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1.
J Hazard Mater ; 421: 126629, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315020

RESUMO

Spent caustic discharges are responsible for increasing oil and grease (O&G) matter in refineries wastewater, leading to increasing treatment costs due to low water quality and environmental constraints associated with high O&G concentration discharges. As a way to settle and optimize treatment technologies for such complex effluents, more insight regarding the effluents impact and deeper characterization is necessary. The present study intends to assess the possibility of a relationship between the processed crude oils with the polar O&G concentration in naphthenic spent caustic as well as in the final wastewater; Sines refinery was considered as case-study. Also, in order to get insights about the nature of the polar O&G compounds, their structures and their prevalence in the effluent treatment system was carried out through detailed analytical characterization studies. Proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC-MS) were chosen. It was found that, for the Sines refinery, spent caustic discharges may increase the refinery effluent management cost up to 3 €/ton of processed crude oil, every time a high kerosene cut acid crude oil is processed. It was also found that the typical spent caustic O&G effluents are composed by organic contaminants with low molecular weight (MW), with aromatic and polar arrangements, like phenolic groups and naphthenic acids. This outcome is crucial for subsequently establishing the best technologies able to deal with such complex effluents.


Assuntos
Cáusticos , Petróleo , Petróleo/análise , Petróleo/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias
2.
J Hazard Mater ; 421: 126677, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34332476

RESUMO

The co-management of different wastewater matrices can lead to synergistic effects in terms of pollutants removal. Here, the co-treatment of real municipal wastewater (MWW) and acid mine drainage (AMD) is comprehensively examined. Under the identified optimum co-treatment condition, i.e., 15 min contact time, 1:7 AMD to MWW liquid-to-liquid ratio, and ambient temperature and pH, the metal content of AMD (e.g., Al, Fe, Mn, Zn) was grossly (~95%) reduced along with sulphate (~92%), while MWW's phosphate content was practically removed (≥99%). The PHREEQC geochemical model predicted the formation of (oxy)-hydroxides, (oxy)-hydro-sulphates, metals hydroxides, and other mineral phases in the produced sludge, which were confirmed using state-of-the-art analytical techniques such as FE-SEM-EDS and XRD. The key mechanisms governing pollutants removal include dilution, precipitation, co-precipitation, adsorption, and crystallization. Beneficiation and valorisation of the produced sludge and co-treated effluent could promote resource recovery paradigms in wastewater management. Overall, the co-treatment of AMD and MWW appear to be feasible, yet not practical due to the excessive volume of MWW that is required to attain the desired treatment quality. Future research could focus on chemical addition for the control of the pH and the use of (photo)-Fenton for enhancing treatment efficiency.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Concentração de Íons de Hidrogênio , Mineração , Fosfatos , Esgotos , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise
3.
J Hazard Mater ; 421: 126722, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34332480

RESUMO

The novel sulfomethylated lignin-grafted-polyacrylic acid (SL-g-PAA) hydrogel was fabricated in this work via a facile and green synthetic strategy for the efficient removal of heavy metal ions from wastewater, and then successively reused for chemiluminescence (CL). The sulfomethylation of lignin was first performed to improve its water solubility and introduce numerous active sites for adsorption of heavy metal ions. The as-synthesized SL-g-PAA hydrogel with high content of lignin exhibited the highly efficient and rapid removal of various metal ions from simulated wastewater. More importantly, the spent hydrogel (M2+@SL-g-PAA) after adsorption was reused for the first time to develop a new CL system by an ingenious strategy, in which these metal ions adsorbed on M2+@SL-g-PAA act as heterogeneous catalytic sites to catalyze the CL reaction between N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and H2O2. The resultant CL system displayed high CL intensity and long duration time, which could be observed by naked eye in the dark and lasted for > 24 h. The combination of facile fabrication process, renewable raw materials, and ingenious strategy for successive application in adsorption and CL endows this lignin-based composite hydrogel with a great potential for application in wastewater treatment, biological imaging and cold light sources.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Hidrogéis , Peróxido de Hidrogênio , Íons , Lignina , Luminescência , Águas Residuárias , Poluentes Químicos da Água/análise
4.
J Hazard Mater ; 421: 126740, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34333409

