With the exacerbation of industrialization, water treatment has become a necessary step for the eradication of dyes, heavy metals, oils, pharmaceuticals, and illicit drugs. These pollutants pose an impending threat to the health of humans by causing chronic or acute poisoning. Albeit they are noxious, the presence of some metals in lower concentrations is indispensable for human health. 3D printing (additive manufacturing) (3DP) can contrive nearly any complicated geometric form in a wide array of objects among various scales by a layer-wise method of manufacturing, which is more indubitably designed than any other conventional method. 3DP could remodel the existing patterns of membrane housing and possibly trim down the power demand and chemical use in saltwater desalinating and wastewater purification plants. Membranes that are 3D printed with correctly arranged apertures and shapes enhance material transport and flow athwart the surface of the membrane and at once lessen membrane soiling. This kind of technology forges membranes of polymers, biopolymers, alloys, metals, and ceramics via computer-aided design (CAD). A polylactic acid porous super-hydrophobic membrane with pore size in the range 40–600 μm showed 99.4% oil-water separating power and 60 kL h⁻¹ m⁻² flux when the pore size was tuned to 250 μm via CAD-aided 3D printing technology. This review focuses on the ability of 3D-printed membranes for the efficient removal of toxic pollutants from wastewater. Graphical abstract 3D-printed membranes for water treatment

Pharmaceutical compounds such as the non-steroidal anti-inflammatory drug ibuprofen and the artificial estrogen 17α-ethynylestradiol (EE2) are contaminants of emerging concern in freshwater systems. Globally, human pharmaceutical use is growing by around ~ 3% per year; yet, we know little about how interactions between different pharmaceuticals may affect aquatic ecosystems. Here, we test how interactions between ibuprofen and EE2 affect the growth and respiration of streambed biofilms. We used contaminant exposure experiments to quantify how these compounds affected biofilm growth (biomass), respiration, net primary production (NPP) and gross primary production (GPP), both individually and in combination. We found no effects of either ibuprofen or EE2 on biofilm biomass (using ash-free dry mass as a proxy) or gross primary production. Ibuprofen significantly reduced biofilm respiration and altered NPP. Concomitant exposure to EE2, however, counteracted the inhibitory effects of ibuprofen upon biofilm respiration. Our study, thus, demonstrates that interactions between pharmaceuticals in the environment may have complex effects upon microbial contributions to aquatic ecosystem functioning.

The particle deposition on the surface of solar photovoltaic panels deteriorates its performance as it obstructs the solar radiation reaching the solar cells. In addition to that, it may cause overheating of the panels, which further decreases the performance of the system. The dust deposition on the surfaces is a complex phenomenon which depends on a large number of different environmental and technical factors, such as location, weather parameters, pollution, tilt angle and surface roughness. Hence, it becomes crucial to investigate the key parameters which influence dust accumulation and their interrelations. In this study, the phenomenon of dust deposition was studied experimentally in the urban area at one of the most polluted cities of Europe, i.e. Kraków, Poland. Solar photovoltaic panels tilted at angles 15° and 35° were exposed to atmospheric conditions for the period of eighteen months from 6 May 2017 until 30 November 2018. Dust samples were collected from the panels for the exposure period which ranged from one day up to 11 days. It was observed that lower tilt angles promote dust accumulation on the surface and that in the absence of wind and rain, deposition of particles on the surface of panels follows the pattern of concentration of PM2.5 and PM10 in the atmosphere. Wind and rainfall usually promote the removal of dust particles from the surface. However, rainfall not always aids the cleaning of panels, and it was observed that low-intensity rain results in a very low rate of PMs in the air and in much higher than typical dust deposition on the panel surface. It also accelerates the cementing of already deposited dust. It was only rainfall whose intensity was at least 38 mm/h that was sufficient to remove dust particles from the panels.

Diclofenac (DCF) exists extensively in sewage treatment plant effluent, and it is one of the most reported environmental pharmaceutical contaminants. In this work, the photocatalytic degradation of DCF by titanium dioxide (TiO₂) in pure water under visible light and the influence of humic acids (HA) (as a kind of dissolved organic matter (DOM), phosphate and ferrous ion (Fe²⁺)) were investigated. The results showed that the lower the pH was, the better the degradation effect of DCF under acidic conditions was. Different concentrations of DOM, phosphate ion, and Fe²⁺ could inhibit the degradation of DCF, and the higher the concentration was, the stronger the inhibition was. Different concentrations of chloride ions had little effect on the degradation. A slight elimination (8–12.9%) of total organic carbon (TOC) was observed during the mineralization of DCF with and without DOM and inorganic ions, indicating poor mineralization during the process of photocatalytic degradation, and DOM, phosphate, and Fe²⁺ had little effect on DCF mineralization. Furthermore, hydroxyl radicals, superoxide radicals, and singlet oxygen radicals were present during the photocatalytic degradation of DCF. DOM and inorganic ions could inhibit the intensity of hydroxyl radical and promote superoxide radicals (O₂–) and singlet oxygen (¹O₂) to varying degrees. Finally, the degradation mechanism and main products were analyzed by liquid chromatography–mass spectrometry (LC–MS), and nine possible intermediates were detected. Hydroxylation, dechlorination, cyclization, and oxidation were the main degradation mechanisms. However, DOM, phosphate, and Fe²⁺ did not affect the type of intermediate products in terms of the mass-to-charge ratio. This paper mainly studied the mechanisms of different influencing factors in simulated environments to provide a theoretical basis for the degradation of DCF in wastewater treatment plants. Graphical abstract

