Donald B. Aulenbach

Energy Models and Cost Models for Water Pollution Control

The pollution control measures needed today and in the future should be controlled by the consideration of capital costs, operation and maintenance costs (O&M costs), and total energy use. A considerable effort to compile these costs has been made by the Federal and local governments, and consulting engineering firms. Based on their data banks, the mathematical models of pollution control equipment costs, O&M costs, electrical energy consumptions and total heating requirements have been developed for simplifying environmental engineers’ decision making process on optimization and selection of pollution control technologies.

Gas Dissolution, Release, and Bubble Formation in Flotation Systems

The theories and principles of gas dissolution, release, and bubble formation in gas flotation systems are introduced in detail for process design, optimization, and operation. Also introduced is a new instrument for real-time measurement of bubble content and size distribution in a typical flotation system consisting of gas bubbles (gas phase) and bulk water (liquid phase). Specific engineering topics included in this chapter are: gas dispersion principles, gas dispersion tester, bubble tester operation, gas dispersion example, gas transfer principles, Henry’s Law constants, partial pressures, solubilities of various gases, gas dissolution and release, gas bubble formation and size distribution, bubble attachment, bubble rising and flotation, gas dissolution in water containing high dissolved solids or high salinity, and engineering design examples.

Monitoring for land application of wastewater.

In order to ensure adequate performance and warn of potential ground water contamination, land application systems must be monitored. The monitoring system for the Lake George Village Sewage Treatment Plant land application system is described, including suction lsyimeters, observation wells and tracer studies.

Algae Removal by Flotation

The importance of algae is discussed. Algae are a significant source of oxygen on Earth due to its capability of photosynthesis. Further they are an efficient biological system for converting solar energy into plant life, a source of energy for higher life. However, at high concentrations, called blooms, they can contribute tastes and odors, and even toxins to the surrounding water. They are best removed before they reach a water treatment plant (WTP) where they may rupture and release their taste and odor oils. Algae at both low and high concentrations may be removed by dissolved air flotation (DAF). Even very high concentrations from wastewater treatment lagoons and algae culture ponds are efficiently removed. The recovered algae have many economical uses. When alum or iron salts are added to improve coagulation for algae removal, phosphorus is also removed, thereby lessening productivity in a lake or stream. The development of algae culture ponds heated by waste heat from a nearby power plant, combined with CO2 and NO X from fossil fueled power plants’ atmospheric discharges, could reduce atmospheric pollution and even global warming. The algae produced and removed can serve as an energy source. A case study is described for the application of a DAF system for upgrading a small drinking WTP. Examples are shown for the separation of algae from wastewater treatment plant lagoons. The use of DAF for separation of algae is an important factor in our lives.

HEAVY METALS REMOVAL IN A RAPID INFILTRATION SAND COLUMN

ABSTRACT Sand filtration has been used as a cost-effective tertiary treatment process for sewage and wastewaters. However, little information is available on the performance of the process for heavy metals removal. In this project, the effect of a rapid infiltration sand filtration system on the removal of total organic carbon (TOC) phosphorus, Cd, Cu, Pb, and Zn from a mixed industrial and domestic wastewater was evaluated. To facilitate observation of the system behavior under varied conditions, the influent samples were also subjected to extreme pH values. Further studies were conducted to determine the effects of calcium carbonate addition for heavy metals precipitation prior to application onto the sand column. The results revealed that sand filtration was remarkably successful in removing phosphorus from wastewater under all conditions. The data further confirmed that in a sand filtration process, the mechanism of phosphorus removal was mainly due to chemical precipitation. Under neutral pH conditio...

Treatment by Application Onto Land

Various land application technologies as means for waste treatment and disposal are introduced. This chapter discusses the engineering topics of: surface spreading, overland flow, infiltration, percolation, slow rate irrigation, crop irrigation, vegetative cover, soil adsorption, soil ion exchange, mineralization, bacteriological activity, waste treatment, water removal, nitrogen removal, phosphorus removal, metal removal, disinfection, process design, land application rate, area requirements, monitoring, organic loading, siting, costs, etc.

Treatment by Subsurface Application

There are two major components of a subsurface wastewater treatment system: (a) a pretreatment tank for gravity separation and accumulation of the settleable solids from the wastewater, and (b) subsurface distribution and final treatment of the supernatant liquid from this pretreatment tank. This chapter covers the topics of subsurface waste treatment theory, anaerobic septic tank, aerobic tank, subsurface disposal, leaching field, tile field, soil percolation, seepage pit, cesspool, upflow permeameter, etc. Many design examples are presented.

REMOVAL OF HEAVY METALS IN ACTIVATED SLUDGE TREATMENT SYSTEMS

Studies were conducted to determine the removal of heavy metals in three normally operating activated sludge wastewater treatment plants having only moderate industrial inputs. The removals of the soluble and particulate fractions varied with primary and secondary treatment, and in one instance a tertiary sand filter.

Lake Restoration Using Dissolved Air Flotation

The steps leading to the demise of a lake are discussed. One of the primary causes of the death of a lake is excessive biological growth, called eutrophication. Biological growth is limited primarily by the availability of the nutrients necessary for growth. It has been shown that phosphorus is most frequently the limiting nutrient to control biological growth in a lake, but nitrogen is also commonly limiting. Phosphorus may be permanently removed from a lake by various processes, whereas nitrogen is difficult to remove permanently due to the fact that certain blue-green algae can fix atmospheric nitrogen as a nitrogen source. Thus, emphasis has been placed on the removal of phosphorus. There are various methods for the treatment of wastewaters to remove the nutrients before being discharged to a body of water. Once in a lake, phosphorus removal is most frequently achieved by producing an insoluble aluminum salt of the phosphorus, but iron salts are effective under aerobic conditions. Calcium salts are effective in removing phosphorus, but they generally adversely increase the pH of the lake. Precipitated aluminum phosphate salts may be allowed to settle to the bottom of the lake, or they may be removed from the water column. A study showed that removing the phosphate-rich hypolimnetic waters from a summer stratified temperate climate lake, precipitating the phosphorus as either aluminum or iron salts, separating the precipitate by DAF, and returning the phosphate reduced water to the lake were very effective in controlling the phosphorus nutrient content in Devils Lake, WI.

Pittsfield Water Treatment Plant: Once the World’s Largest Flotation–Filtration Plant

When the 37.5 MGD (142 million liters per day) Pittsfield, MA, USA water treatment plant was installed in 1986 it became the world’s largest water treatment plant using dissolved air flotation (DAF) and automatic backwash filtration (ABF) technologies. Design features are presented in detail along with the plant’s performance data, and special features on total wastewater recycle. Total detention time of the innovative flotation–filtration (DAFF) plant is less than 20 min compared with a conventional sedimentation–filtration plant requiring 7–9 h of detention time.