Improvement in municipal wastewater treatment alters lake nitrogen to phosphorus ratios in populated regions
Tong, Yindong ; Wang, Mengzhu ; Peñuelas, Josep ; Liu, Xueyan ; Paerl, Hans W. ; Elser, James J. ; Sardans, Jordi ; Couture, Raoul Marie ; Larssen, Thorjørn ; Hu, Hongying ; Dong, Xin ; He, Wei ; Zhang, Wei ; Wang, Xuejun ; Zhang, Yang ; Liu, Yi ; Zeng, Siyu ; Kong, Xiangzhen ; Janssen, Annette B.G. ; Lin, Yan - \ 2020
Proceedings of the National Academy of Sciences of the United States of America 117 (2020)21. - ISSN 0027-8424
Anthropogenic source - Aquatic ecosystem - Nutrient balance - Wastewater treatment - Water quality change
Large-scale and rapid improvement in wastewater treatment is common practice in developing countries, yet this influence on nutrient regimes in receiving waterbodies is rarely examined at broad spatial and temporal scales. Here, we present a study linking decadal nutrient monitoring data in lakes with the corresponding estimates of five major anthropogenic nutrient discharges in their surrounding watersheds over time. Within a continuous monitoring dataset covering the period 2008 to 2017, we find that due to different rates of change in TN and TP concentrations, 24 of 46 lakes, mostly located in China's populated regions, showed increasing TN/TP mass ratios; only 3 lakes showed a decrease. Quantitative relationships between in-lake nutrient concentrations (and their ratios) and anthropogenic nutrient discharges in the surrounding watersheds indicate that increase of lake TN/TP ratios is associated with the rapid improvement in municipal wastewater treatment. Due to the higher removal efficiency of TP compared with TN, TN/TP mass ratios in total municipal wastewater discharge have continued to increase from a median of 10.7 (95% confidence interval, 7.6 to 15.1) in 2008 to 17.7 (95% confidence interval, 13.2 to 27.2) in 2017. Improving municipal wastewater collection and treatment worldwide is an important target within the 17 sustainable development goals set by the United Nations. Given potential ecological impacts on biodiversity and ecosystem function of altered nutrient ratios in wastewater discharge, our results suggest that long-term strategies for domestic wastewater management should not merely focus on total reductions of nutrient discharges but also consider their stoichiometric balance.
Considerations for application of granular activated carbon as capacitive bioanode in bioelectrochemical systems
Caizán-Juanarena, Leire ; Sleutels, Tom ; Borsje, Casper ; Heijne, Annemiek ter - \ 2020
Renewable Energy 157 (2020). - ISSN 0960-1481 - p. 782 - 792.
Charge storage - Electricity production - Electrochemical capacitors - Intermittent operation - Microbial fuel cells - Wastewater treatment
In the last decades, the research in Microbial Fuel Cells (MFCs) has expanded from electricity production and wastewater treatment to remediation technologies, chemicals production and low power applications. More recently, capacitors have been implemented to boost the power output of these systems when applied as wastewater treatment technology. Specifically, the use of granular capacitive materials (e.g. activated carbon granules) as bioanodes has opened up new opportunities for reactor designs and upscaling of the technology. One of the main features of these systems is that charge and discharge processes can be separated, which offers multiple advantages over more conventional reactor types. In this manuscript, we discuss several aspects to consider for the application of capacitive granules as bioanodes in MFCs and other bioelectrochemical systems, as well as the recent advances that have been made in applying these granules in various reactor systems. Similarly, we discuss the granule properties that are key to determine system operation and performance, and show that biofilm growth is highly dependent on the efficiency of discharge.
Sulfate reduction for inorganic waste and process water treatment
Bijmans, M.F.M. ; Buisman, C.J.N. ; Meulepas, R.J.W. ; Lens, P.N.L. - \ 2019
In: Comprehensive Biotechnology / Moo-Young, M., Elsevier - ISBN 9780444640468 - p. 384 - 395.
