paper odour problem- innovative solutions
TRANSCRIPT
◆ THERE IS A SANSKRIT WORD – “PANCHENDRIYANAMIDAM SARIRAM” (FIVE SENSES OF BODY).
◆ HUMAN SENSORY PERSEPTIONS ARE BEST TO JUDGEPAPER QUALITY.
◆ EYES – APPEAL, EARS – RATTLE SOUND, NOSE – ODOUR,TONGUE – COBB, TOUCH – FEEL, SMOOTHNES.
◆ ODOUR IS A PSYCHO-PHYSICAL PHENOMENON
◆ SMELL IS RELATED TO OLFACTORY AND AESTHATICSENSE OF PACKAGING PAPER.
◆ ODOUR QUALITY : THE ODOUR PANEL VS “ELECTRONICNOSE” METHOD.
◆ QUANTIFICATION: THRESHOLD VS INSTRUMENTMEASUREMENT.
SULPHATE PULPING GIVE H2S AND MERCAPTANS BY Na2S REACTIONS.
SULPHITE PROCESS GIVE SO2 EMISSION FROM COOKING/SPENT LIQUOR.
WASTE PAPER, PACKAGING PAPER ALSO GIVE H2S ODOUR DUE TO PROCESS LIMITATIONS AND INPUTS.
ALUMINIUM SULPHATE ACCUMULATES WITH OTHERS. SULPHUR REDUCING BACTERIA PRODUCE H2S IN ANAEROBIC
CONDITIONS. SOME MILLS OPT FOR ANAEROBIC DIGESTERS. SOME MILLS TEND TO DEVELOP ANAEROBIC CONDITIONS. SRB(SULPHUR REDUCING BACTERIA) PRODUCE H2S. OTHER ANAEROBIC /FACULTATIVE MICROBES DEVELOP
VOLATILE FATTY ACIDS. VOLATILE FATTY ACIDS ARE PRECURSERS OF METHANE, H2S.
VFAs AND H2S NAME AND SMELL:
FORMIC ACID - Pungent solvent like/ nail polish Smell
ACETIC ACID – Vinegar Smell
PROPIONIC ACID - Body Odor
BUTERIC ACID - Rancid butter, vomit
ISOBUTERIC ACID - Rancid butter
VALERIC ACID - Fruit like
ISOVALERIC ACID - Body Odor
H2S LOW LEVEL - DETECTABLE MUSTY SMELL
H2S ABOVE 1-3 PPM – DETECATABLE ROTTEN EGG SMELL.
ABOVE THE LEVELS – VERY MUCH HARMFUL
GENESIS OF H2S AND VFA IS FROM SULPHATES AND ANAEROBIC DIGESTION OF SLUDGE.
CAUSITIVE MICROBES ARE: DESULPHOVIBRO, CLOSTRIDIUM AND ACTINOMYCETES SPECIES.
H2S IN LOW LEVEL GIVE MUSTY AND SWAMPY ODOUR.
HIGER LEVEL GIVE ROTTEN EGG SMELL.
ACIDIC MICROBIAL ODOURS ARE: ACETIC ACID, BUTYRIC ACID, PROPIONIC ACID, VALERIC ACID.
THESE ARE ALL CALLED VOLATILE FATTY ACIDS.
VOLATILE FATTY ACIDS ARE PRE-CURSERS OF METHANE GAS IN BIOGAS GENERATION PROCESS.
H2S IS A BI-PRODUCT OF BIOGAS GENERATION IN AEROBIC CONDITIONS.
IN BIOGAS PLANTS TO ENRICH METHANE, H2S IS REMOVED BY SCRUBBING WITH LIQUID AMINES (MEA).
DURING THE RECIRCULATION OF WASTE WATER AND PULP FIBERS, THESE GASES COME BACK TO PAPER .
ENTRAPPED GASES IN PAPER WEB CAUSE SMELL.
PUTRIFIED ORGANICS IN PAPER RELEASE SMELL LATER.
ELECTRICAL M ICROBIALLY INFLUENCED CORROSION (EMIC).
