Membrane Bioreactor

Guide

Dr. Arun M. Isloor

Members

• Amogha V Somayaji

Project Aim

We studied about various types of membranes and it's applications in water purification .We learnt about Membrane Synthesis and about the various additives used in the process. Collected grey water samples and purified it using Membrane Bioreactor. The characterisation of the samples was done to study how well the membrane has performed. Characterisation included the following tests-

• COD-Chemical Oxygen Demand
• BOD-Biochemical Oxygen Demand
• TSS-Total Suspended Solids
• TDS-Total Dissolved Solids

Introduction

Membrane processes have met a large expansion in the purification of water in the last few decades. The importance of membrane technology as a green tool for separation and purification of water has gained new found importance by the employment of new versatile polymeric membranes. Membranes have the ability to allow a selective chemical species in a mixture to pass through, while preventing other species from doing so.

The attractiveness of membrane related processes stem from benefits such as no phase change during separation, low energy expenditure, conceptual simplicity, reduced operating outlays, easy integration and scale up. The capability of the membranes to aid selective permeation is what gives them an important place in this domain. The hydrophilicity of the membranes and their porous structure play an important role in the membrane separation process.

A suitable porous membrane must have high permeability, good hydrophilicity and excellent chemical resistance towards the feed solution. Materials with oxidative, thermal and hydrolytic stability with good flexibility, resistance to extremes of pH and good mechanical and film forming properties are preferred.

Despite these benefits, the main disadvantage of most of the polymer is their hydrophobic nature which makes it poor in permeation and antifouling properties. Hydrophilicity enhancement has been achieved by blending the casting solutions of the membranes with several hydrophilic organic or inorganic additives. After blending, tests like Water uptake and contact angle measurements, FRR % measurement, ATR-FTIR analysis, Morphology of membranes are performed.

Membrane Bioreactor

Membrane bioreactor (MBR) is the combination of a membrane process like microfiltration or ultrafiltration with a biological wastewater treatment process, the activated sludge process. Four samples from our college namely grey water from Block 4 mess (sample1), water polluted with cow dung (sample 2), grey water from Block 3 mess (Smple3), water sample from STP of NITK (Sample 4) were collected and it was filtered in MBR.

Filtration

For each of the sample, aeration was done for 8 hours and later filtration was done using membrane. Grey water was forced to pass through the membrane using a pump. Purified water was collected and was taken to lab for characterization.

Characterization

COD: It is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. COD helps in quantifying the amount of oxidizable pollutants found wastewater. COD gives information about the water quality by providing a metric to determine the effect an effluent will have on the receiving body.

BOD: It is the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

TDS: It is a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular (colloidal sol) suspended form. Although TDS is not generally considered a primary pollutant, it is used as an indication of aesthetic characteristics of drinking water and as an aggregate indicator of the presence of a broad array of chemical contaminants.

TSS: It is the dry-weight of suspended particles that are not dissolved, in a sample of water that can be trapped by a filter that is analyzed using a filtration apparatus.

Result