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The rate of arsenic adsorbing onto FMBO is fast, and most arsenic is removed by the sand filter. UF increases the arsenic removal to a certain extent. 4) ... – PowerPoint PPT presentation

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Title: Overall CEL795 Term Paper Summary Slides

Overall CEL795 Term Paper Summary Slides November
15th 2012
Removal of pesticides from water using Nano
Filtration and Reverse Osmosis
Group members
Karishma Bhatnagar 2012CEV2274 (Group Leader)
Megha Kanoje 2012CEV2283 Shailvee 2012CEV2
273 SreelakshmiBabu 2012CEV2267 MeenakshiKayesth
The main objective of this study is to
investigate the removal of pesticides by NF and
RO membranes and to study the effect of Membrane
characteristics, Pesticide properties, Feed water
and Membrane fouling.
  • The presentation includes
  • Basic information about Nano Filtration and
    Reverse Osmosis.
  • Factors affecting the performance of NF/RO
  • Benefits of using NF/RO system over other
    conventional methods

Nano Filtration
Nano filtration is a process in which membranes
with Nano size pores are used to separate
solutes or salts based on size/and or charge. It
can effectively remove multivalent ions,
pesticides, pathogens, hardness and nitrates.
Reverse Osmosis
RO membranes are effectively non-porous and thus
are very effective in removal of particles with
low molar mass species.

Summary of factors to be considered while
designing a NF/RO system
NF/RO System
Membrane Properties Feed water
composition Pesticide Properties
Water pH
Molecular weight
Membrane Porosity
Solute Concentration
Molecular Size
Membrane material
Ionic Strength
Chemical property

Organic matter
Study on three different membranes NF90, NF270
and NTR7250 for removal of Atrazine
Parameters Effects on all three membrane
Feed Concentration Negligible effect
Pressure Retention increased with increased pressure
pH Best retention at 7 reduces at 4 and 10
Humic Acid Rejection increased
Humic Acid Flux decreased
TiO2 Rejection increased
TiO2 Flux decreased
Effect of membrane material
Property Comments
Membrane molecular weight cut-off Most effective membranes are in range of 200 to 400 Da
Membrane porosity Micro-porous membranes are most effective
Membrane material Synthetic organic polymers are more efficient than ceramic and metallic membranes. Composite Polyamide (PA) are more effective than Cellulose Acetate (CA) Poly Vinyl Alcohol membranes are more effective than SulfonatedPolyehtesulfone Poly Vinyl Alcohol membranes.
Effect of the feed water composition
Property Comments
WATER pH Higher pH values - reduced removal rates. Reason-ion adsorption on membrane surface.
SOLUTE CONCENTRATION No significant effect on removal.
IONIC ENVIRONMENT High ionic concentrations - Better removal. Reason - reduction in electrostatic forces inside membrane.
PRESENCE OF ORGANIC MATTER(OM) Presence of natural OM - Increased removal. Reason - Binding between pesticides and humic substances.
Effect of pesticide properties
Property Property Comments
Physical Properties of Pesticides Molecular size Higher the molecular size, higher will be the rejection
Physical Properties of Pesticides Molecular Length works in positive direction for removal of organic compound
Physical Properties of Pesticides Molecular Width Better indicators for removal of alcohols and carbohydrates
Physical Properties of Pesticides Mean molecular Size Better indicators for removal of alcohols and carbohydrates
Pesticides chemical properties Sorption Capacity Higher the sorpotion capacity, higher will be the rejection
Pesticides chemical properties Hydrogen Bonding Hydrogen bonding between hydrogen component of pesticide and hydrogen component of membranes works in positive direction for removal of pesticides
Pesticides chemical properties Hydrophobic interactions hydrophobic interactions are mostly responsible for pesticides adsorption on membrane
Pesticide polarity Dipole moment Solute rejection decreases
  • Benefits of reverse osmosis
  • RO does not add any other chemical to water.
  • Eco-friendly, do not produce or use any harmful
    chemicals during the process.
  • Can remove contaminants such as arsenic,
    nitrates, sodium, copper and lead,
  • some organic chemicals, and the municipal
    additive fluoride.
  • It requires a minimal amount of power.
  • Works well in home filtration systems because
    they are typically small in size.
  • Removes unpleasant smell, unwanted taste, unusual
    colours and also benefits
  • plumbing because of no corrosion issues.
  • Benefits of nano-filtration
  • Nano Filtration is chemical-free, as it needs no
    salt or chemicals during operation.
  • Reduces nitrates, sulphates and heavy metals,
    colour and turbidity of water.
  • In brackish water, it helps to reduce salt
    content and dissolved matter content (TDS).
  • Nanoflitration softens hard water when specific
    softening membranes are used.
  • The pH of water after nano-filtration is normally
  • Nano-filters are close in size to Reverse Osmosis
    filters, but cost much less to run.
  • Also special properties of nano-sized particles
    can be exploited. We can design new
  • nano-filters that catch particles smaller than
    they would catch based on size alone.

