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.

ANTI-ODOUR TREATMENT ON 100% WOOL FABRIC USING COLORANTS FROM COFFEE GROUND RESIDUES

Coffee ground residues is considered as biomass and organic wastes that can be used for further application due to their deodorant properties. The purpose of this study is applying anti-odor treatment on 100% wool fabric by bi-functional dyeing process with colorant extracted from coffee ground residues. The extraction was done with water at 100ºC with different extracting ratio. The knitted wool fabrics were IR dyed with extracting solutions at 80ºC, 90 min, then dried at 60ºC, 30 min. The effectiveness of treatment on wool fabric was determined by colour strength K/S and FT-IR spectra. The colour fastness after hand wash were tested by AATCC standard to confirm the treatment after laundering, exhibited good color fastness at grade 4-5. The anti-odor effect was also evaluated according to AATCC 2017 Methods for Odor Evaluation of Textiles and other Materials for fabric before and after laundering, which proved the efficiency of deodorization of treated fabric by coffee residues extraction, even with strong odor like onion

Bacterial community diversity in a full scale biofilter treating wastewater odor

Constantly, the odors coming from sewage plants are considered a problem by the population. The purpose of this study was to evaluate the microbial community present in a full scale biofilter used for odor treatment. The filter was packed with peat. The main gas treated was hydrogen sulphide (H2S). The removal efficiency reached 99%, with an empty bed residence time of 30 seconds. Molecular analysis can enhance our understanding of the microbial communities in biofilters treating wastewater odor. The analysis made to characterize microbial community was High-throughput 16S rRNA sequencing analysis MiSeq® Illumina. The sampling, carried out in the year 2015, was seasonal (summer and winter) and spatial (depth and position in the biofilter). In this study, a total of 206,174 raw sequence reads for six samples were analyzed using Mothur software (v 1.33.3) based on MiSeq SOP protocol. After Mothur analysis, the results of the bacterial community were explored at the Phylum and Genus levels. In this study, the efficiency removal of hydrogen sulfide reached values greater than 99% during the monitoring, and the main bacterial genera found were Acidotermus, Telmatobacter, Methylovirgula and Bryobacter representing the bacterial community active in the transformation of H2S into a system with long operating time.