Copper Extraction
Open Book Paper 2002 Copper Extraction Biohydrometallurgy is applied for copper extraction. Low-grade ore and leftovers from conventional mining methods are pilled up on a base of impermeable ground. Then the bacteria Thiobacillus ferro-oxidans and Thiobacillus thio-oxidans are sprayed onto the pile in an acidic leeching solution. The bacteria thrive in this environment and don't need any organic material to live on. All they need is a supply of Fe²+ or S²- and oxygen and carbon dioxide. The overall result is that the insoluble sulphide minerals are converted into a solution of the ions present. As the base is impermeable, the solution containing the copper ions is easily drained off and another solvent removes the copper. T. Ferro-oxidans then renew the leeching solution ready to be used again. The copper is then formed into sheets using an "electro-winning" process. This is basically electrolysis and is a costly process. The chemical process involved in this extraction is "Ligand exchange solvent extraction" where only the Cu²+ ions are extracted. A Ligand is a compound with a lone pair allowing bonding to the metal to form a Complex. The compound that is suitable for Ligand of copper is dissolved in an organic solvent like kerosene, which is immiscible (will not mix) in water. When mixed with water the following reaction takes place: Cu²+(aq) + 2LH(organic)
Biology- enzyme coursework
Biology Coursework: Enzymes By Kerry Douglas Investigate the Effect of Temperature on the Action of the Enzyme Amylase This expirment was set up to find the effect of different tempetures on the enzyme: Amylase. We had two different variables: Independent and Dependent. Independent Variable: The factor to be changed in the investigation. In the this practical it was the temperature. Using water baths we had a range of six temperatures - 25°C to 50°C with 5°C intervals between each. Dependent Variable: The factor to be measured during the investigation. In this practical it was the time taken for starch to break down. We did this using a stop-clock and we were able to calculate the rate of reaction. Rate of reaction= 1/time taken (s-1) Controlled Variables: These are the factors which must be kept constant to create a fair test. In our investigation we used the: . Same enzymes 2. Same substrate 3. Same volume of enzyme and substrate 4. Same time intverals for measurment 5. Same volume of Iodine 6. Same concentration of Amylase Hypothesis : In this invesigation I predict that as the temperature increases, the rate of reaction will increase, but this will only occur up to a certain point and temperature or the enzyme will become denatured- causing the rate to decrease drastically. I believe this because most chemical reaction happens faster when the
To see how Blowfly larvae (Calliphora) react to light.
THE EFFECT OF LIGHT ON BLOWFLY LARVAE (CALLIPHORA) AIM To see how Blowfly larvae (Calliphora) react to light. BACKGROUND KNOWLEDGE The Blowfly is any member of the insect family Calliphoridae (order Diptera). They are metallic blue, green, or black in colour and are noisy in flight, producing a distinctive buzzing sound. The blowflies are on average 8-10 mm in length, slightly larger than the more common housefly larvae. Among the blowfly family, the more important members are the screwworm, bluebottle fly (Calliphora), green bottle fly, and cluster fly. Adult blowflies feed on a variety of materials, but the larvae of most species are scavengers that live on carrion or dung. The adults lay their eggs on the carcasses of dead animals, the eggs hatching in less than a day and the larvae burrow straight down into the food source, and feeding on the decaying flesh. The larvae of some species also sometimes infest open wounds of living animals. Several days before going into the pupal state, the blowfly larvae tend to move away from light source, often ending up under carpets or behind panelling. After 8-10 days the pupae wriggle their way into the light and the adult flies emerge. They are immediately able to fly off, mate and start laying eggs. Stereotyped responses are the unlearned behavioural reactions of an organism to some environmental stimulus. It is an adaptive
To investigate whether pollution affects the diversity of aquatic invertebrate species.
Dyke Dipping Aim: To investigate whether pollution affects the diversity of aquatic invertebrate species. Equipment: Wash tub, Smaller Margerine Tub Plastic Spoon, Milk Container, Net, Species Analysis Chart. The wash tub has the perfect surface area to count the animals without imprisoning them, the smaller margerine tub allows for the animals to be more carefully analysed so that their species can be more easily determined, the spoons are the perfect size to remove the animals individually, using the milk container is much easier than filling up the wash tub with water because if we had to fill the tub itself up, we could fall in, and the net is designed with a tight enough mesh to capture the very miniature creatures, wihout having to bend down and scoop them out ourselves Method: Fill the milk container with water from the first, unpolluted dyke, and tip the contents into the wash tub. Repeat this two or three times, in order to provide sufficient depth to support the creatures from the dyke. Stand on secure ground near to the dyke so as to not slip in, and sweep the net in the dyke and empty the net into the wash tub with the dyke water in it. Tip the net upside down to do this, but make sure you dip the botton of the net into the water aswell, because some very small creatures could be caught in the net's mesh. Use the plastic spoons to remove the specimens
The elephant population in Pilanesberg, South Africa.
