Recherches sur les traitements biologiques
Sushil Kumar, Anita Talan, Kellie Boyle, Banu Ormeci, Patrick Drogui, R D Tyagi (2021), « 5. Water recycling: Economic and environmental benefits« , in Ashok Pandey R. Tyagi Sunita Varjani (eds), Biomass, Biofuels, Biochemicals, 1st Edition, Circular Bioeconomy – Current Status and Future Outlook, Elsevier.
M.R.K Estahbanati, S. Kumar, M. Khajvand, P. Drogui, R. D. Tyagi (2021), « 6. Environmental impacts of recovery of resources from industrial wastewater« , in Ashok Pandey R. Tyagi Sunita Varjani (eds), Biomass, Biofuels, Biochemicals, 1st Edition, Circular Bioeconomy – Current Status and Future Outlook, Elsevier.
B. Yadav, S. Chavan, A. Atmakuri, R.D. Tyagi, P. Drogui (2020), « A review on recovery of proteins from industrial wastewaters with special emphasis on PHA production process: Sustainable circular bioeconomy process development, Bioresource Technology, Vol. 317, December 2020.
The economy of the polyhydroxyalkanoate (PHA) production process could be supported by utilising the different by-products released simultaneously during its production. Among these, proteins are present in high concentrations in liquid stream which are released after the cell disruption along with PHA granules. These microbial proteins can be used as animal feed, adhesive material and in manufacturing of bioplastics. The recycling of the protein containing liquid stream also serves as a promising approach to maintain circular bioeconomy in the route. For this aim, it is important to obtain good yield and limit the drawbacks of protein recovery processes and associated costs. The review focuses on recycling of the liquid stream generated during acid/thermal-alkali treatment for PHA production that would close the gap in linear economy and attain circularity in the process. Examples to recover proteins from other industrial waste streams along with their applications have also been discussed.
Anita Talan, Rajwinder Kaur, Rajeshwar D Tyagi, P Drogui (2020), « Bioconversion of oily waste to polyhydroxyalkanoates: Sustainable technology with circular bioeconomy approach and multidimensional impacts », Bioresource Technology Reports, Vol 11, September 2020.
Sustainable biomaterials and biofuels are a critical matter that researchers are employed in. Polyhydroxyalkanoates (PHAs) are considered as extremely important material produced using PHA producing microorganisms that can be used hereafter due to their properties such as biodegradability, biocompatibility and physicochemical. Designing efficient and profitable processes, focusing on environmental and social advantages, has given an opportunity to researchers from diverse qualifications to progress in the field of bioplastics production. Based on sustainability issues different waste substrates have been utilized for PHA production and one such waste is oily waste. Over the last few years, a remarkable development is seen to utilize oily waste for bioplastics production. Thus, this review is focused on sources of oily waste and their composition, current developments in utilizing them for PHA production. The impact of PHA production on circular bioeconomy and global sustainability covering environmental, social and economic aspects has also been provided.
B. Yadav, A. Pandey, L.R. Kumar, R.D. Tyagi (2020), « Bioconversion of waste (water)/residues to bioplastics-A circular bioeconomy approach« , Bioresource Technology, Vol. 298, February 2020.
Research insight into the technical challenges of bioplastics production has revealed their confoundedness in their niche markets and struggles to enter the mainstream. There is an increasing problem of waste disposal and high cost of pure substrates in polyhydroxyalkanoates (PHA) production. This has led to the future need of upgrading the waste streams from different industries into the role of feedstocks for production of PHA. The review covers the latest developments in using wastes and surplus materials for PHA production. In addition to inexpensive carbon sources, efficient upstream and downstream processes and recycling of waste streams within the process are required to maintain the circularity in the entire process. A view on the link between circular bioeconomy and PHA production process covering the techno-economic, life cycle assessment and environmental aspects has also been provided. Furthermore, the future perspectives related to the topic have also been discussed.
Zhen Liu, Kim Lompe, Madjid Mohseni, Pierre R. Bérubé, Sébastien Sauvé, Benoit Barbeau (2020), « Biological ion exchange as an alternative to biological activated carbon for drinking water treatment« , Water Research, Vol 168, January 2020.
