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Organic Pollutants Removal from Olive Mill Wastewater using a new Ecosystem Treatment
2023
Bougassa, Rim | Tahri, Latifa | Nassri, Ilham | Fekhaoui, Mohammed
Olive mill wastewater is the main by-product derived from olive mills using the three-phase extraction process,displaying a serious environmental risk due to its notable content in organics and phenolics Olive oil production, an agro-industrial of vital economic particularly in Mediterranean countries, is unfortunately associated with the generation of large quantities of OMW (Olive Mill Wastewater) and solid wastes. The OMW is considered a major environmental problem, it is a powerful pollutant rejected in nature without any prior treatment. This research work aims to study the treatment of OMW by a new ecological and economic system, which consists of the use of the following components: gravel, sawdust, soil, activated carbon, bamboo, and the valorization of the solid residues. HPLC analysis showed that hydroxytyrosol is the most abundant biophenol. Many other biophenols were identified (Tyrosol, gallic acid, and eleonic acid). The comparison between before and after filtration by the new system showed an essential degradation of phenolic compounds after treatment and found a new compound resulting from their degradation.
Afficher plus [+] Moins [-]A Review of Air Pollution and Solutions Way Management Related to Ribbed Smoked Sheets (RSS) Production of Community-Level Rubber Cooperatives in Thailand: Smoke, Soot and PAHs particles
2020
Kalasee, W. | Teekapakvisit, C.
In Thailand, RSS chamber of community-level rubber cooperatives can be classified into two models: old and new model, named after the years of their establishment. Hot gas as a heat supply from Para-rubber (PR) wood (Hevea brasiliensis) combustion is used for removing moisture from the natural rubber (NR) sheets. Smoke and soot particles from PR wood burning has effected to the quality of the NR sheet and the pollution in the workplace area and lead to health problems of the worker. Cascade impactors are equipment for measuring the smoke and soot particles size distribution from PR wood combustion. PAHs compounds from PR wood combustion were found 15 different PAHs components (Tekasakul et al., 2005; Furuuchi et al., 2006). Important methods in decreasing smoke and soot particles from combustion of PR wood for rubber smoking chamber are separation equipment and ventilation designed by computational fluid dynamics (CFD) technique. In this article, the separation method is focused on smoke and soot particle collection to maintain the quality of the NR sheet. This equipment is reviewed both indoor and outdoor, for example, an impaction wall, electrostatic precipitator, stainless-wire, etc. This review indicates that the ESP installing between the furnace and the smoking chamber is suitable to eliminate aerosol particles at the rubber smoking industry. In addition, CFD technique reports is aimed at collecting aerosol particles for decreasing smoke and soot particles emission from rubber smoking chamber is presented.
Afficher plus [+] Moins [-]Deposition and mobilization of viruses in unsaturated porous media: Roles of different interfaces and straining
2021
Zhang, Wenjing | Wu, Shengyu | Qin, Yunqi | Li, Shuo | Lei, Liancheng | Sun, Simiao | Yang, Yuesuo
The vadose zone is the first natural layer preventing groundwater pollution. Understanding virus transport and retention in the vadose zone is necessary. The effects of different interfaces and mechanisms on virus transport and retention were investigated by studying Escherichia coli phage migration in laboratory-scale columns under unsaturated conditions. The E. coli phage was used as a model virus. Colloid filtration theory, extended Derjagin–Landau–Verwey–Overbeek theory and two−site kinetic deposition model were used to calculate fitted parameters and interaction energies to assess virus retention at different interfaces. The collector diameters and the size of E. coli phages in the influent and effluent were compared to assess the effect of straining. The results indicated that the roles of solid–water interfaces (SWIs) and air–water interfaces (AWIs) in retaining E. coli phages are strongly controlled by the moisture content and hydrochemical conditions. Decreasing the moisture content and increasing the ionic strength (IS) of the suspension increased E. coli phage retention. At suspension ISs of 0.01 or 0.03 M and various moisture contents, E. coli phages were mainly retained at the SWIs rather than AWIs. When the IS was increased to 0.06 M, the viruses were strongly retained by becoming attached to both SWIs and AWIs. The role of straining in virus retention could not be ignored. Viruses were retained more at the SWIs and less straining occurred under acidic conditions than under neutral or alkaline conditions. This was mainly because of the effects of the pH and IS on surface charges and the model virus particle size. This study has important implications for modeling and predicting virus transport in soil affected by rainfall, snowmelt, and human activities (e.g., irrigation and artificial groundwater recharging).
