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The “cross-linked” copolymers based on styrene, divinylbenzene, and functionalizing monomers namely ethylene glycol dimethacrylate and liquid hydroxyl terminated polymer of butadien Polybd® R-20 LM Resin by miniemulsion polymerization in the presence of a co-stabilizer – hexadecane were prepared. The largest copolymer yield for both functionalizing monomers by amount of hexadecane 5 % wt. was achieved. The industrial latex SKS-30 ARKM-15 by the obtained copolymers in the process of salt coagulation was modified. The mechanical characteristics of vulcanizates made on the basis of rubber SKS-30 ARKM-15, modified by obtained copolymers were studied.

The primary purpose of this study was to investigate the feasibility of applying polymeric cementitious materials to three-dimensional additive construction (3DAC). Specifically, styrene-butadiene rubber (SBR) latex was employed as an admixture to produce SBR-modified cementitious mixtures, and their fresh properties were experimentally investigated to determine the feasibility of their use in the 3DAC process. The SBR/cement ratio was controlled based on four main materials (i.e., cement, sand, silica fume, and fly ash) in order to determine the optimal fresh properties. The test results revealed that the SBR-modified cementitious mixtures showed excellent flowability, extrudability, buildability, and open time, all of which are required for 3DAC materials. The optimal flow of the SBR-modified cementitious mixtures was 70% ± 1%, which is appropriate for 3DAC applications. According to the experiment results, the SBR-modified cementitious mixtures were sufficiently competitive to serve as a new class of materials for 3D additive construction.

● N 2O emissions from a denitrifying SBR were 23 times higher than that of the CSTR. ● Feast famine conditions in SBR uniquely lead to producing undesirable levels of N 2O. ● An MAG closely related to previously identified Thauera is likely a major N 2O driver. ● Post-transcriptional regulation may be linked to higher N 2O production in SBR. Nitrous oxide (N 2O) is a potent greenhouse gas that can be emitted during the biological treatment of wastewater. In this study, a comparison of the long-term performance characteristics and N 2O production of sequencing batch reactors (SBR) and continuous stirred tank reactors (CSTR) during nitrite-based denitrification was undertaken. It was found that both reactors had NO 2 −-N removal efficiencies over 99.9 %, but the N 2O-N emissions from the SBR reached ~2.3 % of the removal nitrite-N load, while in the CSTR it never exceeded 0.1 %. High frequency sampling during one operation cycle of the SBR demonstrated that the N 2O accumulation ratio was ~0.1 % during the feast period, increased to ~1.9 % in the first five hours of the famine period, and then gradually reached ~2.3 % at the end of famine. Batch experiments showed that limiting extracellular electron donor is required for N 2O accumulation in cells from the SBR-famine period and that cells from the CSTR do not accumulate N 2O when either nitrite or carbon is limiting. Another notable difference in the two reactor communities was the high level of accumulation of intracellular granules, most likely polyhydroxybutyrate (PHB), in cells during the feast period in the SBR. Metagenome assembly and binning found that one genome (PRO1), which is a Thauera, accounted for over half the metagenomic reads in both reactors. Neither shifts in gene regulation nor community composition explained the observed differences in reactor performance suggesting some post-transcriptional regulation obligatorily linked to antecedent conditions underly increased N 2O production in the SBR.

Sewage treatment systems can prevent the direct discharge of endocrine disruptors, such as 17α-ethinylestradiol (EE2), into the environment. Treatment systems capable of promoting total phosphorus (TP) removal, such as sequencing batch reactors (SBRs), are promising in this regard. Two lab-scale SBRs with different sludge retention times (SRTs) were assessed for their EE2 and TP removal rates. Anaerobic/aerobic/anoxic phases with cycles of 6 h were used to treat sewage containing EE2 at a concentration of 5 μg L-1. The removal rates of chemical oxygen demand and TP were approximately 80% for both the SBRs. Partial nitrification was observed in the SBRs. Initially, concentrations of EE2 above 1.0 μg L-1 in the treated sewage were measured. These concentrations were smaller in SBR 1, which used lower SRTs; EE2 was removed by sludge sorption. After the 56th cycle, the concentrations of EE2 in the treated sewage were below 0.1 μg L-1 in both the SBRs, indicating that its removal may have occurred by biodegradation due to acclimation to the process. Therefore, both TP removal and nitrification seem to play an important role in EE2 removal by SBRs. Keywords: A2O SBR, EE2 and TP removal, sewage treatments.

