scholarly journals Recovery of Zinc from Treatment of Spent Acid Solutions from the Pickling Stage of Galvanizing Plants

2021 ◽  
Vol 13 (1) ◽  
pp. 407
Author(s):  
Svetlana B. Zueva ◽  
Francesco Ferella ◽  
Valentina Innocenzi ◽  
Ida De Michelis ◽  
Valentina Corradini ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
State Of The Art ◽  
Zinc Content ◽  
Economic Viability ◽  
Acid Solutions ◽  
Physical Chemical ◽  
Galvanic Sludge ◽  
Valuable Metals

Typical methods for the treatment of waste pickling solutions include precipitation by alkaline reagents, most commonly calcium hydroxide. As a result, large volumes of galvanic sludge form, containing iron, calcium, sulphates, and a relatively small quantity of zinc (<20%), making Zn recovery not profitable. In summary, state-of-the-art Zn galvanization processes entail the loss of valuable metals and the irrational and expensive handling of spent pickling solutions (SPSs). The resulting conclusion is that there is room for a significant improvement in the way SPSs are treated, with the double goal of enhancing Zn galvanization methods’ economic viability and achieving a lesser impact on the environment’s processes. The experimental results show that it is possible to use SPS as a coagulant to treat the process wastewaters, kept separated, and added with sodium hydroxide. The results in obtaining precipitates with Zn contents higher than 40%, increasing the added advantage of making Zn recovery profitable. The results show the possibility of using SPS as a coagulant in the process of physical-chemical wastewater treatment and sodium hydroxide to obtain a precipitate with a zinc content of more than 40%.

scholarly journals Wastewater Treatment from Galvanization Industry with Zinc recovery

2021 ◽  
Vol 247 ◽  
pp. 01064
Author(s):  
Svetlana Zueva ◽  
Francesco Ferella ◽  
Nicolò M. Ippolito ◽  
Elena Ruduka ◽  
Ida De Michelis
Keyword(s):  
Wastewater Treatment ◽  
Sodium Hydroxide ◽  
Experimental Results ◽  
Industrial Processes ◽  
High Price ◽  
Zinc Recovery ◽  
Galvanic Sludge ◽  
Pickling Solution ◽  
Rinse Water ◽  
The Cost

The resistance of steel to corrosion is obtained with a number of industrial processes based on Zn galvanization. However, all these methods bear a relatively high price tag due to the cost of Zinc plates and electrolytes as well as the formation of hazardous wastewaters containing metals and acids. Wastewaters from Zn galvanization may be grouped into two main types: Mix of Rinse Water (MRW) and Spent Pickling Solutions (SPS). Ordinarily, these waters are mixed and sent for treatment by precipitation. As a result large volumes of galvanic sludge is formed, containing iron, calcium, sulphates and a relatively small quantity of zinc (<20 %), which makes Zn recovery not profitable. The experimental results presented in this article show that it is possible to use as a coagulant to treat the process wastewaters the spent pickling solution (SPS) from the process, kept separated and added with sodium hydroxide. This results in obtaining precipitates with Zn contents higher than 40%, which brings the further advantage of making Zn recovery profitable.

Building Attention and Edge Convolution Neural Networks for Bioactivity and Physical-Chemical Property Prediction

2019 ◽  
Author(s):  
Michael Withnall ◽  
Edvard Lindelöf ◽  
Ola Engkvist ◽  
Hongming Chen
Keyword(s):  
Message Passing ◽  
State Of The Art ◽  
A Priori ◽  
Model Performance ◽  
Learning Approaches ◽  
Physical Chemical ◽  
Chemical Descriptor ◽  
Derived Properties ◽  
Memory Schemes ◽  
Hyperparameter Selection

We introduce Attention and Edge Memory schemes to the existing Message Passing Neural Network framework for graph convolution, and benchmark our approaches against eight different physical-chemical and bioactivity datasets from the literature. We remove the need to introduce <i>a priori</i> knowledge of the task and chemical descriptor calculation by using only fundamental graph-derived properties. Our results consistently perform on-par with other state-of-the-art machine learning approaches, and set a new standard on sparse multi-task virtual screening targets. We also investigate model performance as a function of dataset preprocessing, and make some suggestions regarding hyperparameter selection.

A state-of-the-art review on wastewater treatment techniques: the effectiveness of adsorption method

2021 ◽  
Vol 28 (8) ◽  
pp. 9050-9066
Author(s):  
Ruhma Rashid ◽  
Iqrash Shafiq ◽  
Parveen Akhter ◽  
Muhammad Javid Iqbal ◽  
Murid Hussain
Keyword(s):  
Wastewater Treatment ◽  
State Of The Art ◽  
Adsorption Method ◽  
Treatment Techniques

scholarly journals Excitonic effects in the optical spectra of Li2SiO3 compound

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nguyen Thi Han ◽  
Vo Khuong Dien ◽  
Ming-Fa Lin
Keyword(s):  
Optical Properties ◽  
State Of The Art ◽  
Plasmon Mode ◽  
First Principle ◽  
Response Behavior ◽  
Electronic And Optical Properties ◽  
Physical Chemical ◽  
Excitonic Effects ◽  
Energy Loss Functions ◽  
Excitonic Effect

