Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation

Algae bloom in coastal waters is partly supported by residual nutrients in treated wastewater (WW) released from coastally located treatment plants. In response, a Chlorella vulgaris-based photobioreactor was recently proposed for lowering nutrient levels in WW prior to release. However, the solution requires maintaining biomass accumulation to within a photobioreactor capacity for optimum operation. For high density Chlorella vulgaris suspensions, this is easily done by monitoring turbidity increase, a property directly related to biomass accumulation. For low density suspensions however, direct turbidity measurement would require a cumbersome process of concentrating large volumes of Chlorella vulgaris suspensions. Here, we demonstrate that by measuring pH of the suspensions, turbidity (T) can be estimated indirectly by the following wastewater-dependent expression: pH = aT + pH0, hence avoiding the need to concentrate large volumes. The term pH0 is the initial pH of the suspensions and a, a wastewater-dependent constant, can be computed independently from a = − 0.0061*pH0 + 0.052. In the event %WW is unknown, the following wastewater-independent Gaussian expression can be used to estimate T: pH = 8.71*exp(− [(T − 250)2]/[2*1.26E05]). These three equations should offer an avenue for monitoring the turbidity of dilute Chlorella vulgaris suspensions in large, stagnant municipal Chlorella vulgaris-based wastewater treatment system via pH measurements.

A Green Enzymatic Extraction Optimization and Oxidative Stability of Krill Oil from Euphausia Superba

Krill oil enriched with polyunsaturated fatty acids is in the form of phospholipid. However, its application as a dietary supplement is limited, because of its rapid deterioration. Thus, this study aims to investigate the oxidative stability of krill oil extracted from Euphausia superba. Under optimal conditions (enzyme concentration 0.16%, enzymolysis time 2.9 h, and enzymolysis temperature of 45 °C) designed by response surface methodology, the extraction yield of krill oil is 86.02%. Five assays, including peroxide value (POV), thiobarbituric acid-reactive substances (TBARS), pH value, and turbidity were used to determine the oxidative stability of krill oil nanoliposomes during storage. Carboxymethyl chitosan (CMCS) nanoliposomes showed a significant reduction in POV and TBARS values, a prevention of pH value decrease and turbidity increase. This study indicated that CMCS nanoliposome can effectively improve the oxidative stability of krill oil during storage. Furthermore, the release profile in vitro illustrated that the controlled release of krill oil carried out by CMCS nanoliposomes is feasible.

Benthic Diatom Communities in Korean Estuaries: Species Appearances in Relation to Environmental Variables

In the Korean Peninsula’s southern estuaries, the distributive characteristics of epilithic diatoms and the important environmental factors predicting species occurrence were examined. The collection of diatoms and measurements of water quality and land-use were performed every May between 2009 and 2016, with no influence from the Asian monsoon and snow. Throughout the study, 564 diatoms were classified with first and second dominant species of Nitzschia inconspicua and N. perminuta. Based on diatom appearance and standing crops, the 512 sampling stations were divided into four groups by cluster analysis, and two regions, namely the West and East Sea. Geographically, G1, G2, G3, and G4 were located in the East Sea, Southeast Sea, West Sea, and Southwest Sea, respectively. Canonical correspondence analysis (CCA) results indicated that environmental factors, such as turbidity, electric conductivity (EC), and total phosphorus (TP), significantly influenced the distribution of epilithic diatoms. A random forest model showed that major environmental factors influencing the diatom species appearance included EC, salinity, turbidity, and total nitrogen. This study demonstrated that the spatial distribution of epilithic diatoms in the southern estuaries of the Korean Peninsula was determined by several factors, including a geographically higher tidal current-driven turbidity increase and higher industrial or anthropogenic nutrient-loading.