Biological ion exchange (BIEX) has proved to remove natural organic matter (NOM) better than biological activated carbon (BAC). This raises the question if BIEX can be integrated into a full-scale drinking water treatment plant to remove NOM and ammonia. In this study, a pilot plant consisting of one BIEX filter, three GAC filters and one BAC filter was set up as second-stage filtration at the Sainte-Rose drinking water treatment plant (Laval, Canada). The pilot plant was operated for a period of nine months without regeneration of the ion exchange resins. The influent water showed low DOC (2.5 mg/L) and high sulfate concentrations (28.2 mg/L). Except of a short peak of DOC released at about 1 000 BV, the BIEX filter achieved a nearly constant removal of 29–36% over the whole study period. The DOC removals of GAC were similar to BIEX at < 8000 BV but then stabilized at 13–24% after 8 000 BV. Most DOC removal in the BIEX filter was achieved at the top 30 cm layer (81%) compared to 62–66% removal in the GAC/BAC filters in the same layer. After the rapid exhaustion of the primary ion exchange capacity (<1 000 BV), sulfate displaced the fraction of NOM with lower affinity than sulfate, corresponding to the initial DOC release in the BIEX filter. The fraction of NOM with higher affinity than sulfate can still replace sulfate, which explains the good long-term performance of the BIEX filter. BIEX released ammonia with an average of 15% in warm water condition, probably related to the small diameter of the column which limited backwash effectiveness.
Bharti, L. R. Kumar and R. D. Tyagi (2019), « Biodiesel production using wastewater sludge derived lipids« , in R. D. Tyagi; Rao Y. Surampalli; Tian C. Zhang; Song Yan; and Xiaolei Zhang (eds), Biodiesel Production: Technologies, Challenges, and Future Prospects, American Society of Civil Engineers.
R. Kaur, S. K. Yellapu, Bharti, L. R. Kumar, R.D.Tyagi (2019), « Biodiesel Basics« , in R. D. Tyagi; Rao Y. Surampalli; Tian C. Zhang; Song Yan; and Xiaolei Zhang (eds), Biodiesel Production: Technologies, Challenges, and Future Prospects, American Society of Civil Engineers.
Bharti, B. Tiwari, R. D. Tyagi, P. Drogui (2019), « Plant oil to biodiesel« , in R. D. Tyagi; Rao Y. Surampalli; Tian C. Zhang; Song Yan; and Xiaolei Zhang (eds), Biodiesel Production: Technologies, Challenges, and Future Prospects, American Society of Civil Engineers.
Bharti, R. D. Tyagi (2019), « Waste cooking oil biodiesel« , in R. D. Tyagi; Rao Y. Surampalli; Tian C. Zhang; Song Yan; and Xiaolei Zhang (eds), Biodiesel Production: Technologies, Challenges, and Future Prospects, American Society of Civil Engineers.
Pathak A.N., Talan A., Gaurav K. (2019) Plant Oil Biodiesel: Technologies for Commercial Production, Present Status and Future Prospects. In: Khurana S., Gaur R. (eds) Plant Biotechnology: Progress in Genomic Era. Springer, Singapore.
Emerging environmental impacts and related health issues, the continuous hike in price of vehicle fuels in sync with the depletion of fossil fuels have urged considerable research to move on alternative fuel sources and there comes the word “Biofuel”. Biofuel is gaining importance and has been a major subject of research for scientists worldwide. Attention has been given to biofuels in various countries because of its positive impacts on environment and in response healthy manpower. One of the most important and concerned topic of biofuel is biodiesel.
