POTENTIAL FACTORS LIMITING PLANT GROWTH IN SALINE BAUXITE PROCESSING RESIDUE

RESEARCH PROJECT TOPIC ON POTENTIAL FACTORS LIMITING PLANT GROWTH IN SALINE BAUXITE PROCESSING RESIDUE
Abstract
Bauxite is processed in alumina refineries by the Bayer process in which Al-containing minerals are dissolved in hot NaOH. The insoluble solids (bauxite processing residue mud and sand) are washed, sometimes partially neutralized (using CO2 or seawater treatment), and deposited in impoundments surrounding the refinery using either wet (15–30% solids) or dry (50–65% solids) disposal techniques. Revegetation strategies for impoundments include constructing a soil cap over the mud deposit, amending the mud with residue sand and other materials or revegetating the sand fraction that surrounds and covers the mud deposit. Major limitations to plant growth in residues include salinity, sodicity, alkalinity, Al toxicity, and deficiencies of macro- and micronutrients. Physical properties are also problematic since residue mud consolidates to form a solid mass that waterlogs easily or dries to form a massive structure, while sand has a very low water holding capacity. Gypsum amendment reduces pH, displaces Na with Ca and tends to improve porosity. Organic amendments supply nutrients, increase CEC, and improve physical conditions while inorganic fertilizers supply essential nutrients. An integrated approach using all of the previously mentioned amendments as well as saline sodic-tolerant plant species is likely to increase the success of revegetation compared to use of only 1 or 2 techniques. There are very few reports on microbial activity in residue but since it is heat and chemically treated, activity is likely to be initially very low. Organic residue addition provides a substrate for heterotrophic microbes and provide the beginnings for a below-ground living ecosystem. Inoculation of plants with appropriate mycorrhiza and legumes with Rhizobium might also increase plant establishment and growth. These aspects deserve future examination. Although much research has concentrated on the establishment phase of revegetation, little consideration has been given to the subsequent growth and self-propagation of the introduced species, changes in residue properties during weathering and leaching of alkalinity from residue over time. These facets need careful study before definitive statements can be made regarding the sustainability of various revegetation strategies.

 

TABLE OF CONTENT

Title Page———i

Certification——–ii

Dedication———iii

Acknowledgement——-iv

Abstract ———vi

Table of Content——–vii

Chapter One

1.0 Introduction ——-1

1.1 Statement of Problem——4

1.2 Purpose of the Study——5

1.3 Significance of Study——8

1.4 Limitation——–9

1.5 Scope of Study——-11

Chapter Two

2.0 Review of Related Literature —-12

2.6 Summary of Literature Review—- 19

Chapter Three

3.0 Research Methodology and Procedure—22

3.1 Population ——–22

3.2 Sample and Sampling Technique—-22

3.3 Validation of the Instrument —-23

3.4 Reliability of the Instrument —–23

3.5 Data Analysis——-23

Chapter Four

4.0 Presentation and Discussion of Result—24

4.1 Analysis and interpretaion of Data—25

4.2 Discussion of Results——38

Chapter Five

5.0 Summary, Conclusion and Recommendation  –40

5.1 Summary——–40

5.2 Conclusion——–41

5.3 Recommendation——42

References ———45

Appendix 1——–47

Appendix ———50

About Writer2

Check Also

MICROBES IN ACID SOIL

RESEARCH PROJECT TOPIC ON MICROBES IN ACID SOIL TABLE OF CONTENT Title Page———i Certification——–ii Dedication———iii Acknowledgement——-iv …

MICROBIAL BIOMASS IN UPLAND SOIL AND RHIZOSPHERE

RESEARCH PROJECT TOPIC ON MICROBIAL BIOMASS IN UPLAND SOIL AND RHIZOSPHERE TABLE OF CONTENT Title Page———i …

ECOLOGY, PHYSIOLOGY AND BIOCHEMISTRY OF PLANT SYMBIOTIC MICRO-ORGANISMS

RESEARCH PROJECT TOPIC ON ECOLOGY, PHYSIOLOGY AND BIOCHEMISTRY OF PLANT SYMBIOTIC MICRO-ORGANISMS TABLE OF CONTENT Title …

CYCLING OF BIO-ELEMENTS IN SOIL ECOSYSTEMS

RESEARCH PROJECT TOPIC ON CYCLING OF BIO-ELEMENTS IN SOIL ECOSYSTEMS TABLE OF CONTENT Title Page———i Certification——–ii …

ORGANIC MATTER DECOMPOSITION, GREENHOUSE GASES, MICROBIAL BIOMASS IN SOIL AND COMPOST

RESEARCH PROJECT TOPIC ON ORGANIC MATTER DECOMPOSITION, GREENHOUSE GASES, MICROBIAL BIOMASS IN SOIL AND COMPOST …

REMEDIATION AND CONTROL OF REGIONAL AND GLOBAL ENVIRONMENTS BY SOIL MICRO-ORGANISMS

RESEARCH PROJECT TOPIC ON REMEDIATION AND CONTROL OF REGIONAL AND GLOBAL ENVIRONMENTS BY SOIL MICRO-ORGANISMS …

Leave a Reply

Your email address will not be published. Required fields are marked *