Biodigested coffee processing wastewater (CPW) presents a high organic load and does not meet the limits imposed by legislation (namely in Brazil) for discharge into water bodies. Anaerobic digestion generally cannot provide a satisfactory organic matter reduction in CPW as a significant fraction of recalcitrant compounds still persists in the treated effluent. So, this study aims to find alternative ways to remove refractory organic compounds from this wastewater in order to improve the biodegradability and reduce the toxicity, which will allow its recirculation back into the anaerobic digester. Three treatment approaches (Fenton’s oxidation - Approach 1, Coagulation/flocculation (C/F) - Approach 2, and the combination of C/F with Fenton’s process - Approach 3) were selected to be applied to the biodigested CPW in order to achieve that objective.The application of the Fenton process under the optimal operating conditions (initial pH = 5.0; T = 55 °C, [Fe³⁺] = 1.8 g L⁻¹ and [H₂O₂] = 9.0 g L⁻¹) increased the biodegradability (the BOD₅:COD ratio raised from 0.34 ± 0.02 in biodigested CPW to 0.44 ± 0.01 after treatment) and eliminated the toxicity (0.0% of Vibrio fischeri inhibition) along with moderate removals of organic matter (51.3%, 55.7% and 39.7% for total organic carbon – TOC, chemical oxygen demand – COD and biochemical oxygen demand - BOD₅, respectively). The implementation of a coagulation/flocculation process upstream from Fenton’s oxidation, under the best operating conditions (pH 10–11 and [Fe³⁺] = 250 mg L⁻¹), also allowed to slightly increase the biodegradability (from 0.34 to 0.47) and reduce the toxicity, whereas providing a higher removal of organic matter (TOC = 76.2%, COD = 76.5 and BOD₅ = 66.3% for both processes together). Approach 1 and Approach 3 showed to be the best ones, implying similar operating costs (∼74 R$ m⁻³/∼17 € m⁻³) and constitute an attractive option for managing biodigested CPW.

The comprehensive sources of particulate matter (PM) require air purification materials to possess both high filtration efficiencies and low air resistances in an effort to provide healthcare. However, the assembly of multiple-layered filters with different functions leads to high pressure drop and high operating cost. Therefore, a multifunctional air filter that can provide excellent air filtration capacity and healthcare is highly desired. Here, a novel bifunctional polyacrylonitrile/attapulgite hierarchical-structured filter with low air resistance and high adsorption capacity was designed and fabricated by embedding attapulgite nanorods during a facile electrospinning process. The hierarchical polyacrylonitrile/attapulgite membranes showed only a ∼64 Pa resistance for 0.1 μm PM. Another benefit of using the attapulgite nanorods is an adsorption effect for hazardous heavy metal ions that accompany airborne ultrafine PMs. Thereby this hierarchical membrane simultaneously exhibits an enhanced filtration performance and hazardous protection ability. Furthermore, due to the electret effect of the attapulgite nanorods, the surface potential of the membrane remains at above 2.2 kV after 600 min of continuous use, which could improve the air filtration efficiency and ensure the long-term service life of the filters. This work may provide a new approach for the design and development of multifunctional air filters for simultaneously capturing ultrafine PMs and any other accompanying hazardous chemicals.

A typical two-day start-up of municipal solid waste incinerators (MSWIs) can yield polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) and polychlorinated biphenyl (PCB) emission quantities around 10 times higher than those from an entire year of normal operations, as measured in this study. Thus, we tested specific control strategies for inhibiting the formation of chlorinated persistent organic pollutants (Cl-POPs), namely, extensively cleaning the ash accumulated beneath the furnace bed of the combustion chamber and deposited on the walls of the superheater and economizer and shortening the residence time of the flue gas in the optimal temperature window for Cl-POP formation. Also, we advanced the injection times of the activated carbon and lime slurry to lower Cl-POP emissions during start-up. Our findings show that these strategies were highly effective and reduced the Cl-POP emissions by > 98%, most of which (96.4–98.2%) was attributable to inhibiting formation. In summary, the proposed control strategies require no modifications to existing air pollution control devices, have little influence on operational cost, and are effective and feasible for the majority of MSWIs.