RESUMO

Azo dye pollution has become a worldwide issue, and the current treatment methods can hardly meet the expected emission standards. Microbial electrochemical systems (MESs) show promising applications for decolorization, but their performance critically depends on the microorganisms. Electrode modification is an interesting method of improving decolorization performance. However, the mechanisms of how the modification can affect microbial communities and the decolorization process remain unclear. Here, a modified anode with polyaniline (PANI) and graphene was fabricated via electro-deposition. Consequently, the highest decolorization efficiency was obtained. The Congo red (CR) decolorization rate of the MESs with the PANI/graphene-modified electrode (PG) reached 90% at 54 h. By contrast, the CR decolorization rates of the MESs with the PANI-modified electrode (P) and those of the MESs with the unmodified electrode (C) only reached 68% and 79%, respectively. Results of the microbial community analysis showed abundant Methanobrevibacter arboriphilus in PG (11%), which was 5.5 times that in C (2%) at 18 h. This phenomenon may be related to the rapid decolorization. The upregulated metabolism pathways, including arginine and proline metabolism, purine metabolism, arginine biosynthesis, and riboflavin metabolism, provided more electron shuttles and redox mediators that facilitated the extracellular electron transfer. Therefore, the PG-modified electrode facilitated the decolorization by altering certain metabolic pathways. This study can help to improve the guideline on the potential application of MESs for wastewater treatment.


Assuntos
Compostos Azo , Grafite , Compostos de Anilina , Corantes , Eletrodos , Águas Residuárias
5.
J Hazard Mater ; 421: 126736, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34333411

RESUMO

Nitrogen removal from mainstream wastewater via DEnitrifying AMmonium OXidation (DEAMOX) is often challenged by undulated actual temperature and high loading rate. Here, we discovered NH2OH addition (HA) and bio-augmentation (BA) tactics on start-up and operation performance of DEAMOXs (R1 and R2) under ambient temperature (11.3-31.7 °C). Over 340-day operation suggested that R2 received 10 mg/L HA and 1:25 BA ratio (v/v, anammox/partial denitrification sludge) achieved desirable nitrogen removal efficiency (NRE) of 97.22% after 145-day, while R1 under higher BA ratio of 1:12.5 without HA obtained lower NRE (90.86%) after 184-day. Batch tests revealed that nitrate-nitrite transformation ratio reached 98.64% at low COD/NO3--N of 2.6 with HA. Significantly, compared with R2, R1 recovered quickly with satisfactory effluent total nitrogen of 4.21 mg/L despite nitrogen loading rate greater than 0.15 kg N/m3/d and temperature decreased to 14.6 °C. The abundant narG represented high nitrate reduction potential, hzsA and hdh were extensively detected as the symbolisation of anammox metabolism. Thauera, Denitratisoma and unclassified f Comamonadaceae dominated nitrite accumulation. Ca. Brocadia as the dominant anammox bacteria, and its population maintained stable against low temperature and load shocks by NH2OH intensification. Overall, this study offers an opportunity for the wide-applications of DEAMOX treating mainstream wastewater.


Assuntos
Compostos de Amônio , Desnitrificação , Reatores Biológicos , Hidroxilamina , Hidroxilaminas , Nitrogênio/análise , Oxirredução , Esgotos , Temperatura , Águas Residuárias
6.
J Hazard Mater ; 421: 126752, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352524

RESUMO

In this study, environmentally-friendly nanocomposite hydrogels were fabricated. These hydrogels consisted of semi-interpenetrating networks of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA), as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups, which were reinforced with different levels of graphene oxide particles (0.5, 1.5 or 3% wt). Field-emission electron scanning microscopy (FESEM) images indicated that the pore size of the nanocomposites decreased with increasing graphic oxide concentration. The presence of the graphic oxide increased the storage modulus and thermal stability of the nanocomposite hydrogels. The hydrogels had an adsorption capacity of 138 mg/g of a model cationic dye pollutant (methylene blue) after 250 min. Moreover, a reusability test showed that the adsorption capacity remained at around 90% after 9 cycles. Density functional theory (DFT) simulations suggested that the adsorption of methylene blue was mainly a result of π-π bonds, hydrogen bonds, and electrostatic interactions with graphene oxide. Our results indicated that the nanocomposite hydrogels fabricated in this study may be eco-friendly, stable, efficient, and reusable adsorbents for ionic pollutants in wastewater treatment.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Resinas Acrílicas , Adsorção , Carboximetilcelulose Sódica , Corantes , Grafite , Cinética , Azul de Metileno , Águas Residuárias
7.
J Hazard Mater ; 421: 126745, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34364206

