Efficient and sustainable phosphate removal from water by small-sized Al(OH)3 nanocrystals confined in discarded Artemia Cyst-shell: Ultrahigh sorption capacity and rapid sequestration

2022 ◽  
Vol 803 ◽  
pp. 150087
Author(s):  
Yaran Song ◽  
Xiaoxin Song ◽  
Qina Sun ◽  
Sufeng Wang ◽  
Tifeng Jiao ◽  
...  
2021 ◽  
Vol 13 (3) ◽  
pp. 1502
Author(s):  
Maria Xanthopoulou ◽  
Dimitrios Giliopoulos ◽  
Nikolaos Tzollas ◽  
Konstantinos S. Triantafyllidis ◽  
Margaritis Kostoglou ◽  
...  

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.


2015 ◽  
Vol 71 (12) ◽  
pp. 1875-1883 ◽  
Author(s):  
HyunJu Park ◽  
Duc Canh Nguyen ◽  
Choo-Ki Na

In this study, we investigated the removal of phosphate from aqueous solutions using (vinylbenzyl)-trimethylammonium chloride (VBTAC) grafted onto poly(ethylene terephthalate) (PET) fibers (PET-g-VBTAC). Batch-mode experiments were conducted using various contact times, initial phosphate concentrations, temperatures, pH values, and competing anions, to understand phosphate sorption onto PET-g-VBTAC. The phosphate sorption capacity of PET-g-VBTAC increased with increasing solution pH and was highest near pH 7. The equilibrium data fitted the Langmuir isotherm model well. The maximum sorption capacity (qm) of PET-g-VBTAC for phosphate was 55.6–56.0 mg/g at 25–45 °C. The sorption process followed a pseudo-second-order kinetic model. The obtained values of the mean free energy indicated that sorption of phosphate on PET-g-VBTAC occurs via ion exchange. Thermodynamic parameters, enthalpy change, entropy change, and Gibb's free energy, confirmed that phosphate sorption was spontaneous and endothermic. The adverse effects of competing anions on phosphate removal by PET-g-VBTAC were insignificant. These results demonstrate that PET-g-VBTAC effectively removes phosphate from aqueous solutions by ion exchange.


2014 ◽  
Vol 59 (2) ◽  
pp. 509-516
Author(s):  
Andrzej Olajossy

Abstract Methane sorption capacity is of significance in the issues of coalbed methane (CBM) and depends on various parameters, including mainly, on rank of coal and the maceral content in coals. However, in some of the World coals basins the influences of those parameters on methane sorption capacity is various and sometimes complicated. Usually the rank of coal is expressed by its vitrinite reflectance Ro. Moreover, in coals for which there is a high correlation between vitrinite reflectance and volatile matter Vdaf the rank of coal may also be represented by Vdaf. The influence of the rank of coal on methane sorption capacity for Polish coals is not well understood, hence the examination in the presented paper was undertaken. For the purpose of analysis there were chosen fourteen samples of hard coal originating from the Upper Silesian Basin and Lower Silesian Basin. The scope of the sorption capacity is: 15-42 cm3/g and the scope of vitrinite reflectance: 0,6-2,2%. Majority of those coals were of low rank, high volatile matter (HV), some were of middle rank, middle volatile matter (MV) and among them there was a small number of high rank, low volatile matter (LV) coals. The analysis was conducted on the basis of available from the literature results of research of petrographic composition and methane sorption isotherms. Some of those samples were in the form (shape) of grains and others - as cut out plates of coal. The high pressure isotherms previously obtained in the cited studies were analyzed here for the purpose of establishing their sorption capacity on the basis of Langmuire equation. As a result of this paper, it turned out that for low rank, HV coals the Langmuire volume VL slightly decreases with the increase of rank, reaching its minimum for the middle rank (MV) coal and then increases with the rise of the rank (LV). From the graphic illustrations presented with respect to this relation follows the similarity to the Indian coals and partially to the Australian coals.


