Adsorption and Removal of Methylene Blue from Aqueous Solution Using Sterile Bract of Araucaria angustifolia as Novel Natural Adsorbent Abstract The aim of this work was to study the adsorption and removal of methylene blue from aqueous solution using sterile bract of Araucaria angustifolia as novel natural adsorbent. Raw and boiling-treated sterile bract samples were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and point of zero charge. The contents of humidity, ash, total extractive content, lignin and cellulose were 13.20, 3.30, 7.12, 44.45 and 30.92%, respectively. The methylene blue adsorption mechanism in the sterile bract was evaluated using non-linear Langmuir, Freundlich, Redlich–Peterson and Sips isotherm models, whereas the adsorption kinetic was evaluated using pseudo-first- and pseudo-second-order kinetic models. The methylene blue removal efficiencies of the raw and boiling-treated bracts were 98.59 ± 0.01 and 99.90 ± 0.01%, respectively, after 480 min. The best adsorption efficiency was found within 480 min of contact, 5.0 g of adsorbent with 500 mesh granulometry, pH = 6, initial adsorbate concentration of 150 mg L−1 and temperature of 292 K. The maximum methylene blue adsorption capacities of the raw and boiling-treated bracts according to the non-linear Langmuir isotherm model were 125.34 and 138.65 mg dye per gram bract, respectively. The kinetic fit depends on the solution pH, determination coefficient and Chi square test statistic. From thermodynamic results, it was concluded that the adsorption process is favorable, spontaneous (ΔG < 0), exothermic (ΔH < 0) and disordered at the solid–solution interface (ΔS > 0). Overall, the sterile bract of Araucaria angustifolia could be applied as low-cost alternative adsorbent for the treatment of textile industry wastewater.

Investigating the Effects of Copper Slag and Silica Fume on Durability, Strength, and Workability of Concrete Abstract Workability, strength, durability, economic considerations, and attention to sustainable development issues are some crucial factors in designing an appropriate mix. The use of copper slag as a partial replacement of cement is an effective method of pollution reduction and conservation of resources, since it reduces cement use. In addition, silica fume is used in combination with copper slag to make concrete structures more durable. The main purpose of this study was optimizing important variables of concrete mix design including cement factor, water-to-binder ratio (w/b), copper slag, and silica fume to improve concrete durability. To achieve this goal, an experimental research was carried out, based on standards, to optimize changes in the said fields. Concrete durability is determined by experiments considering electrical resistance of concrete, bulk electrical conductivity, and chloride migration coefficient. Interfacial transition zone and cement microstructure were evaluated using X-ray analysis and scanning electron microscopy. The results of this research indicated that simultaneous use of copper slag and silica fume with appropriate values of other factors (cement factor and w/b ratio) yields a more durable, workable and strengthened mix design. The optimized mix introduced a workable, durable, resistant, and economical mix design with 7% and 20% of cement replaced with silica fume and copper slag, respectively. This innovative study included simultaneous use of copper slag and silica fume as a replacement for cement.

Assessment of Enhanced Biological Phosphorus Removal Implementation Potential in a Full-Scale Wastewater Treatment Plant in Croatia Abstract The objective of this study was to assess the possibility of retrofitting an existing full-scale wastewater treatment plant (WWTP) based on a sequencing batch reactor (SBR) technology with the enhanced biological phosphorus removal (EBPR) process. Wastewater characterisation showed highly variable influent composition that fluctuated throughout the year with a rather low and unstable SBOD/TP ratio (SBOD—soluble biological oxygen demand; TP—total phosphorus), which is considered unfavourable for EBPR. Characterisation of the sludge showed that the non-EBPR SBR sludge from the WWTP Koprivnica contained no detectable phosphorus accumulating organisms (PAO), but could be transformed in a laboratory into EBPR performing sludge in less than 45 days under favourable conditions for PAOs. The microbial community composition was assessed using an FISH (fluorescence in situ hybridization) analysis, which confirmed that the original sludge from the WWTP, which did not have detectable PAOs, was transformed into the sludge enriched by PAOs belonging to the genus ‘Candidatus Accumulibacter phosphatis’ after 43 days of cultivation. A plant retrofit, based on the results of laboratory experiments, was proposed with the enrichment of the wastewater with volatile fatty acids via primary anaerobic fermentation and step feeding. Results of mathematical modelling (BioWin) showed that such strategy could lead to sufficient P removal through EBPR in this WWTP.