Bioreactors - Sulfate reduction - Wastewater treatment
Many inorganic waste and process streams contain high concentrations of sulfate and are frequently accompanied by high metal concentrations; for example, in the mining and metallurgical industry. Sulfate reduction is a proven process for the treatment of these streams that allows for the recovery of metal sulfides and elemental sulfur. This chapter discusses the knowledge acquired on sulfate reduction from research to full-scale operation. The main focus is on possible electron donors, process conditions, and bioreactor types for sulfate reduction. Current sulfate-reducing applications and future perspectives will be discussed.
Opinion paper about organic trace pollutants in wastewater : Toxicity assessment in a European perspective
Pedrazzani, Roberta ; Bertanza, Giorgio ; Brnardić, Ivan ; Cetecioglu, Zeynep ; Dries, Jan ; Dvarionienė, Jolanta ; García-Fernández, Antonio J. ; Langenhoff, Alette ; Libralato, Giovanni ; Lofrano, Giusy ; Škrbić, Biljana ; Martínez-López, Emma ; Meriç, Süreyya ; Pavlović, Dragana Mutavdžić ; Papa, Matteo ; Schröder, Peter ; Tsagarakis, Konstantinos P. ; Vogelsang, Christian - \ 2019
Science of the Total Environment 651 (2019). - ISSN 0048-9697 - p. 3202 - 3221.
Aquatic ecosystem - Bioassays - Ecotoxicity - Micro-pollutants - Risk assessment - Wastewater treatment
This opinion paper focuses on the role of eco-toxicological tools in the assessment of possible impacts of emerging contaminants on the aquatic ecosystem, hence, on human health. Indeed, organic trace pollutants present in raw and treated wastewater are the pivot targets: a multidisciplinary approach allows defining the basic principles for managing this issue, from setting a proper monitoring campaign up to evaluating the optimal process treatment. Giving hints on trace pollutants fate and behaviour, attention is focused on the choice of the bioassay(s), by analysing the meaning of possible biological answers. Data interpretation and exploitation are detailed with the final goal of providing criteria in order to be able to select the best targeted treatment options. The manuscript deals with conventional and innovative analytical approaches for assessing toxicity, by reviewing laboratory and field assays; illustrative real scale and laboratory applications integrate and exemplify the proposed approach.
Denitrification-potential evaluation and nitrate-removal-pathway analysis of aerobic denitrifier strain Marinobacter hydrocarbonoclasticus RAD-2
Kong, Dedong ; Li, Wenbing ; Deng, Yale ; Ruan, Yunjie ; Chen, Guangsuo ; Yu, Jianhai ; Lin, Fucheng - \ 2018
Water 10 (2018)10. - ISSN 2073-4441
Aerobic denitrification - Denitrifying gene expression - Marinobacter hydrocarbonoclasticus RAD-2 - Nitrogen removal - Wastewater treatment
An aerobic denitrifier was isolated from a long-term poly (3-hydroxybutyrate-co-3- hydroxyvalerate) PHBV-supported denitrification reactor that operated under alternate aerobic/anoxic conditions. The strain was identified as Marinobacter hydrocarbonoclasticus RAD-2 based on 16S rRNA-sequence phylogenetic analysis. Morphology was observed by scanning electron microscopy (SEM), and phylogenetic characteristics were analyzed with the API 20NE test. Strain RAD-2 showed efficient aerobic denitrification ability when using NO3 - -N or NO2 --N as its only nitrogen source, while heterotrophic nitrification was not detected. The average NO3 --N and NO2 --N removal rates were 6.47 mg/(L·h)and 6.32 mg/(L·h), respectively. Single-factor experiments indicated that a 5:10 C/N ratio, 25-40 °C temperature, and 100-150 rpm rotation speed were the optimal conditions for aerobic denitrification. Furthermore, the denitrifying gene napA had the highest expression on a transcriptional level, followed by the denitrifying genes nirS and nosZ. The norB gene was found to have significantly low expression during the experiment. Overall, great aerobic denitrification ability makes the RAD-2 strain a potential alternative in enhancing nitrate management for marine recirculating aquaculture system (RAS) practices.
Retention soil filter as post-treatment step to remove micropollutants from sewage treatment plant effluent
Brunsch, Andrea F. ; Laak, Thomas L. ter; Christoffels, Ekkehard ; Rijnaarts, Huub H.M. ; Langenhoff, Alette A.M. - \ 2018
Science of the Total Environment 637-638 (2018). - ISSN 0048-9697 - p. 1098 - 1107.
