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Water Waste Management
Transcript of Water Waste Management
Management BIOLOGICAL AEROBIC AND ANAEROBIC BY: GROUP 6 Ozonation, Adsorption, Ion Exchange Trickling filtration, Oxidation Ponds and lagoons, Aerobic digestion, Activated sludge treating methods Anaerobic digestion, Anaerobic lagoons Ozone is the triatomic form of oxygen, this is composed of three oxygen atoms. Ozone's chemical symbol is O3. Under normal conditions ozone is unstable and quickly decomposed to the more stable gaseous oxygen, O2. Because ozone is unstable and cannot be stored successfully, it must be generated at the point of application WHAT IS OZONE? Ozonation is a water treatment process that destroys bacteria and other microorganisms through an infusion of ozone, a gas produced by subjecting oxygen molecules to high electrical voltage.
Since ozone is a good disinfectant, ozonation process is more widely used compared to other processes.
OZONATION Ozone has a greater disinfection effectiveness against bacteria and viruses.
Can reduce the concentration of iron, manganese, sulfur by oxidation and reduce or eliminate taste and odor problems.
Organic particles and chemicals will be eliminated through either coagulation or chemical oxidation.
Ozone is unstable, and it will degrade over a time frame ranging from a few seconds to 30 minutes. CHARACTERISTICS OF OZONE Simply put, the goal in ozonation process is to produces ozone generated by passing air through an electrical discharge or spark. The ozone generated will be infused to the contaminated water. Air is passed through the electrical discharge generated by the electrodes.
The ozone generated is infused together with the contaminated water in the storage tank.
Partially filtered water goes through the pressure tanks to pump them through the filtration system.
Other organic substances and chemicals are segregated in the filtration system.
Clean water is pumped through pipes straight going to houses. Process: OZONATION PROCESS high capital cost
high electric consumption
Ozone is less soluble in water, compared to chlorine, and therefore special mixing techniques are needed.
Potential fire hazards and toxicity issues associated with ozone generation. DISADVANTAGES eliminates odors
Ozonation enhances water quality.
increases dissolved oxygen
The treatment process does not add chemicals to the water.
Ozone can eliminate a wide variety of inorganic, organic and microbiological problems and taste and odor problems. ADVANTAGES ADVANTAGES AND DISADVANTAGES OF OZONATION OZONATION Many industrial wastewaters contain substances that:
Are difficult to remove via conventionally secondary treatment
Are toxic and hazardous
Have potential for creating noxious vapors or odors, or for imparting color to the wastewater
Are present in very small concentrations that make their removal via other methods difficult MOTIVATION FOR THE USE OF ADSORPTION PROCESSES IN WASTEWATER TREATMENT ADSORPTION Adsorption is the process through which a substance, originally present in one phase, is removed from that phase by accumulation at the interface between that phase and a separate (solid) phase.
Adsorption is a process, similar to absorption, by which a substance in a gas or liquid becomes attached to a solid. The substance can be a pollutant, called an adsorbate, which is attracted to the surface of a special solid (adsorbent). COMMON ADSORBENTS Activated Alumina Activated Carbon The activated carbon now contains the hazardous material. Therefore, appropriate actions must then be taken to treat the spent activated carbon at the end of the cycle. The carbon may be:
- disposed in a landfill
- destroyed in an incinerator ADSORPTION IN WASTEWATER TREATMENT Adsorption is typically used in wastewater treatment to remove toxic organic pollutants or inorganic contaminants from the wastewater.
Adsorption finds applications in tertiary wastewater treatment as a polishing step before final discharge.
In any adsorption process, the material being adsorbed (pollutant) is simply but effectively removed from one phase (e.g., wastewater) and transferred to another phase (e.g., activated carbon).
This means that adsorption is a physical separation process in which the adsorbed material is not chemically altered.
