Solid Contaminants Research Articles

Universality of mesoporous coal gasification slag for reinforcement and deodorization in four common polymers

Mesoporous adsorbents and polymer deodorants are difficult to implement on a large scale because of their complicated preparation methods. Herein, a mesoporous adsorbent (CGSA) with a specific surface area of 564 m2 g−1 and a pore volume of 0.807 cm3 g−1 was prepared from solid waste coal gasification slag using a simple acid leaching process. The adsorption thermodynamics and adsorption kinetics results verified that the adsorption mechanism of propane on CGSA was mainly physisorption. Then the universality of CGSA in different polymers was investigated by introducing CGSA and its commercialized counterparts (CaCO3, and zeolite) into four common polymers. When the filler content was 30 wt%, the average reinforcement effect of CGSA on the tensile, flexural, and impact strengths of the four polymers was 46.68%, 83.62%, and 211.90% higher than that of CaCO3, respectively. Gas chromatography results also showed that CGSA significantly decreased total volatile organic compound emissions from the composites, and its optimal deodorization performance reached 69.58%, 81.33%, and 91.09% for different polymers, respectively, far exceeding that of zeolite. Therefore, this study showed that low-cost, high-performance, and multifunctional mesoporous polymer fillers with excellent universality can be manufactured from solid contaminants.

Synergistic reinforced superhydrophobic paper with green, durability, and antifouling function

Among the various paper-based technologies that exist today, superhydrophobic paper has attracted considerable attention owing to its incredible repellency and antifouling behavior against both water and oil based liquids. However, its practical applications are limited due to its poor durability and the use of fluorochemicals during the preparation process, which are harmful to both humans and environment. Herein, we developed a synergistic reinforced superhydrophobic paper (SRSP) using green-based waxes as an adhesive for grafting hydrophobic nanoparticles, thereby reducing safety and environmental concerns as well as improving durability. The resulting paper exhibits strong durability to sandpaper abrasion, finger-wipe, knife-scratch, tape-peeling, bending, folding, and sustained exposure to corrosion media. Additionally, not only does the SRSP surface directly prevented adhesion of water-based contaminants (e.g., muddy water, coca cola, or milk), but also indirectly repelled solid contaminants (e.g., hydrophilic or hydrophobic particles) upon washing with water, thereby demonstrating highly efficient antifouling ability. Intriguingly, the silicone oil-infused SRSP surface could easily repelled low-surface-energy droplets such as hot water, oil, or fouled oil. It is envisioned that the SRSP developed in this study can find potential applications in microfluidics, recyclable packaging materials, paper-based flexible electronics, and new sophisticated membrane-type materials.

Lubricity performance of non-ionic surfactants in high-solid drilling fluids: A perspective from quantum chemical calculations and filtration properties

Quantum chemical calculations and mud filtration analysis were used to assess the performance of three types of non-ionic surfactants as lubricating additives in synthetic-based drilling mud (SBM) contaminated with drilled solids. High solid contaminants can have an impact on mud lubricity and can contribute to thicker a mud cake. Experimental results showed that all non-ionic surfactants reduced the coefficient of friction (COF) of mud by approximately 27%. Quantum chemical parameters and molecular electrostatic potential (MEP) provided further insights into the interaction between non-ionic surfactants and metal surfaces. MEP indicated the most lubricious non-ionic surfactant based on polar sites and the electron density distribution. Dipole moment represented the dipole interaction between the polar head of non-ionic surfactant with the metal surface of the drilling tools. Filtration tests showed that despite solid contamination, non-ionic surfactants decreased the fluid loss by 20% due to better solid dispersion in the mud. The mud cake formed was thinner, which may reduce the differential pressure sticking tendency. XRD and SEM observations of the mud cake confirmed the presence of non-ionic surfactants layer adsorbed to the solid particles of SBM. The adsorbed non-ionic surfactants could contribute to a higher lubricity of mud cake, thus minimizing friction during drilling.

