Bioremediation of Heavy Metals PPT PDF

BIOSORPTION OF BIOREMEDIATION HEAVY METALS Bioremediation Utilizing the activity of microorganisms naturally present in the soil and water, or selected organisms inoculated into the environment, to biodegrade or detoxify contaminating compounds in situ. Bioremediation – Concept (Contd..) Recent stud...

BIOSORPTION OF BIOREMEDIATION HEAVY METALS Bioremediation Utilizing the activity of microorganisms naturally present in the soil and water, or selected organisms inoculated into the environment, to biodegrade or detoxify contaminating compounds in situ. Bioremediation – Concept (Contd..) Recent studies in molecular biology and ecology offer opportunities for more efficient biological processes to clean-up of polluted water and land areas Bioremediation allows natural processes to clean up harmful chemicals in the environment. Microscopic “bugs” or microbes that live in soil and groundwater like to eat certain harmful chemicals. When microbes completely digest these chemicals, they change them into water and harmless gases such as carbon dioxide. Schematic Bioremediation is an option that offers the possibility to destroy or render harmless various contaminants using natural biological activity. Bacteria Actinomycetes Fungi Actinomycetes Fungi Actinomycetes Bioremediation is a triple-corners process: Solid Inorganic Organic Pollutants Liquid Gas Environments Organisms Soil Microorganisms Water Plants Air Enzymes Bioremediation related topics Environments Organisms Pollutants Bioremediation of metals polluted environment Phytoremediation Bioremediation Enzymes immobilization Biosurfactants Cells immobilization Bioremediation techniques Enzymes separation and identification Stages of a biodegradation study 1- Isolation of the microorganism 2- Purification of the obtained isolates 3- Identification of the microbial isolate 4- Optimization of the biodegradation conditions 5- Determination of the biodegradation efficiency 6- Identification of the biodegradation products. 7- Cell or enzyme immobilization. 8- Enzyme identification. BIOSORPTION OF HEAVY METALS BIOSORPTION ability of biological materials to accumulate heavy metals from wastewater through metabolically mediated or physico-chemical pathways of uptake BIOSORPTION Advantages 1. low cost 2. high efficiency 3. minimization of chemical or biological sludge 4. regeneration of biosorbent 5. Possibility of metal recovery BIOSORPTION Disadvantage 1. early saturation 2. no potential for biologically altering valency state a. Oxidation state of metals MECHANISMS OF BIOSORPTION LIVING CELLS 1. Adsorption of metal to the surface of the cells 2. Penetration of metal ions DEAD CELLS 1. metal binding combinations Pros: Abcence of toxicity limitations, no need for gorwth media, reuse of regenerated biomass Active mode metabolic dependent Passive mode metabolic independent Temperature 20-25 C Characteristics of biomass (biosorbent) Growth, cell wall composition, biosorption pH biomass binding sites and metal solubility FACTORS AFFECTING BIOSORPTION Biomass concentration low cell densities Initial metal ion concentration increases metal uptake Metal affinity pretreatments can make metal binding groups accessible for binding FACTORS AFFECTING BIOSORPTION BIOSORBENTS biomass used accumulate heavy metals Characteristics: 1. readily available 2. cheap 3. in large amounts 4. rapid growth BACTERIAL BIOSORBENTS small size, ubiquitous resistant against a wide range of various environmental factors Bacillus, Pseudomonas, Streptomyces, Escherichia,Micrococcus FUNGAL BIOSORBENTS high percentage of cell wall materials with excellent metal binding properties in large quantities (from industrial wastes) MICROALGAL BIOSORBENTS high sorption capacity readily available low nutrient requirements minimal toxic substance production Involve ion-exchange Na,Mg, Ca, is displaced by heavy metal ions COMMERCIAL APPLICATIONS Bio-Fix biosorbent Spirulina, Algasorb Chlorella vulgaris for waste water treatment AMT-BIOCLAIM Bacillus for waste water treatment metal recovery = desorption BIODEGRADATION OF PLASTICS Plastics https://doi.org/10.1002/jctb.6675 PHOTODEGRADATION THERMAL DEGRADATION OXO-BIODEGRADATION BIODEGRADATION Plastic Degradation Photodegradation absorption of harmful solar radiation 1. UVA and UVB a. Photolysis 2. Visible part of sunlight a. accelerate polymeric degradation 3. Infrared a. thermal oxidation Thermal Degradation via overheating High temp separate and react with polymers 1. physical 2. optical Oxo-biodegradation Photodegradation and oxidation uses time and heat Biodegradation living organisms aerobic CO2 and water anaerobic CO2, CH4, water 10.1007/s10532-021-09954-x 10.1007/s10532-021-09954-x 10.1007/s10532-021-09954-x Factors affecting microbial degradation MICROBE PH TEMPERATURE SUBSTRATE SURFACTANTS https://doi.org/10.1002/jctb.6675