Rodents infest urban environments, causing damage and acting as vectors for disease transmission. Currently, anticoagulants are the most widely used chemical rodenticides, and their extensive and widespread use can contaminate the environment. To ensure effectiveness and avoid accumulation of rodent baits in the environment, it is important to evaluate how long rodent baits maintain their palatability and efficacy. In rodent control programs, rodent baits are placed in locations such as sewers, but after a few days, baits appear altered, causing doubts about the control efficacy. For this reason, baits are replaced periodically, which increases costs and generation of chemical waste. The objective of this study was to evaluate the palatability and efficacy of commercial paraffin-type rodent bait blocks placed in sewers in São Paulo City over a period of 90 days. Bait blocks were placed in sewers and collected after 30, 60, and 90 days. Additionally, in a laboratory two-choice test, wild-caught urban Norway rats were offered 40–60 g of bait and an equal volume of standard rat pellets. The amount of bait and rat pellet consumed was registered, the palatability was calculated, and the efficacy was measured as the percentage mortality over 14 days. The results showed that, even when they had an altered appearance, bait blocks remained palatable to the rats and were effective after at least 90 days. Leaving bait blocks for longer periods could be an effective strategy for reducing costs and could help to ensure the control of urban rodents in an environmentally sustainable way.

A new synergistic method was developed to inactivate marine microalgae using combined longwave ultraviolet (UVA) and shortwave ultraviolet (UVC)-photocatalysis (UVA/UVC-TiO₂) technology. Five kinds of representative marine microalgae in three phyla were used as inactivating targets to examine the inactivation effect. Compared with the photocatalytic systems using UVA or UVC alone as the light source, the algae inactivation ratio in the newly developed system increased by 0.31 log or 0.19 log, and the chlorophyll a removal rate increased by 17.5% or 9.7%, respectively. Total suspended solids (TSS) of the seawater did not cause remarkable impact on the inactivation process, and the increase of UV radiation intensity improved the treatment effect significantly. Further, UVA/UVC-TiO₂ treatment causes irreversible damage to microalgae cell membrane. The content of lipid peroxidation product malondialdehyde (MDA) increased rapidly within a short period of time, and a large number of proteins leaked out. The results of this study indicated that UVA/UVC-TiO₂ was an effective method to solve the challenge of efficient inactivation of plankton in ballast water containing a high density of suspended matter.

The present work studies the effect of butanol in thumba (Citrullus colocynthis) biodiesel in an IDI CI engine at varying percentages of 5 and 10% in 15 and 10% thumba biodiesel respectively with 80% diesel in each blend. Another blend was introduced with 80% diesel and 20% biodiesel without any additive. The experiment was conducted in a single cylinder four-stroke IDI CI engine at 1500 rpm varying from 25% to full-load (100%) conditions. The results showed diesel with less bio diesel and higher butanol in percentage gives good performance and emission compared to diesel at higher loads. Blend containing 10% bio diesel, 10% butanol, and 80% diesel (D80B10Bu10) showed higher cylinder pressure, heat release rate, BThE, and less NOₓ. Biodiesels gave less UHC, CO emissions. In this work, multi-objective fuzzy-based genetic algorithm was introduced for the best fit result. Four parameters were used for optimization (BSFC, BThE, CO, NOₓ). The result from genetic algorithm was taken for validation and the optimized result was found adequate after validation.

TiO₂ is employed as both photocatalytic and structural materials, leading to its applications in external coatings or in interior furnishing devices, including cement mortar, tiles, floorings, and glass supports. The authors have already demonstrated the efficiency of photoactive micro-sized TiO₂ and here its industrial use is reported using the digital printing to coat porcelain grés slabs. Many advantages are immediately evident, namely rapid and precise deposition, no waste of raw materials, thus positively affecting the economy of the process. Data for the thin films deposited by digital printing were compared with those obtained for the conventional spray method. The use of metal-doped TiO₂ is also reported so that the photoactivity of these materials can be exploited even under LED light. The digital inkjet printed coatings exhibited superior photocatalytic performance owing to both higher exposed surface area and greater volume of deposited anatase, as well as the greater areal distribution density of thinly and thickly coated regions. Moreover, the presence of TiO₂ doped silver increased the efficiency of the materials in NOx degradation both under UVA and LED lights.

The successful establishment of China’s emission trading scheme (ETS) could lead the next generation of global climate carbon markets in industrializing and developing countries. The allocation of ETS revenue from auctioning carbon emission allowance is important for the achievement of China’s joint targets of economic growth, mitigation, and welfare improvement. This study develops a dynamic CGE model to evaluate the effects of different ETS revenue allocation mechanisms and identifies the proper mechanism for China’s ETS design. Ten scenarios including business as usual (BAU), no ETS revenue allocation incentive (NA) and other eight ETS revenue allocation scenarios are designed. Simulation results indicate that the tradeoff between economic cost and environmental benefit exists under different ETS revenue allocation mechanisms. ETS revenue is suggested to allocate to household sector through reducing indirect tax and, after 2020, a certain proportion of ETS revenue could be allocated to production sector for improving energy-saving technology (i.e., STP mechanism). This study provides references for policymakers in China to design effective and realistic ETS-related policies. A similar study could be conducted to explore the proper ETS and the revenue allocation policies in other countries that have similar national conditions to China, such as other BRICS countries.