Nanofunctionalized composite-crosslinked epoxy resin for eco-friendly and robust superhydrophobic coating against contaminants

Superhydrophobic coatings are widely used in daily life and industrial applications due to their low adhesion and efficient antifouling properties. However, their eco-friendliness and robustness in high-demand environments are still inadequate for real-world applications. In this work, we report a facile method for preparing an eco-friendly and robust superhydrophobic coating (ERSC) by using a hydrophobic nano-TiO2/polydimethylsiloxane composite cross-linked epoxy resin. The micro/nano rough structure of the ERSC surface shows good water-repellent behavior, with a water contact angle of 168.7° and a sliding angle of 2.8°. This coating can withstand repeated rubbing with a finger, repetitive scratching with a knife, 60 peel-off cycles with tape, and 88 abrasion cycles with sandpaper. None of these physical abrasion methods affect the superhydrophobicity of the coating. The coating is also highly stable to acid, base, and salt treatments. Moreover, the ERSC surface directly repels the adhesion of water-based mixed liquids (such as muddy water, Coca-Cola, pig blood, and milk) and also indirectly removes solid contaminants via water droplets, exhibiting a highly efficient antifouling ability. This simple, scalable, and effective antifouling coating system shows great promise for use in various harsh environments.

Solid Waste And Its Interference On The Water Quality Of The Igarapé¹ do Quarenta Educandos Basin - Manaus/Am

The “Igarapé do Quarenta”, a stream in Educandos basin, is categorized today as the "worst" and most polluted of the city Manaus, Amazonas, due to the accumulation of solid waste and contamination by heavy metals along its course. The main objective of this research was to verify the influence of solid waste in critical points of the Igarapé do Quarenta, on the water quality of the stream. The area of solid waste accumulation ("garbage") and the water quality in the stream and around and under the bridges of the Igarapé do Quarenta, between the springs (Armando Mendes and Zumbi neighborhoods) and the mouth (Educandos), in the Amazon "summer" and "winter"," were quantified. Water quality was evaluated at each sampling site. The macroscopic analysis demonstrated its importance for the feasibility diagnosis, finding that two of the three springs found are degraded and disturbed. The pH and electrical conductivity values in the sample sites visited, in the upper and middle, of the Igarapé do Quarenta, were very high values in relation to the maximum values recorded in a natural environment in other water streams of Manaus.

Rapid and Robust Surface Treatment for Simultaneous Solid and Liquid Repellency.

A wide range of liquid and solid contaminants can adhere to everyday functional surfaces and dramatically alter their performance. Numerous surface modification strategies have been developed that can reduce the fouling of some solids or repel certain liquids but are generally limited to specific contaminants or class of foulants. This is due to the typically distinct mechanisms that are employed to repel liquids vs solids. Here, we demonstrate a rapid and facile surface modification technique that yields a thin film of linear chain siloxane molecules covalently tethered to a surface. We investigate and characterize the liquid-like morphology of these surfaces in detail as the key contributing factor to their anti-fouling performance. This surface treatment is extremely durable and readily repels a broad range of liquids with varying surface tensions and polarities, including water, oils, organic solvents, and even fluorinated solvents. Additionally, the flexible, liquid-like nature of these surfaces enables interfacial slippage, which dramatically reduces adhesion to various types of solids, including ice, wax, calcined gypsum, and cyanoacrylate adhesives, and also minimizes the nucleation of inorganic scale. The developed surfaces are durable and simple to fabricate, and they minimize fouling by both liquids and solids simultaneously.

Diffusion study of municipal solid waste contaminants in compacted lateritic soil treated with bacillus coagulans

Diffusion study of municipal solid waste contaminants in compacted lateritic soil treated with bacillus coagulans

Treatment Oilfield Produced Water using Coagulation/Flocculation Process (case study: Alahdab Oilfield)

Produced water is a large amount of water wasted throughout the crude oil extraction process, it's a mixture of the well's deposition water and the water of oil wells extraction water. Produced water contains oil, suspended solids and dissolves solid. This study tested produced water collected from Alahdab oilfield/middle oil company for oil content and suspended solid contamination using chemical precipitation and coagulation-flocculation for reinjection and environmental considerations. Coagulation/flocculation is a common method used as primary purification to oily wastewater treatment due to its usability, performance, and low cost. Coagulant experimental was completed by A jar test device, additives of ferric sulfate and aluminium sulfate were in a range about (10 ـ 40) ppm, as well as polyelectrolyte- (polyacrylamide) as an additional flocculent in the range (1.5-3) ppm. The results show that ferric sulfate was more efficient at removing turbidity than aluminium sulfate under the same conditions, with the best removal of turbidity at dose concentration 30 ppm of Ferric sulfate and a flocculent dose concentration of 2.5 ppm of polyacrylamide, also with oil content decreasing from 396.71 ppm to 53.56 ppm.

