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1.
J Environ Manage ; 351: 119777, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38086119

RESUMO

Dual chambered microbial fuel cell (DMFC) is an advanced and effective treatment technology in wastewater treatment. The current work has made an effort to treat petrochemical industrial wastewater (PWW) as a DMFC substrate for power generation and organic substance removal. Investigating the impact of organic load (OL) on organic reduction and electricity generation is the main objective of this study. At the OL of 1.5 g COD/L, the highest total chemical oxygen demand (TCOD) removal efficiency of 88%, soluble oxygen demand (SCOD) removal efficiency of 80% and total suspended solids (TSS) removal efficiency of 71% were seen, respectively. In the same optimum condition of 1.5 g COD/L, the highest current and power density of about 270 mW/m2 and 376 mA/m2 were also observed. According to the results of this study, using high-strength organic wastewater in DMFC can assist in addressing the issue of the petrochemical industries and minimize the energy demand.


Assuntos
Fontes de Energia Bioelétrica , Purificação da Água , Águas Residuárias , Eletricidade , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Eletrodos , Eliminação de Resíduos Líquidos/métodos
2.
Bioresour Technol ; 387: 129587, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37549718

RESUMO

Wastewater disposal in the ecosystem affects aquatic and human life, which necessitates the removal of the contaminants. Eliminating wastewater contaminants using biochar produced through the thermal decomposition of lignocellulosic biomass (LCB) is sustainable. Due to its high specific surface area, porous structure, oxygen functional groups, and low cost, biochar has emerged as an alternate contender in catalysis. Various innovative advanced technologies were combined with biochar for effective wastewater treatment. This review examines the use of LCB for the synthesis of biochar along with its activation methods. It also elaborates on using advanced biochar-based technologies in wastewater treatment and the mechanism for forming oxidizing species. The research also highlights the use of machine learning in pollutant removal and identifies the obstacles of biochar-based catalysts in both real-time and cutting-edge technologies. Probable and restrictions for further exploration are discussed.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Humanos , Ecossistema , Adsorção , Carvão Vegetal/química , Catálise , Poluentes Químicos da Água/química
3.
Environ Technol ; 44(28): 4441-4459, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35757857

RESUMO

The aim of the present work was to provide a viable and active way to remove COD and colour from landfill leachate treated by adopting combined process of electrocoagulation and solar photo Fenton process. Coagulating agents such as metal hydroxides are created by the electrolysis process through self-sacrificial electrodes. Aluminium and iron dissolves at the anode and hydrogen gas are generated at the cathode when aluminium and iron electrodes are utilised. The contaminants interact with the coagulating agent to generate enormous organic flocs. The leachate was obtained from a landfill in Madurai and then it was characterised in terms of its major predominant pollutants. In this study, the electrocoagulation process was used in conjunction with the solar photo Fenton process to treat the leachate under ideal conditions of pH = 7, NaCl = 2 g/L, voltage = 4 V, Al & Fe electrodes and inter electrode distance = 3 cm with a COD and colour removal effectiveness of 75% and 76%, respectively. Furthermore, the effluent from the electrocoagulation process was treated using a solar photo Fenton process at pH = 3, H2O2 = 10 g/L and Fe2+ = 1 g/L with COD and colour reduction effectiveness of 90% and 91%, respectively. In this combination of treatment systems, leachate biodegradability increased from 0.35 to 0.73, favouring the biological oxidation process in conventional treatment plants. This research demonstrates that employing this paired electrocoagulation-solar photo Fenton to treat landfill leachate can achieve consistent treatment effects with high removal efficiencies, and that it is an acceptable treatment technique for landfill leachate.


Assuntos
Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Alumínio , Peróxido de Hidrogênio , Índia , Eletrocoagulação/métodos , Ferro , Oxirredução
4.
Bioresour Technol ; 364: 128103, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36243260

RESUMO

Algae biomass contains various biological elements, including lipids, proteins, and carbohydrates, making it a viable feedstock for manufacturing biofuels. However, the biggest obstacle to commercializing algal biofuels is their high production costs, primarily related to an algae culture. The extraction of additional high value added bioproducts from algal biomass is thus required to increase the economic viability of producing algae biofuel. This study aims to discuss the economic benefits of a zero-carbon economy and an environmentally sustainable algae resource in decarbonizing the environment through the manufacture of algal-based biofuels from algae biomass for a range of potential uses. In addition, research on the algae biorefineries, with an emphasis on case studies for various cultivation methods, as well as the commercialization of biofuel and bioenergy. Overall, the algal biorefinery offers fresh potential for synthesizing various products.

