Process and Technologies of Process and Technologies of Treatment & Pre Treatment & Pre - - treatment treatment for for Municipal & Industrial Municipal & Industrial Wastewater Wastewater Prepared by Prepared by Eng. Nael Ali Ahmad Eng. Nael Ali Ahmad MSc. Sanitary Engineer MSc. Sanitary Engineer – – IHE IHE [email protected][email protected]1 1
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Process and Technologies of Treatment & Pre-treatment for
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Process and Technologies of Process and Technologies of Treatment & PreTreatment & Pre--treatmenttreatment
forforMunicipal & Industrial Municipal & Industrial
WastewaterWastewater
Prepared byPrepared byEng. Nael Ali AhmadEng. Nael Ali Ahmad
- Fulfill the effluent criteria in the permit- Operation and management must be
within the capabilities of the community- It must be economical to build, operate
and maintain
LOW RUNNING COST
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Municipalities are trying to control wastewater quality
The governarates work with the municipalities against all the vacuum tracks who empty their tracks in nearby wadisThe municipalities encourage the vacuum tracks and free of charge to empty their trucks in the treatment plantThere are laws to force the factory to do pre-treatmentIt is forbidden to connect storm water to wastewater system
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Industrial sources and pollutants
Acetic acid Acetate rayon, beet root manufact.Acids Chem manufact.,mines, textiles manufact.Alkalies Cotton and straw kiering, wool scouringAmmonia Gas and coke and chem. manufactureArsenic Sheep dippingCadmium PlatingChromium Plating, chrome tanning, alum anodizingCitric acid Soft drinks and citrus fruit processingCopper Copper plating, copper pickling
Industrial sources and pollutants
Cyanides Gas manufacture, plating, metal cleaningFats, oils, grease Wool scouring, laundries, textile industryFluorides Scrubbing of flue gases, glass etchingFormaldehyde Synthetic resins and penicillin manufact.Free chlorine Laundries, paper mills, textilebleachingHydrocarbons Petrochemical and rubber factoriesMercaptans Oil refining, pulp millsNickel PlatingNitrocompounds Explosives and chemical works
Industrial sources and pollutants
Organic acids Distilleries and fermentation plantsPhenols Gas and coke manufact., chem. plantsStarch Food processing, textile industriesSugars Dairies, breweries, sweet industrySulfides Textile industry, tanneries, gas manufact.Sulfites Pulp processing, viscose film manufact.Tannic acid Tanning, sawmillsTartaric acid Dyeing, wine, leather, chem. manufactureZinc Galvanizing zinc plating, rubber process.
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Pre-treatment definition
Treatment of wastewater before discharging it to the local wastewater treatment facility
Objectives of the Pretreatment
Reducing the amount of pollutants, Eliminating pollutants, or Altering the nature of pollutant propertiesReduce the capital cost and the running cost of the public wastewater treatment plant
Factories that affect the amount of pretreatment
Fee based on the amount and types of pollutants discharged (pay as you pollute).Pollutant or pollutants to be removed.Site constraints, such as space availability for equipment.Amount and variation of wastewater flow and pollutant concentration, both hour to-hour basis and seasonal
Why do not industries applies pre-treatment
In-complete of rules and regulationAbsent of authorityThe economical and social situation of the society
Types of Pretreatment Unit Operations
Biological Processes - Processes where living microbial organisms are used Chemical Processes - An example is heavy metal precipitation by pH adjustment.Physical Processes –Examples are reverse osmosis, and filtration.Thermal Processes
specific types of unit operations used in wastewater pretreatment systems
Aerobic or Anaerobic Pretreatment Disinfection Clarification Simple Filtration Membrane Filtration Reverse Osmosis (RO) Ion Exchange Dissolved Air Flotation (DAF) Adsorption Chemical Precipitation/Redox Reactions Neutralization
Example of heavy metal removals
Most heavy metals will precipitate at higher pH levelsHexavalent chromium, is very soluble in wastewater and must be chemically reduced at lower pH levels to the trivalent formThus, the need for two different pH conditions for the chromium reduction and precipitation stepsThen, third tank is needed for final neutralization before discharge
My advice: Prevention better than care
Each factory has it’s own caseRe-arrangement for manufacturing processRecycling for used water inside the factoryRecycling of the heavy metal inside the factory
Typical Pretreatment Processes for Selected Industries
Textiles:Polluants: BOD, TSS, alkalinityPretreatment Process: Neutralization, chemical precipitaion,biological treatment
Laundry:Polluants: Alkalinity, BOD,turbidityPretreatment Process: Screening, chemical precipitaion, adsorption
Separate pre-treatment in each factory
Separate full treatment for industrial zone
What do municipalities need
Detailed industrial survey studiesFull cooperation of factories ownersComplete rules and regulations, in addition to authorities to apply that.Municipal wastewater treatment plant
Reuse of treated wastewater
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El Bireh treated WW after few Kms
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Nablus East outlet raw ww
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Reuse of treated wastewater
Store the treated wastewater and mixing it with spring water like Wadi Al-Qilt and Wadi Al-BathanUse wadi Al-Zumar as a reservoir to store treated wastewater and storm water as will
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FINALLYFINALLY
-- Remember that you have to work with Remember that you have to work with your neighbor to solve any sanitation issue your neighbor to solve any sanitation issue for clean and safe environmentfor clean and safe environment
-- Remember to think twice before you take Remember to think twice before you take a decision regarding sewage issuea decision regarding sewage issue