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JURUTERA (FEBRUARY 2004) 39REPORTTECHNICAL VISIT TO <strong>KLIA</strong> WASTEWATER TREATMENT PLANT<strong>Report</strong>ed by: Ir. Khew Swee Lian, Environmental Engineering Technical Divisionn 20th of September 2003, aOtechnical visit was organised bythe Environmental EngineeringTechnical Division to Kuala LumpurInternational Airport (<strong>KLIA</strong>) WasteWater Treatment Plant (WTP). 35IEM members participated on thishalf-day visit to the plant.The <strong>KLIA</strong> WTP is a SequentialBatch Reactor (SBR) system which isdesigned to treat 17,250 ml/day[approximately 75,000 populationequivalent (PE)] to meet therequirements of Standard B ofEnvironmental Quality Act (EQA).The plant comprises two streams ofinlet. Stream 1 receives wastewaterfrom major public and administrationarea of the airport, while stream 2takes waste load from domestic andindustrial wastewater includingoutput from hanger facilities.Wastewater from the first streamnormally consists of biodegradablesubstance while wastewater fromthe second stream may containinorganic compounds in the form ofheavy metals like cyanide andarsenic from the maintenanceactivity. There is a pre-treatmentfacility at the engineering areabefore discharging into the sewer.The SBR system is another typeof an activated treatment processdesigned to operate under nonsteadystate conditions. It operateswith aeration and sludgesedimentation process taking placein the same tank. The majoradvantage of the SBR system ascompared to the conventionalsystem is that, it operates in a uniquetime sequence process. In otherwords, the aeration andsedimentation process takes placeIr. Hooi Kam Seng presenting a token tothe representative of <strong>KLIA</strong> (WTP)independently in differentcompartments thereby providingmore treatment capacity thanconventional system (extendedaeration system). Moreover, SBRsystem is capable of accepting anyvariations in the hydraulic loads.The SBR system has fouroperation phases; filing and mixing,aeration, settle & decant and desludge.Alum and lime are addedduring aeration stage forphosphorus removal. During settlingstage, liquid and solids areseparated. Effluent from stream 1 ispumped to tertiary treatmentcompartment while stream 2 isdisinfected before final discharge.By adjusting the timings foraeration, settling and chemicaldosing, good effluent can beachieved both for discharge andreuse. SBR system's effluent hasbetter Biochemical Oxygen Demand(BOD) and nutrient removals(ammonia and phosphorus) and alsothe control of bulking effectPlant monitoring, alarming andreporting functions is controlled by aPLC located in the administrationbuilding control room. Windowsoftware is used with objectoriented, graphical man-machineinterface(MMI) applicationgenerator for process control,supervisory, monitoring andreporting in the form of mimicscreen display. Colour graphicalpresentation and simulation forequipment status, alarms, rawsewage flow into SBR can becaptured during the whole process.There are two processes consistof the following sequentialoperation on each tank:• For 6-hour mode of process, thefollowing sequential timing isfollowed :-• Filling and mixing – 2 hoursAeration – 3 hours (Over lapof 1 hour with filing)• Settle – 1 hour• Decant and de-sludge –1 hour• For 8-hour mode of process, thefollowing sequential timing isfollowed:-• Filling and mixing – 2 hours• Aeration – 3.5 hours• Settle – 1.5 hours• Decant and de-sludge –1 hourEach reactor is capable of handling740 m3 of wastewater in each cycle oftreatment. After the wastewater hasunder gone oxidation andsedimentation, it is decanted from thereactor by means of decanter at a rateof 740 m3/hour. The decanter drawsclarified treated wastewater from thetop of the reactor while the sludgesettles at the bottom of the reactor.


JURUTERA (FEBRUARY 2004)REPORTThe SBR process is intended tonitrify (convert ammonia to nitrate)during the anoxic phase anddenitrify (convert nitrate intonitrogen gas) mainly during settleand decant phases. Biologicaltreatment may help in removingphosphorus removal.Rotary blowers controlled by a setof motorized valves deliver airrequired to generate aerobiccondition required in each process.The three service-reactors share twoblowers while the third blower servesas a standby. Each blower is capableof delivering 65m3/hour of air at0.4kg/cm 2 pressure. At any givenpoint of time at least one blowerwould be operating with a secondblower cutting in when demandpeaks. Submersible mixers areprovided for mixing of pH anddissolved oxygen has been provided.Excess sludge from the SBRreactors is pumped into the sludgeholding tank during decants optionphase. The de-sludge pumps arecontrolled by a set of motorizedcontrol valves. The sludge timing isfreely adjustable from the PLC tomaintain the right level ofmicroorganisms in the reactor.Tertiary treatment plant isdesigned to produce high qualifyeffluent for landscaping, toiletflushing and other non-potablewater requirements of the airport.The treatment capacity of thetertiary treatment plant isapproximately 4200 m 3 per day.Tertiary treatment plant consists oflamella plate separators, ‘dynasand’backwash sand filters, cascadeaerators and reuse waterchlorinatingsystems.The sludge house consists ofrotary drum thickeners andmembrane filters press. Sludge fromthe SBR tanks and the residual fromthe lamella plate separators, which isstored in the holding tank, ispumped by using feed pumps. Theretaining period for the sludge in theThe IEM group at the visitholding tank is two and the half daysand the sludge is aerated in theholding tank by using coarse bubbleair diffusers. Polymer solution isadded to aid the process ofthickening. Thickened sludge fromthe drum thickener is discharged into the sludge pit. The sludgecontents after drum thickener ismaintain around 4%. Thickenedsludge is then pumped into filterpress to achieve 30% dry solidscontent. Polymer is injected in thesuction side of the filter press feedpump to achieve good flocculationof the sludge. Upon unclamping ofthe plates, de-watered sludge cakesdrops into a screw conveyor andtransferred to a bin for final disposal.The filtrate from the filter press isrecycled back to stream 2 SBRtransfer pump sump for furthertreatment.Both inlet area and the sludgehouse are equipped with odourremoval systems. It consists of theFRP scrubber units, a set ofcirculation pumps, chemical dosingmetering pumps and a radialextraction fan. The process ofremoving contaminated air isaccomplished in three stages. Stage1 consists of treatment with waterfor dust removal and other physicalmatters. In stage 2, sulfuric acid isused to remove alkaline compoundslike ammonia and amines. Sodiumhypo chlorite is injected in the thirdstage for the removal of acidiccomponents like hydrogen sulphide.Caustic soda is used to break downand oxidize components which areneither acidic nor alkaline in nature.The members benefited from thesite visit and the site visit ended at12.30pm.REMINDERPlease rememberto pay your 2004SUBSCRIPTION!JURUTERA 200440

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