5.
Bioresour Technol ; 363: 127985, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36126843

RESUMO

A significant ecological problem was developed on disposing the enormous amounts of waste activated sludge (WAS) produced by traditional wastewater treatment. There have been various attempts recently originated to develop innovative methods for substantial sludge treatment. The most frequently used approach for treating sludge to produces methane and reduces sludge is anaerobic treatment. The hydrolysis phase in WAS limits the breakdown of complex macrobiotic compounds. The presence of extracellular polymeric substances (EPS) in biomass prevents the substrate from being hydrolyzed. Enhancing substrate hydrolysis involves removal of EPS preceded by phase separated pretreatment. Hence, a critical assessment of various phase separated pretreatment that has a remarkable effect on the anaerobic digestion process was documented in detail. Moreover, the economic viability and energy requirement of this treatment process was also discussed. Perspectives and recommendations for methane production were also provided to attain effectual sludge management.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Anaerobiose , Hidrólise , Metano/metabolismo , Esgotos/química , Eliminação de Resíduos Líquidos/métodos
6.
Bioresour Technol ; 350: 126904, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35227914

RESUMO

This research work aimed about the enhanced bio-hydrogen production from marine macro algal biomass (Ulva reticulate) through surfactant induced microwave disintegration (SIMD). Microwave disintegration (MD) was performed by varying the power from 90 to 630 W and time from 0 to 40 min. The maximum chemical oxygen demand (COD) solubilisation of 27.9% was achieved for MD at the optimal power (40%). A surfactant, ammonium dodecyl sulphate (ADS) is introduced in optimal power of MD which enhanced the solubilisation to 34.2% at 0.0035 g ADS/g TS dosage. The combined SIMD pretreatment significantly reduce the treatment time and increases the COD solubilisation when compared to MD. Maximum hydrogen yield of 54.9 mL H2 /g COD was observed for SIMD than other samples. In energy analysis, it was identified that SIMD was energy efficient process compared to others since SIMD achieved energy ratio of 1.04 which is higher than MD (0.38).


Assuntos
Alga Marinha , Biomassa , Micro-Ondas , Tensoativos/farmacologia , Termodinâmica
7.
Cureus ; 14(1): e21439, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35198334

RESUMO

OBJECTIVES: A complete and concise pre-clinical experimental research gives detailed information about the disease-specific model, prevents duplication, and saves animal life, money, as well as time. It will also allow readers to effectively interpret and evaluate the work and ensure that others can replicate the experiments described. The present study was conducted to assess the adequacy of animal details provided in published experimental animal studies. METHODS:  All in vivo studies published as full-text articles in two PubMed indexed journals (one Indian and one international) from January 2011 to December 2019 and satisfying the inclusion norms were included. A checklist consisting of 27 discrete items subdivided under three domains, viz. animal details, disease model, and guidelines, was used. Every article was assessed by two investigators independently for determining the reporting quality. RESULTS:  One hundred and seventy-seven studies satisfied the inclusion criteria. Age or age range was reported in 20.34% of the articles in the Indian journal and 5.88% articles in the international journal (p=0.019). Housing and husbandry details were reported in all the articles published in the international journal and 82.7% of the articles in the Indian journal (p=0.001). The disease/pathology studied was given in 70.62% of articles published in the Indian journal and 86.27% of articles published in the international journal (p=0.029). None of the studies provided details of genetic modification, health status, sample size calculation, steps taken to minimize bias, and implementation of randomization. CONCLUSION: There is a need for optimal reporting of certain relevant animal details, disease models, experimental procedures, sample size calculation, and adherence to guidelines by the researchers for which the reporting was found to be sub-par to improve reproducibility and validity of animal research.

