A combination of waste biomass activated carbon and nylon nanofiber for removal of triclosan from aqueous solutions

Triclosan (TCS) is one of the biocide used as antibacterial and antifungal agent to kill and hinder the growth of bacteria and also it is used in many personal care and health care products. However, TCS can cause health and environmental problems such as environmental pollutions, acute toxicity, etc. The aim of this study is to investigate the removal of TCS from aqueous solution by combining the coconut pulp waste (Cocos nuciefera) activated carbon (AC) with nylon 6,6 membrane. To this end, first, the effects of physico-chemical characteristics of the membrane were studied. The nylon 6,6 membrane (14 wt.%] was prepared using electrospinning machine with injection rate at 0.4 mL/h, tip-to-collector distance at 15 cm, rotation speed at 1000 rpm, and applied voltage at 26 kV. The parameters studied for the membrane during the adsorption test were contact time, adsorbent dosage, agitation speed, initial TCS concentration, pH, and temperature of the TCS solution. The filtration test was done using flat sheet membrane test machine at pressure 1.0 bar. The characteristics of the membrane were analysed using the FESEM and FTIR tests. Based on the obtained results, the nylon 6,6 membrane can remove 90.2% of TCS within 5 minutes; the removal rate increased to 100% in less than 5 minutes after the membrane was combined with AC. This study proved that the combination of AC and nylon 6,6 membrane is able to maximize the TCS removal from water

Novel weed-extracted silver nanoparticles and their antibacterial appraisal against a rare bacterium from river and sewage treatment plan

This is the first investigation to demonstrate the use of biochemical contents present within Cyperus rotundus, Eleusin indica, Euphorbia hirta, Melastoma malabathricum, Clidemia hirta and Pachyrhizus erosus extracts for the reduction of silver ion to silver nanoparticles (AgNPs) form. In addition, the antibacterial capability of the synthesized AgNPs and plant extracts alone against a rare bacterium, Chromobacterium haemolyticum (C. haemolyticum), was examined. Moreover, ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and inductively coupled plasma atomic emission spectroscopy (ICPOES) of the synthesized AgNPs were characterized. The smallest AgNPs can be produced when Cyperus rotundus extracts were utilized. In addition, this study has found that the synthesis efficiencies using all plant extracts are in the range of 72% to 91% with the highest percentage achieved when Eleusin indica extract was employed. All synthesized AgNPs have antibacterial capability against all examined bacteria depending on their size and bacteria types. Interestingly, Melastoma malabathricum and Clidemia hirta extracts have demonstrated an antibacterial ability against C. haemolyticum

Silver nanoparticles in the water environment in Malaysia: inspection, characterization, removal, modeling, and future perspective

The current status of silver nanoparticles (AgNPs) in the water environment in Malaysia was examined and reported. For inspection, two rivers and two sewage treatment plants (STPs) were selected. Two activated carbons derived from oil palm (ACfOPS) and coconut (ACfCS) shells were proposed as the adsorbent to remove AgNPs. It was found that the concentrations of AgNPs in the rivers and STPs are in the ranges of 0.13 to 10.16 mg L−1 and 0.13 to 20.02 mg L−1, respectively, with the highest concentration measured in July. ACfOPS and ACfCS removed up to 99.6 and 99.9% of AgNPs, respectively, from the water. The interaction mechanism between AgNPs and the activated carbon surface employed in this work was mainly the electrostatic force interaction via binding Ag+ with O− presented in the activated carbon to form AgO. Fifteen kinetic models were compared statistically to describe the removal of AgNPs. It was found that the experimental adsorption data can be best described using the mixed 1,2-order model. Therefore, this model has the potential to be a candidate for a general model to describe AgNPs adsorption using numerous materials, its validation of which has been confirmed with other material data from previous works

Bisphenol a removal by adsorption using waste biomass: isotherm and kinetic studies

BPA is categorized as a new emerging pollutant that mimics the structure and function of hormone estrogen for humans and animals. The removal of BPA had been concerned because human exposure toward BPA is widespread, and it is harmful to humans and the ecosystem. The aim of the study was to remove BPA by adsorption technique and understand the application of agricultural waste material as potential adsorbent. The increasing of the surface area of post-adsorption from 4.80 m2/g to 5.83 m2/g indicated that the sulphuric acid treatment responsible for the growth in the porosity of the banana bunches, increase the number of available binding sites and its ion-adsorption capacity. The highest removal of BPA by the banana bunch and coconut bunch was obtained in the following condition: the temperature at 25°, pH 3, dosage at 100 mg, and agitation at 150rpm. The adsorption process was well described with the Langmuir isotherm, while the best correlation with the kinetic study of BPA adsorption was the pseudo-second-order model. The negative values of ΔH° suggested that the adsorption of BPA onto banana bunch (-13.748 J mol−1) and coconut bunch (-5693.67 J mol−1) is exothermic in nature

Acceleration of anthraquinone-type dye removal by white-rot fungus under optimized environmental conditions

The decolorization of the recalcitrant dye Remazol Brilliant Blue R (RBBR) by the culture filtrate of Polyporus sp. S133 and the effect of various environmental factors were investigated. Both biodegradation and biosorption were playing an important role in bioremoval mechanisms. The highest biosorption of RBBR in Polyporussp. S133 was shown by all carbon sources such as sucrose, glucose, fructose, and starch. No biosorption was shown by the addition of aromatic compounds and metal ions; 97.1 % RBBR decolorization was achieved in 120-rpm culture for 96 h, as compared to 49.5 % decolorization in stationary culture. Increasing the shaking rotation of the culture to more than 120 rpm was proven to give a negative effect on decolorization. The highest production of laccase was shown at pH 4 and constantly decreases when the pH level increases. The addition of glucose, ammonium tartrate, Cu2+, and protocatechuic acid was the suitable environmental condition for RBBR decolorization. There was a positive relationship between all environmental conditions and laccase production in the decolorization of RBBR

Identification of metabolites from benzo[a]pyreme oxidation by ligninolytic enzymes of polyporus sp. S133

The biodegradation of benzo[. a]pyrene (B. aP) by using Polyporus sp. S133, a white-rot fungus isolated from oil-contaminated soil was investigated. Approximately 73% of the initial concentration of B. aP was degraded within 30 d of incubation. The isolation and characterization of 3 metabolites by thin layer chromatography, column chromatography, and UV-vis spectrophotometry in combination with gas chromatography-mass spectrometry, indicated that Polyporus sp. S133 transformed B. aP to B. aP-1,6-quinone. This quinone was further degraded in 2 ways. First, B. aP-1,6-quinone was decarboxylated and oxidized to form coumarin, which was then hydroxylated to hydroxycoumarin, and finally to hydroxyphenyl acetic acid by addition of an epoxide group. Second, Polyporus sp. S133 converted B. aP-1,6-quinone into a major product, 1-hydroxy-2-naphthoic acid. During degradation, free extracellular laccase was detected with reduced activity of lignin peroxidase, manganese-dependent peroxidase and 2,3-dioxygenase, suggesting that laccase and 1,2-dioxygenase might play an important role in the transformation of PAHs compounds