A novel method for the evaluation of the contamination dispersing ability of lubricants (CONTA-DISP)

Water and solid particulate contamination are the two most common contaminants of lubricated systems and may be highly problematic for these systems. To reduce downtime and prevent failure, lubricant formulations contain detergent and dispersant additives that play an important role in terms of contamination tolerance. In lack of a practical procedure for the determination of the relevant properties, a novel method for the evaluation of the dispersing ability of lubricating oils is introduced. Following and combining established lubricant analysis methods, a procedure with optimum parameters was found. An assessment of the method using fresh and artificially altered lubricating oils allowed a differentiation concerning their dispersing ability.

COAGULATION/FLOCCULATION PROCESS FOR OILY WASTEWATER TREATMENT

Oily wastewater is one of the most dangerous forms of environmental pollution, it is large amount of water that is wasted petrochemical industries, oily waste water contains oil, suspended solids, and dissolved solids. The study investigates the treatment of real oily waste water that was collected from al-Dura refinery (Iraq) /Middle Refineries Company from oil and suspended solid contamination for re-use and environmental consideration using coagulation and flocculation processes. Coagulation /flocculation is a common method used as primary purification processes to oily wastewater treatment due to its usability, performance, and low cost. Coagulation experiments were completed by the Jar Test device. The additives coagulants of ferric sulfate and aluminum sulfate were in a range about (10- 25) ppm, as well as polyelectrolyte- (polyacrylamide) as an additional flocculent in the range (1-4) ppm. The results show that ferric sulfate was more efficient in removing turbidity than Aluminum sulfate under the same conditions, with the best removal of turbidity at dose concentration 20 ppm of Ferric sulfate and a flocculent dose concentration of 3 ppm of polyacrylamide, also with oil content decreasing from 288 ppm to 14.4 ppm and the turbidity removal from 187 to 8.5 NTU.

Confocal spectral microscopy, a non-destructive approach to follow contamination and biofilm formation of mCherry Staphylococcus aureus on solid surfaces

Methods to test the safety of wood material for hygienically sensitive places are indirect, destructive and limited to incomplete microbial recovery via swabbing, brushing and elution-based techniques. Therefore, we chose mCherry Staphylococcus aureus as a model bacterium for solid and porous surface contamination. Confocal spectral laser microscope (CSLM) was employed to characterize and use the autofluorescence of Sessile oak (Quercus petraea), Douglas fir (Pseudotsuga menziesii) and poplar (Populus euramericana alba L.) wood discs cut into transversal (RT) and tangential (LT) planes. The red fluorescent area occupied by bacteria was differentiated from that of wood, which represented the bacterial quantification, survival and bio-distribution on surfaces from one hour to one week after inoculation. More bacteria were present near the surface on LT face wood as compared to RT and they persisted throughout the study period. Furthermore, this innovative methodology identified that S. aureus formed a dense biofilm on melamine but not on oak wood in similar inoculation and growth conditions. Conclusively, the endogenous fluorescence of materials and the model bacterium permitted direct quantification of surface contamination by using CSLM and it is a promising tool for hygienic safety evaluation.

Searching for the mechanisms involved in Antimonium crudum action on macrophage – Leishmania interaction in vitro

Searching for the mechanisms involved in Antimonium crudum action on macrophage – Leishmania interaction in vitro

Impact assessment of solid waste contamination on soil and perched aquifers: a case study of Nsukka and Environs

Impact assessment of solid waste contamination on soil and perched aquifers: a case study of Nsukka and Environs

