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Reduction of organic and inorganic pollutant from waste water by algae

100%

Sahu O.

International Letters of Natural Sciences

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2014

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tom 08

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nr 1

Recently, algae have become significant organisms for biological purification of wastewater since they are able to accumulate plant nutrients, heavy metals, pesticides, organic and inorganic toxic substances and radioactive matters in their cells/bodies. Biological wastewater treatment systems with micro algae have particularly gained importance in last 50 years and it is now widely accepted that algal wastewater treatment systems are as effective as conventional treatment systems. These specific features have made algal wastewaters treatment systems an significant low-cost alternatives to complex expensive treatment systems particularly for purification of municipal wastewaters. By this method 70 % of biological oxygen demand, 66 % of chemical oxygen demand, 71 % total nitrogen, 67 % of phosphorus, 54 % volatile solid and 51 % of dissolved solid was reduced.

2

Reduction of heavy metals from waste water by wetland

100%

Sahu O.

International Letters of Natural Sciences

|

2014

|

tom 07

Constructed wetlands are artificial wastewater treatment systems consisting of shallow ponds or channels which have been planted with aquatic plants, and which rely upon natural microbial, biological, physical and chemical processes to treat wastewater. They typically have impervious clay or synthetic liners, and engineered structures to control the flow direction, liquid detention time and water level. Depending on the type of system, they may or may not contain an inert porous media such as rock, gravel or sand. Constructed wetlands have been used to treat a variety of wastewaters including urban runoff; municipal, industrial, agricultural and acid mine drainage. In this regard’s an attempted has been made to reduce the heavy metal present in waste water.

3

Removal of chromium by biosorption method (chitosan)

63%

Abatneh Y., Sahu O.

International Letters of Natural Sciences

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2014

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tom 03

Discharge of metal containing effluents into water has been a cause of major concern. Traditional treatment methods are proving to be ineffective and expensive. Chitosan was studied as a potential biosorbent due to its positive charge and relatively low cost. The study involves evaluating the metal binding performance of chitosan in a Polymer Enhanced Diafiltration (PEDF) system which uses an ultra filtration membrane to retain the chitosan which, in turn, binds the metal, thereby preventing passage into the permeate stream. Conditions for binding such as pH, concentration of polymer and chromium were studied. Optimal performance was obtained when the system was operated at pH values lower than the pKa of chitosan i.e. 6.3. Using 6 g/L chitosan at pH 4.0, chromium concentration was reduced to less than 1mg/L from a feed concentration of 20 mg/L. Equilibrium dialysis experiments were done to study the kinetics of binding and the uptake of metal per gram of polymer. Rheological measurements demonstrated that in the presence of 1-100 mM chromate, chitosan was found to be slightly shear thickening at low concentrations such as 4 g/L and 6 g/L whereas it was slightly shear thinning at higher concentrations like 12 g/L and 20 g/L This suggests that neutralization of chromium anions is due to the interaction of multiple chitosan molecules. This result is consistent with the relatively stiff nature of the polysaccharide. Overall, this study suggests that some modification of the native polymer would be required to improve uptake and make it an industrially workable process.

4

Minimization of phenol by natural occurrence adsorbent

63%

Joshi J., Sahu O.

International Letters of Natural Sciences

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2014

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tom 11

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nr 1

Phenol and chlorophenols are long-lived pollutants frequently found in industrial effluents. Phenols are widely used for the commercial production of a wide variety of resins including phenolic resins, epoxy resins and adhesives, and polyamide for various applications. Adsorption process has been proven one of the best water treatment technologies around the world and the removal of diverse types of pollutants from water. However, widespread use of commercial adsorbent is sometimes restricted due to its higher costs. Attempts have been made to develop inexpensive adsorbents utilizing for the reduction of phenol from water. Four types of adsorbent clay, algae, moringa oleifera and rice husk has been used. Among all rice husk shown 97 % of phenol adsorption at 1mm particle size, pH 4, 3 g/l dosing and 150min contact time.

5

Extraction of eucalyptus oil as reduction of bacterial growth in drinking water

63%

Dubey A. K., Sahu O.