RESUMO

Sulfide precipitation is an efficient method to remove Cu(II) and As(III) from strongly acidic wastewater, but the instantaneous release of H2S from traditional sulfuration reagents causes serious H2S pollution. Moreover, the obtained precipitates are mixtures of CuS and As2S3, leading to difficulties in resource recovery. In this study, a calcium sulfide-organosilicon complex (CaS-OSCS), in which CaS was coated into a matrix of {[O1.5Si(CH2)3NH]CS}n (OSCS) via the coordination bonding, was developed. OSCS, as a matrix of CaS-OSCS, can ensure the sustained and stable release of H2S under strongly acidic conditions owing to its low swelling (1.75% swelling ratio) and excellent acid resistance. The release longevity of H2S from CaS-OSCS extended from 5 min up to 50 min compared with that from CaS because the hydrophobic OSCS prevented solution diffusing to the pores of CaS-OSCS and thus slowed down the hydrolysis of CaS in pores. 99% of Cu(II)/As(III) was precipitated without H2S escape, and the dosage of sulfuration reagents was reduced by 30%. In addition, CaS-OSCS improved the selective separation of copper from wastewater, and a separation factor between Cu(II) and As(III) reached 2376. This study provides a potential approach for the elimination of H2S pollution and selective recovery of copper.


Assuntos
Sulfeto de Hidrogênio , Águas Residuárias , Compostos de Cálcio , Preparações de Ação Retardada , Sulfetos
8.
J Hazard Mater ; 421: 126734, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34365234

RESUMO

Industrial and textile dyes are the major source of water pollutants in the Coimbatore Districts of Tamil Nadu, India. The highly stable organic dyes from these industries are being discharged untreated into neighboring rivers, lakes, and ponds. Thus, the present study mainly focused on the preparation of bimetallic nanocomposite (Ag-Sn) through Free-facile Teflon autoclave methodology and their subsequent stimulation has given to the photocatalyst by visible light irradiation. This visible light stimulates and irradiates the photocatalysts from steady state to the excited state and might help in absorption of the nanosized dye materials and organic matter. The nanocomposite was characterized using UV, FTIR, Zeta-sizer, XRD and FE-SEM. These parameters exhibited significant lattice structures with an average size of 127.6 nm. Further the nanocomposite treated samples were tested for water quality parameters like TDS, BOD, COD, heavy metals, sedimentation rate and bacterial population. Likewise, the samples irradiated with visible light for photocatalytic activity exhibited a significant intensity of C/C0 at 0.42 and 0.28. The treated water used for green gram seedling assay exhibited significant growth. Scavengers from Ag-Sn bimetallic nanocomposite plays the major role in dye degradation. The results clearly suggest that Ag-Sn bimetallic nanocomposite can be used for wastewater treatment and the subsequent treated water can be utilized for agriculture purposes.


Assuntos
Nanocompostos , Águas Residuárias , Catálise , Índia , Luz
9.
J Hazard Mater ; 421: 126682, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388918

RESUMO

Biofilms are ubiquitous in aquatic environment. While so far, most of the ultraviolet (UV) disinfection studies focus on planktonic bacteria, and only limited attention has been given to UV irradiation on biofilms. To enrich this knowledge, the present paper reviews the up-to-date studies about applying UV to control biofilms in water and wastewater infrastructure. The development of UV light sources from the conventional mercury lamp to the light emitting diode (LED), and the resistance mechanisms of biofilms to UV are summarized, respectively. Then the feasibility to control biofilms with UV is discussed in terms of three technical routes: causing biofilm slough, inhibiting biofilm formation, and inactivating bacteria in the established biofilm. A comprehensive evaluation of the biofilm-targeted UV technologies currently used or potentially useful in water industry is provided as well, after comparative analyses on single/combined wavelengths, continuous/pulsed irradiation, and instant/chronic disinfection effects. UV LEDs are emerging as competitive light sources because of advantages such as possible selection of wavelengths, adjustable emitting mode and the designable configuration. They still, however, face challenges arising from the low wall plug efficiency and power output. At last, the implementation of the UV-based advanced oxidation processes in controlling biofilms on artificial surfaces is overviewed and their synergistic mechanisms are proposed, which further enlightens the prospective of UV in dealing with the biofilm issue in water infrastructure.


