Successful modeling of wastewater treatment plant (WWTP) processes requires an accurate description of the plant hydraulics. Common methods such as tracer experiments are difficult and costly and thus have limited applicability in practice; engineers are often forced to rely on their experience only. An implementation of grammar-based genetic programming with an encoding to represent hydraulic reactor models as program trees should fill this gap: The encoding enables the algorithm to construct arbitrary reactor models compatible with common software used for WWTP modeling by linking building blocks, such as continuous stirred-tank reactors. Discharge measurements and influent and effluent concentrations are the only required inputs. As shown in a synthetic example, the technique can be used to identify a set of reactor models that perform equally well. Instead of being guided by experience, the most suitable model can now be chosen by the engineer from the set. In a second example, temperature measurements at the influent and effluent of a primary clarifier are used to generate a reactor model. A virtual tracer experiment performed on the reactor model has good agreement with a tracer experiment performed on-site.
Keywords: grammar-based genetic programming, hydraulic reactor systems, modeling, operating data
Mathematical models are critical to modern environmental biotechnology—both in research and in the engineering practice. Wastewater treatment plant (WWTP) simulators are used by consulting engineers and WWTP operators when planning, designing, optimizing, and evaluating the unit processes that comprise municipal and industrial WWTPs. Many WWTP simulators have been expanded to include a submerged completely-mixed biofilm reactor module that is based on the mathematical description of a one-dimensional biofilm....
The regulation drawn from the French law on water of 1992 imposes on communities to treat their wastewater, except in case of exceptional rainy events. The seaside towns have also to respect the directive of 1975 concerning the quality of bathing water. Anjou Recherche launched in April 2001 an integrated study on the modelling of the sewage system of Saint Malo (Brittany, France), i.e. sewer network, wastewater treatment plant (WWTP) and receiving water. This study is embedded in a global project, with the...
ABSTRACTGiven the benefits derived from membrane treatment of water and wastewater, interest in using membranes is growing throughout the world, and at an ever increasing rate. As expected, the focus has been on the benefits of the product water (permeate) side of the system, but the system sidestreams (concentrates) bring their own special set of issues. As with any new technology or application, there are benefits and liabilities. Membrane separation is a non-destructive technology: the membranes merely concentra...
ABSTRACTAs more wastewater treatment facilities upgrade to tertiary treatment for pathogen removal and trace pollutant reduction, the options for tertiary filtration expand. The use of cloth-disk media filtration (disk filters) for tertiary filtration is becoming more common because of the effluent quality, lower backwash rates, small footprint, and ability to meet California Department of Health Services Title 22 criteria for the unrestricted reuse of treated effluent. Two manufacturers currently have Title 22...
The use of center wells (CWs) in circular secondary settling tanks (SST) has become a common practice. According to Parker et al. (1996) the main purpose of the CW is to promote the aggregation of remaining dispersed particles into settleable flocs, i.e., to promote the flocculation process inside the settling tank. Parker et al. (1996) and Parker and Stenquist (1986) showed strong evidence that, under similar operating conditions, circular tanks equipped with CWs can achieve lower effluent suspended solids and...
The project involved the dynamic modeling of a wastewater treatment plant (WWTP) treating pharmaceutical wastewater. The WWTP uses an integrated fixed-film activated sludge (IFAS) process with suspended carriers for biological treatment. The plant is unique in that it uses both fungal and bacterial IFAS reactors. The fungal biomass has been shown in laboratory testing to degrade a portion of the waste not degraded by bacterial biomass alone. The GPS-X simulator was used to model the plant. The mantis model, which...
The water reclamation plant at Mt. Dora, Florida
had an odor problem at the headworks collection
well. Several pump stations in the community send
their water to this location. The discharge of the
various lines is random. At times one line may be
discharging water while other lines are idle. At other
times multiple lines are discharging. There are
periods of no water discharge at various times
during the day. As a consequence, hydrogen
sulfide (H2S) levels vary greatly from hour to hour
and even from...
In 1980, Los Angeles began exploring alternatives to control the
H2S concentration in the digester gas produced at the Hyperion
Waste Water Treatment Plant (WWTP), which treats nearly 420
MGD, wastewater generating over 475 tons of raw sludge per
day. The digester gas H2S concentration had to be controlled so
that the SOx emissions from the on-site combustion of the gas
could be kept within acceptable regulatory limits, allowing the
gas to be burned on-site to generate steam for heat or electricity
or...
Untitled Document
Before selecting a
denitrification filter,
designers should
compare all
available systems
and assess their
performance to date
With the development of total
maximum daily loads for nutrient
discharges, many wastewater
treatment plants (WWTPs) face
stringent nutrient limits. Deep-bed denitrification
filters that remove nitrogen and solids are
a proven technology for treating wastewater to
meet low total nitrogen (TN) limits. A variety...
Saint-Malo is an extremely attractive and popular seaside resort on the north coast of Brittany in France. Covering 1,400 hectares, the local population of 50,000 increases to 120,000 in the tourist season. One of the distinguishing features of this part of the Channel coast is a very high tidal range – 14 meters from low to high, with a potential impact back through the sewer network. Combined together, these factors make the effective operation of the sewer system and effluent quality particularly important....
