scholarly journals Modified Rice Straw Enhanced Cadmium (II) Immobilization in Soil and Promoted the Degradation of Phenanthrene in Co-Contaminated Soil

2019 ◽  
Vol 20 (9) ◽  
pp. 2189 ◽  
Author(s):  
Ali Mohamed Elyamine ◽  
Mohamed G Moussa ◽  
Javaria Afzal ◽  
Muhammad Shoaib Rana ◽  
Muhammad Imran ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Carbohydrate Metabolism ◽  
Rice Straw ◽  
Cytochrome P450s ◽  
Natural Material ◽  
Metal Availability ◽  
Limited Information ◽  
Polycyclic Aromatic ◽  
Naoh Solution ◽  
Chemical Contaminant

Very limited information is available about heavy metal-polycyclic aromatic hydrocarbons (PAHs) depollution involving the modified natural material in soil. Using phenanthrene and cadmium (Cd) as model, this study investigated the effect(s) of modified rice straw by a NaOH solution and on PAHs, heavy metal availability, and their interactions. Treatment included chemical contaminant with/without modified/unmodified rice straw. Fourier Transform Infrared (FTIR) analysis revealed that certain functional groups including anionic matters groups, which can a complex with Cd2+, were exposed on the modified rice straw surfaces. Therefore, Cd concentration was significantly reduced by about 60%, 57%, 62.5 %, and, 64% in the root, shoot, CaCl2, diethylenetriaminepentaacetic acid (DTPA), and extractable Cd, respectively. Subsequently, the prediction of the functional profile of the soil metagenome using Clusters Orthologous Groups (COGs) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that the significantly changed individual COGs belonged to the carbohydrate metabolism, ion transports, and signaling (including cytochrome P450s) categories. This indicated that ion transports might be involved in Cd management, while carbohydrate metabolism, including bisphenol, benzoate, ethylbenzene degradation, and cytochrome P450s, were rather involved in phenanthrene metabolism. The exposed functional group might serve as an external substrate, and P450s might serve as a catalyst to activate and initiate phenanthrene metabolism process. These finding offer confirmation that modified straw could promote the reduction of heavy metal and the degradation of PAHs in soil.

scholarly journals Earthworms, Rice Straw, and Plant Interactions Change the Organic Connections in Soil and Promote the Decontamination of Cadmium in Soil

2018 ◽  
Vol 15 (11) ◽  
pp. 2398 ◽  
Author(s):  
Ali Elyamine ◽  
Mohamed Moussa ◽  
Marwa Ismael ◽  
Jia Wei ◽  
Yuanyuan Zhao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Rice Straw ◽  
Contaminated Soil ◽  
Limited Information ◽  
Plant Interactions ◽  
Cd Uptake ◽  
Mobile Form ◽  
Crop Straw ◽  
Mn Oxide

The joint effects of earthworms and crop straw on toxic metal speciation are not clear, and very limited information is available regarding the effects of their interaction on Cd mobility in Cd contaminated soil or in remediation processes involving plants. This study evaluated their impacts on Cd mobile form changes in soil and their effects on Cd uptake by plants. Treatments included both planted and unplanted-Cd-contaminated soil with or without rice straw and/or earthworms. The results revealed that earthworms, rice straw, and plant interactions change the Cd mobile forms in soil. The order of Cd concentration of different chemical forms was as follows: exchangeable > residual > bound to Fe-Mn oxide > bound to organic matter for earthworms, and exchangeable > bound to organic matter > residual > bound to Fe-Mn oxide for rice straw treatment, with a recovery rate of 96 ± 3%. The accumulation of Cd in plants increased in the presence of earthworms and decreased in the presence of rice straw. FT-IR spectra indicated that the degradation of rice straw increases C–O, C–O–H, C–H, and O–H functional groups which could complex with Cd ions. These findings highlighted that earthworms’ activities and crop straw can modify soil properties and structure and promote the remediation of heavy metal. This study suggests that the ecological context of remediation instead of being limiting on soil-earthworms-plant interaction, should integrate the natural resources forsaken which can provide a positive influence on both plant health and the remediation of heavy metal in contaminated soil.

scholarly journals Fabrication of mesoporous lignin-based biosorbent from rice straw and its application for heavy-metal-ion removal

2017 ◽  
Vol 53 ◽  
pp. 132-140 ◽  
Author(s):  
Fang Xu ◽  
Ting-Ting Zhu ◽  
Qing-Quan Rao ◽  
Sheng-Wen Shui ◽  
Wen-Wei Li ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Rice Straw ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Metal Ion Removal ◽  
Ion Removal ◽  
Heavy Metal Ion Removal

Removing heavy metals from effluents with natural and modified clay-containing sorbents

2021 ◽  
pp. 30-37
Author(s):  
А.К. Стрелков ◽  
С.В. Степанов ◽  
О.Н. Панфилова ◽  
А.В. Арбузов
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Specific Productivity ◽  
Natural Material ◽  
Main Process ◽  
Tertiary Treatment ◽  
Modified Clay ◽  
Cartridge Filter

