Potential Use of Eichhornia Crassipes for Treatment of Highly Toxic Sulphur Black Effluent

8/3/2019 Potential Use of Eichhornia Crassipes for Treatment of Highly Toxic Sulphur Black Effluent

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Potential use of Eichhornia crassipes for treatment of highly toxicsulphur black effluent

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The potential of Eichhornia crassipes(water hyacinth) was explored for treatment of highly contaminated wastewater collected from a local

garment processing industry at Mahestala Budge budge. The effluent contained sulphur black dye (C.I.Sulphur black1) which is one of themost important black dyes in the world and widely used for cellulosic fibers.

In the traditional sulfur dyeing process, sodium sulphide is used as areducing agent in the dyebath and ahighly toxic effluent is generated. As aresult, the entire area is under extremeenvironmental pollution. In the present

study the feasibility of a biosorbent prepared from the roots of E. crassipeswas determined for the treatment of

sulphur black effluent. E. crassipes is a fast growing perennial aquatic weed and can grow in severe polluted waters. The roots of E. crassipes wascollected and washed thoroughly in

distilled water to remove theimpurities The dried biomass was powdered and sieved to select particle sizes of about 100m to use asbiosorbent in the batch studies. Theraw effluent and the treated sampleswere characterized in terms of the dyeremoval, turbidity, TSS, COD, pH,Conductivity, TDS etc.

Dye removal was maximum(99.8%) at initial pH of 4 and 1g/l was found asan optimum dose of the adsorbent. The

process was found highly efficient withremoval of turbidity, TSS and COD as99.8% and 69% respectively.

B iosphere is constantly under variousthreats from continuing environmental

pollution. Man made activities onwater and air by domestic, industrial,

agriculture, burning of fuels havenegative influence on abiotic and bioticcomponents of environment. Differentapproaches have been implemented totackle man-made hazards. Among theindustries textile industry plays animportant role in the economy of thecountry. 70% of pollution from textileindustry is caused from chemical

processes of textile industry. Textileindustry involves wide range of raw

materials, machineries and processes toengineer the required shape and

properties of the final product. Wastestream generated in this industry isessentially based on water-basedeffluent generated in the variousactivities of wet processing of textiles.The main cause of generation of thiseffluent is the use of huge volume of
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water either in the actual chemical processing or during re-processing in preparatory, dyeing, printing andfinishing. Different types of dyes areused for colouring the textiles like azo,anthraquinone, acridine,etc. Sulphur dyes are a most common class of dyeshaving the best light fastness and low

price among the dyes applied to naturalfibres. They are cheap, generally havegood wash-fastness and are easy toapply. The dyes are absorbed by cottonfrom a bath containing sodium sulfide or sodium hydrosulfite and are made

insoluble within the fiber by oxidation [1]. During this process these dyesform complex larger molecules whichis the basis of their good wash-fastness. The deep indigo blues of denim blue jeans are a product of sulfur dyes. The alkali metal thiolate isusually necessary as a reducing agentin the dyeing process of sulphur dyes,

bring about serious environment pollution. And, the fiber dyed by this

water-insoluble dye presents poor wetrub fastness. Sulfur dyes are water insoluble. They have to be treated witha reducing agent and an alkali attemperature of around 80 degreesCelsius where the dye breaks intosmall particles which then becomeswater soluble and hence can beabsorbed by the fabric [2]. Hence theeffluents have to be treated beforedischarge to prevent pollution.

Different methods have been used for treatment of dye effluent likeoxidation, adsorbtion [3],

photodetoxification [4], biologicaltreatment [5], etc. Each of the

processes has its own merits andlimitations. In the present studyceramic membrane basedmicrofiltration and an adsorbent

prepared from water hyacinth rootswas used for treatment of sulphur black effluent. Low cost ceramic membranesdeveloped by Central glass & CeramicResearch Institute [6] is explored for treating highly polluted sulphur black effluent. This membrane was used for treatment of reactive dye effluent incombination with coagulants based

pre-treatment process [7].

Experimental

Dyes

Sulphur dye effluent was collectedfrom Mahestala,Budge budge. Sulphur Black 1, in all its forms (C.I. Sulphur Black 1, C.I. Solubilised Sulphur Black 1 and C.I. Leuco Sulphur Black 1) ismostly used for dyeing processworldwide.