Under the extensive implementation of ultra-low emission (ULE) facilities in coal-fired power plants of China, sulfur trioxide (SO₃) has received increasing attention due to its impact on human health and operation safety of power plants. However, systematic research and evaluation for controlling SO₃ emission in various ULE facilities are still lacking. Here, a systematic study was conducted based on 378 in situ performance evaluation tests carried out in 148 coal-fired power plants. The results illustrate that the SO₂/SO₃ conversion rate of the selective catalytic reduction devices can be controlled within 1% before and after ULE retrofit. Also, the synergistic removal efficiency of SO₃ in the low-low-temperature electrostatic precipitator and the wet electrostatic precipitator can be higher than 70%. The removal efficiency of SO₃ in the wet limestone-gypsum flue gas desulfurization scrubber is 33–64% before ULE and 31–81% after, and the average efficiency of the double scrubbers is 8.7% higher than that of the single scrubber. Due to the different SO₃ removing abilities of various technologies, the overall efficiency of SO₃ removal is in the range between 27 and 95% adopting different ULE technical routes. Average concentration of SO₃ emission can be decreased by 51.8% after ULE application.

Six elemental chlorine-free bleaching sequences were studied to see their effect on quality of pulp produced and quantity of pollutants generated during bleaching of wheat straw soda pulp. Impact of parameters like adsorbable organic halogens (AOX), chemical oxygen demand (COD), biochemical oxygen demand (BOD) and sodium adsorption ratio, pH and total dissolved solids generated during bleaching on environment as index of global pollution (IGP) was also studied. The purpose of the study was to investigate six elemental chlorine-free bleaching sequences to compare the pulp quality, effluent properties and their impact on environment. An oxygen delignification stage before D₀EOPD bleaching sequence reduced the AOX, COD, colour and BOD by 44%, 42%, 36% and 33%, respectively, whereas an ozonation stage before bleaching reduced the same by 70%, 66%, 73% and 60%, respectively, as compared to those of control. The generation of pollutants as AOX, COD, colour and BOD was reduced further by 88%, 80%, 90% and 77%, respectively, with the use of short bleaching sequences (DD, DP and PD) as compared to those of control. The environmental impact as IGP with D₀EOPD bleaching sequence was 2.65 which got reduced to 1.44 with bleaching sequence OZPD. Bleaching sequence OZD₀EOPD was found the most effective for improving brightness and whiteness of the pulp, whereas short bleaching sequence OZPD found the most effective for reducing generation of pollutants during bleaching among different bleaching sequences studied. Graphical abstract

Today, environmental problems are increasing and threatening nature and human health. Air pollution is at the top of this threat. Air, the main source of life, is indispensable for humans and living things. Therefore, air pollution causes mass results. Many air pollution studies and many solution techniques have been proposed in the literature to deal with the air pollution problem. In this study, it is called analytical hierarchy process (AHP) and geographic information systems (GIS), which is one of the multi-criteria decision making methods used in the investigation of air pollution in Iğdır city center and its four districts: Tuzluca, Iğdır Central, Karakoyunlu, and Aralik. In this study, spatial analysis of the pollutant parameters using the GIS-AHP technique was performed with the help of the data obtained from Iğdır Weather Monitoring Stations. By determining the pollutant parameters, pollution distribution maps were created, and station-based statistics were evaluated with dynamic mapping. For the first time, 15 parameters of weather and topographic features were used. Based on this result, it is obvious that Iğdır center is the worst place in the air pollution problem for GIS-AHP method. It varies for 15 parameters using GIS-AHP, compared with the review of locations on a daily basis. The aim of this study is primarily to investigate possible places of air pollution. Also, by comparing the results of two methods, GIS and AHP, more accurate results are given.

Wind energy continues to make inroads in Africa due to falling costs and technological advancements. Most African countries are planning, exsiccating and connecting their renewable energy projects with national grid system with giving high propriety to energy security, sustainable energy consumption and low carbon emission. Many policies have been enacted by countries to promote the scaling up of wind energy and renewable energy in particular, across the globe. However, these policies have mixed effects on the deployment of wind energy. For this purpose, current study used panel data and fixed effects model for 17 African countries with wind installed generation capacity to determine the driver of wind energy development on the African continent between 2008 and 2017. The variables were grouped into three thematic areas: policy, socioeconomic, and country-specific factors. After conducting the analysis, socioeconomic variables (GDP, CO₂, energy use) and energy security variables (energy import, electricity consumption) have significant effects in determining the scaling up of wind energy in Africa. However, the policy variables of FITs, licensing during, and Tax did not have significant effects on wind energy capacity addition for the case of Africa. This study adds to the drivers of nascent wind energy deployment literature in Africa. This study suggests that set of effecitive policies are deem necessary to scale up wind energy in Africa.