Soil washing using a strong chelating agent is a common practice for restoring contaminated soils, but significant soil fertility degradation and high operation costs are the major disadvantages. Washing soil with a dissolved organic matter (DOM) solution has been identified as a method that can moderate the loss of nutrients in the soil and enhance metal removal. The DOM solutions were extracted from waste sludge obtained from a local whisky distillery. Single chelating washing and chelate-DOM washing were carried out using ethylenediaminetetraacetic acid (EDTA), citric acid, and DOM solutions to remediate highly Cu-contaminated soil. Two-phase washing using 0.34 M citric acid and then 1500 mg L−1 DOM solution (pH 8.5) was found to be most favorable for the soil. With this treatment, 91% Cu was removed from the topsoil; the organic matter, cation exchange capacity, plant-available nitrogen, and available phosphate content increased by 28.1%, 103%, 17.7%, and 422%, respectively.

Recent technology developments have turned present-day unmanned systems into realistic alternatives to traditional marine animal survey methods. Benefits include longer survey durations, improved mission safety, mission repeatability, and reduced operational costs. We review the present status of unmanned vehicles suitable for marine animal monitoring conducted in relation to industrial offshore activities, highlighting which systems are suitable for three main monitoring types: population, mitigation, and focal animal monitoring. We describe the technical requirements for each of these monitoring types and discuss the operational aspects. The selection of a specific sensor/platform combination depends critically on the target species and its behaviour. The technical specifications of unmanned platforms and sensors also need to be selected based on the surrounding conditions of a particular offshore project, such as the area of interest, the survey requirements and operational constraints.

Animal manure is often anaerobically digested for the purpose of producing biogas. The digested manure, namely digestate, can be applied onto farmlands to enhance crop yields as it is abundant in nutrients. However, intensive livestock farming brings about manure exceeding the carrying capacity of lands nearby. Technologies focused on nutrient recovery from digestate have been studied recently, while many problems and challenges still remain unsolved. In this article, these recovery technologies are reviewed and compared, and challenges are deliberated. Ammonia stripping and struvite formation are easily operated technologies in comparison with membrane technologies. Amongst membrane technologies, electrodialysis reversal and forward osmosis are promising due to their high resistance to membrane fouling. Further studies should be focused on the operational cost, disposal of solid and liquid residuals and marketization of the recovered products.

The presence of antibiotics in animal manure represents a significant concern with respect to the introduction of antibiotic residues to the environment and the development of antibiotic-resistant pathogens. In this review, we have (1) compiled reported detections of antibiotics in poultry litter, swine manure, and cattle manure; and (2) discussed the treatment of antibiotics during conventional agricultural waste management practices. The most reported antibiotics in animal manure were fluoroquinolones, sulfonamides, and tetracyclines, all of which the World Health Organization has listed as critically important for human health. Relatively high treatment efficiencies were observed for antibiotics in composting, anaerobic digestion, and aerobic/anaerobic lagooning. Interestingly, active management of compost piles did not demonstrate a significant increase in antibiotic degradation; however, low- and high-intensity compost systems exhibited high treatment efficiencies for most antibiotics. Anaerobic digestion was not effective for some key antibiotics, including lincosamides and select sulfonamides and fluoroquinolones. Given the potential for energy recovery during anaerobic digestion of agricultural waste, efforts to optimize antibiotic degradation represent an important area for future research. Lagoons also exhibited fairly high levels of antibiotic treatment, especially for aerobic systems; however, the operational costs/complexity of these systems inhibit utilization at the full-scale. No overall trends in antibiotic treatment efficiency during these three agricultural waste management practices were observed. Finally, we posit that increased efforts to include analysis of antibiotic residues in animal manure in national surveillance programs will provide important information to address concerns over the continued use of antimicrobials in animal feeding operations.