Constructed wetlands - Granular activated carbon - Micropollutants - Post-treatment step - Retention soil filter - Wastewater treatment
Retention soil filters (RSFs) are a specific form of vertical flow constructed wetlands for the treatment of rain water and/or wastewater. We have tested 3 pilot RSFs to investigate removal of dissolved organic carbon (DOC) and 14 different organic micropollutants (OMPs) from the effluent of a large scale sewage treatment plant (STP). Two of them were operated as conventional RSF with material (sand with CaCO3 and organic matter) from two different full-scale RSFs. The third pilot RSF contained filter material (sand with CaCO3) with additional biochar in the upper layer (0–10 cm) and granulated activated carbon (GAC) in the lower layer (60–90 cm). The filters were planted with Phragmites australis. The RSFs were operated and monitored for 3 years, and water samples were taken regularly at inflow, outflows and in 3 depths within the filters. In total 523 samples were taken. In the conventional RSF, best median removal was detected for galaxolide, diclofenac 4-hydroxy, metoprolol and clarithromycin (75–79%). No removal was seen for sulfamethoxazole and carbamazepine. The DOC and OMP removal in the conventional RSFs was best in the upper layer with highest organic matter content, increased in time over the three years of operation and also with extended contact time. In the effluent of the RSF with GAC, 10 out of the 14 OMPs could not be detected; 4 OMPs were detected, but only metformin with removal < 80%, thus showing a more efficient removal than the conventional RSF. A decrease in DOC removal was detected in the GAC layer (>88% to 60%) over the 2.5 years of operation. Biochar was most effective in OMP removal in the first operational year. It can be concluded that the increasing removal efficiency of the conventional RSF material – also present in the RSF with biochar and GAC – might mitigate the reduced efficiency of the sorbent additives biochar and GAC. This enables to extend the operational lifetime of the filters with acceptable removal rates. Finally, our study demonstrates that an RSF with GAC shows an enhanced removal of OMPs, which is a suitable post-treatment step for STPs.
(Bio)electrochemical ammonia recovery : progress and perspectives
Kuntke, P. ; Sleutels, T.H.J.A. ; Rodríguez Arredondo, M. ; Georg, S. ; Barbosa, S.G. ; Heijne, A. Ter; Hamelers, Hubertus V.M. ; Buisman, C.J.N. - \ 2018
Applied Microbiology and Biotechnology 102 (2018)9. - ISSN 0175-7598 - p. 3865 - 3878.
Ammonia recovery - Bioelectrochemical systems - Electrochemical systems - Total ammonia nitrogen - Wastewater treatment
In recent years, (bio)electrochemical systems (B)ES have emerged as an energy efficient alternative for the recovery of TAN (total ammonia nitrogen, including ammonia and ammonium) from wastewater. In these systems, TAN is removed or concentrated from the wastewater under the influence of an electrical current and transported to the cathode. Subsequently, it can be removed or recovered through stripping, chemisorption, or forward osmosis. A crucial parameter that determines the energy required to recover TAN is the load ratio: the ratio between TAN loading and applied current. For electrochemical TAN recovery, an energy input is required, while in bioelectrochemical recovery, electric energy can be recovered together with TAN. Bioelectrochemical recovery relies on the microbial oxidation of COD for the production of electrons, which drives TAN transport. Here, the state-of-the-art of (bio)electrochemical TAN recovery is described, the performance of (B)ES for TAN recovery is analyzed, the potential of different wastewaters for BES-based TAN recovery is evaluated, the microorganisms found on bioanodes that treat wastewater high in TAN are reported, and the toxic effect of the typical conditions in such systems (e.g., high pH, TAN, and salt concentrations) are described. For future application, toxicity effects for electrochemically active bacteria need better understanding, and the technologies need to be demonstrated on larger scale.
Glocal assessment of integrated wastewater treatment and recovery concepts using partial nitritation/Anammox and microalgae for environmental impacts
Khiewwijit, Rungnapha ; Rijnaarts, Huub ; Temmink, Hardy ; Keesman, Karel J. - \ 2018
Science of the Total Environment 628-629 (2018). - ISSN 0048-9697 - p. 74 - 84.
