scholarly journals Removal of Cr(III) From Water By Polyurethane Foam Incorporated With Green Liquor Dregs Waste

2021 ◽  
Author(s):  
Guilherme Pereira Schoeler ◽  
Thays França Afonso ◽  
Rafael de Avila Delucis ◽  
Benedict C Okeke ◽  
Robson Andreazza
Keyword(s):  
Polyurethane Foam ◽  
Expansion Method ◽  
Effluent Treatment ◽  
Free Expansion ◽  
Green Liquor ◽  
Removal Capacity ◽  
Green Liquor Dregs ◽  
Foam Composite ◽  
Treatment Facilities ◽  
Low Efficiency

Abstract Water bodies contaminated by heavy metals cause a series of severe environmental and health issues. Chromium compounds stand out as one of the main contaminants since they are widely used by several industries. The low efficiency of effluent treatment facilities and the expensive sanitation procedures needed to remove metals from the water lead to serious concerns about the water quality in Brazil. In this study, a rigid polyurethane foam incorporated with green liquor dregs waste was prepared by the free expansion method. The foam composite and its isolated phases were evaluated for removing Cr(III) from water. The isolated dregs removed 81.93% of the Cr(III), which yielded a removal capacity of 135.45 mg·g-1. Whereas, the foam composite displayed Cr(III) removal percentage and capacity of 36.15% and 58.50 mg·g-1, respectively. Results suggests that the hybrid material may be considered for selective removal and extraction of Cr(III) from contaminated water.

scholarly journals SARS-CoV-2 Removal with a Polyurethane Foam Composite

2021 ◽  
Author(s):  
Guilherme Pereira Schoeler ◽  
Thays França Afonso ◽  
Carolina Faccio Demarco ◽  
Victor dos Santos Barboza ◽  
Tito Roberto Sant'anna Cadaval ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Social Inequalities ◽  
Low Cost ◽  
Paper Industry ◽  
Expansion Method ◽  
New Materials ◽  
Free Expansion ◽  
Pu Foam ◽  
Foam Composite ◽  
Basic Sanitation

Abstract The pandemic of COVID-19 (SARS-CoV-2 disease) has been causing unprecedented health and economic impacts, alerting the world to the importance of basic sanitation and existing social inequalities. The risk of the spread and appearance of new diseases highlights the need for the removal of these pathogens through efficient techniques and materials. This study aimed to develop a polyurethane (PU) biofoam filled with dregs waste (leftover from the pulp and paper industry) for removal SARS-CoV-2 from the water. The biofoam was prepared by the free expansion method with the incorporation of 5wt% of dregs as a filler. For the removal assays, the all materials and its isolated phases were incubated for 24h with an inactivated SARS-CoV-2 viral suspension. Then, the RNA was extracted and the viral load was quantified using the quantitative reverse transcription (RT-qPCR) technique. The biofoam (polyurethane/dregs) reached a great removal percentage of 91.55%, whereas the isolated dregs waste was 99.03%, commercial activated carbon was 99.64%, commercial activated carbon/polyurethane was 99.30%, and neat PU foam reached was 99.96% for this same property and without statistical difference. Those new materials endowed with low cost and high removal efficiency of SARS-CoV-2 as alternatives to conventional adsorbents.

Fate of phosphorus in the recovery cycle of the kraft pulping process

TAPPI Journal ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 139-148
Author(s):  
MARYAM SADEGH MOUSAVI ◽  
NIKOLAI DEMARTINI
Keyword(s):  
Kraft Pulp ◽  
Pulp Mill ◽  
Field Studies ◽  
Kraft Pulping ◽  
Pulp Mills ◽  
Recovery Cycle ◽  
Green Liquor ◽  
Green Liquor Dregs ◽  
Kraft Pulp Mills ◽  
Negative Effect

The accumulation of nonprocess elements in the recovery cycle is a common problem for kraft pulp mills trying to reduce their water closure or to utilize biofuels in their lime kiln. Nonprocess elements such as magne-sium (Mg), manganese (Mn), silicon (Si), aluminum (Al), and phosphorus (P) enter the recovery cycle via wood, make-up chemicals, lime rock, biofuels, and process water. The main purge point for these elements is green liquor dregs and lime mud. If not purged, these elements can cause operational problems for the mill. Phosphorus reacts with calcium oxide (CaO) in the lime during slaking; as a result, part of the lime is unavailable for slaking reactions. The first part of this project, through laboratory work, identified rhenanite (NaCa(PO4)) as the form of P in the lime cycle and showed the negative effect of P on the availability of the lime. The second part of this project involved field studies and performing a mass balance for P at a Canadian kraft pulp mill.

Integrated technology for conditioning low-mineralized cold ground water

2021 ◽  
pp. 4-9
Author(s):  
А.В. Селюков
Keyword(s):  
Drinking Water ◽  
Hydrogen Sulfide ◽  
Oil And Gas ◽  
Residual Concentration ◽  
Stabilization Treatment ◽  
Integrated Technology ◽  
Main Work ◽  
Treatment Facilities ◽  
Low Efficiency ◽  
Iron Manganese