International Letters of Natural Sciences

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2014

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tom 11

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nr 2

Drinking water is acting as life line for living thing on the Earth, without that no life. Due to global industrialization availability of pure water is one of the major issues. The effluent are directly or indirectly discharge through the river stream, which affect the ground as well as sea water and climatically cycle water reach to us. In that condition medicine are required for quire purpose. In the world so many plants and herbs are available which are used as antimicrobial and sources of medicines. Today the large number of drugs in use is derived from plants. The important advantages for therapeutic uses of medicinal plants in various ailments are their safety besides being economical, effective and easy availability. In this regard’s herb plant Eucalyptus extracted oil is used as antibacterial agent to treat the drinking water.

6

Natural treatment of woolen processing industry wastewater

63%

Qurashi S., Sahu O.

International Letters of Natural Sciences

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2014

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tom 05

Wastewater treatment is becoming ever more critical due to diminishing water resources, increasing wastewater disposal costs, and stricter discharge regulations that have lowered permissible contaminant levels in waste streams. The ultimate goal of wastewater management is the protection of the environment in a manner commensurate with public health and socio-economic concerns. The aim of our study is to use natural occurring plant (Pistia stratiotes) to reduce the chemical oxygen demand and color from the industrial waste water. It was found that 120 mg/l of Chemical oxygen demand and 85 mg/l of color reduction was observed with Pistia stratiotes.

7

Low cost alternative fuel from biomass

51%

Zeru D., Gebregergis H., Tilahun M., Sahu O.

International Letters of Natural Sciences

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2015

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tom 05

A major challenge for next decades is development of competitive renewable energy sources, highly needed to compensate fossil fuels reserves and reduce greenhouse gas emissions. Among different possibilities, which are currently under investigation, there is the exploitation of unicellular algae for production of biofuels and biodiesel in particular. Microalgae have the ability of accumulating large amount of lipids within their cells which can be exploited as feedstock for the production of biodiesel. The lipid content of different species of microalgae can range from 30%-70% of their dry weight. In this project a microalgae with lipid content of 60.095% was used. This means that 26gms of oil was obtained from 42gms of microalgae sample from which 17.624gm of biodiesel (FAME) was found at the end of trans-esterification. Algae biofuels avoid some of the previous drawbacks associated with crop-based biofuels as the algae do not compete with food crops. The favorable growing conditions found in many developing countries has led to a great deal of speculation about their potentials for reducing oil imports, stimulating rural economies, and even tackling hunger and poverty. Strong research efforts are however still needed to fulfill this potential and optimize cultivation systems and biomass harvesting.

8

A comparative study on the cleaner production options for fishery wastes around Lake Tana

51%

Getahun E., Wagaw K., Sahu O.

International Letters of Natural Sciences

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2016

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tom 56

Around Lake Tana, there are different types of fish processing cooperatives. These cooperatives simply dump the fish wastes (offal) to the Lake Tana which results environmental pollution for the marine ecosystems. In this study three cleaner production options such as biodiesel, biogas and animal feeding were investigated experimentally for the utilization of fishery wastes around Lake Tana. The study showed that fish species (labeobarbus, tilapia and catfish) wastes have oil yield of 28.65%, 16.35% and 5.63 % and free fatty acid content of 10.5%, 7.5% and 6.03% respectively. In the treatment of the oil, only 3.5% of sulfuric acid was consumed to lower the FFA to the required level (2.5%). In the biodiesel experiment, 6:1 ration of methanol to oil and 1hr of reaction retention time were found to be the optimum operating parameters. The yield of biogas was 0.016ml /gram of fish waste. Nutritional composition of fish wastes were 33.4% protein, 0.007% fiber, 1.26% ash, 44% moisture and 21.367% carbohydrate. The study concluded that biodiesel is the possible cleaner production option among the other for the utilization of fishery wastes around Lake Tana.

Ograniczanie wyników

8 International Letters of Natural Sciences

8 Sahu O.

1 Abatneh Y.

1 Dubey A. K.

1 Gebregergis H.

1 Getahun E.

1 Joshi J.

1 Qurashi S.

1 Tilahun M.

1 Wagaw K.

1 Zeru D.

1 2016

1 2015

6 2014

Reduction of organic and inorganic pollutant from waste water by algae

Reduction of heavy metals from waste water by wetland

Removal of chromium by biosorption method (chitosan)

Minimization of phenol by natural occurrence adsorbent

Extraction of eucalyptus oil as reduction of bacterial growth in drinking water

Natural treatment of woolen processing industry wastewater

Low cost alternative fuel from biomass

A comparative study on the cleaner production options for fishery wastes around Lake Tana