Removal of formaldehyde from the air with a suspended growth bioreactor Abstract In the present study, the root zone of Canna flaccida Salisb. was selected as the biological component. We found that the adsorption rate of formaldehyde (FA) by C. flaccida was initially low, before increasing substantially. 13CNMR analysis indicated that C. flaccida can metabolize H13CHO and the major metabolic products were organic acid and amino acids. On this basis, we had designed a suspended growth bioreactor (SGB) to remove FA. An SGB was tested under a series of different conditions and the results showed that FA removal efficiency was strongly influenced by water volume, root zone weight, and gas flow rate. More than 52% of the FA was removed in 1 h and the maximum elimination capacity reached 35.112 mg m−3 h−1. After 24 h, no FA remained in the SGB. Running for 15 days, the concentration of FA in the lab space decreased from 1.12 to 0.82 mg m−3, and the concentration of FA in the SGB reached a low level. These results confirmed that SGB is an effective way to remove FA.

Assessment of Anthropogenic and Natural Factors on Cheliff River Waters (North-West of Algeria) at Two Contrasted Climatic Seasons Abstract Cheliff River is the most important permanent river of North-west Algeria which plays an essential role for irrigation and drinking water supply, but suffers from high anthropogenic pressure. Multi-dimensional and multi-factorial aspects of water pollution in Cheliff River and its tributary Mina River were evidenced during two contrasting climatic seasons. Urban discharges were identified as a major source of water organic pollution. The inputs of untreated sewages were characterized by maximum concentrations of tryptophan-like (5.7 µmol l−1) and tyrosine-like (9.8 µmol l−1) compounds during the dry period, confirming these amino acids as fingerprints of untreated urban discharges. The synchronous monitoring and assessment of physicochemical parameters, fluorescent organic compounds and metallic elements of Cheliff River waters highlighted its global contamination, mainly in its downstream part. Cheliff River was mainly affected by organic pollution with maximum COD (1536 mg O2 l−1) and BOD5 (12 mg O2 l−1) during the wet period, and by metallic contamination with maximum Fe (287 ± 4.4 µg l−1) and Al (422.4 ± 9.4 µg l−1) during the dry period, exceeding the guideline limits. This chronic contamination was related to untreated domestic sewages, agricultural effluents and technical landfill center discharges in this area. Diffuse pollutions were also evidenced, which made the identification of different contamination sources complicated. Mina River was mostly affected by non-treated domestic sewages with maximum COD (3161 mg O2 l−1) during the wet period and maximum BOD5 (12 mg O2 l−1) during the dry period, exceeding the guideline limits. The correlation Li/Sr showed the contribution of natural influence from saline soils of Mina valley, particularly during the dry period.

Complete Decomposition Analysis of CO 2 Emissions in the Health Sector in Portugal Abstract This study uses the “Complete Decomposition” technique to examine the intensity of CO2 emissions in the health sector in Portugal over the period 1997–2014. Our results suggest that improvements in emission intensity in the health sector depend on the design of incentives of replacing fossil fuels with fuels from renewable energy sources and adopting measures to save energy. In addition, capital investment may also contribute to the reduction of the emission intensity in the sector, if the investment is applied to the acquisition of more efficient equipment. We identify areas for action and recommend that public and private sector health professionals should elevate energy efficiency to a top priority. Our results also highlight the importance of the Kyoto protocol.

Photocatalytic and Kinetic Study on the Degradation of Three Food Pesticides Using Vanadium-Substituted Polyoxotungstates Abstract Mono-, di-, and tri-vanadium-substituted Keggin-type heteropolyoxoanions [SiW12O40]4− and [PW12O40]4− were evaluated as photocatalysts for the photodegradation of three hazardous food pesticides: atrazine, chlorpyrifos, and dieldrin. Kinetic experiments were performed under UV irradiation at 254 nm. The degradation of each pesticide was assessed by investigating its disappearance with time using high-performance liquid chromatography equipped with an ultra-violet spectrophotometer detector. The photocatalytic degradation of the three pesticides exhibited first-order kinetics. It was found that the introduction of vanadium addenda atoms into the Keggin-type polyoxometalates decrease the degradation rate for the photocatalytic transformation of each pesticide as well as the degradation percentage. This effect was significantly related to the number of vanadium metal ions substituting the tungsten addenda atoms. As a general trend, the photocatalytic efficiency of {XVW11} was better than that of {XV3W9}. Accordingly, a marked drop was noticed in the photocatalytic degradation of atrazine, where 90% was decomposed in the presence of [α-SiW12O40]4− at a rate of 1 mg/L min, whereas the degradation percentage decreased to 55% in the presence of [α-SiVW11O40]5− at a decreased rate of 0.7 mg/L min. Hence, the negative effect on the degradation percentage was evident for the Si-based POMs, which drops from 90 to 38%, 83 to 32%, and 60 to 23% for atrazine, chlorpyrifos, and dieldrin, respectively. Similar effect was observed for the P-based POMs under the studied conditions.

