Effects of various compounds on the biological performance of the THIOPAQ® reactor and start-up and stabilization of an ANAMMOX® lab-scale reactor

Abstract

Sulphur is the tenth most abundant element in the universe. It is a key element to sustain life on Earth being present in all living tissues as it is a constituent of many biologically active compounds and therefore involved in many biochemical reactions. It is also a critical plant nutrient in agriculture, an ingredient in sustainable urban development and an essential input in efforts to slow the loss of productive farm land due to soil degradation and its depletion. However, the biological and geological sulphur cycles have been significantly perturbed by human activities mainly because of sulphur dioxide (SO2) emissions to the atmosphere which contributes to several environment problems. Most of these anthropogenic sources are attributed to the combustion of fossil fuels. Acid rain, health problems, odor irritation and corrosion of steel are well known adverse effects of sulphur pollution. Considering these negative effects, there is a growing need of set up emission control strategies to protect the public health and the environment. THIOPAQ® is a gas desulphurisation technology for the removal of hydroxide sulphide (H2S) from gas streams. The H2S is absorbed in a scrubber under alkaline conditions and then goes into a bioreactor where, once in contact with sulphur-oxidizing microorganisms it is converted in elemental sulphur (S0) under aerobic conditions, which later is separated by a settler. The elemental sulphur, produced by the THIOPAQ® can be then used as a high-quality fertiliser. The goal of this project is to study the effects of various organic compounds on the bioreactor performance, such as microorganism activity, foam formation and properties of the produced sulphur. The experiments are conducted in the Water Application Centre (WAC) in Leeuwarden, the Netherlands, with two different experimental setups: a lab-scale THIOPAQ® bioreactor and a Biological Oxygen Monitoring setup for biomass activity monitoring and acute toxicity tests. This work also covers the maintenance of an ANAMMOX® reactor, an innovative technology that aims to remove nitrogen from wastewater in order to reduce its impact on the environment. This project also took place in the WAC installations.