Wastewater pond systems using chemical precipitation (fellings dams): state of the art in Sweden.

Chemical precipitation in wastewater stabilization ponds - in Scandinavia called fellings dams - has been in operation for more than 50 years. Slaked lime and aluminium salts are the most common chemicals used for precipitation. Long and narrow forms of the ponds and a detention time of at least 5 days have shown, even at a low water temperature and below an ice cover, to produce an average effluent quality of 70 mg CODCr/l, 0.2 mg Tot-P/l, 20 mg Tot-N/l (CODCr: chemical oxygen demand; Tot-P: total phosphorus; Tot-N: total nitrogen) and low levels of pathogenic bacteria. The systems use low amounts of energy and no wastewater is by-passed at the plants. Fellings dams have recently been tried to support overloaded wastewater collection systems.

[The Vienna School of Water Hygiene from the End of World War II until now]. / Die Wiener Schule der Wasser-Hygiene nach dem 2. Weltkrieg bis heute.

After the economic stagnation of the 1930s and World War II the water-hygiene had to revive. Besides basic research for large projects as the 3rd Viennese water-conduct, the Danube hydroelectric power station in Hainburg and the Marchfeldkanal new fields were opened. The evidence of fecal spring-water contamination by determination of the spectral-absorption-coefficients avoids the delay by bacterial cultivation and enables immediate satellite-transmission to central stations for turning-off the afflux. Determination of the origin (human and ruminant) of isolated E. coli by Real-time-PCR indicates necessities for sanitation. Investigation on UV-water-disinfection, considering also the formation of carcinogenic and genotoxic compounds, resulted in the only European national UV-norm and the establishment of one of the wordwide four testing institutions of UV-water-disinfection. The department for water-hygiene of the Medical University of Vienna carries out specific duties in various national committees of public health importance as well as in collaboration with EU, WHO, ISO and other international commissions.

Chain effects of clean water: The Mills-Reincke phenomenon in early 20th-century Japan.

This study explores the validity of chain effects of clean water, which are known as the "Mills-Reincke phenomenon," in early 20-century Japan. Recent studies have reported that water purifications systems are responsible for huge contributions to human capital. Although some studies have investigated the instantaneous effects of water-supply systems in pre-war Japan, little is known about the chain effects of these systems. By analyzing city-level cause-specific mortality data from 1922 to 1940, we find that a decline in typhoid deaths by one per 1000 people decreased the risk of death due to non-waterborne diseases such as tuberculosis and pneumonia by 0.742-2.942 per 1000 people. Our finding suggests that the observed Mills-Reincke phenomenon could have resulted in the relatively rapid decline in the mortality rate in early 20-century Japan.

An Assessment of Current and Past Concentrations of Trihalomethanes in Drinking Water throughout France.

In France, 95% of people are supplied with chlorinated tap water. Due to the presence of natural organic matter that reacts with chlorine, the concentrations of chlorination by-products (CBPs) are much higher in chlorinated water produced from surface water than from groundwater. Surface water supplies 33% of the French population. Until the 1980s, almost all surface water utilities pre-chlorinated water at the intake. Pre-chlorination was then gradually banned from 1980 to 2000. Trihalomethanes (THMs) are the only regulated CBP in France. Since 2003, THMs have been monitored at the outlet of all utilities. This study assessed current (2005⁻2011) and past (1960⁻2000) exposure of the French population to THMs. We developed an original method to model THM concentrations between 1960 and 2000 according to current concentrations of THMs, concentration of total organic carbon in raw and finished water, and the evolution of water treatments from 1960 onward. Current and past mean exposure of the French population to THMs was estimated at 11.7 µg·L-1 and 17.3 µg·L-1, respectively. In the past, approximately 10% of the French population was exposed to concentrations >50 µg·L-1 vs. 1% currently. Large variations in exposure were observed among France's 100 administrative districts, mainly depending on the water origin (i.e., surface vs. ground), ranging between 0.2 and 122.1 µg·L-1 versus between 1.8 and 38.6 µg·L-1 currently.

Reconstruction of historical 2,3,7,8-tetrachlorodibenzo-p-dioxin discharges from a former pesticide manufacturing plant to the Lower Passaic River.

Based on chemical fingerprinting and other lines of scientific evidence, a former pesticide manufacturing plant in Newark, New Jersey (U.S.A.) has been implicated in numerous journal articles as the major source of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the sediments of the Lower Passaic River (LPR). Although the site has been extensively studied for over three decades, no previous study has identified a pathway capable of discharging an amount of 2,3,7,8-TCDD comparable to the mass estimates made for 2,3,7,8-TCDD in the sediments of the LPR and Newark Bay, or examined the timing of specific manufacturing processes at the site in relation to 2,3,7,8-TCDD concentrations in dated sediment cores. A reconstruction of the historical operations at this site was performed, supporting it as the major source of 2,3,7,8-TCDD to the LPR. A 2,4,5-trichlorophenol purification process, utilized prior to September 1954, was specifically identified as a significant source of 2,3,7,8-TCDD to the LPR. This purification process generated a dioxin-rich sludge that was discharged to the river prior to September 1954. Annual 2,4,5-trichlorophenol production, coupled with modeling to predict concentrations of 2,3,7,8-TCDD, indicate that 2,3,7,8-TCDD discharges to the LPR from this one process (20-80 kg) are consistent with mass estimates of 2,3,7,8-TCDD in the river (30-50 kg). 2,3,7,8-TCDD and cesium-137 data from nearby sediment cores support this purification process as a major pathway by which 2,3,7,8-TCDD entered the river.