2013 ◽  
Vol 12 (12) ◽  
pp. 2371-2383
Author(s):  
Krishnaswamy Usharani ◽  
Perumalsamy Lakshmanaperumalsamy ◽  
Muthusamy Muthukumar

Author(s):  
A. Safonov ◽  
N. Andriushchenko ◽  
N. Popova ◽  
K. Boldyrev

Проведен анализ сорбционных характеристик природных материалов (вермикулит, керамзит, перлит, цеолит Трейд ) при очистке кадмий- и хромсодержащих сточных вод с высокой нагрузкой по ХПК. Установлено, что цеолит обладает максимальными сорбционными характеристиками для Cd и Cr и наименьшим биологическим обрастанием. При использовании вермикулита и керамзита или смесей на их основе можно ожидать увеличения сорбционной емкости для Cd и Сr при микробном обрастании, неизбежно происходящем в условиях контакта с водами, загрязненными органическими соединениями и биогенами. При этом биообрастание может повысить иммобилизационную способность материалов для редоксзависимых металлов за счет ферментативных ресурсов бактериальных клеток, использующих их в качестве акцепторов электронов. Эффект микробного обрастания разнонаправленно изменял параметры материалов: для Cr в большинстве случаев уменьшение и для Cd значительное увеличение. При этом дополнительным эффектом иммобилизации Cr является его биологическое восстановление биопленками. Варьируя состав сорбционного материала, можно подбирать смеси, оптимально подходящие для очистки вод инфильтратов с полигонов твердых бытовых отходов с высокой нагрузкой по ХПК и биогенным элементам как при использовании in situ, так и в системах на поверхности.The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, Trade zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.


1975 ◽  
Vol 10 (1) ◽  
pp. 214-223
Author(s):  
N.S. Wei ◽  
G.W. Heinke

Abstract This paper presents bench scale experimental results on the electrolysis of raw domestic wastewater. Studies carried out with consumable electrodes are discussed. A mathematical model of a small electrolytic sewage treatment unit for individual household application is developed. The energy consumption and cost of such a device are discussed. Electrolysis can be described as a process in which chemical reactions are induced at each electro-liquid interface by applying an external electrical energy source to a system of electrodes immersed in a liquid. This paper deals only with electrolysis where a direct current power supply is used as the energy source. The process is governed by Faraday' s two laws on electrochemistry. The fundamental process parameter is the electrical charge density, measured as coulombs per litre (c/1) of wastewater treated. There are two basic types of electrolysis depending on the choice of anode material. When the anode is made of dissolvable metallic material such as iron, stainless steel and aluminum, the metal dissolves and goes into the sewage as metallic ions and forms hydrated metallic oxides which act as flocculating agents. The amount of metal dissolved is proportional to the quantity of electrical charges supplied to the system. Results from a series of batch experiments showed that electrolysis with consumable electrodes is capable of removing significant amounts of organic pollutants. Total organic carbon (TOC) removal was found to be a function of charge density. Phosphate removal efficiency of 90 percent or higher was achieved at a relatively low charge density of 240 coulombs per litre with either iron or stainless steel anodes. A mathematical model was derived in the conceptual design of a household electrolytic treatment unit. The model incorporates variables such as decomposition voltage of the electrodes and electrical conductivity of the wastewater as well as the physical configuration of the electrolytic cell. The energy requirement of such a unit can be calculated from the model. It is suggested in this paper that an electrolytic waste treatment unit could be an alternative to the septic tank and tile bed system in areas where the latter is not applicable due to poor soil and terrain conditions.


1991 ◽  
Vol 24 (10) ◽  
pp. 329-332
Author(s):  
P. M. J. Janssen ◽  
J. H. Rensink ◽  
E. Eggers
Keyword(s):  

1994 ◽  
Vol 30 (6) ◽  
pp. 237-246 ◽  
Author(s):  
A. Carucci ◽  
M. Majone ◽  
R. Ramadori ◽  
S. Rossetti

This paper describes a lab-scale experimentation carried out to study enhanced biological phosphate removal (EBPR) in a sequencing batch reactor (SBR). The synthetic feed used was based on peptone and glucose as organic substrate to simulate the readily biodegradable fraction of a municipal wastewater (Wentzel et al., 1991). The experimental work was divided into two runs, each characterized by different operating conditions. The phosphorus removal efficiency was considerably higher in the absence of competition for organic substrate between P-accumulating and denitrifying bacteria. The activated sludge consisted mainly of peculiar microorganisms recently described by Cech and Hartman (1990) and called “G bacteria”. The results obtained seem to be inconsistent with the general assumption that the G bacteria are characterized by anaerobic substrate uptake not connected with any polyphosphate metabolism. Supplementary anaerobic batch tests utilizing glucose, peptone and acetate as organic substrates show that the role of acetate in the biochemical mechanisms promoting EBPR may not be so essential as it has been assumed till now.


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