Assuntos
Raios Ultravioleta , Purificação da Água , Biofilmes , Desinfecção , Estudos Prospectivos , Águas Residuárias , Água
10.
J Hazard Mater ; 421: 126712, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388919

RESUMO

Aquaculture is increasing at the global scale, and beneficial reuse of wastewater is becoming crucial in some regions. Here we selected a unique tertiary treatment system for study over a one-year period. This experimental ecosystem-based approach to effluent management included a treated wastewater pond (TWP), which receives 100% effluent from a wastewater treatment plant, and an aquaculture pond (AP) that receives treated water from the TWP for fish production. We examined the fate of a wide range of pharmaceutically active compounds (PhACs) in this TWP-AP system and a control pond fed by river water using traditional grab sampling and passive samplers. We then employed probabilistic approaches to examine exposure hazards. Telmisartan, carbamazepine, diclofenac and venlafaxine, exceeded ecotoxicological predicted no effect concentrations in influent wastewater to the TWP, but these water quality hazards were consistently reduced following treatment in the TWP-AP system. In addition, both grab and passive sampling approaches resulted in similar occurrence patterns of studied compounds, which highlights the potential of POCIS use for water monitoring. Based on the approach taken here, the TWP-AP system appears useful as a tertiary treatment step to reduce PhACs and decrease ecotoxicological and antibiotic resistance water quality hazards prior to beneficial reuse in aquaculture.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Animais , Aquicultura , Ecossistema , Monitoramento Ambiental , Lagoas , Águas Residuárias/análise , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
11.
Environ Monit Assess ; 193(10): 688, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34601655

RESUMO

At various locations around the world, environments are now becoming greatly polluted by heavy metals, while damage is being done to soil and aquatic life with serious implications for humanity as well. Once heavy metals enter the ecosystem, they persist for a long time, and they are very difficult to eliminate. Discharging of industrial wastes enriched with heavy metals substantially pollutes the soil, water, and air. This study investigated the levels of heavy metals around the industrial area of Brahmanbaria, which is located in Chittagong Division, Bangladesh. Samples of soil, wastewater, vegetable, and grass were collected from the industrial area. The heavy metals were quantified using atomic absorption spectroscopy. The heavy metals found in soil were chromium (Cr) 8.2-18.8, lead (Pb) 3.5-18.3, copper (Cu) 4.6-10.8, zinc (Zn) 48.5-273.4, nickel (Ni) 10.06-26.9, and cadmium (Cd) 0.2 mg/kg, respectively. The metal contents in the wastewater were Cr 0.03-0.5, Pb 0.01-0.05, Cu 0.01-0.02, Zn 0.6-11.2, Ni 0.03-0.14, and Cd 0.003 mg/L, respectively. The metal contents in vegetable and grass were Cr 81.5-247.8, Pb 10.3-34.1, Cu 5.5-6.3, Zn 419.8-435.3, and Ni 8.7-15.5 mg/kg, respectively. The amount of metal in the soil, wastewater, and vegetables and grass followed the sequences: Zn > Cr > Ni > Pb > Cu > Cd, Zn > Cr > Ni > Pb > Cu > Cd, and Zn > Cr > Pb > Ni > Cu, respectively. Compared to the WHO guidelines, the soil in the study area was not polluted with Pb, Cu, and Cd but was moderately polluted with Cr, Zn, and Ni. Continual accumulation of metals in the soil, vegetables and grass could pose a serious risk to the environment as well as many life forms.


Assuntos
Metais Pesados , Solo , Bangladesh , Ecossistema , Monitoramento Ambiental , Águas Residuárias
12.
J Environ Sci (China) ; 110: 2-11, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34593190

