Depuración de aguas residuales urbanas y concentración de metales en fangos digeridos

[ES] La progresiva implantación de plantas de tratamiento de aguas residuales urbanas ha ido estableciendo una experiencia en el conocimiento de la eficacia de tratamiento de los diversos parámetros en plazos largos de funcionamiento. El análisis y comparación de resultados y tecnologías debe pennitir conocer las características de fiabilidad en la operación y el comportamiento frente a los diversos aspectos de la nonnativa legal. Además, el análisis en diferentes épocas del año puede producir distintos resultados o conclusiones. En este trabajo se ha tomado para el análisis una planta de tratamiento convencional, estudiando inicialmente los porcentajes medios de eliminación de diferentes parámetros, en relación asimismo con las necesidades que debe satisfacer. En condiciones de alta carga orgánica, la concentración de nitrógeno y algún tóxico especial parecen plantear las mayores dificultades. Se ha deseado focalizar la atención en el proceso de concentración de metales que se. produce en las plantas con tratamiento anaerobío de fangos. Por este motivo se Uevó a cabo un estudio de la evolución de metales en la depuración y la concentración de fangos digeridos. El fenómeno resulta de interés para analizar la calidad de las aguas que se obtienen, aunque debe considerarse también la concentración de metales en el destino final que se dé a los fangos tratados.

Parámetros de contaminación y normativa en colectores urbanos

[ES] La contaminación por aguas residuales urbanas es uno de los problemas de mayor importancia para mantener un nivel de calidad aceptable del agua, debido al número elevado de fuentes, a la participación de la contaminación difusa y a la elevada concentración de materia orgánica. La normativa legal plantea unos límites eflDidos, pero no se han realizado campañas de seguimiento de forma suficiente para su comprobación, particularmente en estiaje. El problema se complica por la diversidad apreciable que se observa y la necesidad de dar significación estadística a las conclusiones. En este trabajo, junto a un análisis del seguimiento de una docena de parámetros en diversos colectores de aguas residuales de una zona urbana, se pretende eparar/advertir la dificultad que presenta cada uno de eUos para el cumplimiento legal en relación con las caraterísticas de las fuentes de procedencia y la situación estacional durante el análisis. Además, se pretende buscar de una forma incial las posibles relaciones que se presentan entre las variaciones simultáneas de dichos parámetros. Algunos de eUos muestran una relación clara por lo que podría establecerse alguna dependencia funcional, mientras que en otros casos el problema resulta excesivamente complejo por la necesidad de disponer de más información para Uegar a establecer alguna relación.

Studies on the effect of pollution, with special reference to benthos, in Cochin backwaters

Considerable number of factories and related establishments forming an industrial complex are located in the upper reaches of the estuary from Varapuzha about 10km from cochin barmouth to Alwaye while lower down are the retting grounds at Vaduthala and nearby places at about 5km from the barmouth. Muncipal wastes from the city population of over 5 lakhs effluents and solid waste from several fish processing factories and other land washings around Willington island reach the estuary move near its lower reaches close to the barmouth. Cochin estuary is the biggest in the state providing water front for the largest number of industries from the small retting grounds of Vaduthala to the huge fertilizer factories of Udyogamandal and receiving the highest quantity of town sewage and land drainage. The estuary contributes itself as nursery ground for shrimps and related fishery as well. Study of this estuary therefore contributes to a typical environment as regards to pollution problems in the tropics and hence the scope of the present investigation

Outlines of modern farming,

v. 1. Soils, manures, and crops. 1872.--v. 2. Notes, historical and practical on farming and farming economy. 1872.--v. 3. Stock: cattle, sheep, and horses. 1873.--v. 4. The dairy, pigs, poultry. 1871.--v. 5. Utilisation of town sewage, irrigation, reclamation of waste land. 1865.

Influence of anthropogenic contamination on groundwater chemistry in Mulbagal town, Kolar District, India

Geochemical studies are performed to examine the impact of leachate infiltration from on-site sewage disposal systems on the groundwater chemistry in Mulbagal town, Kolar District, Karnataka State, India. The leachate infiltration imposed nitrate concentrations ranging from 4 mg/L to 388 mg/L in the groundwater samples; it was observed that 79% of the samples exhibited nitrate concentrations in excess of drinking water permissible limit (45 mg/L). The average (of 43 measurements) E. coli levels in the groundwater samples corresponded to 189 MPN/100 mL and 55% of the samples tested exhibit pathogen contamination. Results also showed that the groundwater in the study area is characterized by acidic pH, large calcium + magnesium ion and Na/Cl ratios of < unity causing majority of the ground water samples to classify as Ca-Mg-Cl type and Na-Cl type. Saturation index (SI) computation using Visual MINTEQ program showed that the groundwater samples are under-saturated with respect to calcite. The theoretical SI values (of calcite) however suggested that the groundwater samples ought to be over-saturated with calcite. Under-saturation of the groundwater samples with calcite is attributed to increased dissolution of the mineral in the acidic environment of the groundwater.

