ananoxicrotatingbiologicalcontactor.Differentparameters were evaluated such as hydraulic retention time, Carbon/Nitrogen ratio, and nitrate loading. The Nitrate concentration of treated water in all experiments was far belowthestandardlimitationandnitrateremovalefficiency reachedover97%inoptimumvalueofCarbon/Nitrogen= 1.25andHRT=8h.Basedonthatresultsananoxicrotating biological contactor could be an adequate and convenient methodindenitrificationofgroundwater.
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Fig. 3. Rotatingshaft
Aconnectionopeningwasprovidedbetweenthetwotanks of2.5cmdiametertoletthewatermovefromthefirststage tothesecondstage.Theinletandoutletofthemodel was
Table Typicalliquidresinproperties(25
Thematerialsusedtoconstruct/fabricatethetanksusedon thisresearchisSIROPOL 8340fromSaudiIndustrialResins Limited, which is medium viscosity, medium reactivity, generalpurpose,unsaturatedpolyesterresin.
2.1. Rotating Biological Contactor (RBC) Model Fabrication
Fig. 1. Steelframeofmodel
Thedimensionofindividualtankis35×30×25cmasshown onFig2
Therawmaterialsusedinthemanufactureofthisresinare listedasacceptableinFDAregulationTitle21CFR177.2420 for repeated use in contact with food subject to user’s compliance with the prescribed limitations of that regulation.Detailedpropertiesofthesematerialsarelisted onTable1andTable2.
2. Materials and Methodology
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Fig. 2. ModelDimensions
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Palakshappa.K et al (2019), treated diary wastewater usingrotatingbiologicalcontactorasit’seasytooperate,low energysavingandalsolessarearequirement.Threestages RBCwereusedandkeptinseries.TheRBCdiskswere40% submerged and rotating at 40rpm. Different HRT were evaluatedtousetheoptimumHRTwhichis8hrs.Resultsof Palakshappa.K study showed that COD removal from the threetanksreached85%,inadditionofusingtheoptimum COD loading rate of 1300mg/l the COD removal reached 94%. It can also be concluded that using a three stages rotating biological contactor is an effective and efficient reactorfortreatingdairywastewater.
2.2. Materials used
oC) Property Value PercentSolids 60 63% ViscosityBrookfield 400 500Cps Appearance ClearYellowish AcidValue 18 23 SpecificGravity 1.04±.02 PoundsperGallon 9.2
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2.5cmdiameterprovidedataheightof2cmfromtopoffirst tankfortheinletandat12.5cmheightfromtopofsecond tank for outlet.A gap of35cmwas provided betweentwo tanks.Moreover,theproposedRBChasanadvantagethat,it has an imhoff settling tank in the lower part. Hence, final clarifierthereforeisnotrequired. Thesizeofshaftis2.5cm diameter, which was supported along the frame with bushing and bearings on either side as shown on Fig 3 to holddifferentshapesofdiscs.Forbananaleaves,therodwas replaces with a plastic bottle to hold the leaves inside. A motor is equipped on each tank with a gearbox to allow speedcontrolandforthemediatoberotated.Asteelframe isusedineachtankasforsupportingandholding.
Two identical stage RBC models was fabricated using polyester resin (medium viscosity, medium reactivity) of 10mmthicknessforthethreesidesandaclearacrylicforthe fourthside.Themodelliftedonasteelframeasshownon Fig1
2.2.1 Tank materials
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Volume: 09 Issue: 03 | Mar 2022 www.irjet.net ISSN: 2395 0072 2022, IRJET Impact Factor value: 7.529 9001:2008
BarcolHardness 47 ASTMD 2583
Daily incoming water Characteristics to the plant varied according to the source from which that water was produced,accordingtothequantityproducedfromhomes and factories. The concentration of COD after primary treatment ranges between 250 to 550 mg/l, BOD ranges between80to270mg/landTSSrangesbetween60to260 mg/l.
International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056
Property Value Results TestMethod
Fig. 4. Bananaleavesplasticbottle
WaterwaspumpedtotheRBCtanksthroughtheinletofthe first tank then flow to the second tank through the connectionpipelinkbetweenbothofthem.Themodelwas
FlexuralStrength N/mm2 106 ASTMD 790
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2.5 1. Samples Collection
2.5. Samples Collection and Analysis
WaterAbsorption (7dayvalue) Mg 33
Waterusedintheseexperimentsiswaterthatwastreatedin theprimarytreatmentstageandafterleavingtheprimary sedimentation basin from the sewage treatment plant at Zenin,Giza,Egypt.Then,awaterpumpwasusedwithaflow rateof0.025l/storaisethewatertoRBCtanks.
Many previous trials were made to find the best rotation speed, the speed of 5 RPM is found to be the optimum rotationalspeedthatgivesthebestresults.