Since chemical characteristics of the adsorbed material are not changed, the use of adsorption in wastewater treatment is associated with the removal of hazardous materials from the wastewater and its transfer to the activated carbon. ADSORPTION Ion exchange is an exchange of ions between two electrolytes or between an electrolyte solution and a complex. In most cases the term is used to denote the processes of purification, separation, and decontamination of aqueous and other ion-containing solutions with solid polymeric or mineralic 'ion exchangers‘
Typical ion exchangers are ion exchange resins (functionalized porous or gel polymer), zeolites, montmorillonite, clay, and soil humus. Ion exchangers are either cation exchangersthat exchange positively charged ions (cations) or anion exchangers that exchange negatively charged ions (anions). There are also amphoteric exchangers that are able to exchange both cations and anions simultaneously. However, the simultaneous exchange of cations and anions can be more efficiently performed in mixed beds that contain a mixture of anion and cation exchange resins, or passing the treated solution through several different ion exchange materials. ION EXCHANGE Most typical example of application is preparation of high purity water for power engineering, electronic and nuclear industries; i.e. polymeric or mineralic insoluble ion exchangers are widely used for water softening, water purification, water decontamination, etc.
Ion exchange is a method widely used in household (laundry detergents and water filters) to produce soft water. This is accomplished by exchanging calcium Ca2+ and magnesium Mg2+ cations against Na+ or H+ cations.
Industrial and analytical ion exchange chromatography is another area to be mentioned. Ion exchange chromatography is a chromatographical method that is widely used for chemical analysis and separation of ions. For example, in biochemistry it is widely used to separate charged molecules such as proteins. An important area of the application is extraction and purification of biologically produced substances such as proteins (amino acids) and DNA/RNA.
Ion-exchange processes are used to separate and purify metals, including separating uranium from plutonium and other actinides, including thorium, and lanthanum, neodymium, ytterbium, samarium, lutetium, from each other and the other lanthanides. Applications ION EXCHANGE A trickling filter consists of a fixed bed of rocks, lava, , gravel, slag, polyurethane foam, sphagnum peat moss, ceramic, or plastic media over which sewage or other wastewater flows downward and causes a layer of microbial slime (biofilm) to grow, covering the bed of media. Aerobic conditions are maintained by splashing, diffusion, and either by forced air flowing through the bed or natural convection of air if the filter medium is porous.
The terms trickle filter, trickling biofilter, biofilter, biological filter and biological trickling filter are often used to refer to a trickling filter. These systems have also been described as roughing filters, intermittent filters, packed media bed filters, alternative septic systems, percolating filters, attached growth processes, and fixed film processes. Hydraulic or organic loading
High-rate or low-rate FILTER CLASSIFICATION Filter Media
Underdrain System Construction and Design The word "filter" in this case is not correctly used for there is no straining or filtering action involved. Passage of wastewater through the filter causes the development of a gelatinous coating of bacteria, protozoa and other organisms on the media. With time, the thickness of the slime layer increases preventing oxygen from penetrating the full depth of the slime layer. In the absence of oxygen, anaerobic decomposition becomes active near the surface of the media. The continual increase in the thickness of the slime layer, the production of anaerobic end products next to the media surface, and the maintenance of a hydraulic load to the filter, eventually causes sloughing of the slime layer to start to form. This cycle is continuously repeated throughout the operation of a trickling filter. HOW DOES IT WORK? TRICKLING FILTER A man-made (anthropogenic) body of water in which waste is consumed by bacteria, used most frequently with other waste-treatment processes; a sewage lagoon
Oxidation Ponds are also known as stabilization ponds or lagoons.
Typically oxidation ponds need to be less than 10 feet deep.
New oxidation ponds can treat sewage to Standard B effluent level but require maintenance and periodic desludging in order to maintain this standard. OXIDATION PONDS OXIDATION PONDS Suspension mixed lagoons, where there is less energy provided by the aeration equipment to keep the sludge in suspension.
Falcultative lagoons, where there is insufficient energy provided by the aeration equipment to keep the sludge in suspension and solids settle to the lagoon floor. The biodegradable solids in the settled sludge then degrade anaerobically Types of aerated lagoons or basins Also known as aerated pond.
Wastewater treatment lagoon that has a high dissolved oxygen level.
