Therefore, in this thesis work, rotary drum compost of water hyacinth was used as a source for the isolation of microbes. The bacterial diversity in the rotary drum composting of water hyacinth was analyzed by culture-dependent and culture-independent techniques.
List of Symbols
List of Abbreviations
Sooner or later we will have to admit that the Earth also has the right to live without pollution. What humanity needs to know is that humans cannot live without mother earth, but the planet can live without humans.
Introduction
- Overview
- Hypothesis
- Objectives
- Need of the Study
- Scope of the Thesis
- Thesis Organization
Microorganisms and heavy metals are naturally present in the composting environment, aerobic degradation of organic waste is due to the metabolic activities of microorganisms (Ryckeboer et al., 2003; Anastasi et al., 2005). The efficiency of the biosorption method depends on the type of metal ion being investigated to the type of biosorbent (Tunali et al., 2006).
Literature Review
Water Hyacinth
Since water hyacinth can absorb excess nutrients for its rapid growth, it has been used for wastewater treatment (Moran, 2006). Water hyacinth (Figure 2.1) has an ability to grow in water contaminated with heavy metals due to its ability to accumulate metal ions, which has attracted attention for its utilization in phytoremediation for wastewater treatment (Malik, 2007).
Composting
Composting and vermicomposting of water hyacinth is a beneficial alternative treatment, as are methods of utilizing water hyacinth (Gajalakshmi et al., 2001; Gupta et al., 2007; Singh and Kalamdhad, 2013a,b).
Microbiology of Composting
- Bacteria
- Actinomycetes
- Fungi
In the mesophilic and thermophilic stages of composting, the bacterial species Bacillus badius, Bacillus pumilus, Bacillus sphaericus and Bacillus thuringiensis dominate the process (Ryckeboer et al., 2003). Consequently, bacteria play a major role in the initial decomposition and temperature rise during the composting process (Ryckeboer et al., 2003).
Metal-Microbe Interactions
- Mechanisms of Metal-Microbe Interaction
The interaction of living cells with heavy metals generally incorporates the intercellular accumulation as well as surface (Ledin, 2000). b) Metabolism-independent mechanism: This is a surface phenomenon involving interaction between the dead cells and the heavy metals on the cell surface. Mechanisms of biosorption have been investigated and reported to be adsorption, ion exchange, complexation, precipitation and crystallization (Garnham et al., 1992; . Barakat, 2011).
Isolation of Microorganisms from Waste Sources
- Industrial Waste and Wastewater
- Soil
- Plant Roots
- Compost
Thus, these isolates were characterized for their assessment of heavy metal removal from industrial wastewater (Congeevaram et al., 2007). A higher biosorption capacity was observed in a fed-batch system than in a batch system (Çolak et al., 2011).
Adsorption Study of the Bacterial Isolates
These bacteria are present in the metal-laden state of compost, but they break down organic matter. Mostly Pb, Cu, Zn, Cr and Ni were part of research for metal removal by biomass.
Lead and Cadmium in Environment
- Causes and Effects of Lead (Pb(II)) Contamination
- Causes and effects of Cadmium (Cd(II)) Contamination
Routes of cadmium exposure to the environment include air, water, soil, food, and contaminated consumer products. Drinking water: Contamination of drinking water due to the presence of cadmium in solders containing cadmium, water coolers, taps and water heaters (WHO, 2011).
Techniques Adopted for Removal of Heavy Metals
In addition, a special ion exchange resin is required for the heavy metal ion, which increases the operational cost of the process. At liquid-solid interfaces, adsorption occurs in three types, such as (a) physical adsorption due to vander-waals interaction, (b) chemical adsorption due to the formation of a chemical bond between the adsorbate and adsorption sites (c) exchange adsorption, due to the electrical attraction of the adsorbate molecule on adsorbent (Kumar et al., 2008).
Future Perspectives
Concluding Remarks
Materials and Methods
Experimental Design
PHASE I: Microbial Population, Stability and Maturity Analysis of Rotary Drum Composting of Water Hyacinth
- The Compost Material
- Feedstock Preparation
- Rotary Drum Composting
- Sampling and Analysis
- Physico-chemical Analysis
- Biological Analysis
This sample was prepared by taking representative samples at 9 different points, mainly from the center section and end terminals of the pilot-scale rotary drum composter, after rotation of the drum, to ensure a homogenized sample. The electrical conductivity, EC of the filtered sample was measured with a conductivity meter and expressed as dS/m.
