Synthesis of lignin base hydro gels for the removal of organic contaminants and metal ions from water

1. Research proposal on
Synthesis of lignin base hydro
gels for the removal of organic
contaminants and metal ions
from water
Presented
by:-
Deep Modi

2. Abstract:
 Lignin is one of the most abundant natural polymers after
cellulose and has attracted great attention in academia as
well as in industry for miscellaneous applications.
 Lignin also exhibits very high potential as a renewable
sustainable resource for a galaxy of high value biochemical's.
Due to the typical structure of lignin, it can be converted into
different types of useful products.
 From a ligno-cellulose bio-refinery prospective point of view, it
can be regarded as an economic bio product and can also be
used as filler in several polymers to form blends or
composites.
 Recently lignin-based hydrogels have shown excellent
performance for removal of various pollutants from water. The
adsorption properties of lignin based hydrogels can further be
improved by using a combination of nanomaterials and lignin
that results in promising hydrogel nanocomposites.
 So, in current work, we are going to synthesize a
lignin/Polyacrylic acid base hydrogel for the potential removal
of organic pollutants and metal ions from waste water.

3. Introduction:
 The heavy metal ions ― cadmium, lead, copper, and zinc present in
contaminated wastewater has been an epidemic problem to the environment
and living organisms for millennia. Considerable amounts of heavy metals
originate from industrial operations, mainly from mining, storm water run-off
and even agriculture. Heavy metals accumulate in soils, plants, and animals
due to their affinity for binding to solids and organisms. The presence of
heavy metal ions in water causes adverse effects on ecosystems and results
in human health issues such as cancer and other chronic diseases.
Furthermore, through bioaccumulation and bio-magnification, the general
public is vulnerable to both direct and indirect heavy metal ion consumption
through food and water.
 Among the sources of heavy metal contamination in surface water, storm
water runoff is of increasing interest to environmental engineers and
regulators, since other sources have become better managed whereas storm
water runoff treatment is still treated to a limited extent, even though it is
considered as wastewater in the EU legislation. The limited extent of storm
water treatment is because runoff mostly occurs from a non-point source,
unlike other sources of heavy metals. Recently, changes in climate have
added significant challenges to the storm water runoff by changing
precipitation patterns across the world to larger but more scattered rainfall
events. The concentration of heavy metals in storm water varies by region
and land use―residential areas, highways, industrial, farming areas and
sources, such as vehicles (petrol, tire wear, brake linings), building materials
(roofing, walls) etc.

4.  Based on the recent scenario, the concentration of heavy metal ions in storm
water runoff often exceed water quality standard (WQS) values in surface
water. Various methods for removing heavy metals from wastewater, such as
chemical precipitation, membrane filtration, ion exchange, and adsorption,
have not been efficiently applied to the storm water treatment due to the
irregular occurrences of rain events and the highly variable concentrations of
heavy metals in addition to other pollutants in the runoff. Adsorption methods
are better techniques compared to other methods for efficient treatment of
contaminated storm water due to low investment costs and because large
volumes of storm water can be treated within short time periods. The sorption
of heavy metal ions from water has been studied for decades. However,
most of storm water runoff studies have focused mainly on the heavy metal
ions copper, zinc, lead, which mainly originates from building materials.
There have been only few studies of cadmium although it represent a
significant contaminant originating from roads, airfields and parking lots.
 The most widely applied sorption material is activated carbon (AC) since it
has high porosity and low cost. However, when AC is applied in water
treatment it adsorbs a large variety of mostly non-ionic pollutants and
nontoxic solutes, including major cations which compete for the sorption
capacity of the material and cause it to become saturated quickly. To
overcome this hurdle, various minerals have been studied in passive geo-
filters and these have been gradually employed for road runoff in Europe and
North America although these filters are only effective for selected pollutants
such as lead, zinc, and organic pollutants. Previously evaluated the feasibility
of a sulfur-crosslinked sorbent for the removal of soft acid metals. However,
their study was limited to specific metal sorption without testing selectivity,
and the sorption kinetics was too slow for use in storm water cleaning.

5. Problem Statement:
 Now a days water crisis is a very big issue all
over the world and the amount of water is being
used by industries are increasing day by day.
Polluted water which is released from the
industries is also the big problem. The reason
why the majority industries are avoiding the
water treatment before releasing the water in the
reservoir is high treatment cost of purification and
even after the treatment the water is not useful
for the general use, it can be only use in the
gardening. Another problem is about drinking
water. Ground water contains lots of high metals
contamination is there which is not good for
health and the removing of this metal ions are
very costly and complex.

