Municipal Wastewater Collection Research Articles

GENERATION AND CALIBRATION OF STANDARD GAS MIXTURES OR VOLATILE FATTY ACIDS USING PERMEATION TUBES AND SOLID-PHASE MICROEXTRACTION

Volatile fatty acids (VFAs) are major components of odors associated with agricultural operations and livestockhousing, solid waste processing and disposal, industrial and municipal wastewater collection, and treatment systems.Emission estimation and assessment of odor control methods depend on reliable air sampling and analysis methods for VFAs.The objective of this research was to develop and test a method for continuous and reliable generation of standard gas mixturesfor VFAs based on permeation tubes. Standard gas mixtures for acetic, propionic, isobutyric, butyric, isovaleric, valeric, andhexanoic acids were generated with permeation tubes and monitored for a 100-day period. The gravimetric loss of VFAs fromeach tube was measured periodically and used to calculate the emission rate for each permeation tube. Emission rates wereas high as 2,011 ng/(min cm) for acetic acid to as low as 49 ng/(min cm) for isovaleric and hexanoic acids. The emission ratewas combined with the dilution flow rate to calculate standard concentrations. Five different concentrations for each VFAwere obtained by adjusting the dilution flow rate. Gas concentrations were monitored with DVB/Carboxen/PDMS 50/30 .mSPME fibers using triplicate 1 min extractions. Maximum standard gas concentrations ranged from 21.9 ppmv for acetic acidto 0.22 ppmv for hexanoic acid. Minimum standard gas concentrations ranged from 3.0 ppmv for acetic acid to 0.03 ppmvfor hexanoic acid. The relative standard deviations (RSDs) for all VFA concentrations ranged from .1.6% to .7.8%. Rapid(1 min) SPME extractions were sufficient to preconcentrate significant amounts of VFAs for separation on a GC-FID withoutderivatization. The SPME technology proved to be very useful for monitoring standard gas mixtures. Dilution gas flow ratedid not affect the emission rates from permeation tubes. In contrast, low acid levels affected permeation rates of the acidsfrom the tubes. The methodology described in this article could be used to generate and test standard gas mixtures for otherodorous gases.

VALUE, RELIABILITY, AND ACCEPTABILITY KEY CONSIDERATIONS FOR A NEW MILLENNIUM

VALUE, RELIABILITY, AND ACCEPTABILITY KEY CONSIDERATIONS FOR A NEW MILLENNIUMAs a rule, pumping stations in municipal wastewater collection systems receive little notice during design, construction and after startup…..until they fail. By then, it is usually too late to remedy the root causes that have led to failures, lack of reliability and excessive costs of operation and maintenance. With the increased scrutiny by EPA and other regulatory agencies on prevention...Author(s)Garr M. JonesDoug SchneiderSourceProceedings of the Water Environment FederationSubjectSession 42 - Collection Systems Symposium: Odor, Corrosion and Pump StationsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2000ISSN1938-6478SICI1938-6478(20000101)2000:10L.169;1-DOI10.2175/193864700784545379Volume / Issue2000 / 10Content sourceWEFTECFirst / last page(s)169 - 189Copyright2000Word count178

Sugar wastewater treatment with aerated fixed-film biological systems

Wastewater effluents from the sugar industry contain high concentrations of organic materials which are sometimes discharged into the municipal wastewater collection system and processed in wastewater treatment plants along with domestic wastewater. This study examined the performance of a four-compartment, fixed-film system in which the biofilm is attached to submerged ceramic tiles under diffused aeration, known as the aerated submerged fixed-film (ASFF) process. Field experiments were conducted using four ASFF units each of about 100 1 capacity operated at different hydraulic loading rates to provide hydraulic residence time (HRT) of 2, 4, 6 and 8 hours. Process performance was evaluated under both normal operation with domestic wastewater and under pulse and prolonged organic shock loads with sugar wastewater. The influent and effluent of the process was analyzed for solids, BOD, COD, and nitrogen forms to determine both carbonaceous and nitrogenous substrate removal. The ASFF process was found to be able to handle continuous severe organic loads increasing from about 5 to 120 g BOD/m2.d with slight decrease in organic removal efficiency from 97.9% to 88.5% for BOD and from 73.6 to 67.8% for COD. Nitrification was similarly decreased but at higher rates. The system was also able to cope with pulse injection of sugar wastewater and recovery to normal steady-state COD values was achieved in 10 hours for the 200 g COD/l spikes. An increase in the organic loading rate was accompanied by an increase in biofilm specific oxygen uptake rate until reaching a maximum which determines the optimum loading rate for process operation. Substrate removal rates were evaluated for process design.

