The use of pyrolysis to produce oil from sludge by the evaporation–condensation process is a promising technique. However, the resulting lipids are prone to be acidized under exposure to oxygen, which can affect their quality and use. To eliminate the need for this oil separation process, the present work uses blended pyrolysis to preserve the oil in the char and to prevent it from deteriorating. At the same time, metals are eliminated to a secure level of combustion emissions. The sludge was pyrolyzed into a sintering fuel through blended pyrolysis with SiO₂, Al₂O₃, and sand. These materials are the main components of the sintered ceramsite obtained. Therefore, the influence of these substances and residence time on lipid formation and metal residue in the char were investigated. Non-blended pyrolysis required a 40-min duration, whereas sand-pyrolysis required 10 min to achieve the same yield. The concentration of C₁₆:₀ produced by blended pyrolysis with sand reached 2177 mg kg⁻¹, which is 57% higher than that of non-blended pyrolysis. Blended pyrolysis with SiO₂ required at least 20 min to immobilize As metal. In summary, blended pyrolysis simplifies the process, reduces time, and produces char with lipid-rich and low metal leaching, which can be used as a sintering fuel.

Water treatment residuals (WTRs) are by-products of the coagulation and flocculation phase of the drinking water treatment process that is employed in the vast majority of water treatment plants globally. Production of WTRs are liable to increase as clean drinking water becomes a standard resource. One of the largest disposal routes of these WTRs was via landfill, and the related disposal costs are a key driver behind the operational cost of the water treatment process. WTRs have many physical and chemical properties that lend them to potential positive reuse routes. Therefore, a large quantity of literature has been published on alternative reuse strategies. Existing or suggested alternative disposal routes for WTRs can be considered to fall within several categories: use as a pollutant and excess nutrient absorbent in soils and waters, bulk land application to agricultural soils, use in construction materials, and reuse through elemental recovery or as a wastewater coagulant. The main concerns and limitations restricting current and future beneficial uses of WTRs are discussed within. This includes those limitations linked to issues that have received much research attention such as perceived risks of undesirable phosphorous immobilisation and aluminium toxicity in soils, as well as areas that have received little coverage such as implications for terrestrial ecosystems following land application of WTRs.

Microbial removal of C and N in soil-based wastewater treatment involves emission of CO₂, CH₄, N₂O, and N₂ to the atmosphere. Water-filled pore space (WFPS) can exert an important control on microbial production and consumption of these gases. We examined the impact of WFPS on emissions of CO₂, CH₄, N₂O, and N₂ in soil microcosms receiving septic tank effluent (STE) or effluent from a single-pass sand filter (SFE), with deionized-distilled (DW) water as a control. Incubation of B and C horizon soil for 1 h (the residence time of wastewater in 1 cm of soil) with DW produced the lowest greenhouse gas (GHG) emissions, which varied little with WFPS. In B and C horizon soil amended with SFE emissions of N₂O increased linearly with increasing WFPS. Emissions of CO₂ from soil amended with STE peaked at WFPS of 0.5–0.8, depending on the soil horizon, whereas in soil amended with SFE, the CO₂ flux was detectable only in B horizon soil, where it increased with increasing WFPS. Methane emissions were detectable only for STE, with flux increasing linearly with WFPS in C horizon soil, but no clear pattern was observed with WFPS for B horizon soil. Emissions of GHG from soil were not constrained by the lack of organic C availability in SFE, or by the absence of NO₃ availability in STE, and addition of acetate or NO₃ resulted in lower emissions in a number of instances. Emission of ¹⁵N₂ and ¹⁵N₂O from ¹⁵NH₄ took place within an hour of contact with soil, and production of ¹⁵N₂ was much higher than ¹⁵N₂O. ¹⁵N₂ emissions were greatest at the lowest WFPS value and diminished markedly as WFPS increased, regardless of water type and soil texture. Our results suggest that the fluxes of CO₂, CH₄, N₂O, and N₂ respond differently to WFPS, depending on water type and soil texture.