A modified fouling index (MFI40) and fouling predicting approach for ultrafiltration of secondary effluents

Fouling indices for evaluating fouling propensity of secondary effluents (SEF) as feed of ultrafiltration (UF) systems are important parameters for the design and operation of the UF process. However, limited fouling indices have been developed and applied for UF feedwater. This study (i) established a modified UF fouling index (MFI40) by raising operating pressure from 30 psi in a traditional MFI test to 40 psi. Standard deviation of MFI40 tests was lower than that of traditional MFI by 68.6%, indicating better stability and repeatability of MFI40. It (ii) investigated the combined effects of UF feedwater characteristics on MFI40. Biopolymers and turbidity played a dominant and secondary positive role in the MFI40, respectively. The effect of conductivity on MFI40 changed from positive to negative with a turbidity increase. It also (iii) validated the MFI40 in both laboratory- and pilot-scale UF membrane units, and UF fouling rates were linearly correlated to the MFI40 of their feeds, and (iv) explored the practical use of the MFI40. It was applied to determine the maximum allowable UF feedwater quality (MFI40max), which could be used to select an appropriate pre-treatment process. A fouling predicting model was established based on the feedwater MFI40 and the operating flux, with an average predicting error of 26.8%.

Kinetic analysis of the multistep aggregation pathway of human transthyretin

Aggregation of transthyretin (TTR) is the causative agent for TTR cardiomyopathy and polyneuropathy amyloidoses. Aggregation is initiated by dissociation of the TTR tetramer into a monomeric intermediate, which self-assembles into amyloid. The coupled multiple-step equilibria and low-concentration, aggregation-prone intermediates are challenging to probe using conventional assays. We report a 19F-NMR assay that leverages a highly sensitive trifluoroacetyl probe at a strategic site that gives distinct 19F chemical shifts for the TTR tetramer and monomeric intermediate and enables direct quantification of their populations during the aggregation process. Integration of real-time 19F-NMR and turbidity measurements as a function of temperature allows kinetic and mechanistic dissection of the aggregation pathway of both wild-type and mutant TTR. At physiological temperature, the monomeric intermediate formed by wild-type TTR under mildly acidic conditions rapidly aggregates into species that are invisible to NMR, leading to loss of the NMR signal at the same rate as the turbidity increase. Lower temperature accelerates tetramer dissociation and decelerates monomer tetramerization and oligomerization via reduced hydrophobic interactions associated with packing of a phenylalanine (F87) into a neighboring protomer. As a result, the intermediate accumulates to a higher level, and formation of higher-order aggregates is delayed. Application of this assay to pathogenic (V30M, L55P, and V122I) and protective (T119M) mutants revealed significant differences in behavior. A monomeric intermediate was observed only for V122I: aggregation of V30M and L55P proceeds without an observable monomeric intermediate, whereas the protective mutant T119M remains resistant to tetramer dissociation and aggregation.

GEOPROCESSAMENTO APLICADO NO DIAGNÓSTICO DOS CONFLITOS DE USO E OCUPAÇÃO DO SOLO EM ÁREAS DE PRESERVAÇÃO PERMANENTE NO RIBEIRÃO DAS AGULHAS – BOTUCATU (SP)

