Real-time monitoring of individual particles from atmospheric aerosols was performed by means of a specifically developed single-particle fluorescence spectrometer (SPFS). The observed fluorescence was assigned to particles bearing polycyclic aromatic hydrocarbons (PAH). This assignment was supported by an intercomparison with classical speciation on filters followed by gas chromatography-mass spectrometry (GC-MS) analysis. As compared with daily averaged data, our time-resolved approach provided information about the physicochemical dynamics of the particles. In particular, distinctions were made between background emissions related to heating, and traffic peaks during rush hours. Also, the evolution of the peak fluorescence wavelength provided an indication of the aging of the particles during the day.

The assessment of productivity change over time and its drivers is of great significance for water companies and regulators when setting urban water tariffs. This issue is even more relevant in privatized water industries, such as those in England and Wales, where the price-cap regulation is adopted. In this paper, an input-distance function is used to estimate productivity change and its determinants for the English and Welsh water-only companies (WoCs) over the period of 1993–2009. The impacts of several exogenous variables on companies’ efficiencies are also explored. From a policy perspective, this study describes how regulators can use this type of modeling and results to calculate illustrative X factors for the WoCs. The results indicate that the 1994 and 1999 price reviews stimulated technical change, and there were small efficiency gains. However, the 2004 price review did not accelerate efficiency change or improve technical change. The results also indicated that during the whole period of study, the excessive scale of the WoCs contributed negatively to productivity growth. On average, WoCs reported relatively high efficiency levels, which suggests that they had already been investing in technologies that reduce long-term input requirements with respect to exogenous and service-quality variables. Finally, an average WoC needs to improve its productivity toward that of the best company by 1.58%. The methodology and results of this study are of great interest to both regulators and water-company managers for evaluating the effectiveness of regulation and making informed decisions.

Efficient use of energy in farming systems is one of the most important implications for decreasing greenhouse gas (GHG) emissions and mitigating global warming (GW). This paper describes the energy use patterns, analyze the economics, and report global warming potential effects of major crop production systems in East Azerbaijan province, Iran. For this purpose, 110 farmers whose main activity was major crop production in the region, including wheat, barley, carrot, tomato, onion, potato, alfalfa, corn silage, canola, and saffron, were surveyed. Some other data was obtained from the Ministry of Agriculture Jihad of Iran. Results showed that, in terms of total energy input, onion (87,556 Mj ha⁻¹) and potato (80,869 Mj ha⁻¹) production systems were more energy-intensive than other crops. Among the studied crops, the highest values of net return (6563.8 $ ha⁻¹) and benefit/cost ratio (1.95) were related to carrot and corn silage production systems, respectively. Studies have also shown that onion and saffron production systems emit the highest (5332.6 kg CO2eq ha⁻¹) and lowest (646.24 kg CO₂eq ha⁻¹) CO₂ eq. emission, respectively. When it was averaged across crops, diesel fuel accounted for the greatest GHG contribution with 43% of the total, followed by electric power (28%) and nitrogen fertilizer (21%). In the present study, eco-efficiency was calculated as a ratio of the gross production value and global warming potential effect for the studied crops. Out of all the studied crops, the highest values of eco-efficiency were calculated to be 8.65 $ kg CO₂eq⁻¹ for the saffron production system followed by the carrot (3.65 $ kg CO₂eq⁻¹) production. Generally, from the aspect of energy balance and use efficiency, the alfalfa production system was the best; however, from an economical point of view, the carrot production system was better than the other crops.

The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably. In the SwS the Ba, Cd, Cr, Cu, Hg, Ni and Zn contents are above the legally permitted limits. The PTE content of PA are lower, but still somewhat above the permitted values for Ba and Cu. Mixing these two materials together resulted in a decrease in the PTE, but the Ba, Cu and Zn contents are still too high for agricultural application. However, leachates from composites that had been cured for 28 days are highly alkaline, and the As, Ba, Cd, Cr, Hg, Mo, Ni, Pb and Zn contents in them are well below the permitted values. The Cu contents (2.4 to 5.4 mg/kg) are above the permitted limit for inert material, but inside the range for non-hazardous material. In a leachate of composite which was prepared with fresh PA and a lower PA to SwS ratio, the Cu content was 1.4 mg/kg, since fresh PA is more reactive and therefore has a higher ability to immobilise Cu. Therefore, such mixtures can be utilised for covers and liners for sanitary landfills.

The use of biosensors as sensitive and rapid alert systems is a promising perspective to monitor accidental or intentional environmental pollution, but their implementation in the field is limited by the lack of adapted inline water monitoring devices. We describe here the design and initial qualification of an analyzer prototype able to accommodate three types of biosensors based on entirely different methodologies (immunological, whole-cell, and bacteriophage biosensors), but whose responses rely on the emission of light. We developed a custom light detector and a reaction chamber compatible with the specificities of the three systems and resulting in statutory detection limits. The water analyzer prototype resulting from the COMBITOX project can be situated at level 4 on the Technology Readiness Level (TRL) scale and this technical advance paves the way to the use of biosensors on-site.

