scholarly journals Current State of Porous Carbon for Wastewater Treatment

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1651
Author(s):  
Mongi ben ben Mosbah ◽  
Lassaad Mechi ◽  
Ramzi Khiari ◽  
Younes Moussaoui

Porous materials constitute an attractive research field due to their high specific surfaces; high chemical stabilities; abundant pores; special electrical, optical, thermal, and mechanical properties; and their often higher reactivities. These materials are currently generating a great deal of enthusiasm, and they have been used in large and diverse applications, such as those relating to sensors and biosensors, catalysis and biocatalysis, separation and purification techniques, acoustic and electrical insulation, transport gas or charged species, drug delivery, and electrochemistry. Porous carbons are an important class of porous materials that have grown rapidly in recent years. They have the advantages of a tunable pore structure, good physical and chemical stability, a variable specific surface, and the possibility of easy functionalization. This gives them new properties and allows them to improve their performance for a given application. This review paper intends to understand how porous carbons involve the removal of pollutants from water, e.g., heavy metal ions, dyes, and organic or inorganic molecules. First, a general overview description of the different precursors and the manufacturing methods of porous carbons is illustrated. The second part is devoted to reporting some applications such using porous carbon materials as an adsorbent. It appears that the use of porous materials at different scales for these applications is very promising for wastewater treatment industries.

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1914
Author(s):  
Zhenqing Li ◽  
Xin Chen ◽  
Lulu Qiu ◽  
Yu Wang ◽  
Zhiqin Zhou

The by-product of citrus juice processing is a huge source of bioactive compounds, especially polymethoxyflavones (PMFs) and fibers. In this study, a method for the separation and purification of PMFs from citrus pomace was established based on citrus nanoporous carbon (CNPC) enrichment. Different biomass porous carbons were synthesized, their adsorption/desorption characteristics were evaluated, and the CNPCs from the peel of Citrus tangerina Tanaka were found to be best for the enrichment of PMFs from the crude extracts of citrus pomace. Using this method, six PMF compounds including low-abundant PMFs in citrus fruits such as 5,6,7,4′-tetramethoxyflavone and 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavone can be simultaneously obtained, and the purities of these compounds were all higher than 95%, with the highest purity of nobiletin reaching 99.96%. Therefore, CNPCs have a great potential for the separation and purification of PMFs in citrus processing wastes, potentially improving the added value of citrus wastes. We also provide a method reference for disposing of citrus pomace in the future.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).


2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  

Porous carbons with a high specific surface area (2314–3470 m2 g−1) are prepared via a novel KCl-assisted activation strategy for high-performance supercapacitor.


2021 ◽  
Vol 54 (2) ◽  
pp. 1-36
Author(s):  
Sameen Maruf ◽  
Fahimeh Saleh ◽  
Gholamreza Haffari

Machine translation (MT) is an important task in natural language processing (NLP), as it automates the translation process and reduces the reliance on human translators. With the resurgence of neural networks, the translation quality surpasses that of the translations obtained using statistical techniques for most language-pairs. Up until a few years ago, almost all of the neural translation models translated sentences independently , without incorporating the wider document-context and inter-dependencies among the sentences. The aim of this survey article is to highlight the major works that have been undertaken in the space of document-level machine translation after the neural revolution, so researchers can recognize the current state and future directions of this field. We provide an organization of the literature based on novelties in modelling and architectures as well as training and decoding strategies. In addition, we cover evaluation strategies that have been introduced to account for the improvements in document MT, including automatic metrics and discourse-targeted test sets. We conclude by presenting possible avenues for future exploration in this research field.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1280
Author(s):  
Vu Duc Canh ◽  
Seiichiro Tabata ◽  
Shun Yamanoi ◽  
Yoichi Onaka ◽  
Toshiyuki Yokoi ◽  
...  

Porous carbons are well-known efficient adsorbents for a variety of organic and inorganic pollutants; however, they have difficulty in virus removal. In this study, novel porous carbons (NPCs) (NPC-A, NPC-B, and NPC-C) derived from rice husks were compared with commercially available activated carbons (ACs) for their ability to remove MS2 bacteriophages (MS2) in a batch experiment. NPC-A was produced by the silica removal process. NPC-B was prepared with an additional steam activation applied to NPC-A. NPC-C was obtained with an additional acid rinse applied to NPC-B. The NPCs (particularly NPC-C) exhibited effective removal of up to 5.3 log10 of MS2, which was greater than that of less than 2.7 log10 obtained by other ACs under 10 g/L during the same contact time (60 min). The pore size distribution of the porous carbon adsorbents was found to influence their virus removal performance. The adsorbents with a larger proportion of pores ranging from 200–4500 nm in diameter were able to achieve higher virus removal rates. Thus, NPCs (particularly NPC-C), which had a larger volume of pores ranging from 200–4500 nm in size, demonstrated the potential for use as efficient adsorbents for removing viruses during water purification.


RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16575-16581 ◽  
Author(s):  
Mingbo Wu ◽  
Peng Li ◽  
Yang Li ◽  
Jun Liu ◽  
Yang Wang

Porous carbons were prepared from enteromorpha with ZnCl2 as active reagent. The prepared porous carbon with a specific surface area of 1651 m2 g−1 exhibited a specific capacitance of 206 F g−1 and capacity retention of 93% even after 5000 cycles.


2014 ◽  
Vol 487 ◽  
pp. 713-716 ◽  
Author(s):  
Yi Dan Zhou ◽  
Miao Sun ◽  
Li Juan Wang ◽  
Guan Nan Xi

The sources and composition of electroplating waste water are summarized. The common wastewater treatment technology, such as physical and chemical method, physic-chemical process, biological treatment and electrochemical method, and so on. Then the vision for the development of electroplating wastewater treatment technology is made.


RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27860-27867
Author(s):  
Xinxian Zhong ◽  
Quanyuan Mao ◽  
Zesheng Li ◽  
Zhigao Wu ◽  
Yatao Xie ◽  
...  

Biomass-derived heteroatom self-doped porous carbons are expected to become ideal active materials for high performance supercapacitor.


Sign in / Sign up

Export Citation Format

Share Document