William J. Morrison (1860-1926): co-inventor of the cotton candy machine.

William James Morrison (1860-1926), from Nashville, Tennessee was a noted dentist, lawyer, author and leader in civic and political affairs. An 1890 graduate of the University of Tennessee Dental College, Dr. Morrison became President of the Tennessee State Dental Association in 1894. He had a wide interest in both science and politics, and was personally associated with both William Jennings Bryan and President Woodrow Wilson. Additionally, he was a popular author of children's books and particularly effective in fostering reading among youngsters. Also, Dr. Morrison patented several important inventions. He developed a process for extracting oils from cotton seed, and converting them into a lard substitute. Likewise, he devised a chemical process to purify the public drinking water for Nashville. In 1897, he and John C. Wharton (a fellow Nashville candy maker) conceived and co-patented an "electric candy machine" which produced cotton candy (then called "Fairy Floss".) This article provides background information about the production of spun sugar during medieval times and later, it describes the development of their cotton candy machine, the process of its operation and details about its eventual worldwide commercialization. In addition, it discusses the introduction of this new confection to the public, during the 184 day, Louisiana Purchase Exposition, held in St. Louis, MO. in 1904. In late 1926, Dr. Morrison, died of a stroke at age 66.

Role of disinfection in suppressing the spread of pathogens with drinking water: possibilities and limitations.

Transmission of pathogens with drinking water is a widespread problem, which affects not only the countries with low hygienic standards but the industrialized countries as well. The pathogens are excreted by man or animals and are picked up orally. Chlorination of drinking water has been introduced to the water supply in the beginning of the 19th century in order to stop the spreading of pathogens especially typhoid fever by drinking water. Despite the worldwide use of chlorine for disinfection of drinking water, water-mediated disease outbreaks occur again and again. Disinfection of drinking water with chlorine has undoubtedly contributed to the reduction of typhoid fever mortality. However, it must be clear that other factors play an important role in the mortality drop. Filtration of water is a long-known and very effective process for eliminating pathogens from the drinking water. Pathogens in particles cannot be killed sufficiently by a chemical disinfectant. Even small fecal particles have to be eliminated reliably from the water by filtration. Disinfection of drinking water cannot replace filtration. The disinfection should be used to minimize the residual risk due to the presence of pathogens in the water but cannot be used for bringing fecally contaminated water into a hygienically sound condition.

Water-quality control, monitoring and wastewater treatment in Lithuania 1950 to 1999.

The Lithuanian water-management system developed on the basis of Soviet regulations in 1950-1990. Surface-water quality monitoring started in the 1950s, and the system was improved in the 1960s. Today, 48 rivers are being monitored using up to 70 parameters. Statutory monitoring of discharges started in 1962, wastewater standards were issued in 1957 and 1966, and then revised in 1996. Wastewater-treatment plants were built first in rural areas, in factories since the 1950s, and later in towns. Since 1991, large capacity municipal plants have been constructed with foreign assistance. Water quality has improved in some rivers since 1970, but Lithuania's main river, Nemunas, remains moderately polluted. The lower Nemunas is especially affected by discharges of municipal and industrial wastewater from Sovietsk and Neman (Russia), which account for half of the total loading. Hydrobiological data of 1994-1998 indicated the eutrophication of the Curonian Lagoon, and bacteriological pollution and blue-green algae blooms in the Baltic Sea north of Klaipeda.

The struggle for a cleaner urban environment: water pollution in Malmö 1850-1911.

This article focuses on the emergence of water pollution problems in the city of Malmö and on how they were discussed and solved. Various countermeasures were proposed and considered, but finally the discharge of wastewater into the Sound of Oresund was regarded as the best solution. As a result, a local pollution problem was transformed into a regional issue. The solutions adopted in Malmö are briefly compared with decisions made in Gothenburg and Stockholm.

The pollution and protection of the inner Oslofjord: redefining the goals of wastewater treatment policy in the 20th century.

The main source of pollution in the inner Oslofjord in the 20th century has been municipal sewage discharges from the city of Oslo. At the beginning of the 20th century, pollution was limited to the coastal waters and the harbor area of Oslo, in the vicinity of sewer outlets. High bacteria content caused a health hazard that city authorities attempted to reduce by constructing a sewerage system, including intercepting sewers and wastewater-treatment plants. Due to population growth, the impact area of increasing wastewater loading expanded. The entire inner Oslofjord was found to be affected in the 1930s. Scientific studies linked municipal sewage discharges to an increase in the algal production. In the 1940s, the bottom layers were found to be anoxic. The Oslo sewerage authorities were aware of the fjord's pollution, but regarded organic matter as the major problem and the activated sludge method as the best solution. The role of nutrients was not commonly acknowledged until in the late 1960s. Phosphorus removal was taken into use in the 1970s, and nitrogen removal was introduced in the late 1990s. Removal of nutrients has resulted in the slow recovery of the fjord.

