Uranium U(VI) is toxic even at trace levels in aqueous solution and has adverse impacts on the health of human beings. In this study, a sugar-based magnetic pseudo–graphene oxide (SMGO) composite was prepared for the removal of U(VI) from groundwater by graphitization of sugar and ozonation, as well as synthesis with nano-size magnetite particles. To investigate the applicability of SMGO, U(VI)-spiked groundwater as well as U(VI)-contaminated groundwater samples were used in electromagnetic system. The pH-edge adsorption results suggest that adsorption occurs via an inner-sphere surface complex with an optimized pH of 4, where UO₂²⁺ is the dominant U(VI) species. The adsorption isotherm results confirmed that the adsorption of U(VI) onto SMGO occurred via a monolayer process on the homogeneous surface of SMGO and the maximum removal capacity of U(VI) was 28.2 mg/g. The high-gradient magnetic separation (HGMS) principle was applied to U(VI) removal using SMGO to facilitate recovery and the repeated use of the adsorbent during multiple batch cycles. The results indicated that the initial U(VI) concentration (439.1 μg/L) was reduced to a value less than the standard level of U(VI) for drinking water (30 μg/L) during six batch cycles and the separation efficiency was 95.2%. As such, SMGO and electromagnetic system using the HGMS principle are promising technologies for the removal of U(VI) in groundwater.

The application of sewage sludge (SS) in the soil can be a valuable way to increase its content of organic matter. However, the concentration of potentially toxic metal (PTM) in both SS and soil can hinder this route of management. Thus, the main objective of this work was to evaluate the compliance with the restrictions related to PTM contained in SS from wastewater treatment plants (WWTP) for agricultural land application. The regulatory constraints associated with SS and soil in respect to PTM (Cd, Cr, Cu, Ni, Pb, and Zn) were analyzed. These metals showed a deleterious effect on germination of Lepidium sativum seeds, and their phytotoxicity may be ranked as Cd > Cu > Cr(VI) > Cr(III) ~ Zn ~ Ni > Pb. Portuguese SS samples from different WWTP, from a national sludge management operator, and from the literature were considered. The results revealed that the content of these metals, in general, complies with the regulatory threshold values. The content of PTM in the soil is not restrictive to receive SS in at least 90% of the national territory. The assessment of ecological risk based on the geoaccumulation index (Igₑₒ), pollution index (PI), and potential ecological risk index (PERI) showed low risk for all metals. The exception was Igₑₒ of Cd, Cu, and Zn, which presented moderate to high level of pollution. According to the state of the art, no significant negative impacts have been detected on human health and the environment due to SS applications in the soil. Thus, in a country with low carbon content in the land and whenever compliance with regulations is achieved, the main route for SS management may be agricultural soil.

Dependence of rural population on traditional fuel sources namely biomass has increased because of easy accessibility and affordability. The use of biomass fuels results in many environmental and health-related hazards. Rural households have little awareness about the ill effects of using biomass energy sources. This study investigated the patterns of rural household energy use and identified the role of information on the effects of biomasses on human health, in addition to other factors influencing households’ choices of energy sources. For this purpose, primary data from 196 households were collected from four districts of the Punjab province in Pakistan. Results showed that use of clean energy sources was limited to basic appliances and 90% of the respondents depended on biomass fuels. Estimates of the multivariate probit model showed that awareness about adverse impacts of biomass fuels as energy sources were significantly related with the choice of energy sources. Further, household head’s education level, household income, landholding, children under the age of 5 years and higher number of adult females were significantly related with the cleaner energy source choices. Distance to market increased the probability of the use of biomass energy sources. The study concluded that awareness campaigns regarding the benefits of using clean energy sources should be launched through print and electronic media while targeting rural women.

The aim of this study was to find the concentration of lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn), and zinc (Zn) in feed, drinking water, and their residues in meat and internal organs in broilers at three different locations in Charsadda. For this purpose, a total of 48 representative water and feed samples and 240 meat and internal organs of broilers were collected. Significantly (P < 0.05) higher concentrations of Zn and Mn were found in feed samples. In water samples assessed for heavy metals, a significantly (P < 0.05) higher concentration of Pb was observed at Umerabad and Kula Dher as compared with Nisatta whereas a significantly (P < 0.05) higher concentration of Ni was recorded at Umerabad as compared with Nisatta and Kula Dher. Similarly, a significantly (P < 0.05) higher concentration of Mn in water was recorded at Kula Dher as compared with Nisatta and Umerabad. The concentration of Pb in water at all locations and the concentration of Ni at Umerabad were above the maximum permissible limits. A significantly (P < 0.05) higher concentration of Pb in the liver, breast, and thigh muscles and a significantly (P < 0.05) higher concentration of Mn in the liver, gizzard, breast, and thigh muscles of broilers were recorded at Kula Dher. A significantly (P < 0.05) higher mean concentration of Pb, Cd, Ni, Mn, and Zn was recorded in the liver as compared with the gizzard, breast, and thigh muscles. It was concluded from the present study that broiler farms near the roadside/canal and waste disposal site/wastewater drains cause accomulaiton of high concentrations of some heavy metals in meat and internal organs of broiler birds.

