Mass balance of nitrogen and potassium in urban groundwater in Central Africa, Yaounde/Cameroon.

Mass flow of nutrients from innumerous latrines and septic tanks was assessed to best describe the groundwater quality situation in the urban environment of Yaounde. 37 groundwater samples were taken at the end of dry season 2012 and analysed for nutrient related (NO3(-), NH4(+), NO2(-), K(+), Cl(-), HPO4(2-) and TOC) and physico-chemical ambient parameters. A survey on waste water discharge close to water points constrained point sources from sanitation. The results showed that the median of nitrate concentration exceeds the WHO limit. We realized that EC increases from the geogenic background to very high levels in the urban area within short distance, suggesting anthropogenic input. Dug wells showed nitrate and ammonium in equivalent concentrations, indicating incomplete nitrification and mandating their inclusion into water type classification. The mass turnover of nutrients in urban groundwater scales high in comparison to national statistical figures on fertilizer import for 2012. A mass N,K balance for infiltration water overestimates observed concentrations by a factor of 4.5. The marked balance gap is attributed to dynamic non-equilibrium between input and output. Unresolved questions like a) urban sanitation, b) hygiene & health and c) environmental protection urgently call for closing the nutrient cycle. In the light of Cameroonian strategies on rural development, tackling the groundwater nutrient, urban agriculture, food--NEXUS might partially restore urban and periurban ecosystem services under economical constraints and thus improve living conditions.

Performance of a MBR for the treatment of blackwater.

The paper describes the experience gained in operating a membrane bioreactor (MBR) for the treatment of blackwater. Beside a complete characterization of blackwater, operational conditions and removal efficiency concerning parameters such as COD, BOD(5), nitrogen and phosphorus as well as microbiological parameters were determined. Furthermore the membrane performance was investigated. The results show that in blackwater treatment nitrogen removal is limited in the biological process, because of the blackwater matrix (BOD(5):TKN=1.1:1.0). Blackwater contains a high fraction of soluble, inert COD, which is not degradable by biological operation, only. Phosphorus elimination was negligible, probably induced by precipitation of cellular phosphorus. Although the released permeate was free of the fecal indicators E. coli and streptococcus and met guideline values, a direct reuse as service water is not recommended due to the yellowish coloration.

Техническое руководство по эпидемиологическому надзору за болезнями, связанными с водой

Руководство призвано помочь государствам – Сторонам Протокола по проблемам воды и здоровья, являющегося приложением к Конвенции 1992 года по охране и использованию трансграничных водотоков и международных озер, в создании и/или укреплении своих систем своевременного обнаружения и раннего оповещения, в разработке плана действий в чрезвычайных ситуациях, в создании и укреплении потенциала для принятия ответных мер в случае вспышек заболеваний, связанных с водой, в соответствии со статьей 8 Протокола. В данном руководстве проанализированы основные угрозы здоровью, связанные с водоснабжением и водоотведением, содержится упоминание фундаментальных концепций эпидемиологии и эпидемиологического надзора за заболеваниями, а также даны рекомендации в отношении сбора и анализа данных. Руководство поможет странам в успешной реализации их усилий по обеспечению национальной и международной безопасности общественного здоровья в соответствии с требованиями Международных медико-санитарных правил (2005 г.). Стороны Протокола одобрили данное руководство в ноябре 2010 г.

Technical guidance on water-related disease surveillance

This guidance is intended to assist the countries that are Parties to the Protocol on Water and Health, and other countries in establishing and/or strengthening their detection and early warning systems, contingency plans and capacity to respond to outbreaks of water-related disease. The guidance reviews the main threats to health related to water services, recalls basic concepts of epidemiology and disease surveillance, and advises on data management and analysis. It will therefore also support countries’ efforts towards national and international health security, in line with the International Health Regulations (2005). The Parties to the Protocol approved this guidance in November 2010.

Perceptions of water, sanitation and health: a case study from the Mekong Delta, Vietnam.

In the Mekong Delta in the south of Vietnam about 5.7 million people lack access to safe drinking water and 10 million people in rural areas live without adequate sanitation. Between May and August, 2007 a survey was carried out in An Bin, a peri-urban ward in the Mekong Delta, to gain insight into water, sanitation and health as well as to health-related hygiene behaviour. The study employed a combination of quantitative (standardized questionnaire) and qualitative (focus group discussions, semi-structured interviews) methods. The most important features in the choice of drinking water sources are matters of hygiene and the taste of the water. The majority (74%) of the 120 households surveyed indicated their ownership of a sanitation facility, but the fish pond toilet (64%) which is predominantly utilized is considered to be unimproved sanitation. The local peri-urban population link water and hygiene to health, but sanitation instead to environmental pollution. This and other outcomes lead to the assumption that people have a basic knowledge of proper hygiene behaviour. However, hygiene measures such as hand washing are put into practice in an untimely manner, most likely due to a misconception of risks and/or a lack of background knowledge of cause-effect relationships as well as ingrained habits.

Impact of sewage treatment plants and combined sewer overflow basins on the microbiological quality of surface water.

In a small river catchment, microbiological quality of different sewage treatment plants under regular conditions and in case of heavy rainfall, when combined sewage overflow basins (CSOs) are activated, was examined regarding microbial indicators and pathogens. In the watercourse, no self-cleaning effects could be observed. Small compact treatment plants discharge treated wastewater with a poor microbiological quality compared to river water quality and the quality of treated wastewater of larger plants. During storm water events, concentrations of microorganisms downstream of sewer overflows were approximately two logs higher than during dry weather conditions. Concentrations of parasites decreased slowly during the overflow, in parallel to filterable matter and particle-bound substances. The annual load of microorganisms originating from CSOs significantly exceeds the load from treated effluent of the sewage plants. Thus, an improved hygienic quality of the water course could be achieved by preventing overflows and by enhancing sewage treatment plants.

Disinfectant activity against different morphological forms of Helicobacter pylori: first results.

The pathogenic bacterium Helicobacter pylori, which has infected more than one-half of the world's human population, exists in two morphological forms; the viable helical form and the disputed viable-but-not-culturable coccoid form. Infection by the helical form proceeds through the oral-oral route, while that by the coccoid form, if possible at all, is by the faecal-oral and/or the oral-oral route. The present pilot study addresses the question of disinfectant efficacy against both forms of the bacterium.