Nationwide Occurrence and Unexpected Severe Pollution of Fluorescent Brighteners in the Sludge of China: An Emerging Anthropogenic Marker.

Fluorescent brighteners (FBs) are a group of mass-produced dyestuff chemicals that have been extensively used for decades. However, knowledge of their occurrence in municipal wastewater treatment plants on a large geographical scale remains unknown. Herein, we implemented the first nationwide survey for wastewater-derived FBs in sludge across major cities in China. All 25 target FBs were detected in the nationwide sludge. Ionic FBs exhibited much higher concentrations than nonionic FBs. The total sludge concentrations of 25 FBs (∑25FBs) ranged from 7300 to 1,520,000 ng/g, with a median of 35,300 ng/g. A clear geographical distribution of significantly higher concentrations of FBs was found in East and Central China than in West China (p < 0.05). The sludge concentrations of ∑25FBs were correlated well with the gross domestic product (GDP) and population size at the provincial level in China (p < 0.05), demonstrating the significance of anthropogenic impacts on FB levels in urban sludge. The nationwide annual emission of total FBs into sludge in China is estimated to be 835 tons/year, of which 134 tons/year is directly released into sludge-applied soils. Our work highlights another new class of chemicals that significantly contribute to the chemical mixtures in urban sludge and thus require immediate attention.

Preparation of a Chitosan/Coal Gasification Slag Composite Membrane and Its Adsorption and Removal of Cr (VI) and RhB in Water.

At present, there are many kinds of pollutants, including dyes and heavy metal ions, in wastewater. It is very important to develop adsorbents that can simultaneously remove heavy metal ions and dyes. In this study, a renewable composite membrane material was synthesized using chitosan and treated coal gasification slag. The Cr (VI) maximum adsorption capacity of the composite membrane was 50.0 mg/L, which was 4.3~8.8% higher than that of the chitosan membrane. For the adsorption of RhB, the removal rate of the chitosan membrane was only approximately 5.0%, but this value could be improved to 95.3% by introducing coal gasification slag. The specific surface area of the chitosan membrane could also be increased 16.2 times by the introduction of coal gasification slag. This is because coal gasification slag could open the nanopores of the chitosan membrane (from 80 µm to 110 µm). Based on the adsorption kinetics and adsorption mechanism analysis, it was found that the adsorption of Cr (VI) occurred mainly through the formation of coordination bonds with the amino groups on the molecular chains of chitosan. Meanwhile, RhB adsorption occurred through the formation of hydrogen bonds with the surface of coal gasification slag. Additionally, coal gasification slag can improve the mechanical properties of the chitosan membrane by 2.2 times, which may facilitate the practical application of the composite membrane. This study provides new insight into the adsorbent design and the resource utilization of coal gasification slag.

Monitoring the fate and behavior of TiO2 nanoparticles: Simulated in a WWTP with industrial dye-stuff effluent according to OECD 303A.

The use of nanoparticles (NPs) in several consumer products has led to them finding their way into wastewater treatment plants (WWTPs). Some of these NPs have photocatalytic properties, thus providing a possible solution to textile industries to photodegrade dyes from their wastewater. Thus, the interaction of NPs with industrial dye effluents is inevitable. The Organization for Economic Co-operation and development (OECD) guideline for testing of chemical 303A was employed to study the fate and behaviour of TiO2 NPs in industrial dye-stuff effluent. This was due to the unavailability of NPs' fate and behaviour test protocols. The effect of TiO2 NPs on the treatment process was ascertained by measuring chemical oxygen demand (COD) and 5-day biological oxygen demand (BOD5). Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to study the fate and behavior of TiO2 NPs. Acclimatization of bacteria to target pollutants was a crucial factor for the treatment efficiency of activated sludge in a simulated wastewater treatment plant (SWTP). The acclimatization of the activated sludge to the synthetic industrial dye-stuff effluent was successfully achieved. Effect of TiO2 NPs on the treatment process efficiency was then investigated. Addition of TiO2 NPs had no effect on the treatment process as chemical oxygen demand (COD) removal remained >80%. Measured total plate count (TPC) affirmed that the addition of TiO2 NPs had no effect on the treatment process. The removal of total nitrogen (TN) was not efficient as the treatment system was required to have an oxic and anoxic stage for efficient TN removal. Results from X-ray powder diffraction (XRD) confirmed that the anatase phase of the added TiO2 NPs remained unchanged even after exposure to the treatment plant. Removal of the NPs from the influent was facilitated by biosorption of the NPs on the activated sludge. Nanoparticles received by wastewater treatment plants will therefore reach the environment through sludge waste dumped in landfill. About 90% of TiO2 was retained in the activated sludge, and 10-11% escaped with the treated effluents. Scanning electron microscope (SEM) mapping micrographs together with an energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Ti in the sludge.