Widely consumed benzodiazepine drugs are emerging contaminants, some of them being endocrine disruptors. Although many of these drugs remain in wastewater even after conventional treatment, innovative treatability studies are still sparse. The aim of this study was to investigate the efficiency of heterogeneous photocatalysis using synthesized composites based on TiO₂ and activated carbon (TiO₂/AC) as catalysts under sunlight-simulated irradiation. Different ratios and calcination temperatures were tested for the synthesis, and the composite with the best photocatalytic efficiency (based on methylene blue dye removal from water solution) was the one formed by 10% AC calcined at 400 °C (TiO₂/AC10%). This composite was applied in heterogeneous photocatalysis to remove bromazepam, clonazepam, and diazepam at environmentally relevant concentrations (100 μg/L). Such treatment approach has not been reported in the literature to date. Independent variables such as catalyst concentration, pH, and sunlight-simulated irradiation were studied using design of experiments (DoE) to find conditions that provide maximum removal efficiency. TiO₂/AC10% powder was characterized by SEM, XRD, BET, and diffuse reflectance. Under feasible optimized conditions, the efficiency of TiO₂/AC10% to remove benzodiazepine drugs from water was > 97.5%, which is much higher than the removal obtained with commercial catalyst and all controls.

Pharmaceutically active compounds are carried into aquatic bodies along with domestic sewage, industrial and agricultural wastewater discharges. Psychotropic drugs, which can be toxic to the biota, have been detected in natural waters in different parts of the world. Conventional water treatments, such as activated sludge, do not properly remove these recalcitrant substances, so the development of processes able to eliminate these compounds becomes very important. Advanced oxidation processes are considered clean technologies, capable of achieving high rates of organic compounds degradation, and can be an efficient alternative to conventional treatments. In this study, the degradation of alprazolam, clonazepam, diazepam, lorazepam, and carbamazepine was evaluated through TiO₂/UV-A, H₂O₂/UV-A, and TiO₂/H₂O₂/UV-A, using sunlight and artificial irradiation. While using TiO₂ in suspension, best results were found at [TiO₂] = 0.1 g L⁻¹. H₂O₂/UV-A displayed better results under acidic conditions, achieving from 60 to 80% of removal. When WWTP was used, degradation decreased around 50% for both processes, TiO₂/UV-A and H₂O₂/UV-A, indicating a strong matrix effect. The combination of both processes was shown to be an adequate approach, since removal increased up to 90%. H₂O₂/UV-A was used for disinfecting the aqueous matrices, while mineralization was obtained by TiO₂-photocatalysis.

Polychlorinated diphenyl ethers (PCDEs) are a class of potential persistent organic contaminants, which have been widely detected in aquatic environment. In the present study, the effects of 3,4,4′-tri-CDE and its two possible metabolites (2-MeO-3′,4,4′-tri-CDE and 2-HO-3′,4,4′-tri-CDE) on oxidative stress biomarkers in liver of Carassius auratus were evaluated. The fish were treated with these three compounds at different doses (0.1, 1, and 10 μg/L) via semi-static water exposure. The liver samples were individually taken at 3, 7, and 21 days for analysis of oxidative stress indicators, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), and malondialdehyde (MDA). Compare to the control group, the hepatic antioxidant enzyme activity and GSH contents showed significant decreases (p < 0.05) at high-dose treatment (10 μg/L) and prolonged exposure time (21 days) in most of the toxicant-treated groups, indicating the occurrence of oxidative stress in fish liver. However, no consistent trend of the variations of antioxidant parameters was observed at low doses (0.1 and 1 μg/L). Meanwhile, the lipid peroxidation was significantly induced with extending exposure time and increasing dose. In addition, the toxicity order of three compounds was discussed using the integrated biomarker response (IBR) index. Notably, 2-HO-3′,4,4′-tri-CDE was indicated to cause the most severe hepatic oxidative stress.

