Discharges of treated industrial wastewater may impair the receiving surface water quality. Biological early warning systems (biosensors) for continuous holistic water quality monitoring may better ...tackle the wide range of potential threats from industrial activities (e.g. oxygen depletion, metal traces, chemical toxins). Commercial biosensor solutions based on mussels and oysters behavioural assessment have enabled overall water quality monitoring of industrial effluents. Although burrowing clams present worldwide ecological and economic importance and their behavioural changes are potential indicators of concerning environmental conditions, current technologies do not allow their use as biosensors. Proposing an experimental monitoring setup and comprehend the behavioural patterns of burrowing clams in different water quality conditions are the first steps towards reliable biosensor solutions for water quality assessment. The present work proposes an vision-based tool to assess clams' behavioural patterns in different levels of water contamination. It may be basis for building holistic biosensor technology based on clams behavioural assessment for industrial effluent monitoring and early alarm. The proposed system measures the total occupied area by animals through a data acquisition system and data processing pipeline. An off-the-shelf camera setup registers top-view images of the animals inside a container. An image segmentation algorithm properly identify the clams and enables behavioral assessment. System suitability is explored in a case study using the yellow clam Amarilladesma mactroides and DCOIT contaminant. The performance of a Watershed and a machine learning segmentation models are investigated. Obtained results indicate both models can achieve high performance in this task. Behavioural tracking stage enables the use of statistical functions to observe behavioural changes in the animals, which may be proxy to overall water quality condition.
This article aims to list the main sustainable practices developed in the processes of metal forming, casting, heat treatment, welding and electrostatic painting. When analysed the literature about ...sustainable manufacturing, a predominance of studies about machining is observed and the processes mentioned are few explored in academic studies. The research strategy used to reach the objective was systematic literature review, conducted for each process cited. Many sustainable practices were identified with prominence of better materials use and energy efficiency. The authors of this article believe that the information presented here can be useful for researches in their future studies and for industry professionals interested in improving manufacturing processes.
Ca-loaded
Pelvetia canaliculata biomass was used to remove Pb
2+ in aqueous solution from batch and continuous systems. The physicochemical characterization of algae
Pelvetia particles by ...potentiometric titration and FTIR analysis has shown a gel structure with two major binding groups – carboxylic (2.8
mmol
g
−1) and hydroxyl (0.8
mmol
g
−1), with an affinity constant distribution for hydrogen ions well described by a Quasi-Gaussian distribution. Equilibrium adsorption (pH 3 and 5) and desorption (eluents: HNO
3 and CaCl
2) experiments were performed, showing that the biosorption mechanism was attributed to ion exchange among calcium, lead and hydrogen ions with stoichiometry 1:1 (Ca:Pb) and 1:2 (Ca:H and Pb:H). The uptake capacity of lead ions decreased with pH, suggesting that there is a competition between H
+ and Pb
2+ for the same binding sites. A mass action law for the ternary mixture was able to predict the equilibrium data, with the selectivity constants
α
Ca
H
=
9
±
1 and
α
Ca
Pb
=
44
±
5, revealing a higher affinity of the biomass towards lead ions. Adsorption (initial solution pH 4.5 and 2.5) and desorption (0.3
M HNO
3) kinetics were performed in batch and continuous systems. A mass transfer model using the Nernst–Planck approximation for the ionic flux of each counter-ion was used for the prediction of the ions profiles in batch systems and packed bed columns. The intraparticle effective diffusion constants were determined as 3.73
×
10
−7
cm
2
s
−1 for H
+, 7.56
×
10
−8
cm
2
s
−1 for Pb
2+ and 6.37
×
10
−8
cm
2
s
−1 for Ca
2+.
Biosorption is known as an effective way to clean‐up water from organic and inorganic contaminants and has also emerged as a promising technology to recover critical substances. Tannins are renewable ...materials, coming from multiple vegetable sources. A variety of biosorbents have been developed from tannins, including tannin resins, rigid foams, composites with mesoporous silica, cellulose, collagen, and magnetic adsorbents. These materials have shown an excellent ability to uptake heavy‐metal cations (Cd(II), Cu(II), Pb(II), Ni(II), Cr(III)), owning to the chelating ability provided by the plentiful adjacent hydroxyl groups. In addition, tannin‐adsorbents have shown exceptional ability to remove Cr(VI), and to uptake Au(III) and Pd(II) from strong acidic solutions, which has evident application in the recovery of precious metals from e‐wastes leaching. The fact that tannin‐adsorbents can reduce the oxidation state of these adsorbates to Cr(III) and to elemental species of Au and Pd is interesting. Adsorption of dyes, surfactants, pharmaceuticals and antimony is also feasible, but the removal of certain metalloid species, such as arsenic and phosphate, seems to be limited even after applying chemical modifications. This article presents a systematic review on the preparation of tannin‐adsorbents and their application in water decontamination and in the recovery of critical metals.