EMIC CAUSE DAMAGE TO METALS AND PLUMBING WORK.
EXAMPLES: H2S ABOVE 2 PPM GIVE CORROSION EFFECT.
SOLE PURPOSE OF FOOD PACKAGING IS TO PRESERVE FLAVOUR.
IF PACKAGING PAPER ITSELF HAS ODOUR, PURPOSE IS NULLIFIED.
TAINTING AND VFA MIGRATION ARE MAJOR PROBLEM.
PREVENTION IS BETTER THAN CURE.
CHEMICAL ADDITIVES ARE USED TO ABSORB H2S.
SRB (SULPHUR REDUCING BACTERIA) PREVENTED WITH SUITABLE AND SPECIAL BIOCIDE PRGRAM.
SO4 + Organic Matter
PREVENTION OF H2S FORMATION: DOSE SUFFICIENT ClO2 TO KILL BIOFILM LAYER.
SODIUM NITRATE RETARDS SEPTICITY AND PROMOTE BIO-OXYDATION.
SODIUM CHLORATE IS APPLIED TO WATER SYSTEMS, WHERE RETENTION TIME IS MORE THAN 3 HOURS.
2H2S + NaClO2
H2S + CO2
2S + 2H2O + NaCl
H2O2 + H2O2 S + 2 H2O ( less than 8.5pH)
H2S + 4 H2O2 SO4 + H2O (more than 8.5 pH)-2
INDICATOR STRIP METHOD VS H2S GAS ANALYZER.
FROM 1-3 PPM STRIP COLOR TURNS GREY. ABOVE IT GOES DARKER AND DARKER UP TO 400 PPM.
YOU CAN MOISTEN THE PAPER AND CHECK AIR ALSO.
EXACT VALUE COMES WITH GAS ANALYZER PORTABLE.
ION SELECTIVE ELECTRODE FOR H2S DETECTION IN WATER.
CAN BE USED TO MONITOR REGULAR IN EFFLUENT/SLUDGE.
DO METER, ORP METER CAN BE USED TO PREVENT ANAEROBIC CONDITIONS TO PREVENT H2S.
ANALYTICAL AS WELL AS INSTRUMENT METHODS USED.
EXAMPLES:
ANALYTICAL INSTRUMENT METHOD
SAMPLE FOR GC – MS ANALYSISFOR DIFFERENT VOLATILE FATTY ACIDS
A PAPER MILL WITH COMPLETE ETP, CLARIFIER, UNDERFLOW SLUDGE DIGESTION TANK HAD PROBLEM.
H2S LEVELS ARE MOUNTING AS HIGH AS 2OO PPM.
OUR MAXTROL ODOR CONTROL SOLUTION RUN AT 500-600 GM PER TON OF OD SLUDGE FOR TWO DAYS.
H2S LEVELS DROPPED CONSIDERABLY TO 20PPM.
FURTHER DOSAGES CARRIED AT 350-400 GM PER OD TON.
H2S LEVELS CAME DOWN TO 3 PPM AND LATER NON-EXISTENT.
MILL PREFERRED TO CONTINUE USAGE OF CHEMICAL.
THE ODOUR WAS CAUSED MAINLY BY VFA AND H2S.
WE DEVELOPED INNOVATIVE SOLUTIONS.
OUR SOLUTIONS ARE COMBINATION OF ABSORBENTS, BIOCIDES AND OXIDANTS TO CONTAIN ODOR ISSUE.
REGULAR AUDITING BY EXPERTS IS RECOMMENDED.
OUR SKILLED TEAM CAN GIVE YOU SOLUTIONS.
WE HAVE TO MEET INTERNATIONAL STANDARDS
ODOUR NORMS TO BE STRICTLY FULFILLED
TRENDS CHANGED FROM SENSORY PERSEPTIONS TO NUMERICAL VALUE MONITORING.
MAINTAING REQUIRED DISSOLVED OXYGEN LEVELS
CONTROL ALWAYS STRICT ORP VALUES.
PERIODICALLY GET THE PAPER SAMPLES TESTED FOR ODOR.