AbstractLi2SiO3 compound exhibits unique electronic and optical properties. The state-of-the-art analyses, which based on first-principle calculations, have successfully confirmed the concise physical/chemical picture and the orbital bonding in Li–O and Si–O bonds. Especially, the unusual optical response behavior includes a large red shift of the onset frequency due to the extremely strong excitonic effect, the polarization of optical properties along three-directions, various optical excitations structures and the most prominent plasmon mode in terms of the dielectric functions, energy loss functions, absorption coefficients and reflectance spectra. The close connections of electronic and optical properties can identify a specific orbital hybridization for each distinct excitation channel. The presented theoretical framework will be fully comprehending the diverse phenomena and widen the potential application of other emerging materials.

ChemInform Abstract: Membrane Treatment - State of the Art. Part 2. Wastewater Treatment

ChemInform ◽  
2009 ◽  
Vol 40 (39) ◽  
Author(s):  
R. Guest ◽  
R. S. Pickle ◽  
R. K. Bitcon ◽  
D. W. Smith
Keyword(s):  
Wastewater Treatment ◽  
State Of The Art ◽  
Membrane Treatment

State-of-the-art: rheological characterisation of wastewater treatment sludge

2003 ◽  
Vol 16 (1) ◽  
pp. 41-56 ◽  
Author(s):  
Isabelle Seyssiecq ◽  
Jean-Henry Ferrasse ◽  
Nicolas Roche
Keyword(s):  
Wastewater Treatment ◽  
State Of The Art

Modeling of a large-scale wastewater treatment plant for efficient operation

2004 ◽  
Vol 50 (7) ◽  
pp. 123-130 ◽  
Author(s):  
C.F. Gokcay ◽  
G. Sin
Keyword(s):  
Wastewater Treatment ◽  
Dynamic Simulation ◽  
Large Scale ◽  
Treatment Plant ◽  
Quality Standards ◽  
Western World ◽  
Efficient Operation ◽  
Effluent Quality ◽  
Conventional Activated Sludge ◽  
Physical Chemical

Environmental legislations in the Western world impose stringent effluent quality standards for ultimate protection of the environment. This is also observed in Turkey. The current paper presents efforts made to simulate an existing 0.77 million m3/day conventional activated sludge plant located at Ankara, AWTP. The ASM1 model was used for simulation in this study. The model contains numerous stoichiometric and kinetic parameters, some of which need to be determined on case by case bases. The easily degradable COD (SS) was determined by two methods, physical-chemical and respirometric methods, namely. The latter method was deemed unreliable and rejected in the further study. Dynamic simulation with SSSP program predicted effluent COD and MLSS values successfully while overestimating OUR. A complete fit could only be obtained by introducing a dimensionless correction factor (ηO2 = 0.58) to the oxygen term in ASM1.

Effect of Sodium Hydroxide, Calcium Hydroxide, and Potassium Hydroxide on Debranning of Corn

1997 ◽  
Vol 74 (3) ◽  
pp. 254-257 ◽  
Author(s):  
S. K. Singh ◽  
N. Singh ◽  
L. Du ◽  
S. R. Eckhoff
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Potassium Hydroxide

Comparison of sodium hydroxide and calcium hydroxide pretreatments of giant reed for enhanced enzymatic digestibility and methane production

2017 ◽  
Vol 244 ◽  
pp. 1150-1157 ◽  
Author(s):  
Danping Jiang ◽  
Xumeng Ge ◽  
Quanguo Zhang ◽  
Xuehua Zhou ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Methane Production ◽  
Giant Reed ◽  
Enzymatic Digestibility

scholarly journals Analysis and design of wastewater treatment

2018 ◽  
Vol 2 (3) ◽  
pp. 121-135
Author(s):  
Jordan Andres P. Pinoargote ◽  
Jennifer Tatiana R. Alcivar ◽  
Carlos G. Villacreses Viteri
Keyword(s):  
Wastewater Treatment ◽  
Structural Design ◽  
Treatment System ◽  
Residual Water ◽  
Analysis And Design ◽  
Agricultural Engineering ◽  
Physical Chemical ◽  
Technical University ◽  
The Cost ◽  
The City

The work proposes the reuse of wastewater from the Faculty of Agronomic Engineering of the Technical University of Manabí, located in the Lodana parish in the city of Portoviejo, to irrigate the diversity of plantations that exist in the institution as a banana, cocoa and lemon. In the work, the results of the physical-chemical and bacteriological analysis carried out on the residual water generated in the institution are offered, being able to verify that it does not meet the parameters required to be used in the irrigation of crops. The technical scheme of the proposed treatment system is shown, specifying the structure of the zeolite filter. The calculations made for the technical and structural design of each of the devices that make up the proposed treatment system are provided. The analysis of the performance of the system that is illustrated with a series of data reflected in tables is exposed and where an efficiency between 84% and 88% can be verified. A review of compliance with environmental regulations is carried out and an economic analysis is provided on the cost of the investment for the introduction of the system in the Faculty of Agricultural Engineering of the Technical University of Manabí.

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