  • Submitted by
  • Nidhi Gera 2011CEV3063
  • Varsha Singh 2011CEV3064 
  • Swati Sharma 2011CEV3065 
  • Vikas Agrawal 2009TT10835

A significant number of operations within a
tannery are wet operations consuming large
amounts of water, chemicals and energy and
leading to large amounts of polluted water. The
uncontrolled release of tannery effluents to
natural water bodies increases health risks for
human beings and environmental pollution.
Effluents from raw hide processing tanneries
produce wet blue, finished leather, contain
compounds of trivalent chromium (Cr3) ,sulphides
(S2-) and colour. Organic and other ingredients
are responsible for high BOD (Biological Oxygen
Demand), COD (Chemical Oxygen Demand)and TSS
values and represent an immense pollution load,
causing technical problems, sophisticated
technologies and high costs in concern with
effluent treatment. Through this term paper we
will demonstrate that by means of a combination
of biological and physico-chemical treatment
technologies, complex tannery wastewater can be
effectively and efficiently treated with high
reduction rates.
Sr. No. Different Treatment Process Treatment Technologies
1 Primary treatment ( involves Metal grating, shortening the retention time). Primary settling tank is used for removing almost half of suspended solids.
2 Secondary treatment Aerobic Treatment Anaerobic Treatment activated sludge trickling filter - for biological Treatment oxidation ponds Chlorination - applied for disinfection UASB- for Anaerobic treatment of wastewater converts the organic pollutants into a small amount of sludge and large amount of biogas as methane and carbon dioxide
3 Tertiary treatment (involves a series of additional steps to further reduce organics, turbidity, N, P, metals, colour and pathogens) - Coagulation Filtration Activated carbon adsorption of organics Physiochemical Process Disinfection
4 Sludge Treatment Thickening Digestion Dewatering Incineration Final Disposal
Results Different Technologies for effective
removal of pollutants
Sr No. Technologies Efficiency/ Effectiveness (on the basis of data available through experiments)
1 Electro coagulation and Electro-Fenton methods EF Process is much efficient than the EC process in terms of COD and sulfide removal.
2 Catalytic oxidation Aeration is required in Catalytic Oxidation of almost 7 n half with 98 removal efficiency of sulfide to maintain the optimum concentrations of the catalysts. With no catalyst used in the process, the sulfide removal was found to be 80 effective with an 8-hour aeration period.
3 Chemical oxidation using manganese oxide (IV) The amount of sulphides and the pH of solution have an influence on oxidation process duration it is longer when the sulphide amount and pH in WW is higher.
4 Wet Oxidation The pre-treatment is favoured by the fact in wet oxidation that it contains high amounts of NaCI 0.25-4.6.which reduces the phenolic compound/ ammonium Nitrogen/ oxidation of sulfides.
5 Galvanostatic electrolysis Higher current densities resulted in a faster COD removal due to a greater electro generation of active chlorine.
6 Batch Settling Effective in removal of Suspended solids and Total solids and helps in removal of MLSS.
7 Constructed wetland system This study is carried out with Pilot units which is vegetated with plants like Canna indica, Typha latifolia for surface water/ ground water in which it was shown that horizontal subsurface flow can be a viable alternative for reducing the organic matter content from tannery wastewater.
8 Removal of Chromium from Tannery Effluents. By Adsorption/Biological/ Chemical techniques -Cr3 around 98-99 get precipitated as cr (0H)3. Cr (VI) can be removed by biological treatment. Cr(VI) concentration decreases until reach nil after 96hr in all isolates except (S46).- - In Adsorption, chromium removal is controlled by degree of stirring. As rate of stirring increased the removal.
9 Electrodialysis Dimensional stability of membrane (MTS ,MCS) is used which increases as the polymer affinity for water decreases.The membranes had higher resistance due to the residual organic matter present in the effluent, which might have caused the membranes fouling, hindering the transport, and consequently increasing electric resistance thus helping in removal of color.
  • The extent of pollution created by tanneries
    required different biological/chemical /Physical
    treatment and disposal of effluent wastewater for
    effective removal of unwanted toxicological
    exposure to plants and living beings.
  • Biological treatment methods is a better choice
    for removal of organic and certain inorganic
    content yet the process efficiency is questioned.
  • It is generally accepted that anaerobic treatment
    is less energy intensive and superior in most
    respect for the tannery wastewater treatment than
    the aerobic treatment.
  • The application of combined process of physical
    or chemical with biological process to treat
    tannery wastewater would give satisfactory
    results compared to individual treatment

