scholarly journals Organic Contaminant Biodegradation by Oxidoreductase Enzymes in Wastewater Treatment

2020 ◽  
Vol 8 (1) ◽  
pp. 122 ◽  
Author(s):  
Edward A. Barber ◽  
Ziyi Liu ◽  
Stephen R. Smith
Keyword(s):  
Wastewater Treatment ◽  
Organic Contaminants ◽  
Flame Retardants ◽  
Treatment Strategies ◽  
White Rot ◽  
Fungal Enzymes ◽  
Recent Developments ◽  
Substrate Properties ◽  
Electron Withdrawing Group ◽  
Oxidoreductase Enzymes

Organic contaminants (OCs), such as pharmaceuticals, personal care products, flame retardants, and plasticisers, are societally ubiquitous, environmentally hazardous, and structurally diverse chemical compounds whose recalcitrance to conventional wastewater treatment necessitates the development of more effective remedial alternatives. The engineered application of ligninolytic oxidoreductase fungal enzymes, principally white-rot laccase, lignin peroxidase, and manganese peroxidase, has been identified as a particularly promising approach for OC remediation due to their strong oxidative power, broad substrate specificity, low energy consumption, environmental benignity, and cultivability from lignocellulosic waste. By applying an understanding of the mechanisms by which substrate properties influence enzyme activity, a set of semi-quantitative physicochemical criteria (redox potential, hydrophobicity, steric bulk and pKa) was formulated, against which the oxidoreductase degradation susceptibility of twenty-five representative OCs was assessed. Ionisable, compact, and electron donating group (EDG) rich pharmaceuticals and antibiotics were judged the most susceptible, whilst hydrophilic, bulky, and electron withdrawing group (EWG) rich polyhalogenated compounds were judged the least susceptible. OC susceptibility scores were in general agreement with the removal rates reported for experimental oxidoreductase treatments (R2 = 0.60). Based on this fundamental knowledge, and recent developments in enzyme immobilisation techniques, microbiological enzymic treatment strategies are proposed to formulate a new generation of biological wastewater treatment processes for the biodegradation of environmentally challenging OC compounds.

scholarly journals Adsorption Processes in the Removal of Organic Dyes from Wastewaters: Very Recent Developments

2020 ◽  
Author(s):  
Francisco Jose Alguacil ◽  
Felix A. Lopez
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Organic Contaminants ◽  
Organic Dyes ◽  
Scaling Up ◽  
Textile Fabrics ◽  
Recent Developments ◽  
Adsorption Processes ◽  
Adsorption Processing ◽  
Secondary Issue

The problem of the treatment of contaminated wastewaters is of the upmost worldwide interest. This contamination occurs via the presence of inorganic or organic contaminants of different nature in relation with the industry they come from. In the case of organic dyes, their environmental impact, and thus, their toxicity come from the air (releasing of dust and particulate matter), solid (scrap of textile fabrics, sludges), though the great pollution, caused from dyes, comes from the discharge of untreated effluents into waters, contributing to increase the level of BOD and COD in these liquid streams; this discharge is normally accompanied by water coloration, which low the water quality, and caused a secondary issue in the wastewater treatment. Among separation technologies, adsorption processing is one of the most popular, due to its versatility, easiness of work, and possibility of scaling-up in the eve of the treatment of large wastewater volumes. Within a miriade of potential adsorbents for the removal of organic dyes, this work presented the most recent advances in the topic.

Upgrading Wastewater Treatment Plants for Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Design Flow ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Recent Developments ◽  
Removal Technology ◽  
Biological Nitrogen

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.

Radiotherapy for Brain Tumors: Current Practice and Future Directions

2020 ◽  
Vol 16 (3) ◽  
pp. 182-195
Author(s):  
Sarah Baker ◽  
Natalie Logie ◽  
Kim Paulson ◽  
Adele Duimering ◽  
Albert Murtha
Keyword(s):  
Brain Tumors ◽  
Treatment Strategies ◽  
Brain Parenchyma ◽  
Benign Tumors ◽  
Tumor Control ◽  
Normal Brain ◽  
Neurocognitive Deficits ◽  
Close Proximity ◽  
Recent Developments ◽  
High Level