Fig-1 Structure of sulphur Black 1

In the present study raw sulphur black effluent was collected and initialcharacterisation i.e pH, TSS, turbidity,COD, conductivity, TDS, colour etc. of effluent was done which is shown inTable-1. Turbidity was measured in

2100AN IS Turbidimeter, Hach, pH,TDS, conductivity was measured inmultiparameter made of Hach, CODwas measured in COD digestor bySpectralab 2015M. Absorbtion of samples were measured in UV-VISspectrophotometer by Varian.
http://en.wikipedia.org/wiki/Sodium_sulfidehttp://en.wikipedia.org/wiki/Sodium_hydrosulfitehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Denimhttp://en.wikipedia.org/wiki/Blue_jeanshttp://en.wikipedia.org/wiki/Sodium_sulfidehttp://en.wikipedia.org/wiki/Sodium_hydrosulfitehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Denimhttp://en.wikipedia.org/wiki/Blue_jeans


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Table-1: Characterization of raw black sulphur effluent

Adsorbent

Eichhornia crassipes (Water hyacinth)are free floating water plant and is alsoone of the most notorious weedsworldwide. It can vary in size from a

few inches tall to over three feet. This plant has blue-green leaves, thick stalks and a showy purple or lavender flower. It thrives in tropical regionsand in waters that are high in nutrients.Water hyacinth is also known for itsability to grow in severe pollutedwaters. Roots of hyacinth are known toacculmulate heavy metals like Zn, Cd,

Ni, Cu [8]. In the present study water hyacinth was collected from nearby

locality pond. Roots were washedthoroughly with distilled water to freefrom any impurities and dried.Adsorbent had the followingcharacteristics: bulk density - 133kg/m 3, moisture - 9.6%, ash - 44%,

particle size - 0.038mm. Adsorbent prepared from the roots were further study for its removal efficiency of sulphur black dye.

Batch study

Batch scale study was conducted onsulphur black effluent at different pH(4-12) and different dose (0.5 -2g/l) of adsorbent. The optimum dose and pH

obtained from the batch study was usedfor membrane study.

Microfiltration

Membrane study of effluent usingselected dose of adsorbent wasconducted. Microporous low costceramic support element made of alumina and clay was fitted incrossflow microflitration unit. In thestudy uncoated porous support tube intubular multichannel configuration wasused (od 35 mm; channel diameter 4mm, length 200 mm, apparent porosity36%, filtration area 0.0501 m 2).

Experiments were conducted usingfeed volume of 6l and at varyingtransmembrane pressure of 4-1.2kg/cm 2 to observe the effect of pressureon permeate flow and characteristics .Effect of time was observed byoperating the experiment at a constant

pressure of 1 TMP for 2 hours. The permeate flux was measured at specificintervals and characterization of

permeate samples were done for pH,

turbidity, conductivity, dyeconcentration. The ceramic elementand unit was thoroughly cleaned withdeionised water before each run andafter the experiment was over. Thetube was cleaned with dilute nitricacid.

Results and Discussion

Determination of optimum pH

The effect of variation of pH on dyeremoval of the effluent sample wasdetermined (Fig-2). The pH range for the study varied in the range of 4-12.

pH Conductivity(ms/cm)

TDS(mg/l)

Turbidity(NTU)

Dyeconcentration(mg/l)

COD(mg/l)

TSS(mg/l)

12.54 49.5 31,100 5505 612.5 3915 5568


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0 2 0 40 60 80 100 1205 0

6 0

7 0

8 0

9 0

10 0

11 0

12 0

C O DTS SDye concen trat ion

% R

e m o v a l

Time (min )

0 20 40 60 80 100 120

-2 0

0

20

40

60

80

10 0 FluxTurbidity

F l u x ( L M H ) , T u r b i d i t y ( N

T U )

Time (min)

Maximum dye removal of about 84%and COD removal of 68.1% wasobserved at pH 4. Dye removal at pH12 was least i.e 61% and for pH 8 & 6dye removal was about 66-78%.Turbidity and TSS removal was 59%and 64% respectively, in the batchstudy.

Fig-2: Effect of pH in batch study of sulphur black effluent (dose 1g/l).