Biodiesel, Plant oils, Bio diesel properties, Catalysts, Transesterification, Advantages & disadvantages of biodiesel
The objective of this study was to evaluate the treatment efficiency of a short rotation willow coppice (SRWC) vegetation filter for the treatment of wastewater from a municipal primary effluent in a humid continental climate context. The experimental work was carried out at pilot scale on a willow plantation located in Québec, Canada. The experimental design included nine plots that were irrigated with groundwater (L0 = 14 mm/d) or two primary effluents (L1 = 10 and L2 = 16 mm/d) for 111 days. This research showed that SRWCs operated on coarse-textured soils allow efficient removal of organic matter (91% of COD for L1 and L2) and nitrogen (98% of TKN for L1 and L2) from wastewater. It was also shown, in this case, that the total nitrogen loading should be used as the limiting design parameter to minimize the risk of contaminating underground drinking water sources with nitrates. Almost complete removal of total phosphorus was observed during this experiment (98% for L1 and L2). However, a significant increase in soil available phosphorus was observed following the L2 treatment, which suggests an eventual phosphorus soil profile saturation in the event of continued wastewater irrigation. Avoiding such a saturation would require chemical phosphorus removal upstream of SRWC vegetation filters. Finally, an imbalance between irrigation and willows needs was observed as a result of irrigating plots at a constant hydraulic loading rate. Thus, irrigation of an SRWC with wastewater should be modulated according to willow seasonal transpiration trends to allow a better allocation of water and nutrients according to plant needs, and in doing so, increase treatment efficiency and resources valorization.
Roy, D., A. Azaïs, S. Benkaraache, P. Drogui and R. D. Tyagi (2018). « Composting leachate: characterization, treatment, and future perspectives. » Reviews in Environmental Science and Bio/Technology 17(2): 323-349.
The increasing production of waste has led to one of the major environmental challenges of today: waste management. A solution to this problem is the composting of organic wastes. While the composting process transforms organic wastes into biologically stable compost, large amounts of highly contaminated leachates that present a direct risk to the environment are also produced. First off, this review discusses the origin and nature of contaminants found in composting leachates. In a general perspective, composting leachates are characterized by the presence of high concentrations of moderately biodegradable organic matter and nutrients and contain toxic pollutants such as heavy metals and plasticizers. Treatment technologies that have been studied are subsequently reported and discussed (treatment efficiencies and operating costs). This review highlights the lack of available solutions to efficiently remove all contaminants found in these leachates, which is a major concern considering the increasing number of composting facilities. While both, membrane bioreactors and reverse osmosis, show promising results with NH4, COD and TSS removals of > 70, > 85 and > 99.9%, respectively, the resulting effluent remains hazardous for the environment. Further studies are required to assess the use of a combination of biological and advanced oxidation process for the production of a safely disposable effluent.
Composting leachate, Composting wastewater, Treatment, Membrane bioreactor, Advanced oxidation
Ruchi Agrawal, Bharti Bhadana, A. S. Mathur, Ravindra Kumar, Ravi P. Gupta and Alok Satlewal (2018). “Improved Enzymatic Hydrolysis of Pilot Scale Pretreated Rice Straw at High Total Solids Loading.” Frontiers in Energy Research.
Enzymatic hydrolysis at high solids loading has the potential to reduce both capital and operational expenditures. Here, pretreatment of rice straw (PRS) with dilute acid was carried out at a pilot scale (250 kg per day) at 162°C for 10 min and 0.35% acid concentration, followed by enzymatic hydrolysis at different total solids loadings. It showed that although the total sugar concentration increased from 48 to 132 g/l, glucan conversion reduced by 27% (84–66.2%) with increasing solids from 5 to 20% in batch mode. Therefore, two different fed-batch approaches were evaluated to improve the glucan conversion by the sequential addition of a substrate and/or enzyme. At 20% solid loadings and a 3 filter paper units/g enzyme dosage, the highest glucan conversion obtained was 66% after 30 h of hydrolysis in batch mode. However, in an optimized fed-batch approach, the glucan yield was improved to 70% by simply dividing the substrate feeding into three batches, that is, 50% at 0 h, 25% each after 4 h, and 8 h of hydrolysis reaction. The addition of surfactant (Ecosurf E6) further improved the conversion to 72% after 30 h. The role of critical factors, that is, inhibitors, enzyme–lignin binding, and viscosity, was investigated during the course of hydrolysis in the batch and fed-batch approaches. This study suggests a sustainable approach for improved hydrolysis at high solids loadings by fine-tuning a simple process.
Yassine Ouarda, Mehdi Zolfaghari, Patrick Drogui, Brahima Seyhi, Gerardo Buelna, Rino Dubé (2018). « Performance of a membrane bioreactor in extreme concentrations of bisphenol A, QC.« . Water Sci Technol 77 (6): 1505-1513.
