Reduction Of Pollutant Concentrations Research Articles

The nature conservancy: Protecting forests to address climate change

Developing countries are grappling with how to reduce household air pollution (HAP) from cooking with solid fuels and the traditional three stone fire (TSF). Laboratory studies have shown that improved cookstoves may offer reductions in fuel use, emissions of carbon monoxide (CO) and fine particulate matter (PM2.5), yet there is limited evidence from “real-world” settings showing how improved stoves perform compared to the traditional TSF. Our study takes place in a semi-controlled setting in Malawi and was designed to quantify fuel efficiency improvements and air pollutant concentration reductions capabilities of two improved cookstoves. We perform a Water Boiling Test to compare the TSF with the locally produced clay stove known as the Chitetezo Mbaula (CM) and the Philips gasifying stove. We find that the CM uses 53% of the fuel used by the traditional TSF, and produces 59% of CO, and 50% of PM2.5 of the TSF. The Philips stove uses 31% of the fuel, and produces 38% of CO, and 22% of PM2.5 of the TSF. We consider the potential for the wide-scale adoption of these technologies given their relative costs and conclude that lower-cost, intermediate quality cookstoves are an important and realistic first step toward reducing HAP.

Algal-Bacterial Ponding Systems for Municipal Wastewater Treatment in Arid Regions

A pilot plant was constructed to investigate the use of algal-bacterial systems to treat municipal wastewaters in arid regions. The pilot plant consists of sand and oil traps, weir tanks, two facultative ponds (250 m3 holding capacity each), two high-rate ponds (25 m3 holding capacity each), four sedimentation tanks, a sludge digestor, and such auxiliary facilities as a pumping station for wastewater supply, drainage systems, and a site laboratory. The main objectives of the study are to determine the design parameters needed for large-scale algal-bacterial ponds in hot climates and to determine the degree of treatment and disinfection attained in the system by operating the pilot plant. After the algae is separated from the treated water, the final effluent will be used for irrigation, and algae will be used as a soil conditioner. Investigations during start-up, test runs and experiments completed so far focused on the growth of algae and removal of biochemical oxygen demand, chemical oxygen demand, and suspended solids. During the 20-month experimental program, various operating patterns, including series operation of facultative and high-rate ponds, will be investigated. Results obtained so far indicate significant reductions in pollution concentrations.