Resource utilization in the sub-sectors of the textile industry: opportunities for sustainability.

It was aimed to determine the specific resource use and reduction potential profiles in various textile sub-sectors (cotton woven fabric dyeing-finishing, wool woven fabric dyeing-finishing, synthetic woven fabric dyeing-finishing, cotton knitted fabric, synthetic knit fabric dyeing-finishing, non-woven fabric, dyeing-finishing of knitted fabric). The main focus was to elucidate opportunities for sustainability in terms of decreasing resource utilization in the textile sector. On-site surveys and detailed data collection studies were carried out at 150 textile facilities. Average specific values for water, auxiliary chemicals, dyestuff, electricity, and steam consumptions, and related reduction potentials were calculated and compared within facilities and sub-sectors. The minimum specific resource consumption values reported in the Best Available Techniques Reference Document (BREF) for the textile industry and data of similar facilities from the literature were evaluated and used. A detailed environmental performance profile of the Turkish textile sector in terms of resource usage and reduction potential was generated. The highest specific water consumption was found in the wool-woven fabric sub-sector (345 ± 262 L/kg product). Although the specific auxiliary chemical consumption shows similarities within sub-sectors, the highest specific auxiliary chemical consumption (397 ± 237 g/kg product) was found in the synthetic woven fabric sub-sector. The sub-sector with the highest specific dyestuff consumption (30 ± 13 g/kg product) was the cotton knitted fabric sub-sector. The wool woven fabric industry had the highest specific electricity (7 ± 5.3 kWh/kg product) and steam (20 ± 11 kg steam/kg product) consumption. In addition, for all the studied sub-sectors country-wide, the lowest and highest reduction potentials in resource uses were 18 ± 15% and 73 ± 13%, respectively, suggesting a need for major full-scale implementations of cleaner production for enhancing sustainability in the textile industry.

Three polymorphs of a new N,N'-dipropylated isoindigo derivative.

A newly synthesized N,N'-dipropyl-substituted isoindigo derivative, namely, 1-propyl-3-(1-propyl-1,2-dihydro-2-oxo-3H-indol-3-ylidene)-1,3-dihydro-2H-indol-2-one, C22H22N2O2, was found to have three polymorphic forms (denoted Forms I, II and III) under various crystallization conditions. Crystal structure analysis indicated that Form III had a significantly different molecular conformation from the other two polymorphs. Their different packing arrangements were correlated with differences in the intermolecular interactions. Thermal measurements revealed that Forms I and II are enantiotropically related, and Form II exhibits thermally dynamic behaviour.

Effect of reaction pH and CuSO4 addition on the formation of catechinone due to oxidation of (+)-catechin.

A novel hair dyeing technique being milder and safer for a human body is desired. The oxidation product of (+)-catechin, catechinone, was invented as a safer dyestuff for hair colouring under such the situation. The preparation of catechinone by a chemical oxidation is a practical way and the objective of the study is clarify the effect of the solution pH and in the presence or absence of Cu(2+) on the formation rate and yield of catechinone in order to improve the efficiency of the dye formation. The catechinone formation was monitored by ultraviolet-visible spectroscopy. Catechinone was prepared chemically from (+)-catechin in aqueous solution with O2 gas introduced over a pH range of 7.1-11.7. The rate and amount of the dye formation increase with increasing pH. Dissociation of the hydroxyl group of the catechol part of (+)-catechin is significant for the oxidation of (+)-catechin and promotes the dye production. This is because the deprotonated (+)-catechin has a higher reactivity with O2 . The production of catechinone is accelerated by the addition of CuSO4 and the production rate reaches the maximum at pH = 8.8. (+)-Catechin - Cu(2+) complexes are formed and the formation promotes the oxidation of the catechol part of (+)-catechin at pH ≤ 8.8. On the other hand, the complex becomes too stable to proceed for the oxidation reaction at pH > 8.8.

Dyestuff chemistry auxiliary instant immune-network label strategy for immunochromatographic detection of chloramphenicol.

