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Background: Ammonia has hazardous health effects on humans. To begin with, inhalation of ammonia can be harmful to the respiratory system. The main aim of this study is to determine the concentrations of ammonia in water and evaluate its effects on human health. Methods: In this study, 20 drinking water samples were collected from different locations in Khartoum State, Sudan. Results: The concentration of ammonia (NH3 - N) ranged between 0.01 and 1.96 mg/L. The concentration of NH3 - N reported higher than World Health Organization (WHO) standard (0.2 mg/L) in 55% of the collected samples. A questionnaire was distributed to 124 participants from different origins to measure their level of awareness about the effect of ammonia on health. Conclusions: According to the results of the questionnaire and chemical analysis, raising awareness about ammonia is needed. Furthermore, periodical testing and monitoring of drinking water is also necessary to do treatment for polluted water with ammonia. [ABSTRACT FROM AUTHOR]

The use of olive seed powder as a plant-based natural coagulant in treating iron and steel factory wastewater was studied. The concentrations of chemical oxygen demand (COD), total suspended solids (TSS), ammonia-nitrogen (NH3 –N), manganese (Mn), iron (Fe), zinc (Zn), aluminum (Al), and nickel (Ni) in effluent wastewater were investigated. Coagulation experiments on the effects of iron and steel factory wastewater, pH, and olive seed powder dosage on coagulation efficacy were conducted using an orbital shaker and a flocculation device. The maximum removal percentages of COD, TSS, NH3 –N, Mn, Fe, Zn, Al, and Ni by olive seeds powder were 86.3%, 99%, 72.4%, 80.9%, 91.5%, 92.6%, 73.7%, and 84.3% for effluent at natural pH 8 using a 5 g/L dosage, respectively. The Fourier-transform infrared spectroscopy study showed the presence of several functional groups involved in the coagulation process. It is possible to argue that olive seed powder has enormous potential as a plant-based natural coagulant for wastewater treatment and that it might be used to treat wastewater from iron and steel factories. [ABSTRACT FROM AUTHOR]

Solar energy has recently become a viable option for desalinating seawater, primarily in arid regions. However, increasing the productivity of solar still by integrating experimental base and modelling methods is still subject to prediction errors; therefore, the main objective of this research is to postulate and test boosting algorithms for predicting the efficiency and productivity of the system. Five boosting regressors were deployed and evaluated: categorical boosting, adaptive boosting, extreme gradient boosting, gradient boosting machine, and gradient boosting machine (LightGBM). The proposed regressors are implemented based on the system’s actual recorded dataset (consisting of 720 observations). The dataset consists of input variables, which are the wind speed (V), cloud cover, humidity, ambient temperature (T), solar radiation (SR), (Tio), (Tw), (Tv), and (Tt). Also, the output variable is represented by the productivity of the system. The dataset was separated into training (70%) and testing (30%) sets. In order to decrease regressors errors, hyperparameter optimization was employed. GradientBoosting approach provided the best prediction, with 95% R2 accuracy and 39.57 root mean square error (RMSE) error. The LightGBM technique achieved 94% R2 accuracy and 40.07 RMSE error in the testing dataset. The results reveal that GradientBoosting outperforms the cascaded forward neural network in predicting system productivity (CFNN). [ABSTRACT FROM AUTHOR]

Microplastic is an emerging pollutant causing trouble worldwide due to its extensive distribution and potential hazards to the ecological system. Some fundamental questions about microplastics, such as their presence, source, and possible hazards, remain unanswered. These issues develop because of a lack of systematic and comprehensive microplastic analysis. As a result, we thoroughly evaluated current knowledge on microplastics, including detection, characterization, occurrence, source, and potential harm. Microplastics are found in seawater, soil, wetlands, and air matrices worldwide based on findings. Visual classification, which can be enhanced by combining it with additional tools, is one of the most used methods for identifying microplastics. As soon as is practicable, microplastics analytical methods ought to be standardized. New techniques for analyzing nano-plastics are urgently needed in the meantime. Numerous studies have shown that microplastics’ impacts on people and soil are significantly influenced by their size, shape, and surface physicochemical characteristics. Finally, this study suggests areas for future research based on the knowledge gaps in the area of microplastics. [ABSTRACT FROM AUTHOR]

