Wastewater Treatment by Advanced Oxidation Process and Their Worldwide Research Trends

Background: Water is a scarce resource and is considered a fundamental pillar of sustainable development. The modern development of society requires more and more drinking water. For this cleaner wastewater, treatments are key factors. Among those that exist, advanced oxidation processes are being researched as one of the sustainable solutions. The main objective of this manuscript is to show the scientific advances in this field. Methods: In this paper, a systematic analysis of all the existing scientific works was carried out to verify the evolution of this line of research. Results: It was observed that the three main countries researching this field are China, Spain, and the USA. Regarding the scientific collaboration between countries, three clusters were detected—one of Spain, one of China and the USA, and one of Italy and France. The publications are grouped around three types of water: industrial, urban, and drinking. Regarding the research, 15 clusters identified from the keywords analyzed the advanced oxidation process (alone or combined with biological oxidation) with the type of wastewater and the target pollutant, removal of which is intended. Finally, the most important scientific communities or clusters detected in terms of the number of published articles were those related to the elimination of pollutants of biological origin, such as bacteria, and of industrial nature, such as pesticides or pharmaceutical products

Congruency fit: beyond performance in the auto supplier industry

The effects of manufacturing strategy (MS) and technology (T) on performance have been studied separately, but few studies have examined the relationship between MS and T practices clusters that improve effectiveness when implemented jointly, and even then they do not consider possible congruency between the two. This paper develops a congruency (selection) model to test for any interconnection between said clusters, without addressing causation or their combined effect on performance. The implicit outcome is that the plant will achieve a desirable effectiveness level. Through a wide-ranging survey of auto supplier plants, two approaches are considered: 1) grouping both clusters in pairs (canonical correlation analysis); and 2) a more general selection view version, with practices from both clusters related multidimensionally and subordinated by bivariate analysis (regression) to test for any congruent pattern. Both methods find a congruent relationship between manufacturing strategy and technology practice clusters, although the second provides greater detail.Ministerio de Educación y Ciencia DPI-2006-0553

The potential of different marine microalgae species to recycle nutrients from recirculating aquaculture systems (RAS) fish farms and produce feed additives

This study researched the use of six microalgae species (N. gaditana, P. lutheri, I. galbana, T. chuii, P. tricornutum and C. gracilis) and a bloom to treat effluent from a marine fish farm and produce quality biomass. More specifically, simulated water from a recirculating aquaculture system (RAS) was used. Microalgae culture was carried out under controlled conditions using 18 L bubble column photoreactors under batch and semi-continuous operation. The main parameters analysed were micronutritional requirements, biomass productivity, nutrient removal rate (nitrogen and phosphorus), biomass composition, and quality. Also, based on the results obtained, a quantitative classification of the microalgae was carried out. The results showed that all microalgae required at least trace metals. In certain species, the addition of vitamins was also required for viable cultivation. In the case of biomass productivity under batch operation, values were between 67 mg L−1 d−1 and 7 mg L−1 d−1 using T. chuii and C. gracilis, respectively, and between 71 mg L−1 d−1 and 9 mg L−1 d−1 using T. chuii and N. gaditana under semi-continuous operation. In the case of total dissolved phosphorus removal, no differences were found between species, reaching in all cases final concentrations <0.01 mg L−1. Total dissolved nitrogen removal rate varied between species and operating conditions, being the highest obtained using T. chuii under semi-continuous operation (12.6 mg L−1 d−1) and the lowest with C. gracilis batch operation (0.15 mg L−1 d−1). Biomass composition in terms of protein and lipids varied between species and operating conditions, but quality in terms of amino acids and fatty acids profile remained homogeneous in all cases. Finally, according to the developed score methodology, I. galbana was the microalgae with the highest biomass production score, while T. chuii was for wastewater treatment. © 2021This work was carried out within the SUNRAS Project ?Sustainable and Efficient Management of Marine Aquaculture Effluents using Solar Technologies? (N? AGL2016-80507-R; Plan Nacional de I+D+i 2013?2016) funded by Ministry of Economy and Competitiveness, Government of Spain. This study was also supported by a Personal Investigador en Formaci?n (PIF) contract (Ref. UCA/REC01VI/2017) funded by Universidad de C?diz. We also would like to acknowledge the technicians of Servicio Central de Investigaci?n en Cultivos Marinos at the Faculty of Marine and Environmental Science (Universidad de C?diz) and Centro Tecnol?gico de Acuicultura de Andaluc?a (CTAQUA) for their support

Morse decomposition of global attractors with infinite components

In this paper we describe some dynamical properties of a Morse decomposition with a countable number of sets. In particular, we are able to prove that the gradient dynamics on Morse sets together with a separation assumption is equivalent to the existence of an ordered Lyapunov function associated to the Morse sets and also to the existence of a Morse decomposition -that is, the global attractor can be described as an increasing family of local attractors and their associated repellers

Removal of emerging pollutants in conventional and microalgae based biotechnology urban wastewater treatment plants

Wastewater treatment plants (WWTPs) reduce portion of the input of pharmaceuticals in aquatic systems, but there is no data available about the elimination of emerging contaminants with microalgae technology. The aim of this work was to determine the average mass flows and concentrations of pharmaceuticals in influents and effluents from two sewages treatment plants using conventional and microalgae based biotechnologies and to compare the removal of pharmaceuticals using both depuration technologies. Only between 20 to 60% of five pharmaceuticals groups is reduce in both WWTP using conventional technologies consisting of a pretreatment, primary settling and secondary treatment by aerobic biological reactor. Using microalgae based biotechnologies efficiency of removal pharmaceuticals is higher than conventional technologies and it increase by using DAF (Dissolve Air Flotation) technology to separate algae biomass

Ecotoxicity and biodegradability of an alkyl ethoxysulphate surfactant in coastal waters.