In this study, a submerged membrane bioreactor was used to study the effect of low and high bisphenol A (BPA) concentration on the sludge biological activity. The pilot was operated over 540 days with hydraulic retention time and solid retention time of 5.5 hours and 140 days, respectively. As a hydrophobic compound, BPA was highly adsorbed by activated sludge. In lower concentrations, the biodegradation rate remained low, since the BPA concentration in the sludge was lower than 0.5 mg/g TS; yet, at an influent concentration up to 15 mg/L, the biodegradation rate was increasing, resulting in 99% BPA removal efficiency. The result for chemical oxygen demand removal showed that BPA concentration has no effect on the heterotrophic bacteria that were responsible for the organic carbon degradation. In higher concentrations, up to 16 mg of BPA was used for each gram of sludge as a source of carbon. However, the activity of autotrophic bacteria, including nitrifiers, was completely halted in the presence of 20 mg/L of BPA or more. Although nitrification was stopped after day 400, ammonia removal remained higher than 70% due to air stripping. Assimilation by bacteria was the only removal pathway for phosphorus, which resulted in an average 35% of P-PO4 removal efficiency.
Yassine Ouarda, Bhagyashree Tiwari, Antonin Azaïs, Marc-Antoine Vaudreuil, Sokhna Dieng Ndiaye, Patrick Drogui, Rajeshwhar Dayal Tyagi, Sébastien Sauvé, Mélanie Desrosiers, Gerardo Buelna, Rino Dubé (2018). « Synthetic hospital wastewater treatment by coupling submerged membrane bioreactor and electrochemical advanced oxidation process: Kinetic study and toxicity assessment« . Chemosphere 193, pp. 160-169.
In this work, the combination of membrane bioreactor (MBR) and electro-oxidation (EO) process was studied for the treatment of a synthetic hospital wastewater fortified with four pharmaceutical pollutants namely carbamazepine (CBZ), ibuprofen (IBU), estradiol (E-E) at a concentration of 10 μg L−1 venlafaxine (VEN) at 0.2 μg L−1. Two treatment configurations were studied: EO process as pre-treatment and post-treatment. Wastewater treatment with MBR alone shows high removal percentages of IBU and E-E (∼90%). Unlikely for CBZ and VEN, a low elimination percentage (∼10%) was observed. The hydraulic and the solid retention times (HRT and SRT) were 18 h and 140 d respectively, while the biomass concentration in the MBR was 16.5 g L−1. To enhance pharmaceuticals elimination, an EO pretreatment was conducted during 40 min at 2 A. This configuration allowed a 92% removal for VEN, which was far greater than both treatments alone, with lower than 30% and 50% for MBR and EO, respectively. The MBR-EO coupling (EO as post-treatment) allows high removal percentages (∼97%) of the four pharmaceutical pollutants after 40 min of treatment at a current intensity of 0.5 A with Nb/BDD as electrodes. This configuration appears to be very effective compared to the first configuration (EO-MBR) where EO process is used as a pre-treatment. Toxicity assessment showed that the treated effluent of this configuration is not toxic to Daphnia magna except at 100% v/v. The MBR-EO coupling appears to be a promising treatment for contaminated hospital effluents.
Bhagyashree Tiwari, Balasubramanian Sellamuthu, Yassine Ouarda, Patrick Drogui, Rajeshwar D. Tyagi, Gerardo Buelna (2017). « Review on fate and mechanism of removal of pharmaceutical pollutants from wastewater using biological approach. » Bioresource Technology, Volume 224, January, pp. 1-12.
Due to research advancement and discoveries in the field of medical science, maintains and provides better human health and safer life, which lead to high demand for production of pharmaceutical compounds with a concomitant increase in population. These pharmaceutical (biologically active) compounds were not fully metabolized by the body and excreted out in wastewater. This micro-pollutant remains unchanged during wastewater treatment plant operation and enters into the receiving environment via the discharge of treated water. Persistence of pharmaceutical compounds in both surface and ground waters becomes a major concern due to their potential eco-toxicity. Pharmaceuticals (emerging micro-pollutants) deteriorate the water quality and impart a toxic effect on living organisms. Therefore, from last two decades, plenty of studies were conducted on the occurrence, impact, and removal of pharmaceutical residues from the environment. This review provides an overview on the fate and removal of pharmaceutical compounds via biological treatment process.