Сообщается о новой комплексной технологии кондиционирования холодных маломинерализованных подземных вод. Технология разрабатывалась для целей хозяйственно-питьевого водоснабжения нефтегазоносных районов Тюменского Севера. При благополучном соотношении ресурсов пресной воды и фактического объема водопотребления в этом регионе России вопрос питьевого водоснабжения из подземных горизонтов остается острым из-за проблемного качества воды и низкой эффективности очистных сооружений. Технология предназначена для очистки от железа, марганца, сероводорода и обеспечивает стабилизационную обработку воды. Основные работы, включавшие лабораторные исследования и пилотные испытания, выполнены в период 2001–2020 годов. На основе разработанных технологических решений построены и успешно эксплуатируются водопроводные очистные сооружения в городах Ноябрьске (75 тыс. м3/сут, 2006 г.) и Новом Уренгое (65 тыс. м3/сут, 2007 г.). Дополнительные испытания технологии, проведенные в Ханты-Мансийске и Комсомольске-на-Амуре, подтвердили ее эффективность. Технология предусматривает применение в качестве основных реагентов пероксида водорода и перманганата калия для окисления примесей воды, а также щелочного реагента для корректировки рН и стабилизационной обработки. Для обеспечения требований стандарта ВОЗ по содержанию железа и марганца дополнительно может использоваться флокулянт. Обобщены данные по составу подземных вод, использованных для испытаний, и на их основе определена рекомендуемая область применения разработанной технологии. Приведена принципиальная технологическая схема кондиционирования холодных маломинерализованных подземных вод, учитывающая 15-летний опыт эксплуатации построенных станций, а также современные решения по дозированию и смешению реагентов. Указано, что данная технология обеспечивает также частичное снижение содержания кремния в очищенной воде (до 30%). Разработанная технология позволяет получать стабильную питьевую воду при нормативном остаточном содержании железа, марганца и сероводорода. An advanced integrated technology for conditioning low-mineralized cold groundwater is presented. The technology was developed for the purpose of supplying drinking water to the oil and gas-bearing regions of the Tyumen North. With a favorable ratio of fresh water resources and the actual volume of water consumption in this region of Russia, the issue of drinking water supply from underground aquifers remains acute due to the problematic water quality and low efficiency of the treatment facilities. The technology is intended for removing iron, manganese, hydrogen sulfide and providing for the stabilization treatment of water. The main work including laboratory studies and pilot tests was carried out in the period 2001–2020. On the basis of the developed process solutions, water treatment facilities have been built and successfully operated in the cities of Noyabrsk (75 thousand m3/day, 2006) and Novy Urengoy (65 thousand m3/day, 2007). Additional tests of the technology carried out in Khanty-Mansiisk and Komsomolsk-on-Amur confirmed its effectiveness. The technology involves using hydrogen peroxide and potassium permanganate as the basic chemicals for the oxidation of water pollutants, as well as using an alkaline chemical for pH adjustment and stabilization treatment. To meet the requirements of the WHO standard for the concentrations of iron and manganese, an additional flocculant can be used. The data on the composition of groundwater used for testing are summarized, and on their basis the recommended area of ​​application of the developed technology is determined. The basic process flow scheme of conditioning low-mineralized cold groundwater in view of 15 years of experience in operating the existing facilities, and of advanced solutions for dosing and mixing of chemicals, is presented. It is indicated that the technology also provides for a partial reduction in the silicon concentration in purified water (up to 30%). The developed technology ensures stable drinking water with a standard residual concentration of iron, manganese and hydrogen sulfide.

Effects of water hyacinth fiber size on sound absorption properties of advanced recycled palm oil-based polyurethane foam composite

2021 ◽  
Author(s):  
Nathapong Sukhawipat ◽  
Thanathach Yingshataporn-a-nan ◽  
Tanapat Minanandana ◽  
Kitchapat Puksuwan ◽  
Laksana Saengdee ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Palm Oil ◽  
Water Hyacinth ◽  
Sound Absorption ◽  
Absorption Properties ◽  
Foam Composite ◽  
Fiber Size ◽  
Water Hyacinth Fiber

DEVELOPMENT AND RESEARCH OF POLYURETHANE FOAM COMPOSITE MATERIALS WITH LYSOZYME

2021 ◽  
Vol 43 (3) ◽  
pp. 204-213
Author(s):  
T.V. VISLOHUZOVA ◽  
◽  
R.A. ROZHNOVA ◽  
N.A. GALATENKO ◽  
◽  
...  
Keyword(s):  
Glass Transition ◽  
Composite Materials ◽  
Polyurethane Foam ◽  
Single Phase ◽  
Mechanical Tests ◽  
Polyurethane Foams ◽  
Scanning Calorimetry ◽  
Heating Capacity ◽  
Foam Composite ◽  
Treatment Of Wounds

The article is devoted to the development and research of the structure and properties of polyurethane foam (PUF) composite materials with the antibacterial enzyme lysozyme. A series of PUF composite materials with lysozyme of various concentrations (1, 3 and 5 wt %) were obtained. It is established that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds by the method of IR spectroscopy. According to the results of physical-mechanical tests the adhesive strength of polyurethane foam compositions with lysozyme is in the range of 0,82–1,16 MPa. The introduction of lysozyme into the composition of polyurethane foams and an increase its amount causes a decrease in the values of adhesion strength by 18,1–29,3 %. According to differential scanning calorimetry the tested systems are single-phase with a glass transition temperature in the range of -49,20 to -49,86 °C. The introduction of lysozyme into the composition causes an increase heating capacity at the glass transition, which can be associated with a decrease of the packing density of macrochains resulting in an increase in free volume, which leads to an increase molecular mobility. According to the results of the analysis of transmission optical microscopy micrographs the studied PUF have a microporous structure, which depends on the content of filler in their composition. It was found that the presence of lysozyme in the composition of composite materials leads to a decrease in the percentage of porosity, an increase in the number of pores with a diameter of up to 300 μm, which is 76,7–82,4 % (while for PUF – 69,5 %) and the absence of pores with a diameter larger than 990 μm. Thermogravimetric characteristics indicate the heat resistance of the synthesized PUF to a temperature of 179,95 °C, which allows dry sterilization of samples without changing their characteristics. PUF composite materials with lysozyme are promising materials that can be used in medical practice as polymer compositions for the treatment of wounds and burns.

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