Proposing a new strategy to minimize domestic wastewater under the influence of human factor in Antananarivo, Madagascar

Water pollution happens when organic or inorganic materials, even solid materials are poured into the water which degrades its physicochemical quality. The purpose of this study is, to identify, to describe and to highlight the major source of wastewater, and proposing a new strategy for minimization in Antananarivo, Madagascar. Antananarivo is one of the dirtiest cities on the African continent according to the classification made by Forbes magazine and Afrikmag. To know the current situation, an in-situ analysis of the physical parameters: colour, odour, turbidity and electrical conductivity using the turbidimeter and the conductometer are measurable parameters in the field. Major elements analyses, BOD5 using Oxytop method analysis, COD using Potassium dichromate, suspended solids using membrane filtration are measured in the laboratory. The turbidity of the discharges fluctuates from 127 NTU to 421 NTU). For electrical conductivity, it varies from 217 to 977μS.cm−1, BOD5 is of the order 3 to 88mg.L−1, while COD diverges from 279mg.L−1 to 730mg.L−1 and suspended matter oscillates from 400mg.L−1 to 60mg.L−1. Some parameters and concentrations exceeded the discharge standard Malagasy and the international Standard. The best solution for the management of water quality in the face of domestic pollution is the treatment of wastewater before discharge into receiving environments and the sensibilization of the population to take their responsibility.

Measuring the water balance in stormwater control measures

Stormwater control measures (SCMs), also frequently referred to as sustainable urban drainage systems (SUDS), are of growing importance in cities, as part of a global move towards mitigating the impacts of stormwater on receiving environments. They need to be monitored as parts of UDSM systems but require specific and sometimes innovative methods and sensors. This is particularly the case for SCMs such as swales, rain-gardens, bioretention filters, infiltration trenches, green roofs, etc., which have complex and varied configurations and hydrologic behaviour. This chapter deals with measuring the water balance in SCMs by accounting for its various components: inflows, outflows, overflows, storage, infiltration, exfiltration, intrusion, evaporation, and evapotranspiration. It presents a range of suitable methods and tools, indicates key points to consider, and discusses possible difficulties in obtaining accurate monitoring data. Routine monitoring of decentralized and diversified SCMs is still an emerging field for both researchers and practitioners. A significant evolution is therefore expected with its generalization in the next years.

Impact of mine waste on the quality of surrounding agricultural soils in Toussit and Sidi Boubker, Morocco: a case study

The Oriental region, in Morocco, is surrounded by the Algerian border to the East, the Atlas to the West, the Mediterranean to the North and the desert to the south. This region has benefited from the intense mining activity that has played an important role in the national economy. The intensification of mining activity in the Touissit and Sidi-Boubker mines has left behind the closure of tons of waste in the shelter without a plan of conservation. These mine waste storage sites still contain very high levels of metallic elements such as Iron (Fe), which, after a decade of shutdowns, are likely to pollute vulnerable receiving environments, posing a threat to wildlife ecosystems, flora, and to public health. The objective of this study was to assess Fe concentrations at several locations around these mine waste heaps. The results of physicochemical analyses of soils collected over two different periods (wet and dry seasons) showed maximum Fe element concentrations of 10596 mg/kg, with an average concentration of 8913 mg/kg. These Iron contents are found at concentrations exceeding tolerance standards for normal soil.

Advancing Canadian Wastewater Assets (ACWA) bridges laboratory-scale testing of wastewater technologies and effects on receiving environments

Laboratory assessments of organism responses to wastewater are inexpensive, easily replicated, and offer control and precision, yet are often so reduced in temporal and spatial scale that results are difficult to apply to receiving environments. Whole-system experiments are expensive, lack true replication, and can be logistically challenging, yet offer the best insight as to how ecosystems will respond to effluent inputs. Advancing Canadian Wastewater Assets (ACWA), which includes a wastewater treatment plant, analytical labs, and research streams, provides unique infrastructure to test new wastewater treatment technologies, demonstrate technology benefits by direct analytical chemistry, and determine receiving environment effects. The ability to measure temperature, conservative ions, and dissolved oxygen in 12 replicated, naturalized streams allows physical modelling and biological monitoring consistent with larger, natural rivers. Assessments of receiving environment data could guide policy development for safe discharge of emerging contaminants and develop strategies to reduce development and persistence of antimicrobial resistance.