Determination of optimum dose

The effect of varying dose of adsorbentwas determined (Fig-3). The dose was

varied from 0.5-2g/l. It was observedthat maximum dye removal of 84%was obtained at dose 1g/l. CODreduction was maximum compared toother three doses (0.5, 1.5, 2g/l). Hencefor membrane study 1g/l dose of adsorbent was selected.

Fig-3: Effect of adsorbent dose in batchstudy of sulphur black effluent (pH-4).

Microfiltration study

Membrane filtration study wasconducted using adsorbent dose of 1g/l. The pH of the feed was adjustedat 4. After 15 mins dye removal was97.7% which increased to 98.5% after 120 minutes. COD, TSS removal were66% and 94% respectively after 15mins of membrane filtration. It wasincreased to 79% and 96% respectivelyafter 120 minutes. The permeate fluxwas 60 LMH initially which reduced to43 LMH after 120 mins. The reductionin flux value was due to theconcentration polarization across the

membrane surface. Turbidity wasreduced below 1NTU (Fig 4-5).

Fig-4: Effect of time variation inmicrofiltration study of sulphur black effluent at 1 TMP (adsorbent dose 1g/l,pH-4).

Fig-5: Variation of turbidity andpermeate flux with time (adsorbent dose

1g/l, pH-4).

4 6 8 10 12

20

40

60

80

100

120

140CODDye concentrationTSSTurbidity

% R e m o v a l

pH

0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

20

40

60

80

100

120

140 CODDye concentrationTSSTurbidity

% R e m o v a l

Adsorbent dose (g/l)


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0 .4 0 .6 0 .8 1 .0 1 .2

50

60

70

80

90

10 0

11 0

12 0

C O DTS SDye concen trat ion

% R

e m o v a l

Transmem brane pressue (kg/cm2)

0.4 0 .6 0 .8 1.0 1.2

-2 0

0

20

40

60

80

10 0FluxTurbidity

F l u x ( L M H ) , T u r b i d i t y ( N

T U )

Transmembrane pressure (kg/cm2)

The effect of varying transmembrane pressure (0.4-1.2 kg/cm 2) wasobserved. As expected the flux rateincreased with increasing pressure dueto increase in driving force. Maximumflux of about 65LMH was observed at1.2 kg/cm 2 TMP (Fig 6-7). Turbidityalso decreased with increasing TMP.The removal of turbidity, COD, TSS,dye concentration etc. was enhanced inthe combination process of adsorptionfollowed by microfiltration.

Fig-6: Effect of transmembranepressure in microfiltration study of sulphur black effluent (adsorbent dose1g/l, pH-4).

Fig-7: Variation of turbidity andpermeate flux at different

transmembrane pressure (adsorbentdose 1g/l, pH-4).

Conclusion

The experiments showed that effectivetreatment of highly polluting sulphur

black effluent is possible using ceramicmembrane based process incombination with bioadsorbent. The

bioadsorbent was prepared from easilygrown and abundantly found water hyacinth roots. Dye removal was 99%,COD, TSS removal was 79% and 96.5respectively. The permeate flux was

about 43LMH. Turbidity of the permeate samples were


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[5] Erkurt, E.A., Unyayar, A., Kumbur,H., Decolorization of synthetic dyes bywhite rot fungi, involving laccaseenzyme in the process, Elsevier ,

Process Biochemistry , vol-42, October 2007, 1429-1435.

[6] Bandyopadhyay,S., Kundu, D.,Roy, S.N., Ghosh, B.P., Maiti,H.S.,Process for preparing water having an arsenic level of less than 10PPB, United States Patent

[7] Bandyopadhyay, S., Ghosh, S.,Sahoo, G.C., Maiti, H.S., International

Workshop on R&D Frontiers in water and wastewater Management,Treatment of a Textile Dye-BathEffluent Using Coagulant Followed byMicrofiltration.

[8] Cordes, K.B., Mehra, A., Farago,M.E., and Banerjee, D.K, 2000, Uptakeof Cd, Cu, Ni and Zn by the Water Hyacinth, Eichhornia crassipes(Mart.) Solms from pulverised fuel ash

(PFA) leachates and slurries,Springerlink .


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Potential Use of Eichhornia Crassipes for Treatment of Highly Toxic Sulphur Black Effluent