CO 2 evolution by Soda-Lime method (Kalamdhad et al., 2008)
- Heavy metals analysis
- Microbial Analysis
- PHASE II: Microbial Studies on the Best Trial of Water Hyacinth Compost
- Microbial Succession (DNA) From Best Trial
- Culture Dependent Bacterial Identification
- Culture Independent Bacterial Identification
- PHASE III: Biosorption of Lead and Cadmium using Bacillus badius AK Strain Isolated from Compost of Water Hyacinth
- Trace Metal Pb(II) Analysis of Water Hyacinth Compost
- Selection of Microbe for Metal Removal Study
- Metal Removal Study by Living (Non-Pretreated) Bacterial Biomass .1 Effect of Heavy Metal on Bacterial Growth.1Effect of Heavy Metal on Bacterial Growth
- Metal Removal Study by Dried (Pretreated) Bacterial Biomass
- Batch biosorption study of Pb(II) and Cd(II)
- Adsorption Kinetics
- Adsorption Isotherms
- Temperature and Thermodynamics Study
- Adsorption Mechanism
- Desorption, Recovery and Reuse
- Initial Characterisation of Biomass
- Spectroscopic Analysis
- Actual Water Biosorption Experiments
- Column Performance
- Statistical Analysis
- Instruments Used
Modeling of pseudo-first order kinetics was done using the method of least squares or the Fujimoto method as described in Wastewater Engineering (Metcalf et al., 2003). The least squares method involves fitting a curve through a series of data points, so the sum of the squares of the residuals (the difference between the observed value and the value of the fitted curve) must be a minimum. To find out the characteristics of the biosorbent, several spectroscopic analyzes were performed on the sample before and after biosorption. To find out the characteristics of the biosorbent, several analyzes were performed on the sample before and after biosorption.
To reveal the chemical characteristics and functional groups of the biosorbent before and after biosorption, it was done with FTIR spectroscopy.
Rotary Drum Composting and Microbiology of Water Hyacinth Compost
PHASE I: Microbial Population, Stability and Maturity Analysis of Rotary Drum Composting of Water Hyacinth
- Initial characterization of waste materials
- Physio-chemical analysis of compost
- Biochemical Parameters
- Analysis of Microbial community
- Conclusion
Water hyacinth obtains its nutrients directly from water and is used in wastewater treatment plants (Wilson et al., 2006). The successful application of rotary drum composting of water hyacinth has been carried out using cow dung and sawdust (Dhal et al., 2012). OUR will be observed high because the microbial population will feed on the raw material available in the compost sample (Iannotti et al., 1993).
However, the concentration of all total metals decreased for MSW compost (Castaldi et al., 2006).
Phase II: Microbial Studies on the Best Trial of Water Hyacinth Compost .1 Microbial Succession (DNA) from Best Trial
- Taxonomic hits distribution
- Isolation and Identification of Bacteria During Rotary Drum Composting of Water HyacinthWater Hyacinth
Cow dung is the source of the spread of these microorganisms in compost (Yamamoto et al., 2011; Neher et al., 2013). The higher temperatures of natural compost are a consequence of decomposition of Flavobacteria-exerting composting process (Liu et al., 2011). Bacteria belonging to the Alphaproteobacteria have been reported during curing as well as in the uncured compost (Danon et al., 2008).
Distance matrix was generated using RDP database and the phylogenetic tree was constructed using MEGA 5 (Tamura et al., 2013).
Conclusion
Biosorption Studies of Pb(II) and Cd(II) With Live and Dried Biomass of Bacillus badius AK
Biosorption of Pb(II) by Live Cells (Non-pretreated) of Bacillus badius AK Strain Isolated From Water Hyacinth Compost
- Batch Biosorption Studies
- Conclusion
Biosorption studies of Pb(II) and Cd(II) by living and dried biomass of Bacillus badius AK. The potential use of Bacillus badiusAK as a biosorbent for Pb(II) removal has been studied in detail. Biosorption of Pb(II) by living (unpretreated) cells of Bacillus badiusAK strain isolated from water hyacinth compost.
The optimal pH for Pb(II) removal by Bacillus thuringiensis was reported as 6 (Oves et al., 2013), the amount of Pb(II) taken up by B.