Tannins can be extracted from multiple vegetable sources and can be easily converted in biosorbents. The present article reviews the literature on the preparation and properties of tannin materials and their use as green adsorbents to uptake organic and inorganic contaminants from water, and to concentrate and recover critical metals from the liquors obtained in hydrometallurgical processing of e‐wastes. This article is part of an AFOB (Asian Federation of Biotechnology) Special issue. To learn more about the AFOB visit www.afob.org.
Biosorption of chromium and zinc ions by an industrial algal waste, from agar extraction industry has been studied in a batch system. This biosorbent was compared with the algae
Gelidium itself, ...which is the raw material for agar extraction, and the industrial waste immobilized with polyacrylonitrile (composite material). Langmuir and Langmuir-Freundlich equilibrium models describe well the equilibrium data. The parameters of Langmuir equilibrium model at pH 5.3 and 20
°C were for the algae,
q
L
=
18
mg
Cr(III)
g
−1 and 13
mg
Zn(II)
g
−1,
K
L
=
0.021
l
mg
−1
Cr(III) and 0.026
l
mg
−1 Zn(II); for the algal waste,
q
L
=
12
mg
Cr(III)
g
−1 and 7
mg
Zn(II)
g
−1,
K
L
=
0.033
l
mg
−1 Cr(III) and 0.042
l
mg
−1 Zn(II); for the composite material,
q
L
=
9
mg
Cr(III)
g
−1 and 6
mg
Zn(II)
g
−1,
K
L
=
0.032
l
mg
−1
Cr(III) and 0.034
l
mg
−1
Zn(II). The biosorbents exhibited a higher preference for Cr(III) ions and algae
Gelidium is the best one. The pseudo-first-order Lagergren and pseudo-second-order models fitted well the kinetic data for the two metal ions. Kinetic constants and equilibrium uptake concentrations given by the pseudo-second-order model for an initial Cr(III) and Zn(II) concentration of approximately 100
mg
l
−1, at pH 5.3 and 20
°C were
k
2,ads
=
0.04
g
mg
−1
Cr(III)
min
−1 and 0.07
g
mg
−1
Zn(II)
min
−1,
q
eq
=
11.9
mg
Cr(III)
g
−1 and 9.5
mg
Zn(II)
g
−1 for algae;
k
2,ads
=
0.17
g
mg
−1
Cr(III)
min
−1 and 0.19
g
mg
−1
Zn(II)
min
−1,
q
eq
=
8.3
mg
Cr(III)
g
−1 and 5.6
mg
Zn(II)
g
−1 for algal waste;
k
2,ads
=
0.01
g
mg
−1
Cr(III)
min
−1 and 0.18
g
mg
−1
Zn(II)
min
−1,
q
eq
=
8.0
mg
Cr(III)
g
−1 and 4.4
mg
Zn(II)
g
−1 for composite material. Biosorption was modelled using a batch adsorber mass transfer kinetic model, which successfully predicts Cr(III) and Zn(II) concentration profiles. The calculated average homogeneous diffusivities,
D
h, were 4.2
×
10
−8, 8.3
×
10
−8 and 1.4
×
10
−8
cm
2
s
−1 for Cr(III) and 4.8
×
10
−8, 9.7
×
10
−8 and 6.2
×
10
−8
cm
2
s
−1 for Zn(II), respectively, for
Gelidium, algal waste and composite material. The algal waste has the lower intraparticle resistance.