Antibiotics are becoming ubiquitous emerging contaminants in the aquatic environments due to their large amount of production and extensive application, which have received increasing public concern. In this paper, the degradation and mineralization of sulfamethoxazole (SMX) by ionizing radiation in the presence of Fe₃O₄ as Fenton-like catalyst were evaluated, the influencing factors, such as the initial SMX concentration, initial pH, water matrix, and radical scavenger, etc. were examined. The results demonstrated that SMX could be efficiently degraded. The addition of Fe₃O₄ could improve the degradation efficiency of SMX and increased the dose constant at various SMX initial concentrations. More than 98% of SMX was degraded in Fe₃O₄/gamma radiation system at a wide range of pH (about 3.0–11.0). The mineralization of SMX in the presence of Fe₃O₄ was increased by 200%. Adding free radical scavenger (tert-butyl alcohol) inhibited the degradation of SMX. The addition of Fe₃O₄ enhanced the dose constant of ·OH, indicating that Fe₃O₄ promoted the formation of hydroxyl radicals (·OH) and then improved SMX degradation and mineralization. The degradation efficiency of SMX in secondary effluent of WWTP decreased from 100 to 84% in secondary effluent compared with that in deionized water. The intermediate products during the degradation of SMX by ionizing radiation were identified by high-performance liquid chromatography, and a possible pathway of SMX degradation in such a system was tentatively proposed. Graphical abstract Schema illustration of SMX degradation by irradiation in the presence of Fe₃O₄

Thorium (Th) is one of the main sources of natural radiation to ecosystems. However, data regarding Th concentrations in rocks, soil, water and sediments are currently scarce. Accordingly, this study aimed to establish background concentrations and quality reference values (QRVs) for Th in the environmentally impacted Ipojuca River catchment in Brazil, where the weathering of granites releases Th into the environment. Additionally, the study aimed to calculate Th fluxes in water, and both bed and suspended sediment. The mean Th concentration in the study catchment soils was 28.6 mg kg⁻¹. The QRV for Th was estimated to be 21 mg kg⁻¹ and 86.3 Bq kg⁻¹. Bed and suspended sediment–associated concentrations ranged from 2.8 to 32.9 mg kg⁻¹. Suspended sediment–associated discharge (3.42 t year⁻¹) accounted for more than 99% of the total Th flux, while the dissolved phase transport was negligible in comparison. At the downstream cross section in the study catchment, suspended sediment samples exhibited Th concentrations similar to those observed in rivers impacted by mining activities. The discharge of sediment to the ocean from the study area is mainly triggered by soil erosion processes in the hotspot region (middle-inferior course). It is essential to identify Th hotspots before establishing environmental policies regarding human health and environmental protection.

The increasing anthropogenic inputs of Pb and Cd into China’s Nen River (Qiqihar section) owing to rapid urbanization in the past 50 years may pose ecological risks to the river’s aquatic system. To confirm this hypothesis, we determined the Pb and Cd concentrations in the sediments of the Nen River flowing across Qiqihar City by comparing the control group (samplings in the Nen River branch bypassing the city) and bioaccumulation along the food chain. We found significantly higher Pb concentrations in the sediments than in the control group (39.21 mg kg⁻¹ dry weight [dw] vs. 22.44 mg kg⁻¹ dw; p < 0.05). However, the difference between the Cd contents of the two groups was nonsignificant (0.33 mg kg⁻¹ dw vs. 0.30 mg kg⁻¹ dw) (p = 0.07). Accumulated Pb and Cd in the sediments pose a medium risk to the system of Nen River according to the result of risk assessment code analysis. The increased Pb and Cd levels along the food chain had adverse health effects in the species at the top level of the food chain. For example, the feathers of Corvus frugilegus and Sterna hirundo contained 0.28–2.25 mg kg⁻¹ dw of Cd. These values are considered potentially toxic to common avian species. The bone Pb level of C. frugilegus ranged from 4.82 to 7.41 mg kg⁻¹ dw within the increasing Pb range (2–15 mg kg⁻¹ dw) of common water birds. The inputs of Pb and Cd into the local environment should be reduced for the preservation of aquatic system health.

A series of activated carbons (ACs) were prepared by modifying a commercial AC by physical activation using CO₂ during different activation times. The ACs were designated as F, F12, F24, and F40 corresponding to the activation times of 0, 12, 24, and 40 h, respectively. The surface area, total pore volume, micropore volume, and mean micropore width were determined for all the ACs. The textural properties of the modified ACs increased substantially with the activation time, and the capacity of the ACs for adsorbing diclofenac (DCF) was almost linearly dependent upon the surface area of the ACS. The maximum adsorption capacities of F, F12, F24, and F40 carbons towards diclofenac (DCF) from aqueous solution were 271, 522, 821, and 1033 mg/g, respectively. Hence, the adsorption capacities of ACs were considerably enhanced with the activation time, and F12, F24, and F40 carbons presented the highest adsorption capacities towards DCF reported in the technical literature. The F40 adsorption capacity was at least twice those of other carbon materials. The adsorption capacities decreased by raising the pH from 7 to 11 due to electrostatic repulsion between the ACs surface and anionic DCF in solution. The removal of DCF from a wastewater treatment plant (WWTP) effluent was effectively carried out by adsorption on F40. Hence, the capacity of ACs for adsorbing DCF can be optimized by tailoring the porous structure of ACs.

Rural household energy consumption is an important component of national energy consumption. This paper explores the rural household energy consumption status and influencing factors on different sources of rural household energy consumption in western China. Using data from a survey of 240 households conducted in 2017, this study finds that rural households’ energy consumption structure in the study area is a combination of traditional biomass energy and commercial energy sources. Fuelwood is the most commonly used fuel in the study area, while modern energy sources only occupy a low proportion. Rural household energy consumption is influenced by various factors. Individual perceptions of climate change, social trust and networks, and households’ socio-economic and demographic factors (gender, age, education, income per capita, household size, household location, and number of household appliances) are identified as having significant effects on rural households’ consumption of biomass and commercial energies. The research results provide implications for policy makers to formulate related rural energy policies to improve the rural energy consumption structure and future energy policy design in China and other developing countries.