Urban impact in the history of water quality in the Stockholm archipelago.

From the historical perspective, the increasing number of inhabitants in the city of Stockholm has had a negative effect on water quality in the surrounding lakes and coastal region. Government control and measures taken to improve water quality have been in progress since the mid-19th century. Water conditions in the 19th century, compared to later years is difficult to assess from the first chemical and biological investigations, due to infrequent sampling and the different parameters and methods used. However, a retrospective evaluation of water quality can be made on the basis of results from plankton investigations, which began in the early 20th century. The occurrence of the cyanobacteria Planktothrix agardhii, which indicates nutrient-rich conditions, was surveyed during summers with similar temperature conditions throughout the 20th century. The results show that eutrophied conditions probably prevailed in the Stockholm archipelago from the beginning of 20th century until the early 1990s. In the last decade of the 20th century, water quality appeared to be better than 100 years earlier. Today's better water conditions are most probably an effect of proper measures taken in wastewater treatment.

Stages of municipal water protection in Vaasa during the 20th century.

Vaasa, located on the Gulf of Bothnia, is representative of medium-sized cities on the coast of the Baltic Sea. This article discusses Vaasa's impact on the surrounding sea area and the city's reactions to the pollution of the sea. The history of wastewater treatment in Vaasa strongly suggests that first-generation environmental problems, e.g. the pollution problems caused by municipal wastewater discharges, were solved only as a last resort after a prolonged development process. The first wastewater treatment plant was completed in 1953. In the long run, municipal policies became more costly for the environment and for the town itself than would have been the case if the option of constructing a central treatment plant had been accepted in the first instance. In Vaasa, the environment itself did not provide the incentive, the change was motivated by health risks, noxious odors and poor outdoor-bathing possibilities that resulted from municipal wastewater discharges. No action was taken until ultimately forced by necessity. This article also discusses social science approaches to environmental studies.

Some thoughts about future perspectives of water and wastewater management.

The ideals of sustainability have a longer history than is sometimes realised, as they can be traced back to the insights of Von Carlowitz in 1713. However in the intervening centuries early successes in sanitation based on the "flushing sewer" led engineers to focus too much on sewerage-based solutions that are increasingly uneconomic and unequal to the challenges arising from population growth and urbanisation. The future strategy for globally sustainable sanitation will surely involve source separation and recycling and reuse: these are the technologies that environmental scientists and engineers should now be addressing.

"Clever Microbes": bacteriology and sanitary technology in Manchester and Chicago during the progressive age.

A neglected aspect of the history of germ theories is its use in the purification of sewage. In the 1890s, progressive reformers rapidly developed bacteriological methods of wastewater treatment. A comparison of the United Kingdom's Manchester and the United States' Chicago shows, however, that science and technology were mediated by political culture and institutions. In Manchester, a politics of deference and strong extralocal government gave the authority of scientific expertise a decisive role in policy formation. In Chicago, devolution of power to the ward bosses meant a quarter-century of defiance against the national authority and its effort to get the city to install a modern sanitation system.

Reconstructing long-term trends in municipal sewage discharge into a small lake in northern Manitoba, Canada.

Ross Lake lies within the City of Flin Flon (Manitoba, Canada), a mining community originally formed by the Hudson Bay Mining and Smelting Company (now Hudbay Minerals Inc.) in 1927. At the time of this investigation, a continuous effluent stream from Hudbay Minerals (approximately 80 years) and a discontinuous and unknown amount of raw and minimally treated municipal sewage (>20 years, likely ending in 1951) was discharged into the north basin of the lake. Maximum concentrations of fecal sterols, such as coprostanol and terrestrial phytosterols, such as: ß-sitosterol, campesterol, stigmastanol were measured in vertical sections of sediment cores, collected from Ross Lake, in the 15-16-cm section, which likely corresponds to the 1930s. Concentrations of coprostanol increased from <1 µg g(-1) in older sediments, to 252.3 µg g(-1) organic carbon at the peak. Observed changes in concentrations of sterols, in combination with radiometric dating and changes to sediment physicochemical characteristics, support the conclusion that sediments of a depth of less than 17.5-cm depth were deposited during the post-industrial era from approximately 1930 onwards. Ratios of coprostanol to cholesterol>1, peaking at 3.6 are consistent with anecdotal information that municipal sewage was discharged into Ross Lake during the early years of urbanization, prior to changes in treatment of sewage and discharge practices that began in 1951. Finally, historical concentrations of terrestrial phytosterols followed trends similar to those of coprostanol and cholesterol and may possibly be the result of an increase in the flux of terrestrial organic matter into Ross Lake as the result of regional deforestation due to logging and fire.