What should be done with a herd of marauding elephants? This was the problem recently confronting officials at Pilanesberg National Park in South Africa. A number of orphaned male elephants had been transported to the park in order to provide them with a safe and nurturing environment. However, this step to protect the elephant population soon threatened another endangered species. The young elephants had entered musth, like puberty, a state of heightened hormonal activity and increased aggression. The elephants went on a killing spree, slaying almost 40 rhinoceros-including incredibly rare black rhinos. The park officials did not want to kill the young elephants, but they could not afford to have any more rhinos slaughtered. Oddly enough, the solution to this disastrous situation was to bring more male elephants into the park. This time, however, they were full-grown bull elephants. In almost no time at all, a previously impossible hierarchy had been established, and the orphaned males fell right into place. As of yet, no rhino killings have been reported. The Pilanesberg story has a positive ending, but many elephants are not as lucky. The elephant population in Africa has been drastically reduced by loss of habitat to cultivation and urbanization, and many have been orphaned by poachers cashing in on the ivory trade. Some biologists believe that if elephant numbers
Distribution of Species in a field
The Distribution of Daisies in the School Field The results of our research showed that the most daisies (common Bellis Perennis) grew in the middle-trampled area (48 daisy average), as opposed to our (my group's) original predictions that they would grow in the least trampled area (36.8 daisy average). We were however correct when we predicted that there would be least daisies in the most trampled area (0.4 daisy average). I have concluded that there were most daisies in the area in which there had been a medium level of trampling because of three main reasons. Firstly, due to the relatively constant trampling on the ground, the daisies have been forced to adapt to their environment to survive. Therefore they have grown more resistant to trampling and less liable to die or wither from the damage caused by it. They have likely done this in several ways including producing deeper and stronger roots, growing their leaves nearer to the ground and developing faster-growing and thicker stems. They are also shorter (61.4mm average) than the daisies in the least trampled area (65mm average); this is because they are less likely to be caught on shoes and they are stronger as they are less flexible. Secondly, the trampling of the ground churns it up and this causes it to be more aerated. This means that there are more air pockets inside the soil, making it easier for the plant to
Natural Selection
Natural Selection 1. The number of prey decreases whilst the number of predators remains constant however, there might be an increase in the population of the fittest predator even though the total number would not change. In addition to that each predator has different capabilities and those capabilities allow them to survive much better than the other predators, for example the hands were the fittest because they were equipped with the best tools for gathering food, whilst the clothes pegs were the least effective. 2. Predators are predators because they are physically more fit or advantaged than those on who they prey. The predator's phenotypes allow them to survive much better than the prey because they can overpower the prey. However the preys also have their own phenotypic capabilities which enable them to survive by feeding on other organisms, where they become predators momentarily. 3. The variety of predators creates very tough competition amongst the predators in similar regions, and thus the theory of survival of the fittest, the most efficient predator at 'hunting' has a better chance of survival. The forks and pegs definitely would have had a much better chance of survival and a longer lifespan, had the hands not been there; however, the forks would have eventually dominated over the pegs because, as the data shows, the forks were still better predators than
Does Traffic Pollution Cause Asthma?
Introduction In my case study, I aim to research whether there is a correlation between asthma and traffic pollution. I will show this by identifying traffic pollution, asthma and its causes. I will present this through graphs and text which include, how asthma is caused and if traffic pollution has an effect on it or not. I will study a range of articles and arguments whether people believe that traffic pollution is one of the causes of asthma. Page 1 Asthma and the statistics for it in children Page 2 Which gases come out of cars Page 3 Correlation graphs Page 4 Is there a correlation between traffic pollution and asthma Page 5 Reasons why there would be Page 6 Reasons why there wouldn't be Page 7 Conclusion References Asthma Symptoms of asthma occur when a person with asthma comes into contact with something that irritates airways. Airways will then tighten, swell and become narrower. Sticky mucus and phlegm builds up in the airway lining making them even more narrow and irritated. The airways are small tubes that carry air to and from your lungs. This diagram shows a normal air tube and then an inflamed one. STATISTICS FOR ASTHMA IN CHILDREN * In 2005, 27 children (14 and under) died from asthma * 42% of people with asthma say that traffic fumes stop them from walking and shopping in congested areas * One in ten children have asthma and it is
GAS EXCHANGE
Gas Exchange Gas exchange supplies oxygen for cellular respiration and disposes of carbon dioxide: an overview • Gas exchange is the uptake of molecular oxygen (O2) from the environment and the discharge of carbon dioxide (CO2) to the environment. • The source of oxygen, the respiratory medium, is air for terrestrial animals and water for aquatic animals. • The atmosphere is about 21% O2 (by volume). • Dissolved oxygen levels in lakes, oceans, and other bodies of water vary considerably, but they are always much less than an equivalent volume of air. • The part of an animal where gases are exchanged with the environment is the respiratory surface. • Movements of CO2 and O2 across the respiratory surface occurs entirely by diffusion. • The rate of diffusion is proportional to the surface area across which diffusion occurs, and inversely proportional to the square of the distance through which molecules must move. • Therefore, respiratory surfaces tend to be thin and have large areas, maximizing the rate of gas exchange. • In addition, the respiratory surface of terrestrial and aquatic animals are moist to maintain the cell membranes and thus gases must first dissolve in water. • Because the respiratory surface must supply O2 and expel CO2 for the entire body, the structure of a respiratory surface depends mainly on the size of the organism,
Perran sands Investigation - Hypothesis - The Percentage of marram grass decrease as the species diversity increases.
Perran sands Investigation Katie vellenoweth Hypothesis The Percentage of marram grass decrease as the species diversity increases. Method To investigate the species diversity and the percentage of marram grass, we used a belt transect to the collect the data. A belt transect was laid from the beach/dune interface to the dune meadow. Quadrates were laid along on the 000ht side with the left hand bottom corner at the start of each interval along the belt transect. The belt transect was measured every two metres until similarly findings were recorded of each species, of which then we increased the intervals of every 5 metres and finally every 10 metres. The area within each quadrate was examined for different species of which then was recorded. At the same time the percentage of marram grass was recorded from the area within the quadrates. This data was put into a raw data table. Anomalous sets of data were excluded such as paths which were present on the sand dunes, this is because this could influence an error in patterns that may be seen on the graph. Variables Taking the data on the same day, which meant that this was a controlled variable. The time of year is a variable that could have an effect on the species diversity, such as in winter there is more likely to be lower species diversity than in the summer
