scholarly journals Use of Biopolymers in the Stabilization of Clay Soils

2021 ◽  
Vol 16 (2) ◽  
pp. 37-53
Author(s):  
Idoui Imane ◽  
Rehab Bekkouche Souhila ◽  
Benzaid Riad ◽  
Berdi Inas

Abstract The treatment and stabilization of soils make it possible to recycle materials on construction sites in preparation for the installation of a final covering or the construction of a road network. In road geotechnics, various materials such as lime, cement, and pozzolans were used as additions to stabilize clay soils. In recent years, bio-polymers and bacteria are of increasing interest to researchers in the field of stabilization and improvement of the physico-mechanical and chemical characteristics of clay soils. Currently, in place of traditional clay treatment techniques and to minimize environmental problems, natural fibrous waste is being used increasingly and spectacularly. Several studies on biotechnological engineering applications already exist, such as the use of vegetation, algae, bacteria, enzymes, and biopolymers. The northern Algerian region where the urban tissue does not stop expanding contains significant potential in terms of wheat straw, which represents a very present agricultural waste. So, there is a local interest in the sustainable development of several regions known to produce wheat. This study is interested in investigating the effect of wheat straw on the stabilization of swelling clay soil. In order to improve the physico-mechanical characteristics of clay soils, a series of laboratory tests (Atterberg limit, Proctor test, direct shear test, Oedometer test, and unconfident compressive strength test) were carried out on reconstituted clay soil with defined initial properties through numerous analyses (e.g., XRD and XRF) and then treated with different vegetable fiber content. The results indicate that there is an improvement in the compressibility characteristics of the treated soil, a remarkable decrease in the swelling index and the compressibility index respectively with increasing percentages of wheat straw.

This article presents the results of an experimental laboratory study carried out with the odometer and the Richards press on a class A3 clay soil sample that had undergone drying-wetting cycles. These tests allowed us to analyze in fine the influence of the drying-wetting cycles on the compressibility and suction behavior of the soil object of our study. This study reveals that the drying-wetting cycles have a certain influence on clay soils. Indeed, the compressibility index of the soil increases while the swelling index decreases according to the cycles; the pre-consolidation pressure and the oedometric modulus show a more or less constant variation; the permeability of the soil increases clearly when the number of cycles increases. Soil suction decreases as the number of drying-wetting cycles increases under extreme conditions.


2021 ◽  
Vol 11 (13) ◽  
pp. 6066
Author(s):  
Dora Luz Gómez-Aguilar ◽  
Juan Pablo Rodríguez-Miranda ◽  
Deisy Baracaldo-Guzmán ◽  
Octavio José Salcedo-Parra ◽  
Javier Andrés Esteban-Muñoz

The present research shows the results obtained from the biosorption process of Pb, using coffee pulp as a biosorbent in synthetic waters. To do this, the lignin and cellulose content and the percentage of removal of Pb2+ ions was determined; additionally, the sorption’s optimal variables, such as the optimum pH, the point of zero charge (pHpzc), the kinetics and the adsorption isotherm, were determined. A comparison was made with other by-products derived from coffee crops. According to the results obtained in this research, the cellulose percentage was 29.12 ± 0.22% and the lignin percentage was 19.25 ± 0.16% in the coffee pulp, the optimum pH was 2.0 units and the kinetic model, which adjusted to the biosorption’s process, was the pseudo-second order of Ho and McKay, presenting an isotherm of Langmuir’s model and pHpzc of 3.95 units. Lastly, the removal of the pollutant was 86.45%, with a capacity of maximum adsorption of 24.10 mg·g−1 obtained with a particle size of 180 µm, time of contact of 105 min and at 100 RPM. Finally, we express that (a) the coffee pulp can be used as a sustainable alternative for the removal of the pollutant mentioned in synthetic and/or industrial wastewater matrices, to meet goals 3.9 and 6.9 of the Sustainable Development Goals of the 2030 agenda, and (b) the novelty of this research is the use of an agricultural waste of easy acquisition as a sorbent, without chemical modification, since it presented a high percentage of efficiency in the removal of Pb2+ ions. In turn, the challenge of this research is implementing this green technology on a pilot, semi-industrial and/or industrial scale in wastewater treatment systems.


2018 ◽  
Vol 7 (3.2) ◽  
pp. 636
Author(s):  
Tetyana Lvovska ◽  
Tetyana Lytvynenko ◽  
Alla Kariuk

A process of soil compaction methods development including new authors’ methodology is described. The importance of soil compaction for engineering purposes is substantiated. Preconditions for Proctor compaction test appearance are highlighted. Proctor’s approach and suggestions for the degree of soil compaction assessing are analyzed. Soviet version of Proctor’s equipment and Modified Proctor compaction test are given. Principal differences between Proctor test, Standard compaction test and Modified Proctor test are presented. The problems and disadvantages of existent soil compaction tests are revealed. New authors’ physical experiment methodology for patterns establishment of water migration in subgrade embankment depth, in the capacity factors of what it is accepted: clay soil type (its number plasticity); moisture, at what the soil was compacted; soil skeleton density; embankment height; «rest» time after subgrade erection and before it’s operation is developed and realized. By laboratory and field tests water migration patterns in compacted subgrade soils depth are established. As a result of statistical processing of research results, the empirical dependence of compacted clay soil stabilized moisture is obtained. Empirical dependence parameter corresponds to maximum molecular moisture capacity at what it is advisable to do the subgrade clay soils multilayer consolidation for their long-term strength ensuring. 