Six strains of Trichoderma spp. and Piriformospora indica have been studied for cadmium tolerance and bioaccumulation capacities by the poisoned food technique. A quantitative assay for Trichoderma spp. and P. indica was conducted in broth cultures supplemented with different cadmium concentrations (0–500 mg/l). In addition, the growth pattern of P. indica was determined by growing the fungus in a solid medium amended with eight concentrations of cadmium (0–200 mg/l). Generally, an increasing cadmium gradient in the culture medium suppressed the ability of fungi for cadmium accumulation. However, a negative relation was observed between the biomass production of fungi and cadmium uptake (q: mg/g biomass). Results showed that Trichoderma spp., especially T. simmonsii [UTFC 10063], are tolerant to cadmium toxicity and have a high ability to cadmium bioaccumulation. The biomass production of T. simmonsii [UTFC 10063] was significantly stimulated and increased by 46.1% when cadmium concentration increased from 0 to 125 mg/l. Moreover, 91.7 and 31.2% of cadmium removal was observed at 10 and 500 mg/l of the cadmium concentration, respectively. P. indica, however, showed a lower tolerance and removal efficiency for cadmium as compared with Trichoderma spp. Therefore, Trichoderma spp., especially T. simmonsii [UTFC 10063], can be exploited as potent bio-removal agents in cadmium-polluted aqueous solutions. Graphical abstract

Silver nanoparticles (AgNPs) were synthesized by incubating the mixture of AgNO₃ solution and whole-cell aqueous extracts (WCAEs) of Neochloris oleoabundans under light conditions. By conducting single-factor and multi-factor optimization, the effects of parameters including AgNO₃ concentration, pH, and extraction time were quantitatively evaluated. The optimal conditions in terms of AgNP yield were found to be 0.8 mM AgNO₃, pH 5, and 9-h extraction. The AgNPs thus synthesized were quasi-spherical with a mean particle diameter of 16.63 nm and exhibited decent uniformity as well as antibacterial activities, which may facilitate AgNP biosynthesis’s application in the near future.

This study provides a comprehensive assessment of firms’ operation and environmental protection polices in Nigeria and Ghana, where there has been a rising industrial growth amidst low regulatory and institutional frameworks. We analyze the extents to which firms’ adoption of environmental protection policies affect their performances. We use firm-level data of 842 firms (447 for Nigeria and 395 for Ghana) distributed across different regions of both countries for our descriptive and econometric estimations. We find, among other things, that firms’ adoption of internal policies on environmental protection is dismally low in both Nigeria (32%) and Ghana (17%), with policies focused on reducing solid (38%, Nigeria; and 35%, Ghana), gaseous (22%, Nigeria; and 44%, Ghana), and liquid (24%, Nigeria; and 14%, Ghana) pollution. Training appears to be an important intervention that can help improve firms’ adoption of such policies. We also found that firms’ adoption and implementation of environmental protection policies significantly improve their performance.

The significance of the natural geographical characteristics and ecological formation of the Coastline Mediterranean Countries (CMC) suggests a further examination of the dynamics of the renewable energy consumption (renewables) within the aforesaid region. As such, the dynamic impact of carbon emissions and the housing construction policy vis-à-vis dwellings, building and residential developments on the renewable energy consumption is investigated among Spain, France, Slovenia, Greece, Turkey, Lebanon and Israel. The dynamic autoregressive distributed lag methods of the pooled mean group, mean group and dynamic fixed-effect estimators are adopted for the empirical investigation over the periods 1999–2014 with real income and tourism employed as an additional variable. Using the PMG estimators, empirical results show that positive and statistically significant relationship exists among the variables in the long run. A 1% increase in housing construction policy, real income tourism and carbon emissions leads to (0.955), (8.622), (0.007) and (6.805) increase in renewable energy growth, while deviations in the short run significantly adjust to long-run equilibrium under an unforeseen disturbance at a moderate annual speed of about 73% annually. The inference from the short-run estimated coefficients indicates that housing construction policy is not a driver of renewables in Israel. From a policy standpoint, proposed strategic housing development policy and environmental pollution mitigation policy by policymakers should be void of causing a disservice toward the enrichment of renewable energy generation domestically in the panel countries.

Secondary organic aerosol (SOA) is a component of airborne particulate matter in urban areas. However, their toxicities remain incompletely understood. In this study, we investigated the oxidative and inflammatory potency of SOA derived from three different volatile organic compounds (α-pinene, m-xylene, and trimethylbenzene) using human bronchial epithelial cells (BEAS-2B) and macrophages (U937). In BEAS-2B cells, all types of SOA extracts increased the expression of the heme oxygenase 1 (HMOX1) and interleukin-8 (IL8) genes, a typical marker for oxidative stress and inflammatory responses, respectively. Among the three types of SOA, m-xylene-derived SOA showed the strongest induction of the HMOX1 and IL8 genes, and transcriptional activity via the antioxidant response element (ARE). A causal candidate for SOA induction of oxidative stress is 2,6-dimethyl-1,4-benzoquinone (DMBQ) because only this quinone compound increased the transcriptional activity via ARE among components tested in this study. Similar to the case of BEAS-2B cells, SOA extracts increased the expression of HMOX1 and IL8 genes in U937 cells, mainly through oxidative stress, but these responses in U937 cells were prolonged when compared with BEAS-2B cells. Together, these results show that SOA affects lung epithelial cells and macrophages mainly through oxidative stress and inflammation, suggesting their contribution to the development of respiratory diseases.

The use of modified fly ash for preparing porous sound-absorbing materials and the optimum conditions of fly ash modification were studied. The effects of sintering temperature, sintering time, forming pressure, and other experimental conditions on porous sound-absorbing materials were also investigated. Results showed that the average volume density of the finished product was 0.93 g/cm³, the compressive strength was approximately 1.2 MPa, and the average porosity was nearly 60%. The average sound absorption coefficient of the sample in a low-frequency band was approximately 0.353, and the overall average sound absorption coefficient was nearly 0.458. The optimal preparation conditions were as follows: sintering temperature was 1100 °C, sintering time was 5 h, and molding pressure was 2 MPa.