8.
Chemosphere ; 288(Pt 2): 132553, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34653493

RESUMO

Waste activated sludge (biosolids) treatment is intensely a major problem around the globe. Anaerobic treatment is indeed a fundamental and most popular approach to convert organic wastes into bioenergy, which could be used as a carbon-neutral renewable and clean energy thus eradicating pathogens and eliminating odor. Due to the sheer intricate biosolid matrix (such as exopolymeric substances) and rigid cell structure, hydrolysis becomes a rate-limiting phase. Numerous different pretreatment strategies were proposed to hasten this rate-limiting hydrolysis and enhance the productivity of anaerobic digestion. This study discusses an overview of previous scientific advances in pretreatment options for enhancing biogas production. In addition, the limitations addressed along with the effects of inhibitors in biosolids towards biogas production and strategies to overcome discussed. This review elaborated the cost analysis of various pretreatment methods towards the scale-up process. This review abridges the existing research on augmenting AD efficacy by recognizing the associated knowledge gaps and suggesting future research.


Assuntos
Biocombustíveis , Esgotos , Anaerobiose , Biossólidos , Hidrólise
9.
Chemosphere ; 286(Pt 3): 131835, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426273

RESUMO

This paper proposed to interpret the novel method of extracellular polymeric substance (EPS) removal in advance to sludge disintegration to enrich bioenergy generation. The sludge has been subjected to deflocculation using Zinc oxide/Chitosan nanocomposite film (ZCNF) and achieved 98.97% of solubilization which enhance the solubilization of organics. The obtained result revealed that higher solubilization efficiency of 23.3% was attained at an optimal specific energy of 2186 kJ/kg TS and disintegration duration of 30 min. The deflocculated sludge showed 8.2% higher solubilization than the flocculated sludge emancipates organics in the form of 1.64 g/L of SCOD thereby enhancing the methane generation. The deflocculated sludge produces methane of 230 mL/g COD attained overall solid reduction of 55.5% however, flocculated and control sludge produces only 182.25 mL/g COD and 142.8 mL/g COD of methane. Based on the energy, mass and cost analysis, the deflocculated sludge saved 94.1% of energy than the control and obtained the net cost of 5.59 $/t which is comparatively higher than the flocculated and control sludge.


Assuntos
Quitosana , Nanocompostos , Óxido de Zinco , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Conservação de Recursos Energéticos , Matriz Extracelular de Substâncias Poliméricas , Floculação , Metano , Esgotos , Eliminação de Resíduos Líquidos
10.
Perspect Clin Res ; 12(4): 203-208, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34760648

RESUMO

PURPOSE: Psychiatric emergencies (PEs) are defined as acute disturbances of thought, mood, behavior, or social relationships requiring immediate interventions. The common emergency psychiatrics are attempted suicide, severe anxiety, schizophrenia, acute psychosis, substance abuse, acute panic attacks, drug toxicities, and extrapyramidal reactions. Emergency physicians in the general hospital may face the challenge of assessing and managing patients in PEs. This study was conducted to evaluate the clinical pattern and drug use pattern for PEs at a tertiary care hospital. MATERIALS AND METHODS: This was a cross-sectional, observational study where patients presenting to emergency medical services of a tertiary care hospital were recruited after approval from Institutional Ethics Committee and written informed consent. Demographic details, diagnosis, medication details, cost of the treatment, and adherence to guidelines in the management of emergency psychiatric conditions were assessed using a validated questionnaire. Descriptive statistics was applied to analyze the data. RESULTS: In 110 patients, a total number of drugs prescribed were 463 (mean: 4.21 drugs/prescription). The most commonly used psychotropic drug in emergency setting was found to be risperidone (19.39%), followed by lorazepam (13.60%) and clonazepam (4.28%). The most common diagnoses were substance abuse (32.72%) and schizophrenia (21.81%). About 74.5% of the physicians prescribed drugs abiding by the standard guidelines. The average total cost incurred by patients was about Rs. 366. CONCLUSION: The most commonly used drugs in emergency treatment found in this study are risperidone, followed by lorazepam and haloperidol.

11.
Bioresour Technol ; 341: 125810, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34467891

RESUMO

The present investigation is proposed to assess the competency of Sodium Persulphate (SPS) induced enzyme secreting bacterial pretreatment in enhancing the generation of biohydrogen from waste activated sludge (WAS). Alkali activated SPS of dosage 0.015 g/g SS has been opted to disseminate the floc structure to fortify the release of Extracellular polymeric substance (EPS) into aqueous phase. This removal of EPS enhances the bacterial disintegration fostering 18.71% of suspended solids reduction and 21% of COD solubilization which was comparatively higher than bacterially pretreated (BP) and control (C) sludge. Biohydrogen production of control (C), bacterially pretreated (BP) and SPS mediated bacterially pretreated (SPS-BP) sludge were found to be 32.2 mLH2/g COD, 48.3 mLH2/g COD and 103.8 mLH2/g COD respectively. The net energy production of SPS - BP is 0.01 kWh which is higher than the C and BP sample during the entire treatment and obtained energy ratio greater than 1.