  • Nanotechnology manipulates matter at the
    nanoscale (1100 nm) producing nanoproducts and
    nanomaterials -physicochemical properties
  • The Woodrow Wilson Database lists- 1015 consumer
    products in market incorporating NPs -259
    containing silver nanoparticles (AgNPs)- largest
    and fastest growing class of NMs in product
  • Sources of Silver Nanoparticles present in
  • Silver is used as an antimicrobial agent in
    ointments and creams.
  • Manufacturers add silver nanoparticles to
    hundreds of consumer products, including food
    storage containers, computer keyboards,
    cosmetics, pillows, cell phones, and medical
  • Manufacturers of clothing articles exploit its
    antimicrobial property to produce novel items
    like No stink socks.

  • Effect of Silver nanoparticles (AgNPs)
  • Silver is water soluble, unwanted AgNPs are
    formed in the sludge produce by sewage treatment
  • These antimicrobial nanoparticles could adversely
    impact desirable microorganisms that decompose
    waste in sewage treatment plants. For instance,
    they affect many nitrifying bacteria responsible
    for biological oxidation of ammonia with oxygen
    into nitrite followed by the oxidation of these
    nitrite into nitrates.
  • Nanosized silver sulphide applied to agricultural
    land could oxidize in soils and release toxic
    silver ions that kill beneficial soil
  • Occurrence of bio magnification of silver
    nanoparticles along the food chain.
  • High exposures to silver compounds can cause
    Argyria, an irreversible condition in which the
    deposition of Ag in the body tissue results in
    the skin turning bluish in colour.

  • To find the different types of microorganisms
    which biosynthesize Silver nanoparticles under
    controlled laboratory conditions.
  • To analyse different factors affecting Silver
    nanoparticle synthesis.
  • To quantify field study and lab studies done on
    Silver nanoparticles in the past 5 years.
  • The term paper was prepared by referring to
    journals available on published scientific
    research sites like ScienceDirect.
  • Research papers were thoroughly studied -detailed
    analysis was done on our understanding.