Afficher plus [+] Moins [-]HVAC filtration of particles and trace metals: Airborne measurements and the evaluation of quantitative filter forensics
2021
Mahdavi, Alireza | Dingle, Justin | Chan, Arthur W.H. | Siegel, Jeffrey A.
Filters installed in the heating, ventilation, and air-conditioning (HVAC) systems can serve as air-cleaning and sampling devices for indoor particles. The purpose of this article is to evaluate these dual roles. An occupied home with a central HVAC system equipped with a Minimum Efficiency Reporting Value (MERV, from ASHRAE Standard 52.2) 11 filter was monitored for six weeks. Weekly airborne gravimetric and real-time sampling was performed to measure the particle size distribution and the concentration of total suspended particles (TSP), PM₁₀, PM₂.₅, PM₁, and 12 trace metals. The weekly system runtimes were intentionally changed to provide a wide range of weekly filtration volumes. The quantitative filter forensics (QFF) concentrations of particulate matter (PM) and trace metals were calculated using the analysis of the dust collected on the HVAC filter, the filtration volume, and filter in-situ efficiency. The results indicated that filtration was not influential to remove PM and trace metals as the concentrations during the weeks with continuous HVAC operation were not consistently lower than those during the other weeks. This suggests the dominance of other particle and trace metal source and loss mechanisms weakens the influence of filtration in this home. The QFF evaluation results indicated that the concentration of TSP and over half of the tested trace metals (e.g., Pb, Cd, Ni, V, Sb, K, and Sr) could be estimated by QFF within a factor of two when compared to airborne sampling results. PM₁₀, PM₂.₅, and PM₁ concentrations were significantly underestimated by QFF potentially due to the limitations of size distribution analysis by a laser diffraction particle sizer (LDPS) for the detection of <1 μm particles. Overall, while QFF was promising for TSP and some trace metals, improvement in size distribution analysis could extend the application of QFF for airborne sampling.
Afficher plus [+] Moins [-]Concentrations and distributions of neonicotinoids in drinking water treatment plants in South Korea
2021
Kim, Jiwon | Wang, Wenting | Lee, Soohyung | Park, Ju-Hyun | Oh, Jeong-Eun
We investigated the fates of seven neonicotinoids (NNIs) in full-scale drinking water treatment plants and assessed human exposure to NNIs through consuming drinking water. The total NNI concentrations in raw water and treated water samples from the drinking water treatment plants were 20.4–166 ng/L (median 118 ng/L) and 1.11–94.7 ng/L (median 20.4 ng/L), respectively. The dinotefuran (DIN) concentrations in raw water collected in different seasons were different, and the highest DIN concentration was found in summer. The drinking water treatment processes removed >91% of the NNIs except DIN and thiamethoxam (THIAM), for which the mean removal rates were 70% and 74%, respectively. The removal rates for all of the NNIs were higher for the granular activated carbon filtration process (mean 83.5%) than the other drinking water treatment plant processes (coagulation/sedimentation 22.3%, ozonation 29.2%). However, the removal rates in the granular activated carbon process were lower for DIN and THIAM (61.0% and 59.2%, respectively) than the other NNIs. Significant correlations were found between the NNI removal rates and physicochemical properties (solubility in water and log (octanol–water partition coefficient)). The estimated mean human exposure to NNIs in drinking water was 0.528 ng/(kg body weight d).