As áreas de preservação permanente (APP) têm função ambiental de preservar os recursos naturais, a biodiversidade, o fluxo gênico da fauna e flora, o solo e a segurança do bem-estar das populações humanas. Enquanto que a degradação das matas ciliares contribui para o assoreamento, elevação da turbidez da água e para a erosão das margens dos cursos d'água, transportando substâncias poluidoras, como defensivos e fertilizantes agrícolas. O trabalho visou determinar o uso inadequado das áreas de preservação permanente da microbacia do Ribeirão das Agulhas – Botucatu (SP), tendo como base cartográfica, a carta planialtimétrica de Botucatu e a imagem de satélite de 2011. A metodologia consistiu no uso do SIG-IDRISI Selva para realização do georreferenciamento da imagem, geração dos buffer de APPs e o overlay na obtenção dos conflitos de uso e ocupação em APPs. O grande uso da microbacia correspondeu às pastagens com 675,34ha. As APPs (166,10ha) estão sendo usadas inadequadamente por 93,33ha com pastagens. O diagnóstico dessas áreas da microbacia indica a necessidade de uma intervenção vinculada ao plano de proteção ambiental para a recuperação das áreas degradadas e consequentemente permitir uma regeneração da cobertura natural das APPs que estão sendo utilizadas sem respeitar a legislação ambiental brasileira. As ferramentas de geotecnologias foram imprescindíveis para obter o diagnóstico do uso e ocupação do solo em APPs da área.Palavras-chave: Sistema de Informação Geográfica; Uso e Ocupação do Solo; Preservação Ambiental.GEOPROCESSING APPLIED IN THE DIAGNOSIS OF CONFUSED GODS AND SOIL OCCUPATION IN AREAS OF PERMANENT PRESERVATION IN THE STREAM OF THE AGULHAS - BOTUCATU (SP)ABSTRACTThe permanent preservation areas (PPA) have environmental function of preserving natural resources, biodiversity, gene flow of fauna and flora, the soil and the safety of the well-being of human populations. While the degradation of riparian forests contributes to silting, water turbidity increase and the erosion of the banks of waterways, carrying pollutants, such as pesticides and agricultural fertilizers. The objective of this work was to determine the inadequate use of the permanent preservation areas of Stream of the Agulhas - Botucatu (SP) microbasin, based on cartography, Botucatu planialtimetric chart and satellite image of 2011. The methodology consisted of the use of SIG-IDRISI Jungle to perform image georeferencing, generation of PPA buffer and overlay in obtaining conflicts of use and occupation in PPA. The great use of the microbasin corresponded to pastures with 675.34ha. PPA (166, 10 ha) are being used inadequately for 93.33ha with pasture. The diagnosis of these areas of the microbasin indicates the need for an intervention linked to the environmental protection plan for the recovery of the degraded areas and consequently to allow a regeneration of the natural coverage of the PPA that are being used without respecting the Brazilian environmental legislation. The geotechnology tools are essential to obtain the diagnosis of land use and occupation in PPA in the area.Keywords: GIS; Land Use; Environmental Preservation.SIG APLICADOS EN EL DIAGNÓSTICO DE CONFLICTOS DE USO Y OCUPACIÓN DEL SUELO EN ÁREAS DE PRESERVACIÓN PERMANENTE EN EL RÍO DE LAS AGULHAS – BOTUCATU (SP)RESUMENLas Áreas de Preservación Permanente (APP) tienen una función ambiental para preservar los recursos naturales, la biodiversidad, el flujo genético de fauna y flora, el suelo y la seguridad del bienestar de las poblaciones humanas. La degradación de los bosques ribereños contribuye a la sedimentación e incremento en la turbidez del agua, a la erosión de las orillas de los cursos de agua y al transporte de sustancias contaminantes, como pesticidas y fertilizantes agrícolas. El trabajo tuvo como objetivo determinar el uso incorrecto de las áreas de preservación permanente de la cuenca del río das Agulhas – Botucatu (SP), basada en la carta planialtimétrica de Botucatu y la imagen de satélite de 2011. La metodología consistió en el uso de GIS-IDRISI Selva para la georreferenciación, la generación de los amortiguamientos de las APPs y la superposición de los conflictos de uso y ocupación. El gran uso de la cuenca se correspondió con pastizales, 675,34ha. Las APPs (166,10ha) se utilizan inadecuadamente, con 93, 33ha de pastizales. El diagnóstico indica la necesidad de un plan de protección vinculado al medio ambiente, y destinado a la recuperación de áreas degradadas, que permita la regeneración de la cubierta natural de las APPs, que se utilizan sin cumplir con la legislación ambiental brasileña. Las geotecnologías fueron herramientas indispensables para el diagnóstico del uso y ocupación del suelo en el área analizada.Palabras clave: SIG; Uso y Ocupación del Suelo; Preservación del Medio Ambiente.

