Article
Multidisciplinary Sciences
Hua Wang, Wencheng Wang, Song Zhou, Xuchun Gao
Summary: In order to guide the selection of woody-activated carbon for the treatment of Cr(VI)-containing wastewater, adsorption tests were conducted on two varieties of commercial woody-activated carbon powder. The physicochemical properties and structural characteristics of the activated carbon were studied, and the factors affecting the removal of hexavalent chromium were investigated. The results showed that both types of woody-activated carbon have microporous and mesoporous structures, with different adsorption capabilities depending on the concentration of Cr(VI).
Article
Environmental Sciences
A. K. Yadav, S. Singh, R. Sen, P. Jha, K. Tungare, M. Bhori, M. Rangara, N. Desai, R. Jobby
Summary: This study reveals that untreated rice husk can effectively remediate hexavalent chromium through a process involving adsorption, reduction, and desorption.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Hemant Mittal, Ali Al Alili, Pranay P. Morajkar, Saeed M. Alhassan
Summary: The synthesized GO/PEI-NCH hydrogel demonstrated high adsorption capacity for Cr(VI) contaminated water, good stability, and reusability through multiple adsorption-desorption cycles, making it a promising candidate for wastewater treatment.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Environmental Sciences
Yi Fang, Ke Yang, Yipeng Zhang, Changsheng Peng, Aurora Robledo-Cabrera, Alejandro Lopez-Valdivieso
Summary: The efficiency of Cr(VI) removal by ballmilled highly activated carbon (HAC) under neutral conditions was significantly improved due to the increased content of surface acid functional groups. Two mechanisms for Cr(VI) removal were proposed, involving reduction of Cr(VI) to Cr(III) and formation of chromium hydroxides on the surface of HAC, as well as bonding of CrO42- on the surface COOH groups.
ENVIRONMENTAL RESEARCH
(2021)
Article
Green & Sustainable Science & Technology
Mehdi Bahrami, Mohammad Javad Amiri, Mohammad Reza Mahmoudi, Anahita Zare
Summary: One solution to water crisis problems is using agricultural residue capabilities as low-cost and abundant adsorbents to remove pollutants from water. This study evaluated the potential of activated carbon from rice husk (RHAC) for removing caffeine from water. The maximum caffeine uptake capacity was achieved under the optimum conditions of RHAC dosage, solution pH, contact time, and initial concentration. The adsorption process was best described by pseudo-first-order kinetics and Freundlich isotherm, indicating the presence of heterogeneous and varying pores in RHAC.
Article
Chemistry, Physical
Fengming Cao, Yanqing Sun, Ling Zhang, Jie Sun
Summary: The study revealed that PPy-SFB is an efficient adsorbent for the removal of Cr(VI) from water, with adsorption mechanisms involving electrostatic interactions, ion exchange, and surface reduction. Furthermore, the adsorbed Cr(VI) can be recovered through simple incineration.
APPLIED SURFACE SCIENCE
(2022)
Article
Environmental Sciences
Yanan Chen, Yunkun Qian, Jiaxin Ma, Mengjun Mao, Linping Qian, Dong An
Summary: This study systematically evaluated the concurrent adsorption of humic acid (HA) and hexavalent chromium (Cr(VI)) by powdered activated carbon (PAC) in water. It was found that the presence of humic acid significantly enhanced the adsorption of both HA and Cr(VI). The promotion effect of humic acid on Cr(VI) removal was found to decrease with increasing pH. The cooperative adsorption mechanism was attributed to the formation of Cr(VI)-HA and Cr(III)-HA complexes that were readily adsorbed on the PAC surfaces.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Physical
Amel Taha, Enshirah Da'na, Hanaa A. Hassanin
Summary: The study introduced a bio-synthesized Ag/ZnO nanocomposite loaded on activated carbon as a new eco-friendly and effective sorbent for the removal of Cr (VI) ions. The sorption process was found to optimally correlate with Freundlich isotherm and pseudo second order kinetic models, demonstrating the potential of Ag/ZnO-AC as a sorbent for Cr (VI) ions uptake.