Microorganisms which biosynthesize Silver
nanoparticles under controlled laboratory
Sl.No. Name of micro organisms which reduce silver nano particles Amount of AgNO3 added Incubation Conditions Incubation Conditions pH Absorbtion (nm) Size of NPs synthesised (nm) Reference
Sl.No. Name of micro organisms which reduce silver nano particles Amount of AgNO3 added Temp (C) Time (Hr) pH Absorbtion (nm) Size of NPs synthesised (nm) Reference
1 Shewanella oneidensis 1mM 30 48   410 93.5 1
2 Fusarium oxysporum 1mM   72   413 5 to 50 4
3 Escherichia coli 1mM 27 24   390 to 410 35 to 45 6
4 Bacillus subtilis 1mM 40 120 8.5 410 5 to 50 7 23
5 Penicillium fellutanum 1mM 5 24 6 430 5 to 25 8
6 Pseudomonas aeruginosa 0 to 30 mg/l 37 24 5 - 9 425 43  23
7 Micrococcus luteus 0 to 30 mg/l 37 24 5 - 9 425 43  23
8 Bacillus barbaricus 0 to 30 mg/l 37 24 5 - 9 425 43 23 
9 Klebsiella pneumoniae. 0 to 30 mg/l 37 24 5 - 9 425 43 23 
  • Various factors affecting the biosorption and
    toxicity of silver nanoparticles
  • pH
  • salt concentration
  • Maximum adsorption and toxicity of AgNPs on
    bacterial species was
  • observed at pH 5, and NaCl concentration of lt0.5
    M but, very less
  • adsorption was observed at pH 9 and NaCl
    concentration gt0.5 M,
  • resulting in less toxicity.
  • It was also seen that Zeta potential plays an
    important role in
  • adsorption of nanoparticles by microorganisms.
  • In our research on the types of study done on
  • nanoparticles it was found that the laboratory
    work on
  • concentration of nanoparticles have been widely
    done in the
  • past 5 years but the field study on environmental
  • over harmful effects of AgNPs in the wastewaters
    has paced in last
  • three years.


Group Members
  • SWAGAT DAS 2012CEV2275
  • NANDAN 2011CEZ8473
  • FATEMEH ZAHER 2012CE19042

Methodology studied
  • The removal of arsenic by solar oxidation in
    individual units (SORAS) is currently being
    explored as a possible economic and simple
    technology to treat groundwater in Bangladesh and
  • Light plays the role of accelerating the
    oxidation of As(III) to As(V), and also affects
    the nature of the solid and, hence, its sorptive
  • The efficiency of As removal depends on-
  • the mechanism of formation of the solid iron
  • the rate of As(III) oxidation, and
  • the possibility to include As(V) in the growing
  • Given enough Fe and alkalinity, As may be
    removed by the simple dark flocculation.
  • Electrochemistry and membrane ultrafiltration
    methods (electro-oxidation and liquid phase
    polymer based retention technique, LPR,
    respectively) were off-line coupled to remove
    As(III) inorganic species from aqueous solutions
    to achieve an efficient extraction of arsenic
    species by associating a polymer-assisted liquid
    phase retention procedure, based on the As(V)
    adsorption properties of cationic water-soluble
    polymers ,with an electrocatalytic oxidation
    process of As(III) into its more easily removable
    analogue As(V)
  • Treatment by the liquid phase polymer based
    retention technique of aqueous arsenic solutions
    previously submitted to an electrocatalytic
    oxidation to convert arsenic(III) to arsenic (V)
    species quantitatively removes hazardous arsenic
    from these aqueous solutions.

  • in situ precipitated ferric and manganese binary
    oxides (FMBO) adsorption, sand filtration, and
    ultra-filtration (UF) for arsenic removal
  • FMBO shows higher capability of removing arsenic
    than hydrous ferric precipitate (HFO) and hydrous
    manganese oxide (HMO)
  • This is ascribed to the combined effects of
    oxidizing As(III) and adsorbing As(V) for FMBO.
    The continuous experiments indicate that this
    process is effective for arsenic removal.
  • The rate of arsenic adsorbing onto FMBO is fast,
    and most arsenic is removed by the sand filter.
    UF increases the arsenic removal to a certain
  • The structure of modified and unmodified
    clinoptilolite samples from the GördesManisa
    deposit was studied. The elemental composition
    and specific surface areas of zeolitic samples
    were also determined.
  • Iron concentrations in the solution to modify
    clinoptilolite play important role in the
    arsenate adsorption. However arsenate adsorption
    kinetics was slightly affected by them.
  • At lower initial arsenate concentration, arsenate
    exhibited greater removal rates and best removed
    when the Fe1-GC was used for adsorbent. Thus,
    iron modified zeolite can be used as an efficient
    and economic adsorbent for arsenate removal.