Effluent quality - Energy recovery - Microalgae reactor - Nutrient recovery - Wastewater management - Wastewater treatment
This study explored the feasibility and estimated the environmental impacts of two novel wastewater treatment configurations. Both include combined bioflocculation and anaerobic digestion but apply different nutrient removal technologies, i.e. partial nitritation/Anammox or microalgae treatment. The feasibility of such configurations was investigated for 16 locations worldwide with respect to environmental impacts, such as net energy yield, nutrient recovery and effluent quality, CO2 emission, and area requirements. The results quantitatively support the applicability of partial nitritation/Anammox in tropical regions and some locations in temperate regions, whereas microalgae treatment is only applicable the whole year round in tropical regions that are close to the equator line. Microalgae treatment has an advantage over the configuration with partial nitritation/Anammox with respect to aeration energy and nutrient recovery, but not with area requirements. Differential sensitivity analysis points out the dominant influence of microalgal biomass yield and wastewater nutrient concentrations on area requirements and effluent quality. This study provides initial selection criteria for worldwide feasibility and corresponding environmental impacts of these novel municipal wastewater treatment plant configurations.
Removal of emerging organic contaminants in a poplar vegetation filter
Martínez Hernández, V. ; Lealb, M. ; Meffe, R. ; Miguel Garcia, Angel de; Alonso-Alonso, C. ; Bustamante, I. de; Lillo, J. ; Martín, I. ; Salas, J.J. - \ 2018
Journal of Hazardous Materials 342 (2018). - ISSN 0304-3894 - p. 482 - 491.
Emerging organic contaminants - Groundwater - Unsaturated zone - Vegetation filter - Wastewater treatment
Vegetation filters (VFs), a type of land application system, are a robust technology based on natural treatment mechanisms for the removal of wastewater contaminants. Their capacity to attenuate emerging organic contaminants (EOCs) has not yet been evaluated. The present study reports the results of a 2-year EOC monitoring carried out using a poplar VF receiving wastewater primarily treated by an Imhoff tank. The compounds selected included analgesics, a β-adrenergic blocker, stimulants, an anticonvulsant, an anti-depressant, an anti-inflammatory, an antibiotic and analgesic and stimulant metabolites. EOCs were analysed in the Imhoff tank effluent, in the infiltrated water at a depth of 90 cm and in the groundwater at a depth of 10 m. The results demonstrated that EOC attenuation was more significant in the first 90 cm than in the rest of the soil profile. The removal efficiency for all of the selected EOCs was higher than 90% with the exception of ketoprofen, which may pose a higher threat of groundwater contamination. The observed attenuation correlated with the hydrophobicity and charge state of the EOCs. The higher persistence of the metabolites 4-AAA and 4-FAA shows that progression in the degradation pathway does not always imply a mitigation of contamination.
Wastewater treatment by microalgae can generate high quality biodiesel feedstock
Rinna, Francesca ; Buono, Silvia ; Cabanelas, Iago Teles Dominguez ; Nascimento, Iracema Andrade ; Sansone, Giovanni ; Barone, Carmela Maria Assunta - \ 2017
Journal of Water Process Engineering 18 (2017). - ISSN 2214-7144 - p. 144 - 149.
Biodiesel quality - Botryococcus - Microalgae production - Wastewater treatment
Botryococcus braunii strains are high-lipid producers. Despite this, their use as biodiesel feedstock is limited by their slow growth, which increases production costs. B. braunii wastewater bioremediation power, however, may be able to overcome this problem. This research evaluated the performance of two strains (UTEX-USA and IBL-Brazil) grown in pre-treated (influent) and treated (effluent) wastewater. The goal was to optimize algal-productivity and wastewater treatment in order to provide biomass rich in high-quality oil for biodiesel. The standard CHU-medium was used as control. Phosphorus was 100% removed in all treatments for both strains. Nitrogen removal was higher in wastewater (61–65%) than in CHU medium (48 and 61%), respectively for UTEX and IBL strains. Cultivation in the effluent generated higher biomass and lipid productivity for the UTEX strain, while the influent was the best for the IBL strain. The composition of the fatty-acids produced by Botryococcus was used to estimate the biodiesel quality. Hence, the biodiesels may have good fuel quality (high ignition and combustion efficiency) but limited application at low temperatures. The composition of fatty-acids, however, can be optimized by growing or mixing strategies. Therefore, Botryococcus braunii is a potential source for high quality biodiesel production.