The State of Biosolids in America
TAKING the pulse of biosolids management practices in the United States yields a combination of hard data and valuable insights. Between survey responses and telephone conversations, state biosolids coordinators around the country paint an overall picture of progress with the beneficial use of biosolids, along with a dose of reality about political, economic and regulatory pressures that may hamper future advances. The year 2000 was certainly an interesting one in the annals of...
Characterization of groundwater flow regimes in fractured bedrock aquifers on Southern Vancouver Island and the Gulf Islands of British Columbia are presently based on simple hydraulic testing methods and analytical models. Transmissivity, storativity are derived from porous media (radial flow) analytical models that do not fully represent the more complex boundary conditions inherent to fracture bedrock aquifers. Geological and horizontal loop electromagnetic (HLEM) surveys were used to characterize the lithology...
ABSTRACT
As water and sewer costs are expected to increase over the next decade, membrane technology will continue to be a viable and economical option in the recovery and reuse of water. This paper describes the mechanism of membrane effected separation (specifically reverse osmosis, ultrafiltration and microfiltration), membranes commercially available, membrane element configurations, and how complete membrane systems are designed. The paper also discusses case histories of a variety of proven applications,...
Dairy wastewaters are rich in organic carbon and nutrients. When disposed without proper treatment they cause severe pollution of water and land. But if treated by anaerobic fermentation such wastewaters can yield useful clean energy in the form of methane. The systems commonly used for such fermentation throughout the world are Continuously Stirred Tank Reactors (CSTRs). We describe attempts to upgrade CSTR performance by incorporating biofilm support systems (BSSs) within the existing reactors. The focus of the...
The treatment of industrial effluent from the paper manufacturing facilities in British Columbia is a major concern because the effluent is discharged into prime salmon habitat in the marine environment (Cross, 1994). High levels of biological oxygen demand (BOD) in the effluent reduce the dissolved oxygen (DO) available to species in the marine environment. In 1988, the Federal Department of Fisheries and Oceans reviewed the levels of DO and total suspended solids (TSS) that are discharged in the effluent...
Abstract
Africa
The economic and social needs of Africa depends more on its environmental resources but these natural resources are seriously declining and that is really effecting the entire region. Sustainable development in this rapidly changing region has become an imperative, and must take place in the complex context of a diverse and changing ecosystem, political transition and evolution toward market economies.
The region is heading towards integrating environmental components into sectors like...
SCREENING AND GRINDING
When materials from CR&R and other generators are unloaded, a preliminary screening separates out nonorganic contaminants. Even though there are source separated programs in places like Temecula and Lake Elsinore, there is the occasional appearance of plastic and glass that needs to be sorted out. Next, Bodlak’s crews put materials through a Vermeer tub grinder that can process up to 200 tons (or 720 cubic yards) a day.
After the initial grinding, water is sprayed onto the piles,...
Massachusetts became home to two new composting facilities that process MSW and biosolids. Nationally, the total number of operating plants is 19.
Since the mid-1980s, BioCycle has been conducting an annual, nationwide survey of municipal solid waste (MSW) composting facilities. From the late 1980s into the early 1990s, when it was projected that landfill capacity would drop and tipping fees would skyrocket, interest in MSW composting was high. About two dozen companies were marketing systems and equipment, and...
The company has implemented a major waste minimisation strategy that has enabled it to process liquid waste, reduce water usage, reduce chemical and waste disposal costs, and eliminate pollution. It installed new equipment which treats wastewater to remove emulsified fats and oils, grease, heavy metals and all forms of suspended, colloidal and some dissolved solids. Mains water usage has been reduced by over 10 ML per annum and wastewater discharge to sewer reduced by 50 percent. The new technology has produced a...
Protectakote Pty Ltd has implemented a waste water recycling system at its Geelong facility which is saving it approximately $19,600 per annum and had a very attractive payback of 0.7 years, even without full qualification of all the benefits.
Background
Protectakote Pty Ltd (Protectakote) is a small metal plating and powder coating operation located in the Geelong region of Victoria. The company employs approximately 15 people.
The main operation involves cyanide-zinc plating of a range of metal components....
In general, no single technology can remediate an entire site. Several treatment technologies are usually combined at a single site to form what is known as a treatment train. A system diagram of a common treatment train for halogenated VOCs is illustrated below. A ground water pumping system is used to pull contaminated water from the subsurface. The VOC contaminated water is pumped to a liquid phase granulated activated carbon (GAC) adsorption system. The GAC system removes VOCs in the water and the effluent is...
Explosives-contaminated process waste waters can be subdivided into two categories: red water, which comes strictly from the manufacture of TNT, and pink water, which includes any washwater associated with load, assemble, and pack (LAP) operations or with the demilitarization of munitions involving contact with finished explosive. Despite their names, red and pink water cannot be identified by color. Both are clear when they emerge from their respective processes and subsequently turn pink, light red, dark red,...
Introduction
Most people who work with an apparatus unlike any in their previous experience approach it with some apprehension. This is common behavior and fits the way most of us approach unfamiliar things. Perhaps you deal with this kind of uncertainty about the reverse osmosis (RO) machine in your dialysis unit. This article is intended to increase your understanding of the machine and how it operates and will make you as comfortable as possible with the RO machine.
What Does `RO` Mean?
RO stands for...
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