The Wastewater Purification Plant (EDAR) in Cambrils, Tarragona, was the setting for a solution deployed by Bioconservación, a gas absorption and air purification specialist. The project involved covering over the settling tanks to prevent hydrogen sulphide dissolved in the water from polluting the surrounding air.
The H2S (hydrogen sulphide) dissolved in water as it arrives at the tank in mini-waterfalls is released into the atmosphere again, and this can pollute the surrounding air and create social problems. Covering the waterfalls prevents H2S from escaping into the surrounding air, and instead it is conveyed to two gas extraction and treatment units in close proximity. Each unit has a 750 m3/h extraction capacity, and this substantially reduces odours and pollutants.The Catalan Water Agency (ACA) commissioned a project to monitor the efficiency of the facility. This involved fitting a perimeter lining inside both primary tanks and installing two BIO-DS750 SAC units in each, filled with the Biocarb OX adsorbent (80% H2S adsorption capacity by weight). The first surprise was the discovery of H2S concentrations of up to 300 ppm at each BIO-DS750 SAC inlet. It was not possible to conduct the preliminary survey accurately.