PRESENTATION TOPIC CONTAMINATED LAND AND BIOREMEDIATION PRESENTED BY: FAIZA SADDIQUE ROLL NO: 117119 DEPARTMENT: BS BI 6TH

CONTAMINATED LAND Land that is contaminated contains substances in or under the land that are actually or potentially hazardous to health or the environment. Areas with a long history of industrial production will have many sites which may be affected by their former uses such as mining, industry, chemical and oil spills and waste disposal.

These sites are known as brownfield land. Contamination can also occur naturally as a result of the geology of the area, or through agricultural use. Land contamination may impact on health or the environment .

Risks to humans posed by contaminants on land Increased levels of illness have not been observed in people living on contaminated land However ill effects, which may be undetectable using current epidemiological and analytical methods, may occur Impact from contaminated soil can be difficult to separate from other types of pollution Possible health effects of the contaminants are difficult to establish because there are many confounding factors

MOST COMMON CONTAMINANTS

BIOREMEDIATION A treatment process that uses microorganisms (yeast, fungi, or bacteria) to break down, or degrade, hazardous substances into less toxic or nontoxic substances (carbon dioxide and water)

CONDITIONS THAT FAVOR BIOREMEDIATION Temperature favorable for organisms Water available (near field capacity) Nutrients (N, P, K) in adequate supply Material added is similar to naturally occurring organic material Oxygen in sufficient quantity

TYPES OF BIOREMEDIATIONS The two main types of bioremediation are: In situ bioremediation Ex situ bioremediation

IN SITU BIOREMEDIATION In situ bioremediation is when the contaminatant site is cleaned up exactly where it occurred It is the most commonly used type of bioremediation b/c it is the cheapest and most efficient, so it’s generly better to use There are two main types of In situ bioremediation Intrinsic and Accerelated bioremediation

INTRINSIC BIOREMEDIATION Intrincis bioremediation is uses microrganism already present in the environment to biodegrade harmful contaminant There is no human intervention involved in this type, and since it is the cheapest means of bioremediaton available, it is the most commomnlt used When intrinsic bioremediation is not feasible , scientists turn next to accerelated bioremediation

ACCERELATED BIOREMEDIATION In accerelated bioremediation, either subtrate or nutrients are added to the environment to help break down the toxic spill by making the microorganisms grow more rapidly Usually microorganisms are indigenous, but occasionallymicroorganisms that are very efficient at degrading a certain cantaminant are additionally added Main goal of In situ treatment is to manage and manipulate the subsurface environment to optimize microbial degradation

IN SITU BIOREMEDIATION Land treatments Bioventing: is the most common in situ treatments and involves supplying of air and nutrients through wells of contaminanted soil to stimulate the indigenous bacteria

EX SITU BIOREMEDIATION Which is when contaminated land are taken out of the area to be cleaned up by the organisms This type of bioremediation is generally used only when the site is threatenedfor some reason, usually by the spill that needs to be cleaned up Ex situ bioremediation is only used when necessary b/c it’s expensive and damaging to the area, since contaminated land is physically removed

EX SITU BIOREMEDIATION LANDFORMING is a simple tecnique in which contaminated soil is excavated and spread over a prepared bed and periodically tilled until pollutants are degraded COMPOSTING is a tecnique that involves combining contaminated soil with non-hazardous organic compounds such as agricultural wastes The presence of these organic materials supports the development of a rich microbial population and elevated temperature charactristic of composting

BIOREACTORS: Slurry reactors are used for ex situ treatment of contaminated soil and water pumped up from a contaminated plumes.

ADVANTAGES OF BIOREMEDIATION Bioremediation is a natural process and is therefore perceived by public Bioremediation is useful for the complete destruction of a wide variety of contaminants Bioremediation can prove less expensive than other tecnologies that are used for cleanup a hazardous waste

DISADVANTAGES OF BIOREMEDIATION Bioremediation is limited to those compounds that are biodegradable. Not all compounds are susceptible to rapid and complete degradation There are some concerns that the product of biodegradation may b more toxic than the parent compound Bioremediation often takes longer than other treatment options