  • use of Chir pine leaves (Pinus roxburghii) to
    remove As(V) ions from aqueous solutions.
  • Maximum adsorption has taken place at pH 4.0
    while equilibrium was achieved in 35 min.
  • Langmuir, Freundlich, Temkin, Elovich,
    DubininRadushkevich and FloryHuggins isotherm
    models were used to explain the phenomenon.
  • Maximum adsorption capacity of P. roxburghii was
    3.27 mg/g that was compared with the capacities
    of some previous adsorbents used for arsenic
  • Adsorption mechanism was explored by Pseudo
    first- and second-order kinetic models, and it
    was found that the process followed second order
    kinetics. The study concluded that the Chir pine
    leaves can be a good adsorbent for removing As(V)
    from water owing to the fine adsorption capacity.
  • exceptional arsenic removal performance on both
    As(III) and As(V)species.
  • At near neutral pH environment, the maximum
    adsorption capacity of HCO nanoparticles is over
    170 mg/g on As(III), and 107 mg/g on As(V). Under
    very low equilibrium arsenic concentrations,
  • the amount of arsenic adsorbed by HCO
    nanoparticles is over 13 mg/g (Ce at 10 g/L) and
    over 40 mg/g (Ce at 50 g/L).
  • Over awide pH range from 3 to 11, HCO
    nanoparticles demonstrated an unique capability
    to readily remove As(III), which was not observed
    previously and is beneficial to their
    applications for water bodies with various
  • HCO nanoparticles demonstrated fast arsenic
    removal rate and high adsorption capability
    without the need of pre-oxidation and/or pH
    adjustment, which is very attractive for their
    real application.

  • Submiteed to Dr. Arun Kumar
  • Neha Mehta-2012 cev2271
  • Neeraj Golhani-2012cev2281
  • Samarpreet Singh- 2012cev 2270
  • Swati Srivastava- 2012cev3043

  • bioremediation is the use of living organisms,
    primarily microorganisms, to degrade the
    environmental contaminants into less toxic forms.
    Bioremediation techniques prove to be
  • more ecofriendly,
  • low cost and easy technique as it uses naturally
    occurring bacteria and fungi or plants to degrade
    or detoxify substances hazardous to human health
    and/or the environment.
  • The bioremediation techniques prove to be much
    better in comparison to conventional remediation
    methods especially at low concentrations i.e.
    high efficiency in detoxifying very dilute
    effluent and also generate less sludge at the end
    of the treatment (minimum ratio of disposable
    chemical and/or biological sludge volume).
  • Reduction of uranium present in ground water into
    less harmful by-products by using bio-remediation
  • If possible complete removal of uranium from
    affected water by using microbes.
  • Converting soluble uranium compounds to insoluble
    forms to treat water containing uranium.
  • Uranium can enter ground water because of its
    presence in earths crust.
  • Due to radioactive wastes from nuclear industry.
  • Due to institutional use of radioisotopes(medicine
    , industry, agriculture, research reactors and
    test facilities)

Methods used
  • Bioremediation of uranium through reduction of
    the metal-
  • Microbial reduction of soluble U (VI) to
    insoluble U (IV) plays an important role in the
    geochemical cycle of uranium and also serves as a
    mechanism for the bioremediation of
    uranium-contaminated waters. Enzymatic U (VI)
    reduction converts dissolved U (VI) to an
    extracellular precipitate of the U (IV) mineral
    uraninite (UO). Thus this has provided a possible
    mechanism for the removal of contaminating
    uranium from groundwaters.
  • Bioremediation through rhizofiltration-
  • Rhizofiltration is a type
    of phytoremediation, which refers to the method
    of using cultivated plant roots to remediate
    contaminated water through absorption,
    concentration, and precipitation of pollutants.
    In this, suitable plants with stable root systems
    are supplied with contaminated water to acclimate
    the plants. These plants are then transferred to
    the contaminated site to collect the
    contaminants, and once the roots are saturated,
    they are harvested.
  • Biomineralization-
  • The term biomineralization refers to the
    process of production of minerals by biological
    organisms. The complex mineral produced not only
    includes metallic or mineral part but also
    organic part of organism.