A strong basis for friction as the origin of size effect in cutting of metals

A study has been made of the phenomenon of size effect in cutting of metals, namely increase in the specific energy with decreasing chip thickness, in the absence of edge radius effects and under ideal two-dimensional cutting conditions. Freshly cleaved glass knives are used to achieve cutting edges that are sharp on an atomic level. An instrumented ultramicrotomy apparatus is described in which it is possible to achieve two-dimensional orthogonal cutting at small cutting depths in the range of 100 nm to 3 micrometers. Based on observations with three metals (aluminum, copper and zinc), new evidence is presented in support of tool-chip friction as the primary source of the size effect. It is shown that size effect arises as a result of non-proportional decrease of the friction component with the underlying length scale. Calculation of the shear flow stress during cutting showed that this was approximately constant for a given material, independent of the depth of cut. Size dependence of tool-chip friction and contact size is interpreted in terms of the junction growth and adhesion models. Cutting experiments are also carried out with tools covered with solid and liquid contaminants. These results show that contaminant films effectively diminish adhesion and lead to a drastic reduction in the size effect, suggesting practical benefits for industrial manufacturing processes.

Evaluation of pore size distribution and permeability reduction behavior in pervious concrete

Pervious concrete is an environmentally friendly material that improves water permeability, skid resistance, and sound absorption characteristics. However, due to a large number of pores and the absorption capacity, pervious concrete faces the problem of clogging caused by dust particles and solid contaminants entering the internal pores. In this study, both pore size distributions (PSD) of the pervious concrete and permeability reduction behavior are studied by laboratory tests. The extent of permeability reduction is addressed by designing the penetration test for 21 groups of pervious concrete mixes with varying aggregate gradations and specimen thickness. The PSD is determined by the two-dimensional (2D) sliced image scanned by the Computed Tomography (CT). An approach to represent the characteristic pore size of pervious concrete is proposed and verified. Results showed that: the effect of thickness on permeability is negligible while on clogging behavior is significant. The ratio between the clogging sand sizes and the characteristic pore size is an important parameter that affects the clogging behavior and can be used to predict the anti-clogging performance.

Application of 2H and 18O Isotopes for Tracing Municipal Solid Waste Landfill Contamination of Groundwater: Two Italian Case Histories

Groundwater contamination due to municipal solid waste landfills leachate is a serious environmental threat. During recent years, the use of stable isotopes as environmental tracers to identify groundwater contamination phenomena has found application to environmental engineering. Deuterium (2H) and oxygen (18O) isotopes have successfully used to identify groundwater contamination phenomena if submitted to interactions with municipal solid waste landfills leachate, with a significant organic amount. The paper shows two case studies, in central and southern Italy, where potential contamination phenomenon of groundwater under municipal solid waste landfills occurred. In both cases, isotope compositions referred to 2H and 18O highlight a δ2H enrichment for some groundwater samples taken in wells, located near leachate storage wells. The δ2H enrichment is probably caused by methanogenesis phenomena, during which the bacteria use preferentially the hydrogen “lighter” isotope (1H), and the remaining enriched the “heavier” isotope (2H). The study of the isotope composition variation, combined with the spatial trend of some analytes (Fe, Mn, Ni) concentrations, allowed to identify interaction phenomena between the municipal solid waste landfills leachate and groundwater in both case histories. Therefore, these results confirm the effectiveness of 2H isotopes application as environmental tracer of groundwater contamination phenomena due to mixing with municipal solid waste landfills leachate.

Multivariate and Statistical Assessment of Solid Wastes Contamination from Waste Dump Sites on Soil and Perched Aquifers in a Rapidly Developing City

