B
Bacillus- Bacterium with an elongated, rod shape. Bacteria Living organisms, microscopic in size, which usually consist of a single cell. Most bacteria use organic matter for their food and produce waste products as a result of their life processes. Bacteriochlorophyll- Light-absorbing pigment found in green sulfur and purple sulfur bacteria. Bacteriocin- Agent produced by certain bacteria that inhibits or kills closely related isolates and species. Bacteriophage- Virus that infects bacteria,...
Vacuum Filtration
We have already discussed this important technology in Chapter 5, but a review may be helpful in placing its importance to sludge processing into perspective. The vacuum filter for dewatering sludge is a drum over which is laid the filtering medium consisting of a cloth of cotton, wool, nylon, dynel, fiber glass or plastic, or a stainless steel mesh, or a double layer of stainless steel coil springs. The drum with horizontal axis is set in a tank with about one quarter of the drum submerged in...
Chlorine
Chlorine is familiar to most people as it is used to treat virtually all municipal water systems in the United States. Chlorine has a number of problems when used for field treatment of water. When chlorine reacts with organic material, it attaches itself to nitrogen containing compounds ammonium ions and amino acids , leaving less free chlorine to continue disinfection. Carcinogenic trihalomethanes are also produced, though this is only a problem with long-term exposure. Trihalomethanes can...
Chlorination Systems
Water chlorination is carried out by using both free and combined residuals. The latter involves chlorine application to produce chloramine with natural or added ammonia. Anhydrous ammonia is used if insufficient natural ammonia is present in the wastewater. Although the combined residual is less effective than free chlorine as a disinfectant, its most common application is as a post-treatment following free residual chlorination to provide initial disinfection. Free residual chlorination...
An Alternative Analysis The Forgotten Method Of Dimensional Analysis
I often refer to dimensional analysis as lost art - because it is usually not heavily emphasized in engineering education today. However, for well over 100 years its has provided simply a wealth of practical design correlations that are still relied upon in virtually all aspects of chemical engineering, ranging from classes of problems dealing with heat and mass transfer, reaction kinetics, momentum exchanges in flow dynamics. Much of sedimentation theory, and indeed the basis for more...
Iodine
Iodine's use as a water purification method emerged after World War 2, when the U.S. military was looking for a replacement for Halazone tablets. Iodine was found to be in many ways superior to chlorine for use in treating small batches of water. Iodine is less sensitive to the pH and organic content of water, and is effective in lower doses. Some individuals are allergic to iodine, and there is some question about long term use of iodine. The safety of long-term exposure to low levels of...
Ozonated Water 1
A high level of gas preparation usually air is needed before ozone generation. The air must be dried to retard the formation of nitric acid and to increase the efficiency of the generation. Moisture accelerates the decomposition of ozone. Nitric acid is formed when nitrogen combines with moisture in the corona discharge. Since nitric acid will chemically attack the equipment, introduction of moist air into the unit must be avoided. Selection of the air-preparation system depends on the type of...
Recommended Resources For The Reader Inh
The following references include Web sites that you can refer to for specific properties and discussions of applications of alum. 1. Liquid Aluminum Sulfate Viscosity of aqueous solutions of liquid alum A12 S04 2-14.3 H20 at different temperatures , go to the following web site http 2. Pulp and Paper Technical Association of Canada - Standards of Sulphite Waste Liquor, C-3, Jan. 68. Viscosity of Sulphite Waste Liquor, C-4,Jan. 68. F-2, Nov. 70. Wire Screening, F-3, July 92. Alum Solutions, F-4,...
Practical Principles Of Ionexchange Water Treatment
Second Edition 1995, ISBN 0-927188-00-7 By Dean L. Owens 210 pages, hard cover, 55 The Practical Principles of Ion Exchange Water Treatment develops the fundamentals of understanding the ion exchange water treatment process for those people who work with or are concerned with the operation of systems employing this technology. Included are the basics of the mechanics and equipment of ionexchange water treatment, and the effect of these on the operation of the systems. Operation cycles of...
Blending
Stabilization can be aided by the technique of blending sludge. Blending is a process where two or more types of sludge are blended together to facilitate a higher sludge solids concentration and a more homogenous mixture of sludge prior to dewatering. Blending operations tends to decrease the chemical demand for conditioning and dewatering sludge. The blending operation usually takes place in sludge holding tanks normally where primary sludge is mixed with waste activated sludge. The amounts...
Basic Principles Of Water Treatment
1st Printing 1996 ISBN 0-927188-05-8 By Cliff Morelli. Hardcover, 8272 pages. 60. Virtually all industries utilize water in their manufacturing process, either as a heat-transfer medium, as in the steam-electric generating industry or in the employment of cooling towers or as a product as in the case of beverages, foods and pharmaceutical preparations. Water is also employed as a working solvent, as in the case of manufacturing microelectronics, where the final product yield is highly dependent...
The Contaminants Activated Carbon Can And Cannot Remove
Activated carbon AC filtration is most effective in removing organic contaminants from water. Organic substances are composed of two basic elements, carbon and hydrogen. Because organic chemicals are often responsible for taste, odor, and color problems, AC filtration can generally be used to improve aesthetically objectional water. AC filtration will also remove chlorine. AC filtration is recognized by the Water Quality Association as an acceptable method to maintain certain drinking water...