RESUMO

Coagulation and precipitation is a widely applied method to remove F- from wastewater. In this work, the effect of coagulation on the removal of F- and organic matter from coking wastewater was studied using AlCl3 and FeCl3 as compound coagulants. The removal rates of F- and organic matter under different coagulant doses and pH conditions were investigated. The results show that the highest removal rates of F- by AlCl3 and FeCl3 are 94.4% and 25.4%, respectively; when the dosage is 10 mmol/L, the TOC removal rates of FeCl3 and AlCl3 reach 20.4% and 34.7%, respectively. Therefore, the removal rate of F- by AlCl3 is higher than that of FeCl3, but the removal rate of organic matter by FeCl3 is relatively higher. The addition of Ca2+ can promote the removal of F-, but the removal rate of organic matter decreases. In addition, by investigating the effects of different pH and Fe-Al ratio on the removal rate, the removal effect of adding FeCl3 and AlCl3 at the same time was discussed. The results show that the most suitable working condition for the removal of organic matter and F- is that the pH is 6.5 and the molar ratio of Al/Fe is 8:2. Overall, the removal mechanism of F- and organic matter in coking wastewater by FeCl3 and AlCl3 was explored in this study. The experimental results can provide reference for the advanced treatment of coking wastewater.


Assuntos
Coque , Purificação da Água , Águas Residuárias
13.
Sci Rep ; 11(1): 19456, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593871

RESUMO

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerges to scientific research and monitoring of wastewaters to predict the spread of the virus in the community. Our study investigated the COVID-19 disease in Bratislava, based on wastewater monitoring from September 2020 until March 2021. Samples were analyzed from two wastewater treatment plants of the city with reaching 0.6 million monitored inhabitants. Obtained results from the wastewater analysis suggest significant statistical dependence. High correlations between the number of viral particles in wastewater and the number of reported positive nasopharyngeal RT-qPCR tests of infected individuals with a time lag of 2 weeks/12 days (R2 = 83.78%/R2 = 52.65%) as well as with a reported number of death cases with a time lag of 4 weeks/27 days (R2 = 83.21%/R2 = 61.89%) was observed. The obtained results and subsequent mathematical modeling will serve in the future as an early warning system for the occurrence of a local site of infection and, at the same time, predict the load on the health system up to two weeks in advance.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2/genética , Águas Residuárias/análise , Águas Residuárias/virologia , COVID-19/mortalidade , Surtos de Doenças/prevenção & controle , Humanos , Modelos Teóricos , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Eslováquia/epidemiologia , Águas Residuárias/química , Vigilância Epidemiológica Baseada em Águas Residuárias , Purificação da Água
14.
Sci Total Environ ; 799: 150013, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34602307

RESUMO

Wastewater analysis was used to investigate drug prevalence in primary and secondary schools and institutes of higher education located in urban and non-urban areas of six municipalities in Slovenia. Seven-hour composite raw wastewater samples from 44 educational institutions, including 19 primary schools (6-15 yrs.), ten secondary schools (15-19 yrs.), nine higher education institutions (19+ yrs.) and six mixed secondary and higher education institutions (15+ yrs.), were collected at the end of the 2018/2019 academic year. Metabolic residues of licit drugs (nicotine and alcohol), medications of abuse (morphine, codeine and methadone) and illicit drugs (cannabis, cocaine, amphetamine, methamphetamine, ecstasy and heroin) were targeted in the study. The analysis was carried out using solid-phase extraction and direct injection combined ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Biomarkers of nicotine, alcohol and cannabis intake were the most frequently detected, indicating a high prevalence of these drugs. Morphine and codeine were also detected, while among the stimulants, benzoylecgonine had the highest detection frequency. Drug differences were found between different levels of educational institution, geographic location (inter-municipality comparison) and degree of urbanization. However, t-distributed stochastic neighbour embedding (t-SNE) revealed that the level of educational institution was the main factor influencing the differences in drug prevalence. Although a good agreement between data from this study and other studies implementing wastewater analysis was observed, there was a discrepancy with Slovenian epidemiological survey data. Finally, despite certain drawbacks of the method, its application to detect drug residues in educational institutions provides a non-invasive insight into drug use trends.


