DEVELOPMENT OF MATHEMATICAL MODELS FOR REMOVAL OF NITRATES FROM WASTE WATER

PROJECT REFERENCE NO.: 38S1286

COLLEGE : BAPUJI INSTITUTE OF ENGINEERING AND TECHNOLOGY, DAVANGERE

BRANCH : DEPARTMENT OF CHEMICAL ENGINEERING

GUIDE : DR.G.P.DESAI

DR.SURESH B

STUDENTS : MR. ANISH JACOB

MR. ARAVIND RAJAN

MR. SHOBANA RAJAN

Keywords used in the synopsis

Adsorbent, nitrate, model, carbon, waste water.

Introduction / background (with specific reference to the project, work done earlier, etc)

Nitrate (NO3-) is one of the integral parts in growth of life. It is

essential for the growth of many plant species, including most of those

which are edible, but it becomes a problem if it gets into water in which

it is not required. This leads to major environmental problem and also

as a health hazard. Water contamination by nitrate is a global problem

and nitrate is a widespread contaminant of ground and surface water

worldwide. Numerous sources in the environment contribute to the

total nitrate content of natural water mainly by, agriculture, human and

animal wastes etc.

Removal of nitrate from water has been studied by different

researchers but the methods developed are costly and time consuming.

The data generated during the studies are not properly correlated and

hence are not properly quantified and predicted. The present work is an

effort to develop mathematical model for removal of nitrate from water

using bagasse ash which is a waste from sugar industry and available

easily. The results are compared with that of activated carbon.

Objectives To review literature about effects of nitrate pollution

To study different methods of removal of nitrates from waste water

To optimize a suitable method for study

To experimentally determine the process parameters

To correlates the parameters and develop mathematical models for

prediction of the parameters.

Methodology • Carbon was activated by heating and acid treatment.

• Bagasse was got from local sugar industry which was dried and

powdered. The material was burnt in the absence of air and was

used as adsorbent.

• Magnetic stirrer was used for batch studies and UV-Visible

spectrometer was used for analytical work.

• Total of 8 sets of experiments were conducted to evaluate the

change in nitrate concentration with time.

• For each set 500 ml nitrate solution was used.

• Two adsorbents were used; Activated Charcoal and Bagasse Ash,

4 sets for each were conducted.

• Samples were collected in 10 ml sample bottles.

• Samples were collected every hour in seven hour long

experiment.

• Initial concentration of adsorbent was varied for each set of

experiment.

• Samples were analyzed in a UV Spectrophotometer to get the

nitrate concentration.

Results and Conclusions

The results clearly revealed that both the adsorbents showed

positive trend for removal of nitrate. Maximum percentage removal of

nitrate by adsorption is reported in adsorbent dose of 20 gms.

Percentage adsorption increases with adsorbent load at a decreasing

rate. Initial concentration is seen to have a positive effect on adsorption

rate. The positive effect takes a decreasing rate as the adsorbent load

increases. Overall conclusion is that “bagasse ash” can be a good

adsorbent for removal of nitrate from water, which is cheap and easily

available in local environs.

Scope for future work

This work can be continued for evaluating effect of pH on

adsorption. Effect of stirring rate and temperature also can be

studied. After optimizing all the process parameters a rational

design of an adsorber can be undertaken and field tested for

commercialization.