Abstract Background Human herpesvirus (HHV) 5 and 6 remain latent after primary infection and can be reactivated after immunosuppression for organ transplantation. An association between HHV-5 and ...HHV-6 has been reported in liver transplant patients. The coinfection is associated with clinical manifestations and graft dysfunction. Objective The aim of this study was to monitor herpesviruses in liver transplant recipients to better understand issues involving coinfection with HHV-5/6 and correlations with acute cellular rejection episodes and bacterial infections. Methods Forty-five adult liver transplant patients of median age 47 years (range, 18–66), gave blood samples and liver biopsies in the first 6 months after their surgeries. Viremia was detected with the use of nested PCR and antigenemia; the Banff classification was used to detect allograft rejection. Results IgG positive for HHV-5 was observed in 94% of subjects whose main indication (67%) for transplantation was hepatitis C. Twenty-three (51.1%) displayed cytomeg virus (CMV) infections and 12 (26.7%) HHV-6 infection. There were 6 patients (13.3%) with HHV-5/6 coinfections. Eighteen of the 23 patients had CMV disease, showing a strong correlation between a positive test and CMV disease; 6 displayed an acute cellular rejection episode in the same period (χ2 = 6.62; P < .03). Four out of 6 patients who displayed coinfections (HHV-5/6) had concomitant bacterial infections; 3/6 experienced graft rejection episodes. During follow-up, 1 patient had HHV-6 infection diagnosed as encephalitis followed by fever on the 24th day after surgery. The median 32 days for HHV-6 detection by nested PCR positivity was shorter than 38 days for HHV-5. Conclusions HHV-5/6–infected patients displayed more allograft rejection episodes, coinfections, and concomitant bacterial infections, besides an higher risk for CMV disease.
Marine algae
Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during ...one sorption–desorption cycle of Cu(II) in the flow through column fed with 50 and 25
mg
l
−1 of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of ≈13 and 3
mg
g
−1, respectively, for algae
Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1
M HNO
3 solution was 100% effective. After two consecutive sorption–desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.
The use of robots is increasing in different industries, as in the case of large metal structures. The use of mobile robots meets the needs of these industries: it can be easily moved in the ...production line, with gains in repeatability and process efficiency, reducing rework costs. The poor configuration of the robotic and welding system generates problems in the internal structure and the surface of the weld, thus compromising the final quality of the piece. Visual inspections are common to identify problems that may have occurred during these processes. Inspections that use x-rays, ultrasound, or thermal cameras require additional equipment and highly trained inspectors to analyze the results and detect problems. This work presents a computer vision system based on a passive monocular camera for analysis of weld bead textures. Images of weld beads with and without discontinuities are captured and a dimensional reduction algorithm known as Principal Component Analysis (PCA) is applied to select the main characteristics that describe each group. Afterward, the Support Vector Machine (SVM) supervised learning method is applied to recognize the patterns of image groups, making it possible to classify new images of weld beads as welds with or without discontinuities. The system makes use of the same camera coupled to the robot responsible for conducting the welding, without the need for additional sensors, and assists the welding inspector in the evaluation of the performed process.
Image restoration and image enhancement are critical image processing tasks since good image quality is mandatory for many image applications. We are particularly interested in the restoration of ...ill-exposed images. These effects are caused by sensor limitation or optical arrangement. They prevent the details of the scene from being adequately represented in the captured image. We proposed a deep neural network model due to the number of uncontrolled variables that impact the acquisition. The proposed network can converge in a representative model from the training data, loss, optimization and activation functions. The obtained results are evaluated using several image quality index which indicate that the proposed network is able to improve images damaged by heterogeneous exposure. Furthermore, our method offers a significant gain over the state-of-the-art methods both in simulated data and real data.
Vegetable oil refinery wastewaters (VORW) are loaded with organic and oily matter, and cannot be decontaminated by conventional treatment methods. Pretreatment methods with the objective of ...decreasing oil and grease (O&G) and chemical oxygen demand (COD) content either generate hazardous byproducts or may be too costly. In this paper, it is demonstrated that gravity separation is appropriate as a low-cost primary treatment for VORW. The kinetics of the oil/water separation process was studied by measuring O&G and also COD concentrations over time in the aqueous bottom phase of two types of VORW left in quiescence. Removals after 24 h exceeded 90 % for O&G and varied between 58 and 90 % for COD. An empirical model was fitted to the experimental data with good correlation (
r
2
> 0.975 for all datasets). Newton’s laws and Stokes’ law were used to predict the behavior of oil particles according to size. 3D surface plots were drawn to visualize how the time of removal of an oil droplet changed depending on its velocity, diameter and initial height in the separation column. A retention time of 30 min was selected as the optimum treatment in the separating column, thereby combining the advantages of short treatment time with high O&G removal (over 80 % in both wastewaters).
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