Hydrogen sulphide and VOC removal in biotrickling filters: Comparison of data from a full-scale, low-emission unit with kinetic models

Absorption processes in reducing the odor nuisance of wastewater

Deep social awareness, especially in highly developed countries, imposes pressure on entrepreneurs and service providers, forcing them to undertake effective actions to minimize the effects of their activities also in terms of the emission of malodorous substances. The article presents information on the absorption processes harnessed in the deodorization of gases from wastewater management and the characteristics of these gases. Avoiding emissions is not always possible, hence there is a need to conduct an inventory of such gases and use deodorization methods. The specificity of gases from wastewater management and their prevalence urge the search for cheap and easy-to-use deodorization methods. It is obvious that the selection of deodorization technology is driven by many factors and should be preceded by a thorough analysis of the possibilities and limitations of various solutions. The aim of this article is, therefore, to present the characteristics of gases from wastewater management and to discuss various technologies based on absorption processes as a technology for deodorizing such gases in order to help potential investors choose an emission-reducing method suitable for particular conditions.•Malodorous substances in wastewater management.•Deodorization using water and chemical absorption.•Deodorization using biological purification.

Removal of Volatile Organic Compounds (VOCs) from Air: Focus on Biotrickling Filtration and Process Modeling

Biotrickling filtration is a well-established technology for the treatment of air polluted with odorous and volatile organic compounds (VOCs). Besides dozens of successful industrial applications of this technology, there are still gaps in a full understanding and description of the mechanisms of biotrickling filtration. This review focuses on recent research results on biotrickling filtration of air polluted with single and multiple VOCs, as well as process modeling. The modeling offers optimization of a process design and performance, as well as allows deeper understanding of process mechanisms. An overview of the developments of models describing biotrickling filtration and conventional biofiltration, as primarily developed and in many aspects through similar processes, is presented in this paper.

Osmotically assisted reverse osmosis, simulated to achieve high solute concentrations, at low energy consumption

Microbial electrosynthesis (MES), is an emerging technology, for sustainable wastewater treatment. The dilute acetate solution, produced via MES, must be recovered, as dilute solutions can be expensive to store and transport. The acetate is expensive and environmentally damaging to recover by heat-intensive evaporative methods, such as distillation. In pursuit of a better energy economy, a membrane separation system is simulated to raise the concentration from 1 to 30 wt%, at a hydraulic pressure of approximately 50 bar. The concentrate is then simulated to be heat dried. Reverse osmosis (RO) could rase the acetate concentration to 8 wt%. A novel adaptation of osmotically assisted reverse osmosis (OARO) is then simulated to increase the concentration from 8 to 30 wt%. The inclusion of OARO, rather than a standalone RO unit, reduces the total heat and electric power requirement by a factor of 4.3. It adds to the membrane area requirement by a factor of 6. The OARO simulations are conducted by the internal concentration polarisation (ICP) model. Before the model is used, it is fitted to OARO experimental data, obtained from the literature. Membrane structure number of 701 µm and permeability coefficient of 2.51 L/m²/h/bar are ascertained from this model fitting exercise.

Full-Scale Odor Abatement Technologies in Wastewater Treatment Plants (WWTPs): A Review

The release of air pollutants from the operation of wastewater treatment plants (WWTPs) is often a cause of odor annoyance for the people living in the surrounding area. Odors have been indeed recently classified as atmospheric pollutants and are the main cause of complaints to local authorities. In this context, the implementation of effective treatment solutions is of key importance for urban water cycle management. This work presents a critical review of the state of the art of odor treatment technologies (OTTs) applied in full-scale WWTPs to address this issue. An overview of these technologies is given by discussing their strengths and weaknesses. A sensitivity analysis is presented, by considering land requirements, operational parameters and efficiencies, based on data of full-scale applications. The investment and operating costs have been reviewed with reference to the different OTTs. Biofilters and biotrickling filters represent the two most applied technologies for odor abatement at full-scale plants, due to lower costs and high removal efficiencies. An analysis of the odors emitted by the different wastewater treatment units is reported, with the aim of identifying the principal odor sources. Innovative and sustainable technologies are also presented and discussed, evaluating their potential for full-scale applicability.