The Inefficiency of Energy Pricing Policy: The Case of Iran Abstract High-energy consumption leads to a serious threat to climate change and human health, while contributing to environmental pollution. Concerns about climate change, air quality, and water quality and availability have made Iranian people and government increasingly aware of the need to reconcile economic and environmental objectives. Government energy pricing policies have multiple and often conflicting objectives: economic efficiency, government revenues, maintenance or improvement of income distribution, promotion of particular sectors demand management and security of supply. Increasing energy efficiency is the quickest and least costly way of addressing energy security and the environmental as well as economic challenge. According to statistics, since 1988, the Iranian government has increased the price of energy by 23.2% annually to reduce the consumption of energy (Dargahi and Ghorbannejad in Iran Energy Econ 1(4):67–100, 2012). But in this period, the growth rate of energy intensity was about 1.6%. In Iranian economy, people know, in advance, to what extent the government would increase the energy price. People expect an increase in the price of all products due to the increase in energy price. In this paper, we study such a behavior which has led to inefficiency of the government policy. Consumer subsidies are quantified utilizing the price-gap approach that compares end-user prices and reference prices that would predominate in competitive markets where no subsidies are provided. An input–output analysis is undertaken to investigate impacts in the short term. We modify the conventional input–output price model to consider the effect of the increase in energy prices.

Polychlorinated Biphenyls (PCBs) Concentration Levels in Human Gallbladder Stones and Gallbladder Tissues in Jordan Abstract The concentration levels of 12 polychlorinated biphenyl (PCB) congeners in human gallbladder tissue and gallbladder stone samples gathered from patients in the Jordan University Hospital were measured. The total mean concentration of PCBs in gallbladder tissues samples was 491.36 µg/kg wet weight. The total mean concentration of PCBs in gallbladder stone samples was 504.03 µg/kg. Pentachlorobiphenyls were predominant PCB congeners, accounting for 23.85% of the total PCB concentration found in gallbladder tissue samples and 25.48% in gallbladder stone samples which represent the most toxic compound between all congeners dioxin-like PCBs. The TEQ values for PCBs in all samples were found in the range of (0.0001–11.72) µg TEQ/kg for gallbladder tissue samples and (0.00–12.84) µg TEQ/kg for gallbladder stone samples. The distribution coefficients of PCBs were calculated between gallbladder stones and gallbladder tissues in each sample. Kd (Cstone/Ctissue) values for PCBs were found in the range 0.22–3.18. The variations in Kd were found to be dependent mainly on type of gallbladder stone and obesity of patient. The results of this study show that both gallbladder stones and gallbladder tissues can be used to assess levels of background contamination especially if the stone was of pure cholesterol type (lipophilicity of the stones). Also a correlation between PCB concentrations and dysplasia in few samples implied that PCBs could be a potential contribution factor to gallbladder tissue mutations. This needs to be generalized by an extensive future study on representative number of gallbladder tissues with dysplasia.

Highly Selective and Sensitive Sensing of Toxic Mercury Ions Utilizing Carbon Quantum Dot-Modified Glassy Carbon Electrode Abstract In this paper, a novel synthesis of 1 nm sized metal-free carbon quantum dots (CQDs) and their electrochemical application vis-à-vis mercury (Hg) sensing have been demonstrated. The characterization of synthesized CQDs was done by FT-IR, HR-TEM, XRD and UV–Vis analysis. Furthermore, the CQD-modified electrode shows an excellent sensing ability toward deleterious Hg ion even when 600-fold of excess of interfering ions such as Cu2+, Pb2+, Cd2+, Na+, K+, Mg2+, Ba2+, Bi2+, Fe2+, Zn2+ and Hg2+ are present. A wide linearity range (0.5–300 nM) and the lowest limit of detection (2.5 nM) are exhibited by the proposed sensor with potential scanning from − 0.7 to + 0.7 V vs Ag/AgCl at a scan rate of 20 mV. In addition, the CQD-modified electrode displays an outstanding recovery results toward Hg in various real water samples. This study promotes new possibilities of designing various electrochemical sensors based on CQD nanocomposite.