Phosphorus (P), an essential element for living cells, is present in different soluble and adsorbed chemical forms found in soil, sediment, and water. Most species are generally immobile and easily adsorbed onto soil particles. However, P is a major concern owing to its serious environmental effects (e.g., eutrophication, scale formation) when found in excess in natural or engineered environments. Commercial chemicals, fertilizers, sewage effluent, animal manure, and agricultural waste are the major sources of P pollution. But there is limited P resources worldwide. Therefore, the fate, effects, and transport of P in association with its removal, treatment, and recycling in natural and engineered systems are important. P removal and recycling technologies utilize different types of physical, biological, and chemical processes. Moreover, P minerals (struvite, vivianite, etc.) can precipitate and form scales in drinking water and wastewater systems. Hence, P minerals (e.g., struvite, vivianite etc.) are problems when left uncontrolled and unmonitored although their recovery is beneficial (e.g., slow release fertilizers, sustainable P sources, soil enhancers). Sources like wastewater, human waste, waste nutrient solution, etc. can be used for P recycling. This review paper extensively summarizes the importance and distribution of P in different environmental compartments, the effects of P in natural and engineered systems, P removal mechanisms through treatment, and recycling technologies specially focusing on various types of phosphate mineral precipitation. In particular, the factors controlling mineral (e.g., struvite and vivianite) precipitation in natural and engineered systems are also discussed.

Climate change is a global challenge faced by everyone, but the developing countries are highly vulnerable to variations in the environment. This research focuses on the Punjab province of Pakistan and evaluates the impacts and consequences of climate change on general public at local and divisional level. In order to cope with the impacts of climatic changes at all levels, especially divisional level, raising reliable awareness and dispersing actionable knowledge regarding mitigating and adapting measures is significantly important. Therefore, recognition of information gaps, improvements in the level of alertness, and development of preventive measures in each sector is imperative. The impacts of climate change are observed across the country through gradual increase in temperature, human health issues, pest diseases, droughts, floods, and irregular weather patterns leading to changes in lifestyles, and these issues are likely to continue in the future. The main cause of climate change in Punjab, Pakistan, can be attributed to excessive release of greenhouse gases (GHG) into the atmosphere due to human activities involving inefficient energy usage, rapid urban expansion, improper waste management, industrial development, increasing transportation, agricultural activities, and livestock mismanagement. The findings of this study revealed that transportation sector is the major source of GHG emissions in the country, followed by industrialization and waste, at national, as well as divisional, level. The extent of impacts of climate change at divisional level is distinguishable and displayed a direct relationship with climate, geography, variation of effects, and modes of production in various regions of Punjab. The study strategically investigated all nine divisions of the province for comprehensive understanding of climate change phenomenon, and the results indicated that nearly three-fourths of the respondents have never indulged in taking steps towards climate change mitigation and adaptation. The study adopted a mixed (qualitative and quantitative) approach where the findings can act as set of guidelines for governmental authorities in formulating, assisting in preparation, instructing, and guiding policies for climate change mitigation and adaptation at national, local, and divisional levels. Graphical abstract

A new set up of the integral mechanistic BIO_ALGAE model that describes the complex interactions in mixed algal-bacterial systems was developed to overcome some restrictions of the model. BIO_ALGAE 2 includes new sub-models that take into account the variation of microalgae and bacteria performance as a function of culture conditions prevailing in microalgae cultures (pH, temperature, dissolved oxygen) over daily and seasonal cycles and the implementation of on-demand dioxide carbon injection for pH control. Moreover, another aim of this work was to study a correlation between the mass transfer coefficient and the hydrodynamics of reactor. The model was calibrated using real data from a laboratory reactor fed with real wastewater. Moreover, the model was used to simulate daily variations of different components in the pond (dissolved oxygen, pH, and CO₂ injection) and to predict microalgae (XALG) and bacteria (XH) proportions and to estimate daily biomass production (Cb). The effect of CO₂ injection and the influence of wastewater composition on treatment performance were investigated through practical study cases. XALG decreased by 38%, and XH increased by 35% with respect to the system under pH control while microalgae and bacteria proportions are completely different as a function of influent wastewater composition. Model simulations have indicated that Cb production (~ 100 gTSS m⁻³ day⁻¹ for manure and centrate) resulted lower than Cb production obtained using primary influent wastewater (155 gTSS m⁻³ day⁻¹).