Assuntos
Álcalis , Matriz Extracelular de Substâncias Poliméricas , Bactérias , Hidrogênio , Esgotos , Eliminação de Resíduos Líquidos
12.
Indian J Med Ethics ; V(2): 119-123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32393459

RESUMO

BACKGROUND: Protocol non-compliance in clinical research studies is common and can affect both patient safety and data integrity. There are no published studies which actively looked for non-compliance. The present study was carried out, against this background, with the objective of assessing the proportion of protocol non-compliance and evaluating those aspects of protocol where there was non-compliance. METHODS: The study completion reports that were submitted to the institutional ethics committee for the period January 2017 to December 2017 were compared with the approved protocol. A checklist for recording protocol non-compliance was developed, which was validated by five experts and consisted of a 12-point checklist with responses such as yes, no, not applicable, and insufficient information. RESULTS: Out of 193 studies, prospective observational studies were n = 120 (62.17 %), retrospective studies were n = 39 (20.21%), interventional studies n = 28 (14.51 %), and observational studies with both prospective and retrospective study design were n = 6 (3.11%). The study objective was modified in n=18 (9.32%) studies. Only n = 14 (7.24%) satisfied the selection criteria. Six studies (3.10%) did not collect the data as mentioned in the protocol. Fifty-eight studies (30.05%) did not achieve the calculated sample size, whereas n = 78 (40.41%) did not complete the study as per the stipulated study duration. Contrary to 180 protocol deviations found in this study, only 14 protocol deviations were reported by the principal investigator. Aspects like blinding and randomisation, which are relevant to interventional studies (n = 28), showed 100 % compliance. CONCLUSION: The research protocol is not adhered to in all aspects. Adequate training to investigators will help prevent non-compliance and enable us to conduct studies with higher ethical and scientific integrity.


Assuntos
Comitês de Ética em Pesquisa , Projetos de Pesquisa , Humanos , Estudos Observacionais como Assunto , Estudos Prospectivos , Pesquisadores , Estudos Retrospectivos
13.
Bioresour Technol ; 308: 123276, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32251862

RESUMO

Proper treatment and disposal of sludge is a substantial task around the biosphere. To address this issue, sludge deflocculation using photocatalyst was opted to enhance bacterial disintegration which in turn accelerate sludge digestion anaerobically. During this investigation, Direct current (DC) sputtering together with annealing process was used to immobilize Zinc oxide (ZnO). This immobilized ZnO removes the extracellular components at 15 min. The deflocculation mediated bacterial pretreatment induced 22.9% of soluble organics solubilization which auguments the biodegradability to 0.195 g COD/g COD during anaerobic digestion. The quantity of methane generated by deflocculated sludge was 39.2% higher than sludge with bacterial disintegration only with maximum methane yield of 437.14 mL/g COD. Hence, the outcome of the proposed work confirmed that the method is scalable with a net profit of 27 USD with the maximum methane generation of 413.1 kWh. Additionally, this method reduced 57% of dry sludge (solid).


Assuntos
Esgotos , Óxido de Zinco , Anaerobiose , Floculação , Metano , Eliminação de Resíduos Líquidos
14.
Sci Total Environ ; 718: 137287, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32086085

RESUMO

Plastic waste is an environmental burden substance, which poses a high threat to the society during disposal. Rather than disposal, recycling of this waste to liquid fuel gains importance owing to its high utility. Among various techniques, thermo-chemical recycling techniques hold more benefits in generating high value added liquid fuels. In this review, the details of municipal plastic waste generation are provided with a brief description of the plastic waste management option and importance of recycling is explained. The overview of the thermo-chemical treatment focusing on the pyrolysis, gasification and hydrocracking process was elaborated. Catalysts mediated pyrolysis have wide-open their prospective for the generation of bio-oil, hydrocarbons, syngas and deterioration of undesired substances. Generally, advance development of enthusiastic catalysts for the synthesis of bio-oil would be vital for scaling up the pyrolysis process to succeed in commercial manufacture of biofuels from waste plastics. Overall rate treatment depends on operating parameter which determines the process efficiency and product yield. Hence, critical assessment of various parameter that has remarkable effect in the thermo-chemical treatment process was documented in detail. Moreover, endorsements of liquid fuel production, economic viability, and energy requirement of the treatment process, were delivered to attain effectual plastic wastes management.