Diatomaceous Earth
Diatomaceous earths may resemble the forms of the charcoals. The earths are primarily filter aids, precoats or adsorbents, the function of the filter medium being secondary. Fuller's earth and clays are used for decoloring applications diatomaceous earths are used for clarification. The adsorbtivity of diatomaceous earth works in the same fashion as activated carbon, but isotherms affinity for many chemical species like the hydrocarbons is weaker. For this reason, activated charcoal or carbon...
COAGULANTS AND FLOCCULANTSTheory and Practice
1st Printing 1995 ISBN 0-927188-04-X By Dr. Yong H. Kim. Softcover, 96 pages. Price 23. The purpose of this book is to provide engineers and plant operators who are involved in solid-liquid separation with a fundamental understanding of coagulation and flocculation. Applications include water and wastewater treatment, pulp and paper industries, mineral processing, and enhanced oil recovery. The readers of the book will obtain an appropriate knowledge of coagulants and polymeric flocculants,...
Chlorine Dosage Rates And Residuals
Table 3 gives recommended ranges of chlorine dosages for disinfection of various wastewaters. Recommended minimum bactericidal chlorine residuals are given in Table 4. Data in Table 4 are based on water temperatures between 20 C to 25 C after a 10-minute contact for free chlorine and a 60 minute contact for combined available chlorine. The minimum residuals required for cyst destruction and inactivation of viruses are much greater. Although chlorine residuals in Table 4 are generally adequate,...
Introduction Of Physical Methods Of Waste Treatment
We may organize water treatment technologies into three general areas Physical Methods, Chemical Methods, and Energy Intensive Methods. Physical methods of wastewater treatment represent a body of technologies that we refer largely to as solid-liquid separations techniques, of which filtration plays a dominant role. Filtration technology can be broken into two general categories - conventional and non-conventional. This technology is an integral component of drinking water and wastewater...
Air Flotation Systems
Air flotation is one of the oldest methods for the removal of solids, oil amp grease and fibrous materials from wastewater. Suspended solids and oil amp grease removals as high as 99 can be attained with these processes. Air flotation is simply the production of microscopic air bubbles, which enhance the natural tendency of some materials to float by carrying wastewater contaminants to the surface of the tank for removal by mechanical skimming. Many commercially available units are packaged...
Soda Ash
Soda ash, Na2C03, is available in two forms. Light soda ash has a bulk density range of 35 to 50 lb cu ft and a working density of 41 lb cu ft. Dense soda ash has a density range of 60 to 76 lb cu ft and a working density of 63 lb cu ft. The pH of a 1 percent solution of soda ash as 11.2. It is used for pH control and in lime treatment. The molecular weight of soda ash is 106. Commercial purity ranges from 98 percent to greater than 99 percent Na2C03. Soda ash by itself is not particularly...
Lation
Figure 8. Example of an impeller mixer. The proper measure of flocculation effectiveness is the performance of subsequent solids separation units in terms of both effluent quality and operating requirements, such as filter backwash frequency. Effluent quality depends greatly on the reduction of residual primary size particles during flocculation, while operating requirements relate more to the floe volume applied to separation units. Flocculation units should have multiple compartments and...
The Three Regimes Of Settling
The Laminar Regime Best known as Stokes Law for Re lt 2 The Intermediate Regime Best known as the Transition Regime Law, for 2 lt Re lt 500 us 0.78 d043 pp - p 0715 p0 285 i0'43 The Turbulent Regime Best known as Newton's Law, for 500 lt Re lt 200,000 From this point on, it's some very simple algebra. You can solve equation 5 for us, and then substitute an expression in for CD for each of the three flow regimes laminar, turbulent and intermediate . You can work through the details, but the...
It Makes Sense To Select A Filter Press
of When a very low moisture content is required for thermal cake drying or incineration. rar When high f ltrate clarity is required for polishing applications. rar When good cake release assisted by squeezing is required. y When the cake is disposed as land fill for spreading with a bulldozer provided it is hard enough to carry its weight. When large filtration areas are required in a limited space. The shuttle shifter moves the plates one by one towards the follower and the cake discharges....
Stabilization Via Aerobic Digestion
Aerobic digestion is an extension of the activated sludge aeration process whereby waste primary and secondary sludge are continually aerated for long periods of time. In aerobic digestion the microorganisms extend into the endogenous respiration phase. This is a phase where materials previously stored by the cell are oxidized, with a reduction in the biologically degradable organic matter. This organic matter, from the sludge cells is oxidized to carbon dioxide, water and ammonia. The ammonia...
Chemical Mixing
Chemical mixing facilities should be designed to provide a thorough and complete dispersal of chemical throughout the wastewater being treated to insure uniform exposure to pollutants which are to be removed. The intensity and duration of mixing of coagulants with wastewater must be controlled to avoid overmixing or undermixing. Overmixing excessively disperses newly-formed floe and may rupture existing wastewater solids. Excessive floe dispersal retards effective flocculation and may...