This is usually a result of a combination of low organic waste input and sufficient oxygen transfer from the air, and occurs in the last few in a series of lagoons. AEROBIC LAGOONS Aerobic digestion is the process of oxidizing and decomposing the organic part of the sludge by micro-organisms in the presence of oxygen.
Aerobic digestion produces a stable Class B product, reduces mass and volume, and reduces pathogenic organisms and has some key advantages for smaller plants when compared to anaerobic digestion such as low capital equipment cost and simple operational control.
In aerobic wastewater treatment systems, micro-organisms feed on organic materials to stabilize them, and reduce biological oxygen demand and suspended solids in the wastewater. AEROBIC DIGESTION Path of Aerobic Digestion
Aerobic bacteria are very efficient in breaking down waste products. The result of this is; aerobic treatment usually yields better effluent quality that that obtained in anaerobic processes. The aerobic pathway also releases a substantial amount of energy. A portion is used by the microorganisms for synthesis and growth of new microorganisms. In an aerobic system the majority of the energy in the starting material is released as heat by their oxidisation into carbon dioxide and water.
ADVANTAGES AEROBIC LAGOON AND DIGESTION PURPOSE In a sewage (or industrial wastewater) treatment plant, the activated sludge process is a biological process that can be used for one or several of the following purposes:
oxidizing carbonaceous matter: biological matter.
oxidizing nitrogeneous matter: mainly ammonium and nitrogen in biological materials.
driving off entrained gases carbon dioxide, ammonia, nitrogen, etc.
generating a biological floc that is easy to settle.
generating a liquor that is low in dissolved or suspended material. It is a sewage-treatment process in which sludge, the accumulated, bacteria-rich deposits of settling tanks and basins, is seeded into incoming waste water and the mixture agitated for several hours in the presence of an ample air supply. Suspended solids and many organic solids are absorbed or adsorbed by the sludge, while organic matter is oxidized by the microorganisms. The amounts of air and sludge used can be varied to control the level of treatment obtained. The sludge is then separated out in a settling tank. ACTIVATED SLUDGE PRIMARY AND SECONDARY TREATMENT ACTIVATED SLUDGE The lagoon is divided into two distinct layers: sludge and liquid.
The sludge layer is a more solid layer formed by the stratification of sediments from the manure.
After a while, this solid layer accumulates and eventually needs to be cleaned out.
The liquid level wastewater enters at the bottom of the lagoon so that it can mix with the active microbial mass in the sludge layer.
Anaerobic lagoons should retain and treat wastewater from 20 to 150 days.
Lagoons should be followed by aerobic or facultative lagoons to provide further required treatment.
The liquid layer is periodically drained and used for fertilizer. In some instances, a cover can be provided to trap methane, which is used for energy. Anaerobic Lagoon Discovered by Robert Boyle & Stephen Hale.
It is a process where microorganisms break down organic materials, in the absence of oxygen.
Used in: FARMS, at SEWAGE WORKS, at the LATEST SOLID WASTE MANAGEMENT FACILITIES
Importance: it produces biogas, reduce the volume and mass of waste materials, provides fertilizer called “digestate”.
In an anaerobic system the majority of the chemical energy contained within the starting material is released by methanogenic bacteria as methane. Anaerobic Digestion ANAEROBIC DIGESTION AND LAGOON http://www.water-research.net/ozone.htm
http://en.wikipedia.org/wiki/Activated_sludge SOURCES: THANK YOU
GOD BLESS!!! SILICA GEL ==Aerobic bacteria demand oxygen to decompose dissolved pollutants. Large amounts of pollutants require large quantities of bacteria; therefore the demand for oxygen will be high.
==The Biological Oxygen Demand (BOD) is a measure of the quantity of dissolved organic pollutants that can be removed in biological oxidation by the bacteria. It is expressed inmg/l.
==The Chemical Oxygen Demand (COD) measures the quantity of dissolved organic pollutants than can be removed in chemical oxidation, by adding strong acids. It is expressed inmg/l.
==The BOD/COD gives an indication of the fraction of pollutants in the wastewater that is biodegradable.
Biological and chemical oxygen demand