Assuntos
Biomassa , Reciclagem , Biocombustíveis , Plásticos , Estudos Prospectivos
15.
Indian J Med Ethics ; 4(3): 178-183, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31727613

RESUMO

The monitoring of clinical trials is an integral function of the institutional ethics committee (IEC)to ensure the ethical conduct of research. The National Ethical Guidelines for Biomedical and Health Research Involving Human Participants, 2017, of the Indian Council of Medical Research, underline a strong need for active monitoring of clinical trials. A previous study by the authors, of research studies initiated between 2008 and 2010, had found many lapses after site monitoring. In the present study, 12 clinical studies-both sponsored and investigator initiated-were monitored by members of the King Edward Memorial Hospital (Mumbai) IEC between 2011 and 2017. The most common violations seen were related to informed consent (8/12 sites). The other violation themes were lack of investigator understanding of protocol (6/12), deviation from the investigational plan (5/12), non-reporting of the study's progress to the IEC (4/12), and patient recruitment prior to IEC approval (2/12). The IEC took various corrective actions, such as ordering retaking of consent and good clinical practice (GCP) re-training and requiring interim reports, explanations for deviations, upgradation of facilities, and payment of pending compensation. The IEC even froze review of protocols from a frequently defaulting Principal Investigator's (PI) site and put study recruitment on hold for the same PI. This study demonstrates that active site monitoring by IECs is a must for ensuring the ethical conduct of studies.


Assuntos
Ensaios Clínicos como Assunto/ética , Comissão de Ética , Ética em Pesquisa , Centros de Atenção Terciária/ética , Humanos , Índia , Consentimento Livre e Esclarecido/ética , Seleção de Pacientes/ética , Estudos Retrospectivos
16.
J Environ Manage ; 238: 251-256, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30852401

RESUMO

In this study, an attempt has been made to reduce the sludge using novel homogenizer coupled solar photo Fenton (HPF) process. At an optimum pH of 3 and Fe2+ to H2O2 dosage of 1:6, PF process yielded 63.7% solids reduction at a time interval of 45 min. Coupling of homogenizers with photo Fenton (PF) process effectively enhanced treatment efficiency. When homogenizer (specific energy - 1150.694 kJ/kg TS) was coupled with PF, a sharp increase in solid reduction 73.5% and decrease in reaction time (20 min) were observed. Cost benefit analysis revealed the efficiency of HPF process and achieved a net cost of 15.59 USD whereas PF achieved a negative net cost of -82.69 USD. Based on the above study it can be concluded that coupling of homogenizers with PF not only increased its efficiency but also make it field applicable.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Estudos de Viabilidade , Peróxido de Hidrogênio , Ferro , Oxirredução
17.
Bioresour Technol ; 279: 132-139, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30716605

RESUMO

This study reports the result of sodium citrate induced exopolymer extraction on the photocatalytic thin film (TiO2) pretreatment efficiency of waste activated sludge (WAS). TiO2 is immobilized through DC spluttering method followed by annealing process. The exopolymer removal of 94.2% by sodium citrate (0.05 g/g SS) promotes better disintegration. This TiO2 thin film efficiently extricate the intracellular components of exopolymer extracted sludge at 50 min increasing the solubilization to 19.33%. As a result, the exopolymer extracted sludge shows high methane generation (0.24 gCOD/gCOD) than the other (pretreated sludge without exopolymer removal - 0.12 gCOD/gCOD and raw sludge without treatment - 0.075 gCOD/gCOD). The methane generated in sodium citrate induced TiO2 thin film pretreated sludge is 398.99 kWh. In cost analysis, it gives net cost of -57.46 USD/ton of sludge. In addition, the proposed method also accounts 51.3% of solid reduction.