2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Antônio Italcy de Oliveira Júnior ◽  
Michelly Matos Pereira ◽  
Celme Torres Ferreira da Costa

RESUMO: No momento de instabilidade econômica em que se encontra o país, ações que minimizem os gastos e que aumentem a produtividade na construção civil visando ao desenvolvimento sustentável dos meios de produção estão cada vez mais sendo solicitadas. Com o intuito de realizar um diagnóstico da disposição, organização e práticas nos canteiros de obra da região do Crajubar, foram estudadas dez construções em execução na região. A amostra selecionada contemplava edificações horizontais e verticais, com finalidade de uso comercial, residencial e mista. Os dados foram obtidos a partir do método de diagnóstico que consiste na aplicação de uma lista de verificação (check-list) padronizada, que contemplava três grupos a serem analisados: instalações provisórias, segurança na obra e movimentação e armazenagem de materiais. Para a visualização e identificação de falhas nos canteiros foi feito um registro fotográfico de itens pré-determinados. De posse das informações coletadas foram atribuídas notas para os grupos, calculada a nota global (que é a média aritmética das notas de grupo) e as obras foram distribuídas em quatro categorias: ótimas, boas, regulares e ruins. As obras horizontais obtiveram as piores notas, entre 4,01 e 6, enquanto as obras verticais que apresentavam políticas de gestão de qualidade se destacaram com as melhores notas, entre 8,01 e 10. O tipo de obra foi o fator que mais influenciou na qualidade dos canteiros de obras avaliados no Crajubar cearense.ABSTRACT: At a time of economic instability in the country, actions that minimize expenditures and increase productivity in civil construction aimed at the sustainable development of the means of production are increasingly being requested. In order to make a diagnosis of the layout, organization and practices in the construction sites of the Crajubar region, ten constructions were studied in the region. The sample selected included horizontal and vertical buildings, for commercial, residential and mixed use. The data were obtained from the diagnostic method, which consists of the application of a standardized checklist, which included three groups to be analyzed: temporary installations, handling and storage of materials. Along with this list, a photographic record of predetermined items was made for the visualization and identification of defects in the construction. From the information collected, the group notes and a global grade (the arithmetic mean of the group notes) were assigned and the works were distributed into four categories: great, good, regular and bad. The horizontal construction obtained the worse notes, between 4.01 and 6, while the vertical construction that presented policies of quality management stood out with the best notes, between 8,01 and 10. The type of construction was the factor that most influenced the quality of the construction sites evaluated in Crajubar cearense.


2020 ◽  
Vol 32 (1) ◽  
pp. 115-124
Author(s):  
Hasan Sardar ◽  
Muhammad Akbar Anjum ◽  
Aamir Nawaz ◽  
Safina Naz ◽  
Shaghef Ejaz ◽  
...  

AbstractAgricultural waste disposal is one of the main concerns in today's world that can cause environmental pollution. Utilisation of agro-waste materials to grow mushrooms is an eco-friendly method to reduce pollution. Therefore, various agricultural waste materials, such as wheat straw, rice straw and cotton waste, were utilised for the production of milky mushroom. Among the substrates used in this study wheat straw showed superior substrate for the production of milky mushroom. The agronomic traits studied such as total yield, number of fruiting bodies, the maximum diameter of pileus and stalk length, biological efficiency, protein contents, phosphorous and potassium contents were observed on wheat straw substrate. Peat moss, loam soil and spent mushroom substrate were used as casing materials. Among the casing materials used, the highest yield and biological efficiency were observed on peat moss. The results also indicated that the addition of supplements with the substrate improved yield and yield contributing characteristics. Among the tested supplements (wheat bran and rice bran), wheat bran was the best supplement for wheat straw substrate to cultivate milky white mushroom.


2021 ◽  
Vol 90 (2 - Ahead of print) ◽  
pp. 70-85
Author(s):  
Mervat Abdel-Moneauim Mostafa El-Genaidy ◽  
Mohamed Abd El-Aziz Mohamed Hindy ◽  
Nehad Abdel-Hameed Soliman