In this study, MgO-modified palygorskite (MgO-PAL) was used for simultaneous recovery of ammonia nitrogen (AN) and phosphate, and the effects of pH, ions, and organic acids on nutrient recovery were investigated. The highest removal amount of AN and phosphate separately reached 42.6 mg/g and 69.8 mg/g at pH of 9.0, 0.6 g/L dosage of modified palygorskite, and 180 min of the reaction time. MgO-PAL provided a wide range of pH (3–9) for nutrient removal. Mg released concentration was tested to investigate the removal mechanisms. The individual presence of four cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) showed negative effect on AN removal at different mass concentrations. However, those cations, except Na⁺, exhibited positive influence on phosphate removal. Compared with SO₄²⁻, CO₃²⁻showed more negative effect on nutrient removal due to the reaction between Mg²⁺ and CO₃²⁻. The results showed that the nutrient removal amount and the morphology and composition of collected products were not affected in the presence of acetic acid. Citric acid, humic acid, and fulvic acid displayed the inhibition effects on the morphology of the crystallized products.

Both cadmium (Cd) contamination in agricultural soils and drought stress pose a serious problem for crop quality and human health. Owing to the specific physical and chemical characteristics, zinc oxide (ZnO) nanoparticles (NPs) can be used in agriculture as a nanofertilizer but their impact on Cd accumulation in wheat (Triticum aestivum) grains under normal and limited water conditions remains insufficient. In this study, the efficiency of ZnO NPs on Cd intake by wheat was investigated under normal and water-limited conditions grown in Cd-contaminated soil for 125 days after seed sowing. The lower biomass and higher oxidative stress were observed in the tissues of the control and drought stress further decreased the plant biomass and caused oxidative stress. Zinc oxide NP treatments increased the tissue dry weight and minimized the oxidative stress either Cd stress alone or combined with drought. Drought stress enhanced the Cd contents in wheat tissues and grains, while ZnO NPs significantly reduced the Cd accumulation in tissues and grains by reducing the soil bioavailable Cd and its accumulation by roots. These findings depicted that NP application to contaminated soils can promote wheat productivity and effectively alleviate soil Cd contamination either alone or under water-limited conditions. The baseline data demonstrated in this study provide insights that pave the way towards safer wheat production under combined drought and metal stress. However, the application of NPs at field levels with numerous crops and climatic conditions needs to be investigated before final recommendation.

Mine drainage water from the Schlenze stream, Mansfeld Region, Central Germany, which have shown an increase in heavy metal concentrations of Cd²⁺, Cu²⁺, Pb²⁺, and Zn²⁺, was used to investigate the bioremediation potential of charophytes. The removal of heavy metals by Chara subspinosa from the water was tested in single- and multi-metal additions. The uptake capacity of C. subspinosa decreased during the course of the experiment and was higher in single-metal addition than in multi-metal addition of Pb²⁺, Zn²⁺, and Cd²⁺. Accumulation of heavy metals in the carbonate encrustation of charophytes was far lower than those to which they were exposed. Cu, Cd, Pb, and Zn co-precipitated more in the encrustation of C. subspinosa exposed to single-metal approach than to multi-metal approach. The carbonate composition of charophytes was influenced by the water chemistry. Content of Na in the carbonate encrustation correlated with the Na⁺ concentration of the respective water. The toxic effect of heavy metals on photosynthesis was species-specific. Electron transport rates (ETRₘₐₓ) were higher in Chara tomentosa than in C. subspinosa. Charophytes withstand the heavy metal concentrations when diluted with river water from the Altarm cut-off lake and can therefore be used for the bioremediation of diluted mine drainage waters by co-precipitating Cd, Cu, and Zn.

Various perovskite-type catalysts including La₂CoMnO₆, LaCoO₃, and LaMnO₃ are first evaluated for the activities toward C₇H₈ removal. Experimental results indicate that double-type La₂CoMnO₆ shows better activity if compared with single perovskites due to high lattice oxygen content and good reducibility. Subsequently, perovskite catalysts are combined with plasma (NTP) to form in-plasma catalysis (IPC) and post-plasma catalysis (PPC) systems. The results indicate that IPC systems have better higher performance than that of NTP-alone and PPC. Especially, high C₇H₈ conversion (100%) and mineralization efficiency (96.8%) can be achieved with the applied voltage of 18 kV and temperature of 120 °C when La₂CoMnO₆ is integrated with NTP to form IPC system. Also, it owns the highest energy efficiency (0.14 g/kWh). It is concluded that IPC performance for C₇H₈ removal is closely related with the properties of catalyst surface. In addition, the kinetics of IPC systems are investigated by a simplified model, and the result indicates that IPC with La₂CoMnO₆ as catalyst has a higher overall energy constant. This study reveals that double-type La₂CoMnO₆ is of higher activity than single perovskites for C₇H₈ removal, and demonstrates that double-type La₂CoMnO₆ is of high potential to form plasma catalysis system for VOCs removal.