Commercial immunochromatographic assay (ICA) is a convenient tool for controlling antibiotic abuse. Although great efforts have been made to improve the detection performance and quantitative capabilities, simplify the manufacturing process of commercial ICA is rarely mentioned. Here, a proof-of-principle work are developed to solve the above problem. Inspired by dyestuff chemistry, we developed an instant immune-network label strategy by dynamic protonation capacity of neutral red (NR), achieving a desirable labeling efficiency (＜1min), and applying for ICA detection of chloramphenicol (CAP). Benefits from the efficiently protonation of NR, lengthy probe production time and organic reagents can be avoided, displaying excellent strip production efficiency and detection performance. Eventually, this strategy presents a visual limit of detection (vLOD) at 3 ng/mL, cut-off value is 9 ng/mL. The assay recoveries in milk and honey were 74.45-107.15 %, with the total RSD of 1.62-6.90 %. We envision that this strategy raises the possibility of commercializing of laboratory prototype products.

Enzymatic synthesis of indigo derivatives by tuning P450 BM3 peroxygenases.

Indigoids, a class of bis-indoles, have long been applied in dyeing, food, and pharmaceutical industries. Recently, interest in these 'old' molecules has been renewed in the field of organic semiconductors as functional building blocks for organic electronics due to their excellent chemical and physical properties. However, these indigo derivatives are difficult to access through chemical synthesis. In this study, we engineer cytochrome P450 BM3 from an NADPH-dependent monooxygenase to peroxygenases through directed evolution. A select number of P450 BM3 variants are used for the selective oxidation of indole derivatives to form different indigoid pigments with a spectrum of colors. Among the prepared indigoid organic photocatalysts, a majority of indigoids demonstrate a reduced band gap than indigo due to the increased light capture and improved charge separation, making them promising candidates for the development of new organic electronic devices. Thus, we present a useful enzymatic approach with broad substrate scope and cost-effectiveness by using low-cost H2O2 as a cofactor for the preparation of diversified indigoids, offering versatility in designing and manufacturing new dyestuff and electronic/sensor components.

Co-metabolic biodegradation of structurally discrepant dyestuffs by Klebsiella sp. KL-1: A molecular mechanism with regards to the differential responsiveness.

In this study, an attempt was made to decipher the underlying differential response mechanism of Klebsiella sp. KL-1 induced by exposure to disparate categories of dyestuffs in xylose (Xyl) co-metabolic system. Here, representative reactive black 5 (RB5), remazol brilliant blue R (RBBR) and malachite green (MG) belonging to the azo, anthraquinone and triphenylmethane categories were employed as three model dyestuffs. Klebsiella sp. KL-1 enabled nearly 98%, 80% or 97% removal of contaminants in assays Xyl + RB5, Xyl + RBBR or Xyl + MG after 48 h, which was respectively 16%, 11% or 22% higher than those in the assays devoid of xylose. LC-QTOF-MS revealed an increased formation of smaller molecular weight intermediates in assay Xyl + RB5, whereas more metabolic pathways were deduced in assay Xyl + RBBR. Metaproteomics analysis displayed remarkable proteome alteration with regards to the structural difference effect of dyestuffs by Klebsiella sp. KL-1. Significant (p-value<0.05) activation of pivotal candidate NADH-quinone oxidoreductase occurred after 48 h of disparate dyestuff exposure but with varying abundance. Dominant FMN-dependent NADH-azoreductase, Cytochrome d terminal oxidase or Thiol peroxidase were likewise deemed to be responsible for the catalytic cleavage of RB5, RBBR or MG, respectively. Further, the differential response mechanism towards the structurally discrepant dyestuffs was put forward. Elevated reducing force associated with the corresponding functional proteins/enzymes was transferred to the exterior of the cell to differentially decompose the target contaminants. Overall, this study was dedicated to provide in-depth insights into the molecular response mechanism of co-metabolic degradation of refractory and structurally discrepant dyestuffs by an indigenous isolated Klebsiella strain.

Synthesis of a starch-based sulfonic ion exchange resin and adsorption of dyestuffs to the resin.