As the proportion of renewable energy gradually increases, it brings challenges to the stable operation of the combined heat and power (CHP) system. As an important flexible resource, energy storage (ES) has attracted more and more attention. However, the profit of energy storage can’t make up for the investment and operation cost, and there is a lack of measurement system for multiple values, which seriously hinders the development of energy storage industry. Based on this, this paper makes a quantitative analysis on the system value of multiple energy storage in CHP. Firstly, the uncertain output of renewable energy is characterized by Kullback–Leibler (KL) divergence, and a two-level dispatching model is constructed based on the distributionally robust optimization method, so as to study the optimal operation strategy of the ES-CHP system. Secondly, based on the system value theory, this paper analyzes the system value of multiple energy storage, including internal value and external value, and constructs the value quantitative model, respectively. Finally, in a typical ES-CHP system, the system value of multiple energy storage is quantified. The effectiveness of the two-level model constructed in this paper can be seen from the simulation results, and the influence of different electricity prices on the system value of multiple energy storage is further analyzed.

Dissolved air flotation (DAF) is a widely used treatment process in drinking water and wastewater treatment plants despite high energy cost associated with operation and maintenance (accounts 50% of the total annual operation cost). In recent years, the focus has been diverted to optimizing or reducing energy, and a microbubble generation without a saturator was developed and used in small treatment facilities because of its simple structure. Thus, in this study, DAF and low-energy flash-pressurized flotation (FPF) efficacies were investigated in a pilot plant based on organic precursors, different molecular weight (MW) fractions, and disinfection byproduct reduction. The organic fractions with different MW was analyzed by liquid chromatography-organic carbon detector. Both DAF (550 kPa) and FPF (300 kPa) showed similar removal of dissolved organic carbon (DOC) and chromatographic DOC; however, the removal tendency of different MW fractions found was different. There was no significant difference in the removal of biopolymers, building blocks, and low molecular weight (LMW) neutrals for both DAF and FPF. Interestingly, the removal of LMW acids was found to be higher (93.8%) for DAF, whereas only 35.8% removal was observed for FPF. The total trihalomethanes concentration in a DAF-treated water sample was found to be 10% lower than that of FPF. Also, the reduction in haloacetonitriles was found to be slightly higher for a water sample treated by using DAF than by using FPF (1.5 and 1.8 μg L⁻¹, respectively). Moreover, the formation of chloral hydrate was observed to be the same (1.9 μg L⁻¹) for DAF- and FPF-treated water, with a total reduction of 40.6%. FPF with low pressure enabled a reduction in energy of around 55% when compared with DAF. Thus, FPF with low-pressure energy provides an alternative to DAF by reducing the annual operation cost and carbon footprint.

This paper investigates the impact of several comprehensive risks such as credit risk, capital risk, liquidity risk, and insolvency risks on Pakistani banks’ technical efficiency to assess the nexus between environmental investments with technical efficiency of banks. It also probes into the effect of competition among the Pakistani banks on technical efficiency. The data envelopment analysis (DEA) CCR and BCC models are used to estimate technical, purely technical, and scale efficiencies of the Pakistani banks. The Lerner index measures the banking competition. For estimation, the bootstrap truncated regression is used as an econometric technique. The robustness of results is cross-checked by using an alternative econometric technique (fractional logit regression) and an alternative competition measure (Boone indicator). The study revealed that capital risk has a positive impact on scale efficiency and insolvency risk has a negative impact on technical and pure technical efficiencies. Similarly, there is a positive significant relationship between technical efficiency and environmental investment. Furthermore, the competition has a significant negative effect on Pakistani banks’ technical and pure technical efficiencies. The results suggest that the efficiency of the Pakistani banks is significantly affected by bank size, taxation, diversification, operational cost management, banking development, trade openness, and infrastructure development, which ultimately promotes environmental efficiency and protection. The comparative study indicates that the state-owned banks have higher technical, pure technical, and scale efficiencies than the private, foreign, and Islamic banks.