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Forthebananaleaves,whichisthefocusofthisresearch,a plasticbottlewithholesonallsidesalongthelengthofthe basin(RBCstage),withadiameterof25cmwasfilledwith bananaleavesasshownonFigure4
operated for five continuous days without stopping to achievethesteadystateconditions.Thebananaleavesbottle wassubmergedat40%. Rotationalspeedwas5RPM.The hydraulic retention time ranged from one, two and three days,uptosevendays.Astheremovalratewasstableafter thethirdday,sotheoptimumhydraulicretentiontimewas chosentobethreedays.
2.5.2. pH analysis
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2.4. RBC Operation
FlashPointRange,oC 33
Theconcentrationofhydrogenionisoneoftheimportant indicatorsofwastewater.Theextentoftheappropriatefocus forthepresenceofmostofthebiologicallifeisverysmall and critical. Waste water with a pH outside the range is difficulttotreatinabiologicalway,andthereforeifthe(pH) isnotadjustedbeforedrainage,itwilladverselyaffectthe (pH)inthenaturalwater.pHwasmeasuredusingpHmeter.
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2.3 Wastewater Properties
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Table 2: Typicalphysicalpropertiesofcuredcastings
2.2.2. Banana leaves Plastic bottle
TensileElongation% % 2.2 ASTMD 638
Samples were taken from both the first and second RBC tanks,fromthewateroutletinbothtanks.Sampleswerealso taken from the water inlet of the first tank to analyze the watercharacteristicsbeforeanytreatmentapplied.Samples werecollectedonadailybasisevery24hours.ThepH,COD, BOD and TSS tests were conducted in accordance with internationalstandardsforeachtestthatwasconductedfor all and every sample collected periodically. Results were noted for each day separately with respect to where each samplewastakenfrom.Itwasalsotakenintoaccountthat the jars used for collecting samples as on Fig 5 do not interactwiththecollectedwateranddonotchangeanyofits properties or characteristics to ensure that the actual propertiesarepreservedtoobtainaccurateresults.
TensileStrength N/mm2 68 ASTMD 638
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Fig. 5. Samplescollectionjars
Deflectiontemperature oC 60 ASTMD 648
2.5.3. BOD analysis
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2.5 5. TSS analysis
Table 3: WastewaterparametersforRun7beforeand aftertreatmentforbothphaseIandphaseIIat5RPM usingbananaleavesasmedia
Figure 6: BODremovalpercentagewithtimeat5rpmfor BananaLeaves
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AspresentedonFigure6,BODremovalratesincreasesover time. However, on the third day the BOD removal rate becomes constant. It is obvious that, the ratio of BOD removal increased from (43.75%) on the first day to (58.33%) on the third day and it kept constant after that regardingthefirstphase.Forphasetwo,theBODremoval rateincreasedfrom(68.75%)onthefirstdayto(79.16)on thethirdday.Thatmeans,thebestHRTisfoundtobeonthe thirdday,inwhichthebiologicallayerthatisformedonthe surface That layer is composed of organic materials and bacteria,whichgivethebestremovalratesinordertobear thatlayeroforganicloadswell.TheTSSconcentrationonthe thirddaywas20mg/l,whichdoesnotexceeds30mg/l, matchingtheEgyptianspecificationsforwaterintendedfor irrigationpurposes.
COD is used to measure the oxygen amount required to chemically oxidize the organic material and inorganic nutrients,suchasAmmoniaorNitrate.CODwasmeasuredin laboratory in which a sample is incubated with a strong chemicaloxidantforadefinedtimeintervalandatconstant temperature (150°C). Oxidant used is potassium dichromate,incombinationwithboilingsulphuricacid.
Figure 7: CODremovalpercentagewithtimeat5rpmfor BananaLeaves
COD removal rates increases over time as per Figure 7 However,on thethirddaytheCODremoval ratebecomes constant. It is obvious that, the ratio of COD removal increasedfrom(49.43%)onthefirstdayto(56.96%)onthe thirddayanditkeptconstantafterthatregardingthefirst phase.Forphasetwo,theCODremovalrateincreasedfrom (85.31%)onthefirstdayto(90.6%)onthethirdday.That
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3. Result and Discussion
BOD is to measure the dissolved oxygen consumed by microorganismsintheprocessofbiochemicaloxidationof organicmatter.Tomeasuretheabsorbedbiologicaloxygen, dilutions of wastewater are made with oxygen saturated waterinspecialbottlestowhichbacteriaareadded.Onthe otherside,acontrolbottleisfilledwithwaterandbacteria only.Thebottlesareplacedinanincubationforfivedaysata temperatureof20º C,sotheprocessiscalledthefive day BOD5 tests. The difference between the oxygen concentrationinthecontrolbottleandtheremainingoxygen in the other bottles after five days is used to calculate the BOD,estimatedinmg/L.BODwasmeasuredusingdissolved oximeterdevice.