A starch-based ion exchange resin (SIR) was synthesized by copolymerizing raw starch with sodium methallyl sulfonate and styrene. The structural and surface properties of the SIR were characterized by 13C nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, Brunauer-Emmett-Teller surface area analysis, and laser particle size analysis. The SIR was physicochemically and thermally stable and resistant to acids, bases, and enzymes. In static adsorption tests, the SIR had decolorization ratios (DRs) for mixed dyestuffs in wastewater of up to 84.04%, which was higher than the DR for a synthetic ion exchange resin (001 × 7, DR 77.14%). In dynamic adsorption tests, the SIR bed had a DR of 99.85% and a wastewater handling capacity 25 times the column volume. After three adsorption-regeneration cycles, the DR of the resin bed had decreased by <7.5%. The properties of the SIR, particularly the adaptability of the SIR to continuous column adsorption, make the SIR suitable for removing dyestuffs from industrial wastewater and a potential substitute for traditional sorbents such as activated carbon and synthetic resins.

Effect of chloride on the one step electrochemical treatment of an industrial textile wastewater with tin dioxide anodes. The case of trichromy procion HEXL.

The resulting solutions from the cotton fabrics dyeing using the trichromy Procion HEXL, with NaCl as electrolyte, were electrochemically treated. These dyes have two azo groups as chromophores and two monochlorotriazinic groups as reactive groups in their structure. The combined oxidation/reduction at 125 mA cm-2 in a filter-press cell without compartment separation was carried out using an anode of Ti/SnO2-Sb-Pt and a cathode of stainless steel. This procedure has been effective in previous experiments using sulphate as electrolyte. A significant decrease in total organic carbon (TOC), chemical oxygen demand (COD), and total nitrogen (TN) was obtained. Moreover, the process took place efficiently. The average oxidation state (AOS) and the carbon oxidation state (COS) data confirmed the presence of stable oxidized intermediates in the electrolysed solution. The chromatography and the UV-Visible spectrophotometry assays indicated that full decolourisation is obtained at a loaded charge of around 0.81 Ah L-1 which is associated with an electrical energy per order (EEO) of 1.20 kWh m-3.

Eco-electrogenic treatment of dyestuff wastewater using constructed wetland-microbial fuel cell system with an evaluation of electrode-enriched microbial community structures.

This work studied eco-electrogenic treatment of real dyestuff wastewater along with characterization of electrode-enriched microbial community structures in Fimbristylis dichotoma planted closed-circuit constructed wetland-microbial fuel cell (CW-MFC) system. The CW-MFC-2 (experimental system) achieved 82.2 ±â€¯1.7% ADMI removal and 70 ±â€¯2% COD reduction; that were found to be 9% and 7.4% higher than the standalone constructed wetland (CW) system (bioremediation control) respectively. Likewise, the CW-MFC-2 system achieved maximum power density of 198.8 mW/m2, which was 85.6 ±â€¯2.47% higher than the CW-MFC-1 system (eco-electricity control). Quantitative reverse transcription PCR (qRT-PCR) assays revealed significant down-regulation of hepatic oxidative stress response biomarker genes in Oreochromis niloticus exposed to CW-MFC-2 system treated dyestuff wastewater as compared with untreated wastewater. The biofilms associated with the anode and cathode of the CW-MFC-2 system exhibited selective enrichment of electrochemically active and dye degrading microbial communities.

Dyed Poly(styrene-methyl Methacrylate-acrylic Acid) Photonic Nanocrystals for Enhanced Structural Color.

In the present work, we investigated the combined effect of poly(styrene-methyl methacrylate-acrylic acid) [P(St-MMA-AA)] PCs with the disperse dye C.I. Disperse Red 343 on the photonic crystals (PCs) shape, distribution, organization, iridescence, chemical structure, thermal stability, and reflectance. PCs were successfully produced in the form of highly spherical, monodisperse colloidal structures. Presence of dye in the PCs inner core-shell structure was confirmed via Fourier-transformed infrared spectroscopy. The PCs brightness and iridescent effect was enhanced by the presence of the dyestuff, which also promoted the self-assembly of the colloidal nanospheres in the form of arrays. The P(St-MMA-AA) PCs thermal stability did not alter with the introduction of the dye. In a side experiment, dyed PCs were also coated onto dyed polyamide fabrics. Data reported successful coating of the textile fabric and an improvement of its reflectance. Fabric immobilization fostered the self-assembling of the dyed colloidal nanospheres in the form of well-organized face-centered cubic, closed-packed arrays. This is the simplest and most energy favorable organization for PCs. The combination of disperse dyes with PCs is a very recent and challenging idea and could open new ways to understand the influence the PCs photonic-band structure may exert on the photoluminescence properties of the dyes embedded in the PCs inner space, and vice versa.