Alkyl ethoxysulphates (AES) are anionic surfactants widely used in numerous commercial and industrial applications. In spite of the high AES volume consumption a few data concerning the occurrence, fate and effects of AES in marine environments are reported in literature. The objective of this study is to evaluate the biodegradability and toxicity of AES in pristine sea water. Ultimate biodegradation was studied according to the guideline 835.3160 “Biodegradability in sea water” proposed by the United States Environmental Protection Agency (USEPA). Acute toxicity of AES was studied to the microalgae Nannochloropsis gaditana, Isochrysis galbana, Chaetoceros gracilis, Dunaliella salina and Tetraselmis chuii and the invertebrate Artemia franciscana, using culture growth inhibition and death, respectively, as effect criteria. During the degradative process two different stages were observed, which were better described with the first order and logistic kinetic models, respectively. Lag times were 3.3 (stage A) and 26.5 (stage B) days whereas half-lives were 18.6 (stage A) and 49.8 (stage B) days. AES inhibited the microalgae growth, with 96-h EC50 values ranging from 4.68 g L− 1 for D. salina to 24.02 mg L− 1 for I. galbana. Mean 48- and 72-h LC50 values for A. franciscana were 38.30 and 23.92 mg L− 1, respectively. The results indicate an extensive biodegradability of AES in sea water, although at a very slow rate. Acute toxicity was highly dependent on the species tested, being the green alga D. salina the most affected organism. The present study provides relevant data concerning the biodegradability and adverse effects of an AES surfactant on marine organisms, which are useful to establish water quality criteria in a regulatory framework

Towards an integrated proposal for performance measurement indicators in Advanced Production Practices

Starting with an analysis of the financial and operational indicators that can be found in the specialised literature, this study aims to contribute to improvements in the performance measurement systems used when the unit of analysis is the manufacturing plant. For this a search was done in the highest impact Journals of Production and Operations Management and Management Accounting , with the aim of determining the financial and operational indicators used to evaluate performance when Advanced Production Practices have been implemented, more specifically when the practices implemented are Total Quality Management, JIT/Lean Manufacturing and Total Productive Maintenance. This has enabled us to obtain a classification of the two types of indicators based on how much each is used. For the financial indicators we have also prepared a proposal that can be adapted to manufacturing plants- accounting features. In the near future we will propose a model that links practices implementation with financial and operational indicators and these two last with each other. We aim to will test this model empirically with the data obtained in the High Performance Manufacturing Project.Junta de Andalucía (PAIDI Investigación, Desarrollo e Innovación de Andalucía Plan Proyectos de excelenciaP08-SEJ-03841Ministerio de Educación y Ciencia DPI 2009-1114

Microbial indicators of faecal contamination in waters and sediments of beach bathing zones

This study presents the results obtained of the microbial characterization of waters and sediments of 18 coastal bathing zones of the south-western coast of the Iberian Peninsula. To make this characterization, two indicators of faecal contamination have been selected: faecal coliforms (FC) and Clostridium perfringens (CP). The results show that low concentrations of FC and CP in water not necessarily implies that their concentration in sediment and elutriates has to be low as well. The highest concentrations were found in locations close to the mouth of rivers, and in beaches of low energy and hence low water renewal, and high accumulation of fine sediments. The concentrations of FC were lower than those obtained for CP in most of the sampling locations. Although quality standards for bathing waters do not take the parameter CP into account, it has been demonstrated that it should be a good indicator of faecal contamination

Effect of the test media and toxicity of LAS on the growth of Isochrysis galbana.

In this paper, the toxicity of linear alkylbenzene sulfonate (LAS) was evaluated in the marine microalga Isochrysis galbana using data of growth inhibition toxicity tests at 96-h exposure time. Toxicity was examined in standard conditions and by means of the modification of two variables of the test media: (1) the dilution water and (2) the content of nutrients in the test medium. For this purpose, a total of 10 toxicity test were designed: five dilution waters, four natural marine waters and one synthetic seawater; each in two different nutritive conditions, saturated nutrient concentration (SC) by the addition of modified f/2 nutritive medium, and natural nutrient concentration (NC), i.e., without the addition of f/2. At threshold toxicity levels, the dilution waters used in the test and the nutrient concentrations did not affect the toxicity of LAS. At IC50 concentrations, the toxicity of LAS is influenced by both variables: under SC conditions, the toxic effect of LAS diminishes, obtaining in all the tests IC50 > 10 mg/L LAS. Under NC conditions, IC50 concentrations ranging between 3.15 and 9.26 mg/L LAS have been obtained

Microalgae biotechnology for simultaneous water treatment and feed ingredient production in aquaculture br

The use of Tetraselmis chui to produce sole feed ingredient and the recovery of nutrients from a recirculating aquaculture system (RAS) aquaculture facility was studied. The microalga was cultured in a pilot-scale (6 m3) outdoor raceway reactor located in a sole production plant. First, the growth of the microalgae, the addition of phosphorus and the quality of the resulting water were studied. It was possible to cultivate in semi-continuous mode T. chui using the purge stream of a RAS, obtaining productivities of 15 mg L1 d1, and reaching 36 mg L1 d1 when phosphorus was added. In terms of water quality of the effluent, the pollutants concentration were below discharge limits (suspended solids and total dissolved nitrogen, phosphorus and carbon) -directive 91/ 271/EEC. In the case of Vibrio sp., the concentration in the culture water at the end of the experiments remained below typical environmental concentrations (10 % microalgae