METHODS AND ANALYSIS TOOLS FOR REDEVELOPMENTS IN AN ESTUARY WITH HIGH SUSPENDED SEDIMENT CONCENTRATIONS

One of the largest estuaries in Germany, the Ems estuary, identified a dramatic turbidity increase up to more than 10 g/l over the last years. Due to this fact ecologists and water management authorities try to find restoration measures, which are able to reduce suspended sediment concentrations and to increase oxygen supply. The assessment of these potential restoration measures is described in the following paper and is based on a highly resolved numerical representation of the present situation of the Ems with extreme high turbidities by including effects of flocculation and hindered settling. Therefore two different approaches for the settling velocity due to flocculation were compared. An analysis of these restoration measures delivers important findings and shortcomings of each measure. Finally the restoration potentials are quantified by key indicators for hydrodynamics and suspended sediment transport behavior and were evaluated due to their relevance in reduction of high turbidities.

Inhibition of Thrombin in Plasma by Heparin or Arginine

The inhibition of plasmatic thrombin is of clinical importance in a broad range of diseases. To obtain reliable data the assay system should be as similar to physiology as possible. Using a newly developed physiologic assay system for fibrinogen/thrombin interaction (the FIFTA), the inhibition of plasmatic thrombin by heparin or by arginine was studied. The standard fibrinogen functional turbidimetric assay (FIFTA) was performed, varying heparin or arginine concentrations and varying the time point the inhibitor was added to the FIFTA. Plasmatic heparin concentrations equal to or greater than 0.63 IU/mL completely inhibit thrombin in the assay system described. The IC50 is 0.1 IU/mL heparin. Heparin can only inhibit fibrin generation within the first 2 minutes at room temperature (RT=23°C). The 50% inhibitory time point, that is, the time point that a 10 IU/mL final concentration of heparin results in 50% inhibition of FIFTA, is 30 seconds at RT. A final arginine concentration of at least 125 mM in the first 100 seconds of the FIFTA reaction at RT completely inhibits turbidity increase. Half-maximal turbidity increase occurs at 63 mM arginine. Final arginine concentrations of at least 250 mM completely inhibit turbidity increase, when arginine acts in the first 4 minutes (RT) of the thrombin/ fibrinogen interaction. A final arginine concentration of 477 mM added at the 12-minute or 30-minute thrombin/ fibrinogen reaction time point decreases the resulting turbidity by 50% after an additional 30 minutes at RT. Pathologic disseminated intravascular coagulation occurs in a multitude of diseases; in common is always the generation of thrombin either by the contact phase or by the tissue factor phase of coagulation. Such pathologically elevated thrombin activity in blood or blood products must be prevented or inhibited. This study demonstrates the efficiency of two physiologic thrombin inhibitors: heparin and arginine.

Use of an estuarine environment (Barra do Saí lagoon, Brazil) as nursery by fish

Studies were carried out at the Barra do Saí lagoon, on the northern coast of Santa Catarina State, Brazil, to evaluate the function played by this estuary in the life cycle of fish found at the coastal zone. Samplings were performed using beach seine net from December 2000 to November 2001. The continental influence is strong, as showed by the occurrence of freshwater fishes, although most of the 43 species recorded are marine ones. It was verified that around summer, when the temperature of the water is high, the values of salinity decrease and those of turbidity increase. At this time there is also an increase in the abundance of juvenile fish in the lagoon. Because of its average depth of less than 0.7 m, the lagoon is inhabited primarily by juveniles, which may enter either by active movement or passive displacement, originating from the sea or the river to which the lagoon is connected. The lagoon is not used for sheltering spawning individuals. It is showed that a shallow, small estuary with a blind bottom can conceal an importance for the coastal ichthyofauna that is greater than it could be expected from the occurrence - in this case, modest - of large individuals.