Mining activity constitutes a potential source of heavy metal pollution in the environment. Long-term exposure to heavy metals (e.g., cadmium) has adverse health effects. Rodents frequently serve as bioindicators to monitor the levels of heavy metals in the environment. In the present study, concentrations of 10 heavy metals (Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Sb, and Zn) in kidney, liver, and muscle tissue of the Persian jird (Meriones persicus) were evaluated. This is the first study to examine the histopathological changes in Persian jird tissues caused by the bioaccumulation heavy metals. The samples were taken at location that surrounded by Sangan Iron Ore Mine (SIOM) mining activities, in northeastern Iran. The results show that the highest concentrations for the metals were observed in kidney and liver, whereas lowest concentrations were found in muscle of Persian jirds. The concentration of Pb was below the limit of detection. Sex and age were two factors that could explain the different levels of heavy metal bioaccumulation, which affects the concentration of some metals. Adults had significantly higher Cu and Cd levels compared to juveniles. Males bioaccumulated more Zn in their kidneys than females, whereas females bioaccumulated more Fe in their livers. As expected, heavy metals affected various organs of the studied specimens. Hyperemia, hemorrhage, necrosis, and degenerative damage to the epithelial cells of the tubules, the presence of hyaline casts, and in one case, mononuclear leukocyte infiltration, were observed in samples of renal tissue. Hemorrhage and hepatocyte vacuolization were the most common histopathological changes found in samples of hepatic tissue. These effects and the concentrations of heavy metals in the studied specimens indicate the need for monitoring and frequent sampling to evaluate long-term persistent pollutants.

Camorim is a small, eutrophic reservoir in Rio de Janeiro, Brazil, with a phytoplankton community dominated most of the year by the filamentous diatom Aulacoseira spp. and the toxic cyanobacterium Cylindrospermopsis raciborskii. As filamentous species can be a poor food for grazers, we hypothesize that phytoplankton from this reservoir would constrain cladoceran fitness due to nutritional limitation and/or toxicity when animals fed mixtures of cultured green algae and natural seston. Clones of different cladoceran species were exposed either to seston from Camorim reservoir sampled in different seasons or to a C. raciborskii strain (CYLCAM-2) isolated from the reservoir. In short-term assays, cladocerans were exposed to either 100% seston or mixtures of 50% seston added to green algae (200 μg C L⁻¹), and their survivorship and somatic growth were measured for 4 days. In life table assays, neonates were exposed to the same seston treatments over 14 days and age at first reproduction, survivorship, fecundity, total offspring, and the intrinsic rate of natural increase (r) were assessed. In general, seston negatively affected cladoceran survivorship and fitness (r), but this response was seasonally and species specific. Stronger effects of CYLCAM-2 than those caused by seston on survivorship, somatic growth, and r were found for all cladoceran species, especially when the proportion of CYLCAM-2 was higher than 50% in relation to green algae in a fixed total food concentration. Our results suggest that both nutritional (C/P and morphology) and toxicity factors can act to impair cladoceran fitness and help explain the absence of cladocerans in Camorim reservoir.

The higher economic growth of China intensifies the consumption of fossil fuel, such as coal and oil, for electricity generation, transportation etc., which is responsible for environmental degradation through the emissions of carbon, sulfur, and nitrogen etc. The objectives of this study are to investigate the impact of greenhouse gas emission on health issues and provide the effective solution to overcome health-related issues, caused by carbon, sulfur, and nitrogen emission. For this purpose, we propose that higher afforestation activities can help to mitigate the carbon emission and can help to reduce the health diseases. The findings of quantile regressions reported that an increase in carbon emission causes significantly higher health issues. On the contrary, afforestation activities reported a negative coefficient, suggesting that growth of forests can be useful measure in control of health issues. The findings of the current study can be utilized in policy making and to explore the nexus between greenhouse gas emission, afforestation, and health issues.