  • Bioaccumulation refers to the accumulation of
    substances, such as pesticides, or other organic
    chemicals in an organism. Bioaccumulation occurs
    when an organism absorbs a toxic substance at a
    rate greater than that at which the substance is
  • Bioremediation of uranium through biosorption-
  • Biosorption is a physiochemical process that
    occurs naturally in certain biomass which allows
    it to passively concentrate and bind contaminants
    onto its cellular structure. The chemical
  • of microbes to radionuclides/heavy metals
    rather than radiation tolerance is therefore
    preferable for remediation of metal

  • Reduction of uranium from U (VI) to less toxic,
    insoluble U (VI) has been the method of choice
    for many scientists. Since this reaction is
    performed by bacteria, the results are obtained
    generally at a fast rate and with more
    efficiency. Handling bacteria both at lab scale
    and in fields is easier as their growth rate is
    high and short if optimum conditions are
    provided. Bacteria and few algae are able to use
    a number of metals as electron acceptors e.g.
    Uranium. Many a times the change in the redox
    state alters the toxicity or solubility of the
  • Bioaccumulation processes are under study, for
    removal of uranium, and researches show that
    bioaccumulation processes are used In acidic
    medium only.
  • application of biosorption by the brown alga in
    purification of wastewater for the removal of
    uranium ions from industrial wastewaters can be
    suitable for large-scale exploitation. More
    studies are needed to optimize the system from
    the regeneration point of view and economic
  • Adsorption of uranium ions was quite sensitive to
    pH of the medium and the maximum biosorption was
    obtained at acidic pH between 4.5 and 5.5.
    Temperature has not a favourable effect on
    biosorption capacity of fungal biomass in the
    range of 535 ?C.

  • Rhizofiltration allows in-situ treatment,
    minimizing disturbance to the environment.
    Various plant species have been found to
    effectively remove toxic metals such as cadmium,
    zinc, uranium etc.
  • Bioremediation can provide final treatment to
    the contaminated water by reducing uranium levels
    upto 20 µg/L which is even lower than the US EPA
  • Limitations-
  • cases include where the metal removal by means of
    algae was not feasible in practice even though it
    showed satisfactory results under lab study.
  • Sometimes the living organism is able to intake
    or tolerates uranium upto a certain concentration
    only. Beyond which uranium proves toxic to the
    organism as well.
  • If substantial portion of the U(VI) is strongly
    associated with the sediments then it cannot be
    reduced microbially..
  • In all the methods , efficiency of processes is
    highly dependent on pH of the system, and
    efficiency may drasticlly reduce in basic or
    alkaline mediums. Considering the abundance and
    diversity of microorganisms in the natural
    domain, it is of immense importance to identify
    and characterize microbial strains with high
    metal accumulation capacity and specificity,
    Understanding and exploring potential of
    microbemetal interaction.

A potential of Biosorption derived for removal of
Arsenic from contaminated water
  • The experiment was conducted for banana peel due
    to its natural, renewable, abundance and thus
    cost effective biomass.
  • Maximum efficiency found to be 82 at pH 7,
    contact time 90 minute, dosage 8g, temperature 35
    degree and 10 mg/L ion concentration of arsenic.

Effect of pH
  • removal of As increased with pH of solution and
    reached optimum value of 86 at pH 7.
  • If pH value is lowered below 7, electrostatic
    repulsion between metal ions and H increased and
    removal of As was seen.
  • If pH is above then 7, electrostatic repulsion
    decreases and metal adsorption process enhances
    and it is found to be maximum at a range of 6-8
    i.e. at neutral condition.

Effect of temperature
  • removal increases with the increase in
    temperature but upto 35 degree and then decreases
    due to breaking down of bond on the surface of
    biomass at higher temperature.

Effect of dosage
  • Maximum removal is observed at 8 g/L.
  • It is observed that increase in biosorbent dose
    results in increase in the number of active
    sites, which lead to increase in the percentage
    removal of As ion.
  • However no significant increase in the percentage
    removal was observed with the increase in
    biosorbent concentration beyond 8g/L.

Effect of contact time
  • At initial stage of removal there is rapid
    removal of As ion and later on removal becomes
    slow and reaches optimum stage at 90 minutes.
    Further time wont significantly effect removal
    due to the accumulation arsenic species.
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