Radiotherapy is an important component of the treatment for primary and metastatic brain tumors. Due to the close proximity of critical structures and normal brain parenchyma, Central Nervous System (CNS) radiotherapy is associated with adverse effects such as neurocognitive deficits, which must be weighed against the benefit of improved tumor control. Advanced radiotherapy technology may help to mitigate toxicity risks, although there is a paucity of high-level evidence to support its use. Recent advances have been made in the treatment for gliomas, meningiomas, benign tumors, and metastases, although outcomes remain poor for many high grade tumors. This review highlights recent developments in CNS radiotherapy, discusses common treatment toxicities, critically reviews advanced radiotherapy technologies, and highlights promising treatment strategies to improve clinical outcomes in the future.

Sustainable development of wastewater treatment strategies for the food industries

2002 ◽  
Vol 45 (12) ◽  
pp. 315-320 ◽  
Author(s):  
I. Sekoulov
Keyword(s):  
Sustainable Development ◽  
Wastewater Treatment ◽  
Treatment Strategies ◽  
Future Generations ◽  
The Sustainable Development ◽  
Total Cost ◽  
Integrated Production ◽  
Food Industries ◽  
Production Processes ◽  
Process Wastewater

The sustainable development of environmental protection is a newly created philosophy. It means continuous development of better protection of the air, soil, water and resources, used from the industry, to be saved also for future generations. The globalization of the economy is another process, which interferes with environmental ideas, and an equilibrium with the socio-eco-sustainable development is wanted. The industry is subjected to big changes depending on economic development. Thus the treatment plants at the end of the pipe must be constructed with maximum flexibility. A removal of constructed devices, if not necessary, must be considered from the beginning as a possibility. Priority is given to integrated production processes solving wastewater problems directly by production devices. The treatment of the process wastewater streams separately will become more important. The end of the pipe solutions will be less complicated and more reliable. The reuse of valuable waste substances and treated water will reduce the total cost of the treatment plants substantially.

scholarly journals Short investigation on occurrence and removal of semivolatiles during wastewater treatment processes

2021 ◽  
Vol 3 (2) ◽  
pp. 130-140
Author(s):  
Maria Diana Puiu ◽  
Keyword(s):  
Wastewater Treatment ◽  
Organic Contaminants ◽  
Biological Treatment ◽  
Organic Matter Content ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Matter Content ◽  
Physical Treatment ◽  
Dissolved Air Flotation ◽  
Treatment Processes

The food industry wastewater is known to present a high organic matter content, due to specific raw materials and processing activities. Even if these compounds are not directly toxic to the environment, high concentrations in effluents could represent a source of pollution as discharges of high biological oxygen demand may impact receiving river's ecosystems. Identifying the main organic contaminants in wastewater samples represents the first step in establishing the optimum treatment method. The sample analysis for the non-target compounds through the GC-MS technique highlights, along with other analytical parameters, the efficiency of the main physical and biological treatment steps of the middle-size Wastewater Treatment Plant (WWTP). Long-chain fatty acids and their esters were the main abundant classes of non-target identified compounds. The highest intensity detection signal was reached by n-hexadecanoic acid or palmitic acid, a component of palm oil, after the physical treatment processes with dissolved air flotation, and by 1-octadecanol after biological treatment.

Wastewater Treatment With Activated Carbon

1972 ◽  
Vol 7 (1) ◽  
pp. 1-12
Author(s):  
A. Benedek
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Chemical Treatment ◽  
Technological Development ◽  
Municipal Waste ◽  
Research Needs ◽  
Physico Chemical ◽  
Recent Developments

Abstract Recent developments in the application of activated carbon to wastewater treatment are reviewed. Particular emphasis is placed on the physico-chemical treatment of municipal waste. Technological development, adsorptive behaviour, and research needs serve as the three primary discussion topics.

Sustainable metallic nanomaterials based wastewater treatment strategies: Achievements, challenges and future perspectives

Chemosphere ◽  
2021 ◽  
pp. 132606
Author(s):  
Shakeel Ahmad Bhat ◽  
Farooq Sher ◽  
Mariam Hameed ◽  
Omar Bashir ◽  
Rohitashw Kumar ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Treatment Strategies ◽  
Future Perspectives ◽  
Metallic Nanomaterials
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