Sugar wastewater treatment with aerated fixed-film biological systems

Wastewater effluents from the sugar industry contain high concentrations of organic materials which are sometimes discharged into the municipal wastewater collection system and processed in wastewater treatment plants along with domestic wastewater. This study examined the performance of a four-compartment, fixed-film system in which the biofilm is attached to submerged ceramic tiles under diffused aeration, known as the aerated submerged fixed-film (ASFF) process. Field experiments were conducted using four ASFF units each of about 100 1 capacity operated at different hydraulic loading rates to provide hydraulic residence time (HRT) of 2, 4, 6 and 8 hours. Process performance was evaluated under both normal operation with domestic wastewater and under pulse and prolonged organic shock loads with sugar wastewater. The influent and effluent of the process was analyzed for solids, BOD, COD, and nitrogen forms to determine both carbonaceous and nitrogenous substrate removal. The ASFF process was found to be able to handle continuous severe organic loads increasing from about 5 to 120 g BOD/m2.d with slight decrease in organic removal efficiency from 97.9% to 88.5% for BOD and from 73.6 to 67.8% for COD. Nitrification was similarly decreased but at higher rates. The system was also able to cope with pulse injection of sugar wastewater and recovery to normal steady-state COD values was achieved in 10 hours for the 200 g COD/l spikes. An increase in the organic loading rate was accompanied by an increase in biofilm specific oxygen uptake rate until reaching a maximum which determines the optimum loading rate for process operation. Substrate removal rates were evaluated for process design.

Development of sludge treatment and disposal strategies for large conurbations: case study – Warsaw

The development of appropriate strategies for the treatment and disposal of sewage sludge is a major problem for all conurbations throughout the world. Sludge treatment and disposal not only represents half of the total costs of municipal wastewater collection, treatment and disposal, but it is also strongly regulated, more so than almost any other form of waste, and readily attracts adverse media and public attention. Thus the challenge for wastewater authorities is to find affordable, sustainable and safe approaches to sludge management, which are also publicly acceptable. This paper describes the Best Environmental Option (BPEO) approach to identifying optimum sludge treatment and disposal strategies and its application to the sludge management problems of city of Warsaw and the surrounding region.

Development of sludge treatment and disposal strategies for large conurbations: Case study — Warsaw

The development of appropriate strategies for the treatment and disposal of sewage sludge is a major problem for all conurbations throughout the world. Sludge treatment and disposal not only represents half of the total costs of municipal wastewater collection, treatment and disposal, but it is also strongly regulated, more so than almost any other form of waste, and readily attracts adverse media and public attention. Thus the challenge for wastewater authorities is to find affordable, sustainable and safe approaches to sludge management, which are also publicly acceptable. This paper describes the Best Environmental Option (BPEO) approach to identifying optimum sludge treatment and disposal strategies and its application to the sludge management problems of city of Warsaw and the surrounding region.

An industrial pretreatment facility inspector training program

The US federal pretreatment regulations have created a demand for qualified pretreatment facility inspectors. The objectives of the General Pretreatment Regulations are to protect publicly owned treatment works (POTWs), prevent pollutants from upsetting treatment processes, improve opportunities to reclaim or recycle wastewaters and sludges and reduce health and environmental risks from discharge of toxic pollutants to POTWs. Pretreatment inspectors have the responsibility of protecting municipal wastewater collection systems, treatment plants and the environment from the damage that may occur when industries discharge hazardous or toxic materials into a wastewater collection system. The inspectors must possess the knowledge and skills to perform their jobs safely and fairly. To meet this need, a training program using the independent-study (correspondence) format was developed and field tested. Experienced inspectors active in the field prepared the training material on the basis of what pretreatment facility inspectors “need to know” to do their job. The training program has been implemented and used by inspectors as home-study or self-paced instruction (correspondence) as well as by colleges and universities as a textbook in formal classes. Since 1988 over 1600 persons have successfully completed this training program and over 7000 copies of the training manual have been sold throughout the world. In areas where the training program has been used, the results of an effective pretreatment program using qualified inspectors is very impressive. An agency with a training program that produces competent inspectors can have an effective pretreatment program.

Treatment of Landfill Leachate At Publicly Owned Treatment Works

This project investigates the discharge of landfill leachate into a municipal wastewater collection system with subsequent treatment at the municipal treatment plant. Leachates from disposal sites can be mixed with municipal wastewater and treated by wastewater treatment plants using secondary aerobic treatment. The leachates are effluents, high in organic content which are in many instances similar to industrial effluents. Experimental studies with simulated landfill leachate have shown that if a wastewater treatment plant is to accept this type of effluent, the following conditions must be met. First, air supply and oxygen transfer capacity must be sufficient to maintain aerobic conditions within the aeration basin with the increase in the organic loads. Second, sufficient nutrient concentrations (especially phosphorus) must be observed in order to maintain necessary operating conditions.

National Needs for Combined Sewer Overflow Control

The national extent of the combined sewer overflow problem is investigated in terms of (1)Regional populations and acreages served; and (2) a range of potential costs for the control of overflows. Combined sewers in the United States serve approx 37 million people and 2.7 million acres (10.9 × 109 m²) of urban land. Cost estimates are presented for the control of runoff from combined sewer service areas based on a single design storm and eight hypothetical control strategies. Capital costs range from $1.2 billion - $68 billion (June 1973 dollars), and vary with the amount of storage and degree of treatment provided. Annual operation and maintenance expenses for the eight options range from $46 million - $400 million. These costs are compared with similar estimates for new and upgraded municipal wastewater collection and treatment systems required under Public Law 92-500.