6. Objectives:
 Now a day the increasing industrial activities have worsened the
environmental health. So the demand for the use of combination of natural
polymers has improved to alleviate the poor environmental health. The
primary pollution of the textile effluents emerge from the dyeing process.
Dyeing and finishing wastes are highly colored in textile industries and
possesses high organic contents. Almost all the dye varieties are toxic,
carcinogenic as well as mutagenic; thus they can cause health problems to
living organisms.
 Removal of these dyes before the discharge of wastewater into the natural
water bodies is highly important. It possess ionic functional groups, these
groups may adsorb and trap cationic dyes such as methylene blue or metal
ions from waste water. With the advent of new and effective separation
technologies different techniques are being used to remove heavy metals
from wastewaters such as ion exchange chemical precipitation,
preconcentration, reverse osmosis, membrane filtration, and adsorption
biological treatment. Among these technologies, adsorption is the most
common technique for the removal of heavy metal. The development of
suitable adsorption techniques for the removal of dyes from aqueous medium
becomes fascinating move towards. This process is convenient and effective
and shared with appropriate bioadsorbent and regeneration steps. Thus a
significant engrossment has been given to super absorbent hydrogels with
efficient groups for the adsorption and separation of dyes from waste water.

7.  Hydrogels belong to a category of soft matter comprising a polymeric cross-
linked three-dimensional structure. The characteristics of hydrogels such as
flexibility, elasticity and permeability are attributed to their high water
absorption ability. They show both half liquid-like and half solid-like
properties. These physico-chemical properties of hydrogels make them
suitable materials to be used for drug delivery applications, tissue
engineering, wound dressings or agricultural/environmental applications.
Biopolymer-based materials such as hydrogels and fibres are a currently
highlighted topic and represent the most promising bio-renewable materials
for various applications. Tunable and degradation characteristics are
advantages of bio-polymer based hydrogels. The use of lignin for different
applications has been reported, due to the inherent advantages of lignin. It
also includes the use of lignin for removal of contaminants from water. Also
in the earth, after cellulose, lignin is most abundant aromatic natural complex
polymer. Lignin is found in plants and most of the plant biomass can consist
of 30% of lignin.
 Different toxic organic compounds can be found in processing residual water
streams. Organic dyes are included in this group of molecules as they are
commonly used in several industries such as textile, cosmetic or
papermaking. It is estimated that about 2% of these compounds are directly
discharged into water resources. These organic dyes, can be very harmful
for the aquatic life and food chain due to mutagenic and carcinogenic effects
even at low concentrations. Several methods, such as coagulation-
flocculation, oxidation, membrane separation or electrochemical processes,
could be employed to remove these toxic compounds. To this end,
adsorption is an effective and simple method to remove pollutants from
wastewater. In this scenario, hydrogels represent valuable alternative as

8. Preliminary Literature Review:
 All the previous research is based
on the high metal ions removal
through the hydrogel and some other
methods but no one is discussing the
removal of dyes and oil from the water
which is very hard to remove from the
water and it is very harmful to human
life as well as aquatic life.

9. Methodology:
 We’ll try to synthesis the hydrogel which should be
biodegradable so that it will not hamper the environment after
the use of it. So, for that I and my team has planned to
produce the hydrogel from the lignosulphonate sodium salt.
 Sodium lignosulphonate is our main compound which should
be polymerize. We’ll polymerize it with the help of acrylamide
and we will also try to use the crosslinker as the crosslinked
polymer is much more efficient compare to the linear polymer.
 Acrylic Acid and Sodium Hydroxide is some of the famous
cross linking agents. To initiate the polymerization process we
are planning to use different initiators which are currently
available in the market and by experimentation we’ll suggest
the best initiator and cross linking agent which makes the
hydrogel more efficient environment friendly and economic to
use in the industry.
 As per the literature survey the reaction time is 16 to 24 hour
at 700 C temperature which we will try to reduce with the help
of some catalyst which we can judge after making the
hydrogel and study the reaction and its kinematics properly.

10. Applications:
 The present proposal aims the current concerns and
environmental hazard of the state. Schemes like “Make
in India “and ease of industrial policies attracts many
industries and manufacturing units to Gujarat.
 Gujarat is hub of textile industry, pharmaceutical
industry, and Dye stuff industries which generates huge
quantity of wastewater with a lot of metal ions and
organic impurities. With stringent environment
regulations and norms, the conventionally methods like
ion-exchange, Reverse osmosis, chemical precipitation,
etc. either aren’t capable to remove enough toxics or
are energy hungry processes.
 With the present lignin based hydrogels research we
can contribute in developing the lab scale technology to
industry scale and develop feasible waste water
treatment process consisting lignin based hydrogels.

11. Outcomes Expected:
 Effect of functionalization of lignin with
acrylic acid and with other different
groups in removal efficiency of organic
pollutants and metal ions.
 Providing scientific findings in some
journal so as to facilitate development
of lignin based hydrogels for waste
water treatment.

12. Proposed Budget Amount:
Consumables Chemicals and
Glassware
120000
Equipments Magnetic Stirrer, pH meter 55000
Characterization 10000
Total 185000

13. References:
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management in response to climate change impacts: lessons
from the chesapeake bay and great lakes regions, United
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