This study aims to investigate the performance plant-based natural coagulant from rosehip seed powder in the treatment of iron and steel factory wastewater. The concentrations of COD, total suspended solids (TSS), ammonia-nitrogen (NH3–N), manganese (Mn), iron (Fe), zinc (Zn), aluminum (Al), and nickel (Ni) in effluent wastewater were examined. Coagulation investigations were carried out using an orbital shaker and a flocculation apparatus to investigate the effects of iron and steel factory effluent, pH, and rosehip seeds powder dosage on coagulation efficacy. The rosehip powder removes a large amount of COD, TSS, NH3–N, Mn, Fe, Zn, Al, and Ni from effluent at pH 8 with percentages of 86.1%, 99%, 79%, 86%, 91.7%, 90.6%, 73.7%, and 100%, respectively, at 1 g/L. The effects of pH ranges ranging from (5–10) reveal that the wastewater sample’s natural pH (8) demonstrates the maximum practicable removal effectiveness. FTIR analysis revealed the presence of numerous functional groups involved in the coagulation process. One may argue that rosehip seed powder holds great potential as a natural plant-based coagulant for water treatment and could be used to treat effluent from iron and steel factories. [ABSTRACT FROM AUTHOR]

Utilization of pinecone powder as a plant-based natural coagulant for the treatment of iron and steel factory effluent was examined. The concentrations of chemical oxygen demand (COD), total suspended solids (TSS), ammonia-nitrogen (NH3 –N), manganese (Mn), iron (Fe), zinc (Zn), aluminum (Al), and nickel (Ni) in effluent wastewater were investigated. Results showed that the maximal removal of COD, TSS, NH3 –N, Mn, Fe, Zn, Al, and Ni using pinecone powder were 83.3%, 99%, 83.9%, 86.8%, 93.7%, 89.7%, 73.7%, and 86.7%, respectively for effluent at natural pH 8 using a dosage of 3 g/L. The Fourier-transform infrared spectroscopy result showed the existence of various functional groups involved in the coagulation process. Overall, this study shows that pinecone powder has enormous promise as a natural coagulant for water treatment and it could be utilized to treat effluent from iron and steel plants. [ABSTRACT FROM AUTHOR]

Nanoscale zero-valent iron (nZVI) has been extensively investigated for the remediation of soil, wastewater, and groundwater contaminated with heavy metals. This paper presents a collective review of nZVI synthesis, nZVI interaction mechanisms with heavy metals, factors affecting nZVI reactivity, recent applications of nZVI for heavy metals removal, and the environmental concerns of nZVI application for soil microorganisms and plants. Modified nZVI, spatially biochar supported nZVI (BC@nZVI) and sulfidation nanoscale zero-valent iron (S-nZVI) showed high heavy metals removal efficiency and more stable performance compared to nZVI alone. The removal of heavy metals by nZVI is as a synergistic process where adsorption, oxidation/reduction and precipitation occur simultaneously or in series. pH and organic matter are the main factors that significantly affect nZVI reactivity. Toxic effects of nZVI are observed for the soil microorganisms as the direct contact may cause a decrease in cell viability and membrane damage. A low concentration of nZVI promotes the growth of plant whereas high concentration decreases root length. It is observed that, further research is needed to enhance nZVI recovery techniques, evaluate the effectiveness of novel modified nZVI and their effects on the environment, and the full-scale application of nZVI. [ABSTRACT FROM AUTHOR]

Landfill remains as the most common municipal waste disposal method in the world. However, the production of leachate associate with landfill persists as a major drawback, which bring harmful effect to the environment. Persulfate oxidation is recently used for stabilized leachate treatment. Persulfate alone is still limited for leachate oxidation and an activation method is required to improve its performance. Accordingly, this study aims to investigate and compare the performance of persulfate subjected to thermal activation in treating stabilized leachate. Different experimental operational factors were considered and evaluated such as, S2 O8 2–/chemical oxygen demand (COD) ratio, temperature, and reaction time. Experiments were designed and optimized by using response surface methodology, and results were analysed by using analysis of variance. The removal efficiencies for COD and colour using inactivation persulfate were reported only at 14% and 29%, respectively. However, the efficiencies were improved to 93.39% and 94.00% for COD and colour after thermal activation of persulfate under an optimum condition of 10 S2 O8 2–/COD ratio, 80°C and 120 min. The maximum efficiency was achieved at the treatment cost of RM0.66 per litre of leachate. [ABSTRACT FROM AUTHOR]