Dynamic modeling of the INAPRO aquaponic system
Karimanzira, Divas ; Keesman, Karel J. ; Kloas, Werner ; Baganz, Daniela ; Rauschenbach, Thomas - \ 2016
Aquacultural Engineering 75 (2016). - ISSN 0144-8609 - p. 29 - 45.
Aquaponics - Dynamic modeling - Two player system - Wastewater treatment
The use of modeling techniques to analyze aquaponics systems is demonstrated with an example of dynamic modeling for the production of Nile tilapia (Oreochromis niloticus) and tomatoes (Solanum lycopersicon) using the innovative double recirculating aquaponic system ASTAF-PRO. For the management and control of aquaponic systems, as dynamic two player systems with intra and inter feedback characteristics, dynamic models are required. In this study, it is shown how dynamic models based on differential equations for diverse aquaponic processes, such as crop and fish growth, waste production and filtration, greenhouse climate and hydroponics, can be integrated to a realistic and complex aquaponic model. The proposed models have been implemented in VBA Excel and can be used to demonstrate how different ASTAF-PRO configurations can be found, controlled and managed, increasing the chances of understanding and therefore future large-scale production in environmentally sustainable aquaponic systems.
Influence of salinity on fungal communities in a submerged fixed bed bioreactor for wastewater treatment
Cortés-Lorenzo, C. ; González-Martínez, A. ; Smidt, H. ; González-López, J. ; Rodelas, B. - \ 2016
Chemical Engineering Journal 285 (2016). - ISSN 1385-8947 - p. 562 - 572.
Fungal communities - Pyrosequencing - Saline wastewater - Submerged fixed bed bioreactor - Wastewater treatment
Salinity is known to influence the performance of biological wastewater treatment plants. While its impact on bacterial communities has been thoroughly studied, its influence on fungal communities has been largely overlooked. To address this knowledge gap, we assessed the effect of saline influents (0, 3.7, 24.1 and 44.1. g. NaCl/L) on the community structure and diversity of fungi in a submerged fixed bed bioreactor (SFBBR). For this purpose, denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing of PCR-amplified fungal 18S rRNA gene fragments and ITS regions, respectively, were used. Significant differences in the fungal community structure were found in relation to the NaCl concentration. Fungal diversity increased as salinity increased to a concentration up to 24.1. g. NaCl/L, but was significantly reduced at 44.1. g. NaCl/L. Basidiomycota dominated the fungal community in the absence of NaCl but decreased in relative abundance with increasing salinity, being replaced progressively by Ascomycota.
Production of volatile fatty acids from sewage organic matter by combined bioflocculation and alkaline fermentation
Khiewwijit, R. ; Temmink, B.G. ; Rijnaarts, H.H.M. ; Keesman, K.J. - \ 2015
Volatile fatty acids - Bioflocculation - Anaerobic fermentation - Alkaline pH - Wastewater treatment
This study explored the potential of volatile fatty acids (VFA) production from sewage by a combined high-loaded membrane bioreactor and sequencing batch fermenter. VFA production was optimized with respect to SRT and alkaline pH (pH 8–10). Application of pH shock to a value of 9 at the start of a sequencing batch cycle, followed by a pH uncontrolled phase for 7 days, gave the highest VFA yield of 440 mg VFA-COD/g VSS. This yield was much higher than at fermentation without pH control or at a constant pH between 8 and 10. The high yield in the pH 9 shocked system could be explained by (1) a reduction of methanogenic activity, or (2) a high degree of solids degradation or (3) an enhanced protein hydrolysis and fermentation. VFA production can be further optimized by fine-tuning pH level and longer operation, possibly allowing enrichment of alkalophilic and alkali-tolerant fermenting microorganisms.