Assuntos
Drogas Ilícitas , Transtornos Relacionados ao Uso de Substâncias , Poluentes Químicos da Água , Cromatografia Líquida , Humanos , Instituições Acadêmicas , Detecção do Abuso de Substâncias , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Espectrometria de Massas em Tandem , Águas Residuárias/análise , Poluentes Químicos da Água/análise
15.
Waste Manag ; 135: 448-456, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34624743

RESUMO

In the present study, a combined technology for energetic brewery spent grain (BSG) use in co-digestion with sewage sludge (SS) was presented. A holistic approach that includes the impact of co-substrates and their carriers on the anaerobic digestion (AD) process, and the energetic aspects, was involved. Prior to AD, BSG was pretreated involving the hydrodynamic cavitation (HC); two different carriers were applied: MPW (municipal pre-settled wastewater) and mature landfill leachate (MLL). An orifice plate with a conical concentric hole of 3/10 mm (inlet/outlet diameter) was applied as cavitation device. The initial pressure was 7 bar and the number of recirculation passes through the cavitation zone was 30. The AD experiments were performed in semi-flow reactors, under mesophilic conditions at HRT of 20 and 21 d. In both co-digestion series, the constant co-substrate dose of 6% v/v was adopted. In the presence of cavitated BSG and MPW, a significant increase in biogas/methane production was provided as compared to SS mono-digestion, with the related improvement in kinetic constant by 3.5%. The average biogas yield was 0.48 ± 0.03 m3 kg-1 VS added, while in the control run 0.41 ± 0.03 m3 kg-1 VS added. Using cavitated BSG and MLL, such a beneficial effect was not observed. In both co-digestion series, slightly lower VS removal (as for the control) and stable process performance occurred. Moreover, the improved energy balance was provided. Due to the technological aspects, only co-digestion of cavitated BSG and MPW with SS is recommended for implementation into a full-scale.


Assuntos
Biocombustíveis , Esgotos , Anaerobiose , Reatores Biológicos , Digestão , Metano , Águas Residuárias
16.
Artigo em Inglês | MEDLINE | ID: mdl-34639592

RESUMO

As a complement to clinical disease surveillance, the monitoring of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in wastewater can be used as an early warning system for impending epidemics. This study investigated the dynamics of SARS-CoV-2 in untreated wastewater with respect to the trend of coronavirus disease 2019 (COVID-19) prevalence in Southern Italy. A total of 210 wastewater samples were collected between May and November 2020 from 15 Apulian wastewater treatment plants (WWTP). The samples were concentrated in accordance with the standard of World Health Organization (WHO, Geneva, Switzerland) procedure for Poliovirus sewage surveillance, and molecular analysis was undertaken with real-time reverse-transcription quantitative PCR (RT-(q) PCR). Viral ribonucleic acid (RNA) was found in 12.4% (26/210) of the samples. The virus concentration in the positive samples ranged from 8.8 × 102 to 6.5 × 104 genome copies/L. The receiver operating characteristic (ROC) curve modeling showed that at least 11 cases/100,000 inhabitants would occur after a wastewater sample was found to be positive for SARS-CoV-2 (sensitivity = 80%, specificity = 80.9%). To our knowledge, this is the first study in Italy that has applied wastewater-based epidemiology to predict COVID-19 prevalence. Further studies regarding methods that include all variables (meteorological phenomena, characteristics of the WWTP, etc.) affecting this type of wastewater surveillance data would be useful to improve data interpretation.


Assuntos
COVID-19 , Humanos , Itália/epidemiologia , SARS-CoV-2 , Esgotos , Águas Residuárias
17.
J Environ Manage ; 300: 113784, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34649310

RESUMO

This study investigated chemical oxygen demand (COD), color number (CN), and UV254 removal from dye manufacturing wastewater via electrocoagulation (EC) and electro-Fenton (EF) processes. The effects of current density, initial pH, reaction time, and H2O2/COD ratio on the EC and EF processes were evaluated and optimum operating conditions were determined. The effects of EC and EF processes on COD fractions and the specific energy consumption of both processes were evaluated. Sludge analyses were conducted by organic removal to sludge ratio (ORSR) and Fourier Transform Infrared Spectroscopy spectra were assessed for characterization of generated sludge. Optimum operation conditions for the EC process were 21 mA/cm2 current density, 7.3 initial pH, and 25 min reaction time while they were 21 mA/cm2 current density, 3.5 initial pH, 1.25 H2O2/COD ratio, and 35 min reaction time for EF process. Under optimum conditions COD, CN, and UV254 removal efficiencies were 38.5%, 90.1%, and 52.5%, respectively in EC process and 54.8%, 94.2%, and 88.1%, respectively in EF process. Both processes have a positive effect on the increase of biodegradable and soluble COD fractions. Higher ORSR and lower specific energy consumption were provided by the EF process under optimum conditions. The EF process is more effective when pollutant removal efficiencies, ORSR, and specific energy consumption are considered.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Análise da Demanda Biológica de Oxigênio , Eletrocoagulação , Peróxido de Hidrogênio , Esgotos , Eliminação de Resíduos Líquidos
18.
J Environ Manage ; 300: 113786, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34649311