The impact of solid and liquid wastes from a rural town on the Chorobamba River Oxapampa, Peruvian Amazon

The goal of this study was to determine the instantaneous vs. integrated effects of waste on the water quality of the Chorobamba River. I sampled 9 stations upstream and downstream of the Town of Oxapampa, Peru during the dry season (June-August) of 2004. I measured in-situ parameters such as pH, DO, temperature, etc. as well as vegetation, riverbank erosion, nutrients (N03, NH4, P04), coliform bacteria and macroinvertebrate communities to determine the current conditions of the river, as well as the integrated effects of pollution. Although water quality conditions remained stable, high fecal coliform concentrations and macroinvertebrate communities indicate deterioration in river health over a longer period of time. If riparian areas along the Chorobamba continue to decrease and if inputs of sewage into the rivers continue to increase, as a function of population, then, conditions will continue to deteriorate in the coming years.

Sewage disposal and wildlife health in Antarctica

Sewage and its microbiology, treatment and disposal are important to the topic of Antarctic wildlife health because disposal of untreated sewage effluent into the Antarctic marine environment is both allowed and commonplace. Human sewage contains enteric bacteria as normal flora, and has the potential to contain parasites, bacteria and viruses which may prove pathogenic to Antarctic wildlife. Treatment can reduce levels of micro-organisms in sewage effluent, but is not a requirement of the Environmental Protocol to the Antarctic Treaty (the Madrid Protocol). In contrast, the deliberate release of non-native organisms for any other reason is prohibited. Hence, disposal of sewage effluent to the marine environment is the only activity routinely undertaken in Antarctica knowing that it will likely result in the release of large numbers of potentially non-native species. When the Madrid Protocol was negotiated, the decision to allow release of untreated sewage effluent was considered the only pragmatic option, as a prohibition would have been costly, and may not have been achievable by many Antarctic operators. In addition, at that time the potential for transmission of pathogens to wildlife from sewage was not emphasised as a significant potential risk. Since then, the transmission of disease-causing agents between species is more widely recognised and it is now timely to consider the risks of continued discharge of sewage effluent in Antarctica and whether there are practical alternatives.

Comparison of molecular markers to detect fresh sewage in environmental waters

Human-specific Bacteroides HF183 (HS-HF183), human-specific Enterococci faecium esp (HS-esp), human-specific adenoviruses (HS-AVs) and human-specific polyomaviruses (HS-PVs) assays were evaluated in freshwater, seawater and distilled water to detect fresh sewage. The sewage spiked water samples were also tested for the concentrations of traditional fecal indicators (i.e., Escherichia coli, enterococci and Clostridium perfringens) and enteric viruses such as enteroviruses (EVs), sapoviruses (SVs), and torquetenoviruses (TVs). The overall host-specificity of the HS-HF183 marker to differentiate between humans and other animals was 98%. However, the HS-esp, HS-AVs and HS-PVs showed 100% hostspecificity. All the human-specific markers showed >97% sensitivity to detect human fecal pollution. E. coli, enterococci and, C. perfringens were detected up to dilutions of sewage 10_5, 10_4 and 10_3 respectively.HS-esp, HS-AVs, HS-PVs, SVs and TVs were detected up to dilution of sewage 10_4 whilst EVs were detected up to dilution 10_5. The ability of the HS-HF183 marker to detect freshsewagewas3–4 orders ofmagnitude higher than that of the HS-esp and viral markers. The ability to detect fresh sewage in freshwater, seawater and distilled water matrices was similar for human-specific bacterial and viral marker. Based on our data, it appears that human-specific molecular markers are sensitive measures of fresh sewage pollution, and the HS-HF183 marker appears to be the most sensitive among these markers in terms of detecting fresh sewage. However, the presence of the HS-HF183 marker in environmental waters may not necessarily indicate the presence of enteric viruses due to their high abundance in sewage compared to enteric viruses. More research is required on the persistency of these markers in environmental water samples in relation to traditional fecal indicators and enteric pathogens.

Evaluation of multiple sewage-associated bacteroides PCR markers for sewage pollution tracking

The host specificity of the five published sewage-associated Bacteroides markers (i.e., HF183, BacHum, HuBac, BacH and Human-Bac) was evaluated in Southeast Queensland, Australia by testing fecal DNA samples (n = 186) from 11 animal species including human fecal samples collected via influent to a sewage treatment plant (STP). All human fecal samples (n = 50) were positive for all five markers indicating 100% sensitivity of these markers. The overall specificity of the HF183 markers to differentiate between humans and animals was 99%. The specificities of the BacHum and BacH markers were > 94%, suggesting that these markers are suitable for sewage pollution in environmental waters in Australia. The BacHum (i.e., 63% specificity) and Human-Bac (i.e., 79% specificity) markers performed poorly in distinguishing between the sources of human and animal fecal samples. It is recommended that the specificity of the sewage-associated markers must be rigorously tested prior to its application to identify the sources of fecal pollution in environmental waters.