For this trial, banana leaves was used as a media for both phaseoneandphasetwo.Therotationspeedwassettobe5 RPM.Table3showsthewastewaterparametersbeforeand aftertreatmentforthisrun.
Wastewatercontainsaproportionofsuspendedsolids,some ofwhicharesuspendedSettleableandsomenotSettleable. ThemethodusedtomeasureTSSisthemostcommonand accurateway,whichisbyweight.Awastewatersampleis filtered,driedinadryingovenat123°Cforaboutanhour, andthenweighed.
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2.5 4. COD analysis
[6] JuanhongLiandXiwuLu.(2017)."Performanceand MicrobialDiversityinaLow EnergyANF WDSRBC System for the Post Treatment of Decentralized DomesticWastewater". MDPI, Basel, Switzerland. Water2017,9,330;doi:10.3390/w9050330.
[8] Dr.Palakshappa.K, Sneha.M.K, Chiranjeevi.M.R. (2019). "Feasibility Studies on the Treatment of Dairy Wastewater UsingRotating Biological Contactor (RBC) UnderVariable Experimental Conditions". Proceedings of Second International Conference on Emerging Trends in Science & Technologies for Engineering Systems (ICETSE 2019).SJCInstituteofTechnology,Chickballapur, Karnataka,India.
[9] TheEgyptianCodefortheUseofTreatedSewage in Agriculture,(2015),ECP501 2015.
This research has concluded that, rotation speed is a key factoraffectingtheremovalratesforCODBODandTSSas 5RPMrotationspeedshowedthehigherresults.Usingtwo phases rather than one phase greatly contributed to increasing the removal ratesofBOD,CODandTSS. Asthe mainaimofthisresearchistoreusethewaterforirrigation, the resulted concentrations are completely matching the Egyptianspecificationsofusingtreatedwaterforirrigation purpose[ECP501 2015].TheidealHRTisfoundtobeon thethirddayoftreatment.RemovalratesofBOD,CODand TSS using banana leaves were almost 79.16%, 90.6% and
International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056
5. References
78.95%at5RPMrespectively.
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means,thebestHRTisfoundtobeonthethirdday,inwhich thebiologicallayerthatisformedonthesurface Thatlayer iscomposedoforganicmaterialsandbacteria, whichgive thebestremovalratesinordertobearthatlayeroforganic loadswell TheTSSconcentrationonthethirddaywas31 mg / l, which does not exceeds 50mg / l, matching the Egyptian specifications for water intended for irrigation purposes.
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[5] Jayamala,NitinA.Deshpande.(2016)."Treatmentof Sewage by Partially Submerged Three Stage Rotating Biological Contactor (RBC)". IJSTE International Journal of Science Technology & Engineering.Volume3|Issue01.July2016.
[7] JuanhongLiandXiwuLu.(2017)."Performanceand MicrobialDiversityinaLow EnergyANF WDSRBC System for the Post Treatment of Decentralized DomesticWastewater". MDPI, Basel, Switzerland. Water2017,9,330;doi:10.3390/w9050330.
ItcanbenotedfromFigure8,TSSremovalratesincreases overtime.However,onthethirddaytheTSSremovalrate becomesconstant.Itisobviousthat,theratioofTSSremoval increasedfrom(53.62%)onthefirstdayto(56.57%)onthe thirddayanditkeptconstantafterthatregardingthefirst phase.Forphasetwo,theTSSremovalrateincreasedfrom (72.46%)onthefirstdayto(78.95%)onthethirdday.That means,thebestHRTisfoundtobeonthethirdday,inwhich thebiologicallayerthatisformedonthesurfaceThatlayer iscomposedoforganicmaterialsandbacteria, whichgive thebestremovalratesinordertobearthatlayeroforganic loadswell TheTSSconcentrationonthethirddaywas16 mg / l, which does not exceeds 50mg / l, matching the Egyptian specifications for water intended for irrigation purposes.
[1] Abdel Kader,A.M.andS.M.Abdel Rassoul.(2010). ProspectsofWaterConservationinEgypt(Special Reference to Wastewater Reuse). Fourteenth InternationalWaterTechnologyConference,IWTC, Cairo,Egypt.
4. Conclusions
Figure 8: TSSremovalpercentagewithtimeat5rpmfor BananaLeaves
[4] S.A. Mirbagheri, S. Ahmadi, N. Biglari Joo. (2016). "Denitrification of nitrate contaminated groundwater in an anoxic rotating biological contactor: a case study". Desalination and Water Treatment,Vol.57,p4694 4700,(2016).
[3] H. GHAWI, J. KRIŠ. (2009). "Use of a rotating biological contactor for appropriate technology wastewater treatment". Slovak Journal of Civil Engineering,Vol.93,p1 8(2009).
[2] World Bank. (1995). From scarcity to security: avertingawatercrisisintheMiddleEastandNorth Africa,WashingtonDC,USA.