Peach fruit fly, Bactrocera zonata (Saunders, 1841) is a destructive polyphagous pest threatening the horticultural production in Egypt. Licorice, Glycyrrhiza glabra (Linnaeus, 1753) is a plant growing in Egypt and many other countries and famous for saponins groups that have insecticidal effect against broad spectrum of insect pests. In the present study, the insecticidal effect of licorice roots aqueous extract (LRAE), petroleum oil, KZ light mineral oil 96% (EC), water and an emulsion (1/4 L LRAE + ¼ L petroleum oil + ½ L KZ light oil 96% (EC)) treatments in a ratio 1 L: 29 L water were used in Matabi® sprayer of 30 L capacity against B. zonata pupae in sandy and clay soils. In sandy and clay soils LRAE reduced B. zonata population by 74.44% and 87.55% while petroleum oil, KZ light mineral oil 96% (EC) prevented flies emergence (100% reduction). Water treatment suppressed B. zonata population by 78.61% in sandy soil but caused 100% population reduction in clay soil. The emulsion reduced B. zonata population by 96.94% in sandy soil and 100% in clay soil. The best method for application of the emulsion was to spray as one target spray technique for eight seconds that was sufficient to obtain suitable coverage on soil with spray speed 1.2 km / hour. The persistence of the emulsion that highly reduced B. zonata larval populations was 3.5 and 4.5 days in sandy and clay soils, respectively. The flies emerged from B. zonata pupae treated with the emulsion neither feed nor move naturally. The histological studies showed that these flies suffered changes in the eyes, labellum, muscles and midgut tissues that were different from the emerged control treatment flies.


2018 ◽  
Vol 4 (3) ◽  
pp. 594 ◽  
Author(s):  
Davood Akbarimehr ◽  
Esmael Aflaki

With respect to the increasing production of tire wastes, the use of these wastes as an additive in civil engineering has always gained attentions of researchers due to their positive effects on material properties and reduction of environmental problems. Clay soils, as problematic soils, have always caused geotechnical problems including high Atterberg limits and consequently low workability. Tire powder, as one of the products of tire wastes, lacks clay cohesion and it can be effective in altering the plasticity of clay soils. As no comprehensive study has been conducted in this regard specifically on Tehran clay soil yet, this research studies experimentally the effect of adding different percentages of tire powder to clay soil at the Atterberg limits of clay soils with two different types of plasticity. More over according to previous studies, the effect of tire powder on other geotechnical properties of clay soils and the advantages and disadvantages of using tire powder in clay soils are discussed. The results indicate that addition of tire powder to clay soils has positive effects on reducing the Atterberg limits, increasing efficiency, and improving resistance, permeability, swelling reduction, and settlement properties, and reducing soil density and it can be used as an additive in improving clay soils.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Georgios I. Zervakis ◽  
Georgios Koutrotsios ◽  
Panagiotis Katsaris

Two-phase olive mill waste (TPOMW, “alperujo”) is a highly biotoxic sludge-like effluent of the olive-oil milling process with a huge seasonal production. One of the treatment approaches that has so far received little attention is the use of TPOMW as substrate for the cultivation of edible mushrooms. Fifteen fungal strains belonging to five species (Basidiomycota), that is,Agrocybe cylindracea,Pleurotus cystidiosus,P. eryngii,P. ostreatus, andP. pulmonarius, were evaluated for their efficacy to colonize media composed of TPOMW, which was used either raw or composted in mixtures with wheat straw in various ratios. Qualified strains exhibited high values of biological efficiency (e.g., 120–135% forPleurotusspp. and 125% forA. cylindracea) and productivity in subsequent cultivation experiments on substrates supplemented with 20–40% composted TPOMW or 20% raw TPOMW. Only when supplementation exceeded 60% for raw TPOMW, a negative impact was noted on mushroom yields which could be attributed to the effluent's toxicity (otherwise alleviated in the respective composted TPOMW medium). Earliness and mushroom size as well as quality parameters such as total phenolic content and antioxidant activity did not demonstrate significant differences versus the control wheat-straw substrate. The substrates hemicellulose content was negatively correlated with mycelium growth rates and yields and positively with earliness; in addition, cellulose: lignin ratio presented a positive correlation with mycelium growth and mushroom weight forA. cylindraceaand with earliness for all species examined. TPOMW-based media revealed a great potential for the substitution of traditional cultivation substrates by valorizing environmentally hazardous agricultural waste.


2020 ◽  
Vol 8 (2) ◽  
pp. 60-67
Author(s):  
Seyed Hamidreza Ghaffar

2014 ◽  
Vol 1010-1012 ◽  
pp. 610-613
Author(s):  
Xiao Deng ◽  
Chun Yuan Wu ◽  
Yi Li ◽  
Jing Kun Liu ◽  
Qin Fen Li

Using pot experiment to study the influence of three organic fertilizers of chicken manure compost (CM), activated sludge (AS) and cassava residue compost (CR) on the degradation of p, p'-DDT in clay soil under flooding conditions. The results showed that the two kinds of organic fertilizers of AS and CM could effectively accelerate the degradation of p, p'-DDT in clay soils, and the degradation effect was the best when adding 2% CM or 3% AS in clay soil. However, the influence of CR on the degradation of p, p'-DDT was not obvious. The degradation rates of P, P′-DDT in the treatment on adding 1% AS were from zero to 7.4% higher than that of 1% CM. The degradation rates of P, P′-DDT in the treatment on adding 2% AS were from zero to 11.3% higher than that of 2% CM. The degradation rates of P, P′-DDT in the treatment on adding 3% AS were from 8.3% to 27.4% higher than that of 3% CM. which indicated that AS is more conducive to the degradation of p, p'-DDT in the clay.


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