Distribution Characteristics of Per- and Polyfluoroalkyl Substances (PFASs) in Human Urines of Acrylic Fiber Plant and Chemical Plant

Per- and polyfluoroalkyl substances (PFASs) are persistent and bio-accumulative substances that have many adverse effects on human bodies. This study investigated the PFASs distribution characteristics in urine samples of workers from an acrylic fiber plant and a chemical plant. It was found that perfluorobutanoic acid (PFBA) was the predominant PFASs both in urine samples from the chemical plant (detection frequency: 86.52%; median value: 39.01 ng/mL) and the acrylic fiber plant (detection frequency: 88.16%; median value: 44.36 ng/mL). Meanwhile, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected with very low frequencies and low concentrations. Furthermore, the results showed that PFASs levels in urine samples of workers from different units of the plants were quite different. PFASs concentrations of urine samples in males were higher than those in females, especially for PFBA, PFHxA, and PFDoA. The age had limited effects on the PFASs distribution in urine samples in this study, as short-chain PFASs were the dominant compounds. The correlations between PFASs concentrations in urine and gender/ages of workers were finally analyzed by Person correlation. The overall results may indicate that short-chain PFASs (such as: PFBA and PFBS) were becoming dominant for human exposure, especially occupational workers.

Grafting of Acrylic Membrane Prepared from Fibers Waste for Dyes Removal: Methylene Blue and Congo Red

Dyes are a type of pollutant that have been discharged into water streams by various industries and had harmful effects on the environment and human health. Therefore, present work was directed to recycle acrylic fibers waste to be used as an adsorbent to exclude dyes such as methylene blue (MB) and Congo red (CR) from dyes-polluted wastewater. Acrylic fibers waste was converted into membrane followed by chemical grafting with p-phenylenediamine monomer to form functional modified membranes. Afterwards, some characterization analyses; Fourier transform-infrared, scanning electron microscope, swelling behavior, and porosity properties were performed for the acrylic fiber grafted membrane (AFGM). For obtaining the best conditions that permit the highest adsorption capacity of the AFGM, some preliminary experiments followed by general full factorial design experiments were displayed. Langmuir, Freundlich isotherms and kinetic studies evaluations were applied. Results revealed that, the adsorption capacities of the AFGM were 61% for Methylene blue and 86% for Congo red that stated the high affinity of the AFGM to the anionic dyes. The reusability of the AFGM membranes in different cycles for 3Rs processes “Removal, Recovery, and Re-use” indicated the efficiency of the AFGM to be used in wastewater treatment.

Removal of Methylene Blue and Congo Red Using Adsorptive Membrane Impregnated with Dried Ulva fasciata and Sargassum dentifolium

Biosorption is a bioremediation approach for the removal of harmful dyes from industrial effluents using biological materials. This study investigated Methylene blue (M. blue) and Congo red (C. red) biosorption from model aqueous solutions by two marine macro-algae, Ulva fasciata and Sargassum dentifolium, incorporated within acrylic fiber waste to form composite membranes, Acrylic fiber-U. fasciata (AF-U) and Acrylic fiber-S. dentifolium (AF-S), respectively. The adsorption process was designed to more easily achieve the 3R process, i.e., removal, recovery, and reuse. The process of optimization was implemented through one factor at a time (OFAT) experiments, followed by a factorial design experiment to achieve the highest dye removal efficiency. Furthermore, isotherm and kinetics studies were undertaken to determine the reaction nature. FT-IR and SEM analyses were performed to investigate the properties of the membrane. The AF-U membrane showed a significant dye removal efficiency, of 88.9% for 100 ppm M. blue conc. and 79.6% for 50 ppm C. red conc. after 240 min sorption time. AF-S recorded a sorption capacity of 82.1% for 100 ppm M. blue conc. after 30 min sorption time and 85% for 100 ppm C. red conc. after 240 min contact time. The membranes were successfully applied in the 3Rs process, in which it was found that the membranes could be used for five cycles of the removal process with stable efficiency.

Design of an acrylic wastewater treatment method based on deep oxidation technology

Acrylic fiber is one of the earliest developed chemical fiber species in China. Acrylic products are fluffy, warm, soft to the touch, and have good weather resistance and anti-mildew and anti-moth properties. Acrylic fiber has a wide range of applicability, but the wastewater generated during its production is a major problem facing the world. The complex composition and high toxicity of acrylic wastewater pollutants, the presence of many oligomers and other difficult to biodegrade, as well as the presence of sulfate, sulfite and other bioinhibitory components, make the biochemical properties of acrylic wastewater very low, making it very difficult to treat. In this paper, we propose an acrylic wastewater treatment method based on deep oxidation technology to solve this problem, which can effectively carry out wastewater treatment and make it meet the national discharge standards.

A PILOT STUDY OF MECHANOMYOGRAPHY-BASED HAND MOVEMENTS RECOGNITION EMPHASIZING ON THE INFLUENCE OF FABRICS BETWEEN SENSOR AND SKIN

Multi-channel mechanomyography (MMG) signals were acquired from the forearm when the subjects were performing eight classes of hand movements related to rehabilitation training. Ten time domain (TD) features and wavelet packet node energy (WPNE) features were extracted from each channel of MMG, and the hand movements were classified by support vector machine (SVM), extreme learning machine (ELM), linear discriminant analysis (LDA) and [Formula: see text]-nearest neighborhood (KNN) and the classifying results of three methods of collecting MMG (sensors directly on skin, sensors on cotton fabric and sensors on acrylic fiber) were compared. When all TD features were selected and SVM was adopted as the classifier, the total recognition rates of hand movements were 94.0%, 93.9% and 93.6%, respectively, of three collection methods. Using ELM can obtain similar results as SVM, with the recognition rates of 94.3%, 94.3% and 94.1%, respectively, better than using LDA (88.5%, 88.6% and 88.0%) or KNN (88.9%, 89.4% and 89.0%). For each algorithm, using TD features can acquire the highest recognition rates. Once the feature set and the classifier were selected, the total recognition rates were almost equally among three collection methods (especially for some feature sets, the differences are smaller than 1%). The results confirmed that satisfactory effects could be acquired even when the MMG was collected from sensors on fabrics with specific material, thus indicating that MMG has a unique potential value for developing wearable devices.

Strength Properties of Concrete with M-Sand as Fine Aggregate Incorporating with Acrylic Fiber

The river sand is the natural sort of fine aggregate material which is employed within the concrete and mortar. It’s usually obtained from the river bed and mining has disastrous environment consequences. Rather than the river sand we are using M-sand as fine aggregate within the concrete. The event of acrylic concrete marks a crucial milestone in improving the merchandise quality and efficiency of the concrete. Usage of acrylic within the concrete will increase the strength and durability of the concrete. It enhances the performance of the concrete and increase energy absorption compared with plain concrete. Within the present work we are getting to analysis the strength properties of fiber reinforced M-sand concrete like compressive strength, flexural strength, split tensile strength, and bond strength.