Assuntos
Biocombustíveis , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Anaerobiose , Catálise , Metano/biossíntese , Processos Fotoquímicos , Polímeros/metabolismo , Esgotos
18.
Indian J Pharmacol ; 51(6): 400-406, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32029962

RESUMO

OBJECTIVE: The objective of the study is to evaluate the perception of postgraduate pharmacology students toward computer-simulated method (CSM) in comparison to the prevalent isolated live tissue-based bioassay method. MATERIALS AND METHODS: A questionnaire-based survey was conducted in 30 postgraduate pharmacology students who had used the animal simulation software and had completed at least five isolated tissue experiments. Students' opinions on the usage, logistics, advantages, disadvantages, and usefulness of CSM compared to live animal experiments (LAE) were analyzed. RESULTS: Four tissues were used for LAE, whereas with CSM, students could perform experiments using 11 different tissues. Of the total nine bioassay methods, students had performed six assay methods using both LAE and CSM. Majority of the students (23/30) agreed that CSM reduces anxiety, technical errors and is less time consuming when used before LAE. Most of the students agreed that CSM can be used for difficult, lengthy experiments (19/30), and for UG/PG teaching (19/30). However, opinions regarding replacing LAE with CSM in PG teaching were divided (agree: 7, neutral: 12, and disagree: 12). CONCLUSION: CSM should be integrated alongside LAE to complement, reinforce, and enhance learning from other techniques.


Assuntos
Alternativas aos Testes com Animais , Simulação por Computador , Modelos Animais , Farmacologia/educação , Estudantes/psicologia , Animais , Anuros , Bioensaio , Gatos , Educação de Pós-Graduação , Cobaias , Humanos , Percepção , Coelhos , Ratos , Inquéritos e Questionários
19.
J Environ Manage ; 206: 999-1006, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30029350

RESUMO

In this study, recalcitrant rich retting-pond wastewater was treated primarily by anaerobic treatment and subsequently treated with a solar photofenton process to remove phenol and organics. The anaerobic treatment was carried out in a granulated laboratory scale hybrid upflow anaerobic sludge blanket reactor (HUASBR) with a working volume of 5.9 L. It was operated at different hydraulic retention times (HRT) from 40 to 20 h over a period of 140 days. The optimum HRT of the anaerobic reactor was found to be 30 h, with corresponding chemical oxygen demand (COD) and phenol removal of 60% and 47%, respectively. Primary anaerobically treated wastewater was subjected to secondary solar photofenton treatment which was carried out at pH 3.5. Response surface methodology (RSM) was used to design and optimize the performance of the solar photofenton process. Regression quadratic model describing COD removal efficiency of the solar photofenton process was developed and confirmed by analysis of variance (ANOVA). Optimum parameters of the solar photofenton process were found to be: 4 g/L of fenton as catalysts, 25 mL of hydrogen peroxide, and 30 min of reaction time. After the primary anaerobic treatment, solar photofenton oxidation process removed 94% and 96.58% of COD and phenol, respectively. Integration of anaerobic and solar photofenton treatment resulted in 97.5% and 98.4% removal of COD and phenol, respectively, from retting-pond wastewater.


Assuntos
Fenol , Eliminação de Resíduos Líquidos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Lagoas , Esgotos
20.
Bioresour Technol ; 244(Pt 1): 776-784, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28822951

RESUMO

In the present study, the deflocculated sludge was disintegrated through thin layer immobilized titanium dioxide (TiO2) as photocatalyst under solar irradiation. The deflocculation of sludge was carried out by 0.05g/g SS of sodium citrate aiming to facilitate more surface area for subsequent TiO2 mediated disintegration. The proposed mode of disintegration was investigated by varying TiO2 dosage, pH and time. The maximum COD solubilization of 18.4% was obtained in the optimum 0.4g/L of TiO2 dosage with 5.5 pH and exposure time of 40min. Anaerobic assay of disintegrated samples confirms the role of deflocculation as methane yield was found to be higher in deflocculated (235.6mL/gVS) than the flocculated sludge (146.8mL/gVS). Moreover, the proposed method (Net cost for control - Net cost for deflocculation) saves sludge management cost of about $132 with 53.8% of suspended solids (SS) reduction.


Assuntos
Esgotos , Titânio , Análise da Demanda Biológica de Oxigênio , Floculação , Metano
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