Afficher plus [+] Moins [-]Microplastic pollution in the Weser estuary and the German North Sea
2021
Roscher, Lisa | Fehres, Annika | Reisel, Lorenz | Halbach, Maurits | Scholz-Böttcher, Barbara | Gerriets, Michaela | Badewien, Thomas H. | Shiravani, Gholamreza | Wurpts, Andreas | Primpke, Sebastian | Gerdts, Gunnar
Microplastics (MP) are defined as synthetic organic pollutants sized <5 mm and have been recorded in various environments worldwide. Due to their small size, they pose a potential risk for many organisms throughout the food web. However, little is known about MP distribution patterns and associated transport mechanisms. Rivers may act as pathways for MP into marine environments. In this study, we investigate the occurrence of MP in the estuary and lower stretch of the second-largest German River, the Weser, representative of a significant interface between fresh water and marine environments. The aim of the study was to enhance the general understanding by providing novel, comprehensive data and suggestions for future studies on estuarine systems. Surface water samples of two different size classes were collected by ship using an on-board filtration system (11–500 μm fraction) and net sampling (500–5000 μm fraction). After a thorough sample preparation, all samples were analysed with Focal Plane Array (FPA) Fourier Transform Infrared (FTIR) spectroscopy and Attenuated Total Reflection (ATR) FTIR spectroscopy in order to obtain information on MP concentrations, polymer composition and size distribution. Our findings show highest concentrations in the 11–500 μm fraction (2.3 × 10¹ − 9.7 × 10³ MP m⁻³), with the polymer cluster acrylates/polyurethanes(PUR)/varnish being dominant. The >500 μm fraction was dominated by polyethylene. Estimated MP concentrations generally increased in the Turbidity Maximum Zone (TMZ) and decreased towards the open sea. This study contributes to the current research by providing novel insights into the MP pollution of the estuary and lower stretch of an important European river and provides implications for future MP monitoring measures.
Afficher plus [+] Moins [-]Disinfection by-products in drinking water: Occurrence, toxicity and abatement
2020
Srivastav, Arun Lal | Patel, Naveen | Chaudhary, Vinod Kumar
Disinfection means the killing of pathogenic organisms (e.g. bacteria and its spores, viruses, protozoa and their cysts, worms, and larvae) present in water to make it potable for other domestic works. The substances used in the disinfection of water are known as disinfectants. At municipal level, chlorine (Cl₂), chloramines (NH₂Cl, NHCl₂), chlorine dioxide (ClO₂), ozone (O₃) and ultraviolet (UV) radiations, are the most commonly used disinfectants. Chlorination, because of its removal efficiency and cost effectiveness, has been widely used as method of disinfection of water. But, disinfection process may add several kinds of disinfection by-products (DBPs) (∼600–700 in numbers) in the treated water such as Trihalomethanes (THM), Haloacetic acids (HAA) etc. which are detrimental to the human beings in terms of cytotoxicity, mutagenicity, teratogenicity and carcinogenicity. In water, THMs and HAAs were observed in the range from 0.138 to 458 μg/L and 0.16–136 μg/L, respectively. Thus, several regulations have been specified by world authorities like WHO, USEPA and Bureau of Indian Standard to protect human health. Some techniques have also been developed to remove the DBPs as well as their precursors from the water. The popular techniques of DBPs removals are adsorption, advance oxidation process, coagulation, membrane based filtration, combined approaches etc. The efficiency of adsorption technique was found up to 90% for DBP removal from the water.
Afficher plus [+] Moins [-]Does microplastic ingestion by zooplankton affect predator-prey interactions? An experimental study on larviphagy
2020
Van Colen, Carl | Vanhove, Brecht | Diem, Anna | Moens, Tom
Litter is omnipresent in the ocean where it can be ingested by marine biota. Although ingestion of microplastics (MPs) is abundantly reported, insights into how MP can influence predator-prey interactions currently limits our understanding of the ecological impact of MPs. Here we demonstrate trophic transfer of MPs from zooplankton to benthic filter feeders, through consumption of contaminated prey (i.e. prey with ingested MP). However, predation rates of contaminated prey were significantly lower as compared to predation rates of prey that had no MPs ingested. As filter feeder clearance rates were not affected by consumption of MPs, the lower predation rates of contaminated prey appear to be primarily explained by disruption in zooplankton swimming behaviour that reduces their filtration risk. This is the first study that shows how MPs can change predator-prey interactions that are involved in the coupling between the pelagic and seabed habitat.