The study was conducted to evaluate metabolic answer of Lepidium sativum L. on Hg, compost, and citric acid during assisted phytoextraction. The chlorophyll a and b contents, total carotenoids, and activity of peroxidase were determined in plants exposed to Hg and soil amendments. Hg accumulation in plant shoots was also investigated. The pot experiments were provided in soil artificially contaminated by Hg and/or supplemented with compost and citric acid. Hg concentration in plant shoots and soil substrates was determined by cold vapor atomic absorption spectroscopy (CV-AAS) method after acid mineralization. The plant photosynthetic pigments and peroxidase activity were measured by standard spectrophotometric methods. The study shows that L. sativum L. accumulated Hg in its aerial tissues. An increase in Hg accumulation was noticed when soil was supplemented with compost and citric acid. Increasing Hg concentration in plant shoots was correlated with enhanced activation of peroxidase activity and changes in total carotenoid concentration. Combined use of compost and citric acid also decreased the chlorophyll a and b contents in plant leaves. Presented study reveals that L. sativum L. is capable of tolerating Hg and its use during phytoextraction assisted by combined use of compost and citric acid lead to decreasing soil contamination by Hg.

A pulse of nitrous oxide (N₂O) emission has been observed following the disappearance of floodwater by drainage. However, its mechanism is not well understood. We conducted a column study to clarify the mechanism for N₂O production during floodwater disappearance by using a microsensor and determining the bacterial gene expression. An increase in N₂O flux was observed following floodwater disappearance after the addition of NH₄ ⁺, with a corresponding increase in the concentrations of NO₃ ⁻ and dissolved N₂O in the oxic and anoxic soil layers, respectively. The transcription level of the bacterial amoA mRNA did not change, while that of nirK mRNA increased sharply after an hour of floodwater disappearance. An additional anoxic soil slurry experiment demonstrated that the addition of NO₃ ⁻ induced the expression of nirK gene and caused a concomitant increase in N₂O production. These findings suggest that NO₃ ⁻ production in the oxic layers is important as it provides a substrate and induces the synthesis of denitrification enzymes in the anoxic layer during N₂O production.

Trend and change-point analyses of water quality time series data have important implications for pollution control and environmental decision-making. This paper developed a new approach to assess trends and change-points of water quality parameters by integrating locally weighted polynomial regression (LWPR) and segmented regression (SegReg). Firstly, LWPR was used to pretreat the original water quality data into a smoothed time series to represent the long-term trend of water quality. Then, SegReg was used to identify the long-term trends and change-points of the smoothed time series. Finally, statistical tests were applied to determine the significance of the long-term trends and change-points. The efficacy of this approach was validated using a 10-year record of total nitrogen (TN) and chemical oxygen demand (CODMₙ) from Shanxi Reservoir watershed in eastern China. Results showed that this approach was straightforward and reliable for assessment of long-term trends and change-points on irregular water quality datasets. The reliability was verified by statistical tests and practical considerations for Shanxi Reservoir watershed. The newly developed integrated LWPR-SegReg approach is not only limited to the assessment of trends and change-points of water quality parameters but also has a broad application to other fields with long-term time series records.

Due to the existence of complexities of heterogeneities, hierarchy, discreteness, and interactions in municipal solid waste management (MSWM) systems such as Beijing, China, a series of socio-economic and eco-environmental problems may emerge or worsen and result in irredeemable damages in the following decades. Meanwhile, existing studies, especially ones focusing on MSWM in Beijing, could hardly reflect these complexities in system simulations and provide reliable decision support for management practices. Thus, a framework of distributed mixed-integer fuzzy hierarchical programming (DMIFHP) is developed in this study for MSWM under these complexities. Beijing is selected as a representative case. The Beijing MSWM system is comprehensively analyzed in many aspects such as socio-economic conditions, natural conditions, spatial heterogeneities, treatment facilities, and system complexities, building a solid foundation for system simulation and optimization. Correspondingly, the MSWM system in Beijing is discretized as 235 grids to reflect spatial heterogeneity. A DMIFHP model which is a nonlinear programming problem is constructed to parameterize the Beijing MSWM system. To enable scientific solving of it, a solution algorithm is proposed based on coupling of fuzzy programming and mixed-integer linear programming. Innovations and advantages of the DMIFHP framework are discussed. The optimal MSWM schemes and mechanism revelations will be discussed in another companion paper due to length limitation.

In this study, reduced graphene oxide (rGO) embedded with bimetallic nanoparticles of cobalt-manganese oxide (CoMn₂O₄) was fabricated by hydrothermal treatment. The obtained product was characterized and applied for the heterogeneous activation of peroxymonosulfate (PMS) to degrade acid orange 7 (AO7). The characterization results revealed that 10–20 nm nanosized CoMn₂O₄ was homogenously decorated on the surface of rGO. The effect of different CoMn₂O₄ loadings showed that catalyst with a CoMn₂O₄ contents higher than 20% performs stronger capability for catalytic degradation of AO7 compared to pure CoMn₂O₄. In a system containing 4 mM PMS and 0.05 g/L 50% CoMn₂O₄/rGO, 100% conversion of AO7 (70 mg/L) and 43% mineralization could be achieved within 12 and 60 min, respectively. Recycling experiment along with XRD data demonstrates good stability of the catalyst for five successive runs. Inhibition confirmation results suggest that surface-bound SO₄ •⁻ and HO• radicals both played a key role in degradation of AO7. Therefore, this material demonstrates a very efficient catalytic performance for the degradation of organic dyes.