This study aims to investigate the long-run and causal effects of energy consumption, economic growth, urbanization, and trade openness on CO₂ emissions in Turkey using newly developed econometric techniques. To our best knowledge, there has been no study examining the relationship between CO₂ emissions, energy consumption, trade openness, urbanization, and economic growth in Turkey. Therefore, this study proposes to fill this gap in the literature. In this study, we use time series data covering the years between 1960 and 2015. To capture long-run effects, we used ARDL, FMOLS, and DOLS estimators, while wavelet coherence technique is used to explore causal effects among the variables. Our results reveal that (i) there is a long-run equilibrium relationship between CO₂ emissions and energy consumption, economic growth, urbanization, and trade openness; (ii) in the long-run, CO₂ emission in Turkey is significantly triggered by energy consumption, economic growth, and urbanization; and (iii) the results of the wavelet coherence–based causality test provide supportive evidence to the long-run estimations of this study.

Methane (CH₄) and nitrous oxide (N₂O) are two important greenhouse gases (GHG) and contribute largely to global warming and climate change. The impact of physiological characteristics of rice genotypes on global warming potential (GWP) and greenhouse gas intensity (GHGI) is not well documented. A 2-year field experiment was conducted with eight summer rice varieties: Dinanath, Joymoti, Kanaklata, Swarnabh, IR 64, Tapaswami (modern varieties), Number 9, and Jagilee Boro (indigenous varieties) for two successive seasons (December–June, 2015–2016 and December–June, 2016–2017) to estimate their GWP and GHGI. The GWP of the rice varieties ranged from 841.52 to 1288.67 kg CO₂-equiv. ha⁻¹ and GHGI from 0.184 to 0.854 kg CO₂-equiv. kg⁻¹ grain yield. Significant differences (p < 0.05) in seasonal GHG emission, GWP, GHGI, CEE (carbon equivalent emission), photosynthetic efficiency, stomatal conductance, transpiration rate, and grain productivity among the rice varieties were observed during the investigation. A good correlation of GWP (p < 0.01) was recorded with rate of stomatal conductance and transpiration rate of the varieties. The present study reveals a strong relationship between plant biomass (p < 0.01) with GWP and CEE of the rice varieties. The variety IR 64 and Number 9 are identified as the most suitable variety with lowest GWP (909.85 and 876.68 kg CO₂-equiv. ha⁻¹ respectively) and GHGI (0.192 and 0.227 kg CO₂-equiv. kg⁻¹ grain yield respectively) accompanied by higher grain productivity (4839 and 3867 kg ha⁻¹ respectively). Observations from the study suggest that agricultural productivity and GHG mitigation can be simultaneously achieved by proper selection of rice genotypes.

The Sub-Saharan Africa (SSA) is far lag behind the sustainable targets that set out in the United Nation’s Sustainable Development Goals (SDGs), which is highly needed to embark the priorities by their member countries to devise sustainable policies for accessing clean technologies, energy demand, finance, and food production to mitigate high-mass carbon emissions and conserve environmental agenda in the national policy agenda. The study evaluated United Nation’s SDGs for environmental conservation and emission reduction in the panel of 35 selected SSA countries, during a period of 1995–2016. The study further analyzed the variable’s relationship in inter-temporal forecasting framework for the next 10 years’ time period, i.e., 2017–2026. The parameter estimates for the two models, i.e., CO₂ model and PM₂.₅ models are analyzed by Generalized Method of Moment (GMM) estimator that handle possible endogeneity issue from the given models. The results rejected the inverted U-shaped Environmental Kuznets Curve (EKC) for CO₂ emissions, while it supported for PM₂.₅ emissions with a turning point of US$5540 GDP per capita in constant 2010 US$. The results supported the “pollution haven hypothesis” for CO₂ emissions, while this hypothesis is not verified for PM₂.₅ emissions. The major detrimental factors are technologies, FDI inflows, and food deficit that largely increase carbon emissions in a panel of SSA countries. The IPAT hypothesis is not verified in both the emissions; however, population density will largely influenced CO₂ emissions in the next 10 years’ time period. The PM₂.₅ emissions will largely be influenced by high per capita income, followed by trade openness, and technologies, over a time horizon. Thus, the United Nation’s sustainable development agenda is highly influenced by socio-economic and environmental factors that need sound action plans by their member countries to coordinate and collaborate with each other and work for Africa’s green growth agenda.