The growing production of coke and, consequently, coke wastewater is a significant problem for the environment. Coke wastewater, because it contains high amounts of toxic substances, is classified as an extremely hazardous industrial wastewater. The treatment of such wastewater requires a combination of advanced physicochemical and biological methods. The aim of the research was to investigate the effectiveness of the application of the ultrasonic disintegration of coke wastewater in a sequencing batch reactor (SBR). The tests were conducted in two stages, wherein the first stage involved determining the most favorable sonication conditions, that is, time and amplitude. The authors used the following amplitudes: 31 µm; 61.5 µm; 92 µm; 123 µm and times: 120 s; 240 s; 480 s; 960 s. The second stage focused on treating coke wastewater in SBRs (Reactor A—a proportion of coke wastewater in the mixture: 5%, 10%, and 20%; reactor B—sonicated coke wastewater, proportion in mixture: 5%, 10%, 20%). The efficiency of the treatment process was determined based on the rate of removal of selected parameters: chemical oxygen demand (COD), total organic carbon (TOC), inorganic carbon (IC), ammoniacal nitrogen (N-NH4), total nitrogen (TN), the course of pH changes. The study revealed that sonication of coke wastewater increased biodegradability and reduced its toxicity. The use of the preliminary sonication of coke wastewater before biological treatment improved the degree of removal of the tested parameters by approximately 10%. The volumetric ratio of coke wastewater in the mixture had the greatest impact on the obtained results. The use of an ultrasound field allows the treatment process to be executed with a coke wastewater addition exceeding 10%. In addition, it was found that in order to increase the coke wastewater treatment efficiency, one should optimize individual phases in the SBR and the pollution load.

Buffing Dust Collagen (BDC) is a hazardous waste product of chromium tanning bovine hides. The aim of this study was to investigate whether BDC has the desirable properties required of modern fillers. The microstructural properties of BDC were characterized by elemental analysis (N, Cr O ) of dry residue and scanning electron microscopy (SEM). The BDC was applied (5 to 30 parts by weight) to styrene butadiene rubber (SBR), obtaining SBR BDC composites. The physicochemical properties of the SBR BDC composites were examined by Fourier transform infrared analysis, SEM, UV-Vis spectroscopy, swelling tests, mechanical tests, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The biodegradability of the SBR BDC composites and their thermo-oxidative aging were also investigated. The filler contributed to increase the cross-link density in the elastomer structure, as evidenced by enhanced mechanical strength. The introduction of a filler into the elastomer structure resulted in an increase in the efficiency of polymer bonding, which was manifested by more favorable rheological and mechanical parameters. It also influenced the formation of stable interfacial bonds between the individual components in the polymer matrix, which in turn reduced the release of compact chromium in the BDC filler. This was shown by the absorption bands for polar groups in the infrared analysis and by imaging of the vulcanization process.

It is unusual to observe completely treated textile wastewater in Ethiopia. It is impossible to get better quality of treated effluent with a single treatment stage. Therefore, in this study the removal of COD and color was carried out on a wastewater which was obtained from acrylic fiber processing textile industry using a single-stage Fenton oxidation, single-stage sequencing batch reactor (SBR) and also with the integration of SBR with Fenton oxidation. Optimum amount of process factors was used for both Fenton oxidation and SBR treatment stages. The combination of SBR and Fenton oxidation was revealed better removal efficiency than single SBR-stage treatment. The effluent obtained from SBR at steady-state conditions indicated a maximum COD and color removal of 74.1% and 64.6%, respectively. The effluent obtained from Fenton followed by SBR (Fenton + SBR) at steady-state conditions was indicated a maximum COD and color removal efficiency of 86.3% and 84%, respectively. The effluent obtained from SBR followed by Fenton (SBR + Fenton) for three Fenton oxidation experimental runs indicated a maximum COD and color removal of 80.2% and 73.6%, respectively. Among the three wastewater treatment schemes, chemical treatment before biological stage (Fenton + SBR) was the best treatment option and also showed better quality of effluent.