The effect of waste dumps on groundwater quality on perched aquifers in Nsukka and environs was investigated by applying multivariate statistical analyses using Statgraphics Centurion XVII, ArcGIS 10.2.2 and Surfer 10 software on hydrochemical parameters from soil (0 cm and 15 cm depth) and groundwater media. Factor analysis, correlation, principal component analysis and cluster analysis reflect biodegradable domestic solid contaminants, automobile contaminants and construction or building contaminants. The significant or positive correlation between parameters was taken at value equal to or greater than 0.5. Chromium showed positive or significant correlation with copper (0.98), cadmium (0.91), nitrate (0.87) and potassium (0.82) indicating that they are from the same source. Zinc showed positive correlation with manganese (0.89) and pH (0.70) showing similar source. The first cluster showed chromium, copper, cadmium, nitrate, potassium and iron which could be attributed to market and domestic biodegradable wastes. The second cluster showed parameter association for lead, EC and mercury which could be attributed to automobile wastes. The third cluster showed zinc, manganese and pH which could be attributed to construction and building wastes. This showed that the third cluster is the major contributor to the soil pH. Based on the Normality Tests (Shapiro-Wilk significance test) to determine P-Value of the analyzed parameters, in the study area; there was no significant spatial variation (@p > 0.05) in the values of parameters such as chromium, iron, pH in the impact zone and the control area. Conversely, the other parameters were statistically significant. For the groundwater analysis, the dendrogram extracted three clusters highlighting the parameter associations according to their possible sources of occurrence. The first cluster showed potassium, sodium, DOI, manganese, and bicarbonate, which could be attributed to construction and building wastes. The second cluster showed parameter association for sulfate, nitrate, calcium and chloride; which could be domestic biodegradable solid waste. The third cluster showed pH, EC, TDS, Cu+, Pb2+, Hg+, Fe2+, Cr2+ and Cd2+ which could be attributed to automobile wastes.

Effects of process parameters and solid particle contaminants on the seal strength of low‐density polyethylene‐based flexible food packaging films

Seal strength is a key indicator of heat seal quality in flexible packaging. In this study, the effect of seal bar geometry, material composition and food particle contamination on the seal strength of widely used low‐density polyethylene (LDPE)‐based compound films was examined. Additionally, the maximum level of allowable solid food particle contamination was determined for ground coffee particles and powdered sugar. The results showed that adding metallocene LLDPE compound decreases seal initiation temperature (SIT) and increases overall seal strength. Also, changing seal bar geometry from flat to grooved bar with 0.56‐mm pitch height enhanced the seal strength significantly. Moreover, pressure mapping and T‐peel tests at SIT pointed out that grooved bars alter the pressure distribution and first contact points through the seal surface. Contamination of ground coffee particles at the seal interface as occurs during the packaging process when a powdery product is dropped in a package did not affect the seal strength up to 10 g/m2 at 0.5‐s dwell time. Above that amount, seal strength dropped dramatically. In the case of powdered sugar, threshold contaminant level was 2 g/m2 at 0.5‐s dwell time. Consequently, it has been revealed that knowing the type and the amount of contaminant during the food packaging process is important to maintain the seal quality, to find optimum process values between dosing and filling and to choose the right seal bar design because they can have a critical influence, especially at seal initiation phase.

Study regarding the Determination of the Flammability Characteristics of the Residue Collected from Natural Gas Transport

In the natural gas pipelines, the so-called black powder is formed. It can take many forms, including wet tarred substance or fine dry powder. Black powder occurs in both newer and older natural gas pipelines. This can disrupt the distribution of natural gas either by interrupting distribution to the customer or by reducing the quality of products delivered to customers. This residue, black powder can damage operations that take place in the transport pipelines, such as reduced inspection accuracy, erosion of the control valve and reduced flow. In addition, this powder also presents a health hazard due to the fact that it may contain pyrophoric sulphides, which require specific handling and storage procedures. Black powder is a solid contaminant found in natural gas distribution systems around the world. Drilling mud, dust, construction dirt, sand, iron oxide, iron carbonate, iron sulfides, welding slag, salt crystals, valve grease, corrosion inhibitors, and other organic materials can contribute to the formation and the presence of this residue, also called black powder. In this paper were analyzed the flammability properties of black powder collected from natural gas transmission pipelines of an operator in Romania.

An Offshore Cleaning Vessel Based On Integrated Treatment Of Solid-liquid Pollutant

Aiming at the diversity pollutant species in offshore waters, people can’t collect the liquid contaminants and solid contaminants pollutants at the same time. So we designed a new type of offshore cleaning vessel based on integrated treatment of solid-liquid pollutant for practical. We proposed the general design of the program, completed the structural design and functional development. And we implement the integrated efficient monitoring and clean-up of the solid pollutants mainly composed of floating garbage and the liquid pollutant dominated by oil, by using the integration cleaning of solid-liquid pollutants technology and the intelligent recognition pollutants technology. We verified the control and function of the cleaning vessel through the production of ship prototype and the ship experiment.