Layer-by-Layer Assembly of Polyelectrolyte Multilayer onto PET Fabric for Highly Tunable Dyeing with Water Soluble Dyestuffs.

Poly(ethyleneterephthalate) (PET) is a multi-purpose and widely used synthetic polymer in many industrial fields because of its remarkable advantages such as low cost, light weight, high toughness and resistance to chemicals, and high abrasion resistance. However, PET suffers from poor dyeability due to its non-polar nature, benzene ring structure as well as high crystallinity. In this study, PET fabrics were firstly treated with an alkaline solution to produce carboxylic acid functional groups on the surface of the PET fabric, and then was modified by polyelectrolyte polymer through the electrostatic layer-by-layer self-assembly technology. The polyelectrolyte multilayer-deposited PET fabric was characterized using scanning electron microscopy SEM, contact angle, Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The dyeability of PET fabrics before and after surface modification was systematically investigated. It showed that the dye-uptake of the polyelectrolyte multilayer-deposited PET fabric has been enhanced compared to that of the pristine PET fabric. In addition, its dyeability is strongly dependent on the surface property of the polyelectrolyte multilayer-deposited PET fabric and the properties of dyestuffs.

Phosphomolybdic acid immobilized on graphite as an environmental photoelectrocatalyst.

A new phosphomolybdic acid (PMA)/Graphite surface was prepared based on electrostatic interactions between phosphomolybdic acid and graphite surface. The PMA/Graphite was characterized by cyclic voltammetry (CV) analysis and scanning electron microscope (SEM). SEM images showed that the phosphomolybdic acid particles were well stabilized on the graphite surface and they were evidenced the size of particles (approximately 10 nm). The CV results not only showed that the modified surface has good electrochemical activity toward the removal of the dyestuff, but also exhibits long term stability. The PMA/Graphite was used as a photoanode for decolorization of Reactive Yellow 39 by photoelectrocatalytic system under UV irradiation. The effects of parameters such as the amount of phosphomolybdic acid used in preparation of PMA/Graphite surface, applied potential on anode electrode and solution pH were studied by response surface methodology. The optimum conditions were obtained as follows: dye solution pH 3, 1.5 g of immobilized PMA on graphite surface and applied potential on anode electrode 1 V. Under optimum conditions after 90 min of reaction time, the decolorization efficiency was 95%.

[Removal of AOX, Chroma and TOC in Chemical Dyestuff Wastewater with Iron Scraps-Fenton-Coagulation Combined Process].

Iron scraps-Fenton-coagulation process was applied to chemical dyestuff wastewater. The removal performance of absorbable organic halogens(AOX), chroma and total organic carbon (TOC) was investigated at different molar ratios of Fe2+ to H2O2 (1:3-1:15), iron scraps reaction time (2-5 h) and Fenton reaction time (20-80 min). The results showed that the removal ratios of AOX, chroma and TOC firstly increased and then decreased with the decrease of the molar ratio of Fe2+ to H2O2, while continuously increased with the increase of iron scraps and Fenton reaction time. The optimal condition was determined as Fe2+:H2O2 ratio of 1:8, iron scraps reaction time of 4 h and Fenton reaction time of 60 min, under which 94.2% of AOX, 93.7% of chroma and 27.2% of TOC were removed. A comparison study revealed that the iron scraps-Fenton-coagulation combined process could achieve much better removal of AOX, chroma and TOC than any other single or combined processes of iron treatment, Fenton oxidation and coagulation. GC-MS analysis revealed that halogenated compounds and anilines were efficiently removed, as well as nitrobenzenes, phenols, benzaldehydes, ethers, nitriles and heterocyclic compounds.·OH was found to devote much in the Fenton reaction according to the tert-butyl alcohol trapping hydroxyl radicals test.

Utilization of activated carbon produced from fruit juice industry solid waste for the adsorption of Yellow 18 from aqueous solutions.

The use of activated carbon obtained from sour cherry (Prunus cerasus L.) stones for the removal of a basic textile dye, which is Yellow 18, from aqueous solutions at different contact times, pH values and solution temperatures was investigated. The surface area and micropore volume of chemically modified activated carbon were 1704 m(2) g(-1) and 0.984 cm(3) g(-1), respectively. The experimental data indicated that the adsorption isotherms were well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacity was 75.76 mg g(-1) at 318 K. The adsorption kinetic of Yellow 18 obeys the pseudo-second-order kinetic model. The thermodynamic parameters were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 0.71-2.36 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal of Yellow 18 from wastewater.