A novel Fenton-SBR-microwave pyrolysis integrated process is developed to treat liquid crystal wastewater possessing complex components, high toxicity and strong stability. In this integrated process, Fenton-SBR and microwave pyrolysis are for the removal of chemical oxygen demand (COD) and disposal of iron mud generated in the Fenton process respectively. The effects of H O :Fe molar ratio and Fenton dosage on COD removal were optimized. The experimental results revealed that the removal efficiencies for COD and total organic carbon (TOC) were 99.8% and 99.2%, and the values for MLSS and SVI were stable at 4,500 mg L and 65%, respectively. Microscopic examination proved that there were rotifer, Epistylis galea, Opercularia coarctata, vorticella and mormon genus which are indicative microbes for good water quality. Iron mud waste produced in the Fenton reaction was handled with microwave pyrolysis, producing ɑ-Fe O commercial byproduct. The estimated cost including chemical reagents and electricity for this integrated process is about $320 T , without consideration of the added value of the ɑ-Fe O byproduct. TOC removals in the Fenton and SBR processes both fit well with pseudo-first-order kinetics and the corresponding half-life times are 0.15 and 7 h, respectively.

This study investigated and compared the microbial communities between a sequencing batch reactor (SBR) without carriers and a hybrid SBR with addition of carriers for the treatment of saline wastewater. The two systems were operated over 292 days with alternating aerobic/anoxic mode (temperature: 28℃, salinity: 0.0–3.0%). High removal efficiency of chemical oxygen demand (COD) and total inorganic nitrogen (TIN) was achieved in both the SBR (above 86.7 and 95.4% respectively) and hybrid SBR (above 84.4 and 94.0%) at 0.0–2.5% salinity. Further increasing salinity to 3.0% decreased TIN removal efficiency to 78.4% in the hybrid SBR. Steep decline of biodiversity and relative abundance of ammonia-oxidizing bacteria (AOB) contributed to the worse performance. More genera related to sulfide-oxidizing and sulfate-reducing bacteria were detected in the hybrid SBR than the SBR at 3.0% salinity. The abundance of halotolerant bacteria increased with the salinity increase for both reactors, summing up to 25.5% in the suspended sludge (S-sludge) from the SBR, 28.9 and 22.9% in the S-sludge and biofilm taken from the hybrid SBR, respectively. Nitrification and denitrification via nitrate was the main nitrogen removal pathway in the SBR and hybrid SBR at 0.0 and 0.5% salinity, while partial nitrification and denitrification via nitrite became the key process for nitrogen removal in the two reactors when the salinity was increased to 1.0–3.0%. Higher abundance of anaerobic ammonium-oxidizing (ANAMMOX) and sulfide-oxidizing autotrophic denitrification (SOAD) bacteria were found in the hybrid SBR at 3.0% salinity.

Purpose The purpose of this study is to explore the dynamics of trust creation in an early buyer–supplier relationship phase at the interpersonal level. The authors use a brand-based communication approach to investigate the trust–risk–commitment link. Design/methodology/approach Survey data from 204 senior managers in small and medium-size enterprises (SMEs) in Australia were collected and analyzed. Findings Results indicate that ability, credibility, benevolence and persona of supplier brand representatives (SBRs) relate significantly to a buyers’ trust in SBR, leading to diminished perceived risk, and increased relationship commitment between the parties. These findings support the importance of using individual representatives who are able to broadcast their supplier’s brand values, and increase trust in exploratory buyer–supplier relationships. Research limitations/implications This research focused on SMEs in Australia, investigating exploratory phase of the interpersonal relationships. Future research can investigate large firms interacting in different relationship phases in the light of brand-based communication. Practical implications The study describes several strategies for both buying and supplying firms to use, to best use brand-based communication as a means to build trust in the early phases of buyer–supplier relationships. Originality/value Prior research has focused on interorganizational trust and established or mature buyer–supplier relationships. This study investigates the initial phase of buyer–supplier relationships, and at the interpersonal exchange level. It also incorporates a role for brand-based communication in the buyer–supplier relationship which has received limited attention in the literature.