Railways, Urban Development and Town Planning in Britain: 1948–2008, Haywood R. Ashgate (2009). £65.00, ISBN: 9780754673927

This book is a thorough investigation of the relationship between land use planning and the railways in Britain, through review of the factors affecting the two sectors and their integration during the period of public ownership. The rationale behind the book is explained as a timely analysis of the dynamic correlation involving town planning and management of the railway in a period when growing congestion on the road network is forcing people to look for alternative modes and capacity is badly needed to accommodate this increased demand for travel. The book calls for a modal shift from road to rail for passenger and freight traffic.

Evaluating sewage associated JCV and BKV polyomaviruses for sourcing human fecal pollution in a coastal river in Southeast Queensland Australia

In this study, the host-sensitivity and -specificity of JCV and BKV polyomaviruses were evaluated by testing wastewater/fecal samples from nine host groups in Southeast Queensland, Australia. The JCV and BKV polyomaviruses were detected in 48 human wastewater samples collected from the primary and secondary effluent suggesting high sensitivity of these viruses in human wastewater. Of the 81 animal wastewater/fecal samples tested, 80 were PCR negative for this marker. Only one sample from pig wastewater was positive. Nonetheless, the overall host-specificity of these viruses to differentiate between human and animal wastewater/fecal samples was 0.99. To our knowledge, this is the first study in Australia that reports the high specificity of JCV and BKV polyomaviruses. To evaluate the field application of these viruses to detect human fecal pollution, 20 environmental samples were collected from a coastal river. Of the 20 samples tested, 15% and 70% samples exceeded the regulatory guidelines for E. coli and enterococci levels for marine waters. In all, 5 (25%) samples were PCR positive for JCV and BKV indicated the presence of human fecal pollution in the studied river. The results suggest that JCV and BKV detection using PCR could be a useful tool for the identification of human sourced fecal pollution in coastal waters.

Quantitative PCR assay of sewage-associated Bacteroides markers to assess sewage pollution in an urban lake in Dhaka, Bangladesh

This paper aimed to assess the magnitude of sewage pollution in an urban lake in Dhaka, Bangladesh by using Quantitative PCR (qPCR) of sewage-associated Bacteroides HF183 markers. PCR was also used for the quantitative detection of ruminant wastewater-associated CF128 markers along with the enumeration of traditional fecal indicator bacteria, namely, enterococci. The number of enterococci in lake water samples ranged from 1.1 x 104 to 1.9 x 105 CFU/100 ml of water. From the 20 water samples tested, 14 (70%) and 7 (35%) were PCR positive for the HF183 and CF128 markers, respectively. The numbers of the HF183 and CF128 markers in lake water samples were 3.9 x 104 to 6.3 × 107 and 9.3 x 103 to 6.3 x 105 genomic units (GU)/100 ml of water, respectively. The high numbers of enterococci and the HF183 markers indicate sewage pollution and potential health risks to those who use the lake water for non-potable purposes such as bathing and washing clothes. This is the first study that investigated the presence of microbial source tracking (MST) markers in Dhaka, Bangladesh where diarrhoeal diseases is one of the major causes of childhood mortality. The molecular assay as used in this study can provide valuable information on the extent of sewage pollution, thus facilitating the development of robust strategies to minimise potential health risks.

Communicating friendships : a case study of women in an Australian 'seachange' town

This thesis proposes =friendworks‘ as an important sub-group of social networks, comprised of networks of friends. It investigates friendworks of a particular group of adult Australian women as a way of understanding neglected aspects of social networking practices. Friendworks are contextualised to highlight two main themes of interest: population mobility and communication practices. The impact of relocation on individuals, local communities and the wider society is explored through a case study of female friendworks in a seachange community. Research findings point to the importance of friendworks in building and cohering social and emotional support, well-being, belonging and senses of place and community. Different types of communication methods were used by research participants for mediating different kinds of social ties within the friendworks considered here. Communication patterns were influenced by geographical proximity to friends, and the type of social support required of them (emotional, instrumental or companionship). Most findings were consistent with broader social patterns of communication. For example, face-to-face interactions were the dominant and most favoured communication method between local friends, regardless of whether they were weak or strong ties. The fixed-telephone and the internet were commonly in use to maintain old and geographically distant social ties, while mobile phones were used the least among friends in comparison with other communication methods. The key finding of this thesis is that friendworks are an extremely important solid network in contemporary society, providing mooring relations in a mobile world. Paradoxically, however, for women in this study, the mobile phone, which is popularly perceived as a flexible, multi-purpose communication technology for people on the move, was the least versatile of all technologies for maintaining friendworks. The cost of services was the main inhibitor here. The internet was found to be the most versatile communication technology and was used to support various types of social ties: strong, weak, local and distant. This thesis also highlights the value of the concept of friendworks as well as networks for communication research and policy investigating individuals‘ motivations and practices.