RESUMO

Acoustic cavitation (AC) and hydrodynamic cavitation (HC) coupled with advanced oxidation processes (AOPs) are prominent techniques used for industrial wastewater treatment though most studies have focused on simulated effluents. The present review mainly focuses on the analysis of studies related to real industrial effluent treatment using acoustic and hydrodynamic cavitation operated individually and coupled with H2O2, ozone, ultraviolet, Fenton, persulfate and peroxymonosulfate, and other emerging AOPs. The necessity of using optimum loadings of oxidants in the various AOPs for obtaining maximum COD reduction of industrial effluent have been demonstrated. The review also presents critical analysis of designs of various HCRs that have been or can be used for the treatment of industrial effluents. The impact of operating conditions such as dilution, inlet pressure, ultrasonic power, pH, and operating temperature have been also discussed. The economic aspects of the industrial effluent treatment have been analyzed. HC can be considered as cost-efficient approach compared to AC on the basis of the lower operating costs and better transfer efficiencies. Overall, HC combined with AOPs appears to be an effective treatment strategy that can be successfully implemented at industrial-scale of operation.


Assuntos
Ozônio , Purificação da Água , Hidrodinâmica , Peróxido de Hidrogênio , Oxirredução , Águas Residuárias
19.
J Environ Manage ; 300: 113790, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34649313

RESUMO

Accurate modeling of wastewater ultraviolet disinfection is fundamental as support for process optimization and control. Detailed modeling of hydrodynamics and fluence rate via computational fluid dynamics, coupled to laboratory studies of inactivation kinetics, are usually the preferred approach for UV disinfection modeling. Despite this approach often provides accurate predictive performance, it requires significantly high computational time, making it unfeasible for real-time process control. In this study, to enable an effective process control, black-box regression models were assessed as a modeling alternative for UV disinfection, synthesizing hydrodynamics, fluence rate and inactivation kinetics. UV disinfection of a full-scale wastewater treatment plant in Italy was monitored for 10 months, measuring influent and effluent E. coli concentration, turbidity, absorbance at 254 nm, temperature and flow rate at different UV doses. Considering the usually observed distribution of effluent E. coli concentration and the zero inflation of the collected dataset, Poisson, zero-inflated Poisson and Hurdle generalized linear models were tested, as well as two-part models coupling a classifier describing the E. coli zero-count events and a regressor estimating the magnitude of E. coli concentrations in positive-count events. The two-part artificial neural network model showed the best predictive performance, being able of both describing nonlinearities and handling the high proportion of null values in the dataset. The deployment of this model to control ultraviolet disinfection was simulated, estimating a plausible 63% energy saving.


Assuntos
Desinfecção , Purificação da Água , Escherichia coli , Redes Neurais de Computação , Raios Ultravioleta , Águas Residuárias/análise
20.
J Environ Manage ; 300: 113831, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34649321

RESUMO

Wastewater and activated sludge present a major challenge worldwide. Wastewater generated from large and small-scale industries, laundries, human residential areas and other sources is emerging as a main problem in sanitation and maintenance of smart/green cities. During the last decade, different technologies and processes have been developed to recycle and purify the wastewater. Currently, identification and fundamental consideration of development of more advanced microbial-based technologies that enable wastewater treatment and simultaneous resource recovery to produce bioenergy, biofuels and other value-added compounds (organic acids, fatty acids, bioplastics, bio-pesticides, bio-surfactants and bio-flocculants etc.) became an emerging topic. In the last several decades, significant development of bioprocesses and techniques for the extraction and recovery of mentioned valuable molecules and compounds from wastewater, waste biomass or sludge has been made. This review presents different microbial-based process routes related to resource recovery and wastewater application for the production of value-added products and bioenergy. Current process limitations and insights for future research to promote more efficient and sustainable routes for this under-utilized and continually growing waste stream are also discussed.


Assuntos
Águas Residuárias , Purificação da Água , Biocombustíveis , Biomassa , Humanos , Esgotos
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