Afficher plus [+] Moins [-]Emissions from a fast-pyrolysis bio-oil fired boiler: Comparison of health-related characteristics of emissions from bio-oil, fossil oil and wood
2019
Sippula, Olli | Huttunen, Kati | Hokkinen, Jouni | Kärki, Sara | Suhonen, Heikki | Kajolinna, Tuula | Kortelainen, Miika | Karhunen, Tommi | Jalava, Pasi | Uski, Oskari | Yli-Pirilä, Pasi | Hirvonen, Maija-Riitta | Jokiniemi, Jorma
There is currently great interest in replacing fossil-oil with renewable fuels in energy production. Fast pyrolysis bio-oil (FPBO) made of lignocellulosic biomass is one such alternative to replace fossil oil, such as heavy fuel oil (HFO), in energy boilers. However, it is not known how this fuel change will alter the quantity and quality of emissions affecting human health. In this work, particulate emissions from a real-scale commercially operated FPBO boiler plant are characterized, including extensive physico-chemical and toxicological analyses. These are then compared to emission characteristics of heavy fuel-oil and wood fired boilers. Finally, the effects of the fuel choice on the emissions, their potential health effects and the requirements for flue gas cleaning in small-to medium-sized boiler units are discussed.The total suspended particulate matter and fine particulate matter (PM₁) concentrations in FPBO boiler flue gases before filtration were higher than in HFO boilers and lower or on a level similar to wood-fired grate boilers. FPBO particles consisted mainly of ash species and contained less polycyclic aromatic hydrocarbons (PAH) and heavy metals than had previously been measured from HFO combustion. This feature was clearly reflected in the toxicological properties of FPBO particle emissions, which showed less acute toxicity effects on the cell line than HFO combustion particles. The electrostatic precipitator used in the boiler plant efficiently removed flue gas particles of all sizes. Only minor differences in the toxicological properties of particles upstream and downstream of the electrostatic precipitator were observed, when the same particulate mass from both situations was given to the cells.
Afficher plus [+] Moins [-]Mercury transport, transformation and mass balance on a perspective of hydrological processes in a subtropical forest of China
2019
Sun, Tao | Ma, Ming | Wang, Xun | Wang, Yongmin | Du, Hongxia | Xiang, Yuping | Xu, Qinqin | Xie, Qing | Wang, Dingyong
Forest ecosystem has long been suggested as a vital component in the global mercury (Hg) biogeochemical cycling. However, there remains large uncertainties in understanding total Hg (THg) and methylmercury (MeHg) variations and their controlling factors during the whole hydrological processes in forest ecosystems. Here, we quantified Hg mass flow along hydrological processes of wet deposition, throughfall, stemflow, litter leachate, soil leachate, surface runoff, and stream, and litterfall Hg deposition, and air-forest floor elemental Hg (Hg⁰) exchange flux to set up a Hg mass balance in a subtropical forest of China. Results showed that THg concentration in stream was lower than that in wet deposition, while an opposite characteristic for MeHg concentration, and both THg and MeHg fluxes of stream were lower than those of wet deposition. Variations of THg and MeHg in throughfall and litter leachate had strong direct and indirect effects on controlling variations of THg and MeHg in surface runoff, soil leachate and stream, respectively. Especially, the net Hg methylation was suggested in the forest canopy and forest floor layers, and significant particulate bound Hg (PBM) filtration was observed in soil layers. The Hg mass balance showed that the litterfall Hg deposition was the main Hg input for forest floor Hg, and the elemental Hg vapor (Hg⁰) re-emission from forest floor was the dominant Hg output. Overall, we estimated the net THg input flux of 13.8 μg m⁻² yr⁻¹ and net MeHg input flux of 0.6 μg m⁻² yr⁻¹ within the forest ecosystem. Our results highlighted the important roles of forest canopy and forest floor to shape Hg in output flow, and the forest floor is a distinct sink of MeHg.
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