SURFACES AND INTERFACES
(2021)
Article
Environmental Sciences
Arfin Imam, Sunil Kumar Suman, Raghuvir Singh, Bhanu Prasad Vempatapu, Anjan Ray, Pankaj K. Kanaujia
Summary: This study successfully immobilized laccase on the surface of functionalized rice straw biochar, achieving high stability and immobilization yield. Through adsorption and kinetic studies, the optimal immobilization concentration was found at 25 degrees C. The immobilized system was applied for anthracene degradation, resulting in complete degradation within 24 hours.
ENVIRONMENTAL POLLUTION
(2021)
Article
Environmental Sciences
Xiaohong Guo, Weiwei Hu, Zheng Gu, Jiali Li, Zongfan Xie, Caixia Fang, Haisheng Tao
Summary: In this study, a high adsorption performance activated carbon was prepared from soybean straw residue for efficient removal of chromium(VI) from water. The generated soybean straw-based activated carbon had a large specific surface area and electron-donating groups on the surface, which promoted a high adsorption capability. The adsorption process was found to be spontaneous, endothermic, and dominated by reduction and electrostatic adsorption mechanisms.
WATER AIR AND SOIL POLLUTION
(2021)
Article
Chemistry, Multidisciplinary
Ilyasse Loulidi, Maria Jabri, Abdelouahed Amar, Abderahim Kali, Awad A. Alrashdi, Chaimaa Hadey, Mbarka Ouchabi, Palsan Sannasi Abdullah, Hassane Lgaz, Youngjae Cho, Fatima Boukhlifi
Summary: In this study, used coffee grounds were chemically activated to produce powdered activated carbon, which was compared with commercial activated carbon. The activated carbon was characterized using various techniques and its performance in adsorbing crystal violet and hexavalent chromium was tested. The results showed that the adsorption followed pseudo-second order kinetics and the Langmuir isotherm best described the equilibrium data. Thermodynamic analysis revealed that the adsorption process was spontaneous, exothermic, and resulted in a decrease in disorder at the solid-liquid interfaces. This study suggests that the prepared activated carbon can be utilized as an alternative adsorbent for removing cationic dyes and heavy metals from aqueous solutions.
APPLIED SCIENCES-BASEL
(2023)
Article
Environmental Sciences
Sousan Hadi, Ensiyeh Taheri, Mohammad Mehdi Amin, Ali Fatehizadeh, Tejraj M. Aminabhavi
Summary: This study focused on the use of magnetized activated carbon pomegranate husk for the adsorption of 4-chlorophenol from synthetic wastewater. The results showed that adsorption efficiency was highly dependent on ionic strength, solution pH, and temperature, with equilibrium being reached in 60 minutes. Kinetic models and equilibrium isotherms were used to assess the adsorption data, with the Liu model showing the best fit and providing maximum adsorption capacities for different MPHAC concentrations.
Article
Engineering, Multidisciplinary
Jie Zhu, Keiji Komatsu, Heng Li, Yuto Kudo, Rui Okuda, Yoshikuni Ishibashi, Takumi Yamada, Ikumi Toda, Shigeo Ohshio, Yoshinori Tuda, Hidetoshi Saitoh
Summary: A method for measuring the true density of nanoporous carbon (NPC) fabricated from rice husks based on a gas constant-volume expansion method was developed in this study. Results showed that this method provided accurate determination of true density with higher stability, particularly in NPC materials with higher specific surface area.
Article
Energy & Fuels
Niladri Saha, Lopamudra Das, Papita Das, Avijit Bhowal, Chiranjib Bhattacharjee
Summary: The study utilized rice husk, rice husk charcoal, and activated rice husk charcoal as adsorbents to remove malachite green dye from water. Different conditions were tested, and it was found that activated rice husk charcoal was the most effective adsorbent for the removal of the dye.
BIOMASS CONVERSION AND BIOREFINERY
(2021)
Article
Engineering, Environmental
Yutian Hu, Tong Liu, Nan Chen, Chuanping Feng, Wang Lu, Huaming Guo
Summary: In this study, ball milling was used to disrupt the structure of straw, enhancing its availability for the simultaneous bioreduction of nitrate and Cr(VI). The ball milling process changed the composition of organic matter in the straw and increased the release of water-soluble organic matter. Increasing the ball milling time increased the surface area of the straw, promoting microbial adhesion and improving the bioavailability of the energy in the straw.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