PHASE III: Biosorption of Pb(II) by Dried Biomass of Bacillus badius AK Strain Isolated From Water Hyacinth CompostIsolated From Water Hyacinth Compost
- Initial Characterization of the Pretreated (dried) Biomass
- Batch Biosorption Studies
The relationship between the metal concentration and the amount of biomass concentration was found to be an important factor in the biosorption of the metals (Deng et al., 2007). The specific metal uptake was observed to increase with the increase in initial metal concentration (Figure 5.14b). Similar improvement in metal uptake was observed during the biosorption of Pb(II), Cd(II) and Zn(II) by Citrobacterstrain MCMB-181, the observed improvement in metal sorption could be due to the increase in the electrostatic interaction involving lower affinity sites for metal ions (Puranik and Paknikar, 1999).
The XRD pattern of Bacillus badius AK before and after Pb(II) biosorption is shown in Figure 5.17.
Desorbents
Time 0.5 (min 0.5 )
The slope of the linear part of the graph was defined as a rate parameter that indicates the rate of adsorption in the region where intraparticle diffusion is the limiting rate. The value of the cross section of the graph, on the other hand, indicates the extent of the boundary layer effect, i.e. the intraparticle diffusion parameter (kd) was calculated from the slopes, and the intercept values are summarized in Table 5.11.
A high value of the cross section indicates that the adsorption process occurred mostly due to surface adsorption and very little adsorption due to intraparticle diffusion.
Time (min)
Effect of Dried Biomass of Bacillus badius AK on Actual Water Sample
It was observed that Bacillus badiusAK was effective in removing Pb(II) from the water sample. The biomass dosage of 2 g/l was optimized for the removal of Pb(II) at an initial concentration of 100 mg/l for 2.5 hours. Initial concentration of Pb(II) in mg/l. b) Change in percent removal of Pb(II) from the actual water sample.
This study shows that a biomass dose of 2 g/L is optimal for the removal of Pb(II) from the aqueous solution.
Conclusion
PHASE III: Biosorption of Cd(II) by Dried Biomass of Bacillus badius AK Strain Isolated from Water Hyacinth Compost
- Batch Biosorption Studies
- Conclusion
The effect of initial cadmium concentration on the biosorption capacity of dried biomass of Bacillus badius AK was investigated in the range of 50-200 mg/L Cd(II) solution. Similarly, metal uptake enhancement was observed during biosorption of Cd(II), Pb(II) and Zn(II) by the bacterial strain CitrobacterStrain MCMB-181 (Puranik and Paknikar, 1999). The current study indicated that the dried biomass of Bacillus badiusAK can be used effectively as a biosorbent for the removal of Cd(II) from aqueous solutions in batch system.
The results indicated that the bacterium Bacillus badiusAK was effective in removing Cd(II) which could be beneficial in the large-scale treatment of the contaminated wastewater.
PHASE IV: Biosorption Studies of Pb(II) Dead Biomass in Column Mode Opera- tion
- Bed Depth Service Time (BDST) Model
In addition, the breakthrough capacity of the biosorbent is higher in case of column process compared to the batch process. In continuous mode, the residence time of metal ions in contact with the adsorbent was short compared to the batch system. Whereas the batch system ensured the longer duration of exposure time for the metal ions in the solution.
Although a low flow continuous system is impractical for maintenance, the absorption capacity in the batch system is also above the column mode.
Conclusion
Conclusions and Recommendations
Conclusions
The loading rate test proved that the optimal dosage for the biomass is 2 g/l. The biosorption followed pseudo second-order kinetics, with the Langmuir isotherm fitting better than the Fruendlich isotherm, indicating the possibility of monolayer adsorption. The FTIR and EDX analysis data indicated the presence of several functional groups on the surface of the biomass and their participation in the biosorption process. The recovery of biosorbent after bioabsorption was 39% of the initial value and the recovery after desorption was 68.2%.
The column mode operation gave a spectacle of the application of biosorbent in the industrial process.
Future Recommendations
Other biomass pretreatment technologies can modify the biomass in favor of its use at an industrial level.
Bibliography
Enhancement of selective heavy metal removal in cyanobacteria by NaOH treatment.” Journal of bioscience and bioengineering. Biosorption of heavy metals by lyophilized Pseudomonas stutzeri cells.” World Journal of Microbiology and Biotechnology. Azadirachta indica (Neem) leaf powder as a biosorbent for the removal of Cd (II) from aqueous medium.” Journal of hazardous materials.
The removal of heavy metals from aqueous solutions by sawdust adsorption ˚Uremoval of copper.” Journal of Hazardous Materials.
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