Представлены результаты исследований сорбции ионов тяжелых металлов глиносодержащими сорбентами из сточных вод гальванического производства. Цель испытаний, проведенных на пилотной установке, – разработка технологической схемы для доочистки сточных вод от ионов тяжелых металлов и извлечения отработанного сорбента с применением намывного патронного фильтра со слоем перлита. В испытаниях использовались: термически модифицированный сорбент на основе природных материалов – модифицированная глина, а также смесевый сорбент, состоящий из монтмориллонита, торфа и доломита в соотношении 5:4:1 без термической обработки. Исследования проводились по восьми ионам тяжелых металлов в диапазоне низких концентраций, характерных для сточных вод, поступающих на доочистку после отстаивания с корректировкой рН. Основные технологические параметры доочистки: pH8; продолжительность контакта сорбента с обрабатываемыми водами 90 мин, доза сорбентов 1–1,6 г/л. Отделение отработанного сорбента от очищенной воды было предусмотрено в две ступени – отстаиванием и фильтрованием на патронном намывном фильтре. Введение коагулянта «Аква-АуратÔ-30» дозой 40 мг/л по Al2O3 позволило снизить концентрацию взвешенных веществ в осветленных сточных водах, подаваемых на намывные фильтры, до 8 мг/л для модифицированной глины и 15 мг/л для смесевого сорбента. Удельная производительность намывного слоя составила 23 м3/(ч×м2), расчетная удельная нагрузка по взвеси на поверхность фильтра составила для модифицированной глины 850 г/м2, для смесевого сорбента – 680 г/м2. Расчетная продолжительность фазы фильтрования намывного слоя при использовании предварительного реагентного отстаивания составила 4,6 и 2 ч для модифицированной глины и смесевого сорбента соответственно. Обеспечена эффективность очистки сточных вод от ионов тяжелых металлов на уровне ПДК для водных объектов рыбохозяйственного значения. The results of studies of the sorption of heavy metal ions by clay-containing sorbents from plating effluents are presented. The purpose of the tests carried out in a pilot plant was developing a process scheme for the removal of heavy metal ions from effluents and extraction of the spent sorbent in a precoat cartridge filter with a layer of perlite. The materials used in the tests were as follows: thermally modified sorbent based on natural material, i. e., modified clay, as well as mixed sorbent consisting of montmorillonite, peat and dolomite in a ratio of 5:4:1 without heat treatment. The studies were carried out on eight ions of heavy metals in the low concentration range typical for the effluent coming for tertiary treatment after sedimentation with pH adjustment. The main process parameters of tertiary treatment were: pH 8; the duration of the sorbent contact with the effluent was 90 min, the dose of sorbents was 1–1.6 g/l. The separation of the spent sorbent from the effluent was executed in two stages – sedimentation and filtration in a precoat cartridge filter. The addition of Aqua-AuratTM-30 coagulant with a dose of 40 mg/l as Al2O3provided for reducing the concentration of suspended solids in the clarified effluent supplied to the precoat filters to 8 mg/l for modified clay and 15 mg/l for the mixed sorbent. The specific productivity of the alluvial layer was 23 m3/(h‧m2), the specific load of the suspension on the filter surface was 850 g/m2for modified clay, and 680 g/m2 for mixed sorbent. The estimated duration of the filtration phase of the alluvial layer while using preliminary chemical sedimentation was 4.6 and 2 h for the modified clay and mixed sorbent, respectively. The efficiency of removing heavy metal ions from effluents was provided at the level of the maximum permissible concentration for fishery water bodies.

Macroalgae as Biomonitors of Heavy Metal Availability in Coastal Lagoons from the Subtropical Pacific of Mexico

2000 ◽  
Vol 64 (6) ◽  
pp. 846-851 ◽  
Author(s):  
F. Páez-Osuna ◽  
M. J. Ochoa-Izaguirre ◽  
H. Bojórquez-Leyva ◽  
I. L. Michel-Reynoso
Keyword(s):  
Heavy Metal ◽  
Coastal Lagoons ◽  
Metal Availability

scholarly journals The availability of Cd, Pb and Zn and their relationships with soil pH and microbial biomass in soils amended by natural clinoptilolite

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
G. Mühlbachová ◽  
T. Šimon ◽  
M. Pechová
Keyword(s):  
Heavy Metal ◽  
Microbial Biomass ◽  
Contaminated Soils ◽  
Metal Availability ◽  
Maximum Increase ◽  
Glucose Addition ◽  
Soil Microbial ◽  
Significant Relationships ◽  
Metal Contents ◽  
Natural Clinoptilolite

The relationships among soil microbial biomass, pH and available of heavy metal fractions were evaluated in longterm contaminated soils during an incubation experiment with the amendment of zeolite (natural clinoptilolite) and the subsequent addition of glucose. The values of pH after the addition of glucose decreased during the first day of incubation approximately at about one unit and corresponded with the maximum increase of microbial biomass. The available heavy metal contents extracted by H<sub>2</sub>O, 1 mol/l NH<sub>4</sub>NO<sub>3</sub> and 0.005 mol/l DTPA increased during the first two days of incubation. Only a few significant relationships were found between the available metal contents and pH or microbial biomass. This fact could be ascribed to the different dynamics of the microbial biomass, pH and metal availability after glucose addition, when the highest metal contents during the incubation were usually reached one day later in respect to the greatest changes of pH and microbial activity. In comparison to soils without zeolite addition, the variants with natural clinoptilolite showed lower heavy metal contents in all used extractants with the exception of Cd which in H<sub>2</sub>O extracts tended to increase.

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