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A novel application of building demolition waste for removal benzene from aqueous solutions. In this research, demolition waste from buildings has been studied for possible use as benzene removal adsorbent from aquatic solution. The effect of adsorbent dosage, contact time, initial benzene concentration, and initial pH on benzene adsorption capacity have been investigated in the batch adsorption experiments. The adsorption effects initially happened very rapidly and achieved equilibrium within 180 min. Benzene removal was observed to decrease by an increase in the initial concentration of benzene of 300–700 mg·L–1, an increase in the adsorbent dose of 0.4–2.4 g per 100 mL, where an optimum adsorbent dose equal to 1.2 g per 100 mL was found. The potential of adsorption increases with pH 3.0–7.0 to reach the maximum removal efficiency at pH 6.0. The findings showed that equilibrium data were adequately adapted and correlated with the Freundlich isotherm models. The average percentage of the removal at room temperature was about 98%. Results suggest that building demolition waste can be used effectively in industrial wastewater treatment for the removal of aromatic hydrocarbon, benzene, as a low-cost option.

Removal of cephalexin residues from wastewater is one of the most concerned issues in treatment plants due to the growing of the antibiotics consumption level around the world. In this study, the impact of the initial concentration of cephalexin residues on its removability by lemna minor was investigated by developing a grau model accounting for the cephalexin initial pH value. In the model, the second-order kinetic constants of adsorption were linked linearly with the influent pH values. Results showed that using lemna minor along with phytoremediation process increased the removal efficiency value to 86.5% and dropped chemical oxygen demand (COD) to 0.012 mg/L in effluent, making the removability of cephalexin from the polluted water easier. In addition, it was found that changing the grau model kinetic constants linearly (positively or negatively) with pH affects the removal efficiency. Based on the results, the best removability can be noticed at the pH level of 7 with a value of 71%.

Iron slag is a byproduct generated in huge quantities from recycled remnants of iron and steel factories, therefore, the possibility of using this waste in the removal of benzaldehyde from contaminated water offers an excellent topic in sustainability field. Results reveal that the removal efficiency was equal to 85% for the interaction of slag and water contaminated with benzaldehyde at the best operational conditions of 0.3 g/100 mL, 6, 180 min, and 250 rpm for the sorbent dosage, initial pH, agitation time, and speed, respectively with 300 mg/L initial concentration. The maximum uptake capacity of iron slag was 118.25 mg/g which was calculated by the Langmuir model. Physical sorption may be the major mechanism for the removal of benzaldehyde onto iron slag based on the analysis of isotherm and kinetic sorption data and thermodynamically, the process was spontaneous and endothermic. Finally, the X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and energy-dispersive spectroscope (EDS) tests for reactive material certified that the dissolution of calcium oxide can enhance the removal of benzaldehyde by the formation of bridge cations.

Various experimental studies have highlighted the negative consequences of Portland cement on health and the environment, such as toxic emissions and alkaline sewage. The development of environmentally acceptable substitutes for cement is thus one of the objectives of current investigations. The proposed environmental alternatives to cement, nevertheless, might have detrimental impacts on the concrete’s characteristics. This investigation intends to study the suitability as alternatives to cement in cement mortar, using industrial wastes like silica fume and cement kiln dust. As a replacement for cement, the cement mortars developed in this research continue from 0% to 60% silica fume and cement kiln dust. Ultrasonic pulse velocity tests at 1 to 4 weeks of age were conducted on hardened specimens. The findings showed that a low reduction in the pulse velocity resulted from high proportions of silica fume and cement kiln dust replacements, whereas an improvement in the characteristics of the mortars with low replacement ratios. Using low kiln dust and silica fume of 20 to 40%, the durability of mortars may increase.

The current study utilizes the carbon derived from the lemon peel (CLP) as an adsorbent to remove Pb (II) ions from solutions. Activation of the lemon peels was carried out by adding 1 part of the lemon peels to 1.8 parts of concentrated sulphuric acid, and well-mixed before heating the mixture at a temperature of 150 °C for 24 hours. The produced material, CLP, was employed for lead adsorption from water. A number of parameters namely, treatment times, pH, and doses of CLP were studied to assess their influence on the removability of Pb (II) by the CLP. The results indicated that the optimum contact time, pH, and dosage values for the best removal of lead were 80 min, 5, and 3 g/L respectively. To analyze the observed data gained from batch equilibrium tests, isotherm models (Freundlich and Langmuir), kinetic models (the pseudo-first-order, and the pseudo-second-order), and inter-particle diffusion using non-linear regression techniques were applied for this purpose. The obtained results proved that the equilibrium data have reasonable and good fitness and correspondence with the Freundlich isotherm models. The highest adsorption capacity and the highest removal percentage for Pb (II) were 32.98 mg/g and 99% respectively at ambient temperature.

Manganese (Mn) is expected in the majority of freshwater sources due to the wide usage of this element in many industries, such as steel and battery industries, where its concentration in some water bodies could exceed 9600 μg/L. High concentrations of Mn cause many diseases such as Parkinsonism, and lung diseases. The present investigation explores an electrocoagulation unit to remove manganese from water. The electrodes of the electrocoagulation unit are made from iron and aluminium (iron anode, and aluminium cathode). This cell is employed to remediate water samples with 2000 μg/L of manganese. The impacts of many different operating factors, specifically the initial pHs, electric currents, and distances between electrodes, on manganese removals was tested to attend the best performance of manganese removal. The central composite method was applied for the optimization of the operating conditions. Additionally, the estimated power consumption was calculated under the optimum conditions. The outcomes of this investigation revealed that at initial pH of 6.0, the current density of 0.5 mA/cm2, and inter-electrode distances of 5 mm, the maximum manganese removal efficiency (97.2 %) was achieved. Additionally, the reuired power consumption was 3.2 kWh/m3, while the operating cost was £0.48 per m3.

The current study explores the possibility of using granular activated carbon derived from wasted coconut shell (CCS) as a bio adsorbent to purify aqueous solution from Al(II) ions. A number of different parameters including treatment time, pH, and dosage of adsorbent (CCS) were tested to assess their influence on the Al(II) removability. The optimum conditions for best removal were contact time of 90 min, pH of 7, and a dosage of 1 g/L. Freundlich and Langmuir isotherm models and kinetic models including the pseudo-first-order, the pseudo-second-order, and interparticle diffusion were employed to analyse the observed data which were gained from batch equilibrium tests using nonlinear regression methods. The obtained results revealed that the equilibrium data have good and reasonable fitness and correspondence with the Langmuir isotherm models. The maximum adsorption capacity for CCS and the maximum Al(II) removability were 120.6801335 mg/g and about 100%, respectively, at ambient temperature.

The recent studies about water quality indicated a clear increase in the concentrations of many pollutants in the sources of freshwaters, such as nitrate, phosphate, and inorganic pollutants. This increase is attributed to the expansion of the global population, industries, and climate changes. These studies represented a call for the need for efficient treatment for water and wastewater. The current study investigates the possibility of using activated red mud (ARM) as an adsorbent to eliminate nitrates from water/wastewater. The operational parameters such as treatment times, pH, and doses of ARM were tested to assess their effects on the Nitrate removability by ARM. The optimum treatment times, pH, and dose for best removal within this study were 60 min, 7, and 75 g/L for treatment times, pH, and doses, respectively. Freundlich and Langmuir isotherm models and kinetic models including the pseudo-first-order, the pseudo-second-order, and interparticle diffusion using non-linear regressions were utilized to analyze the observed data which were gained from batch equilibrium tests. The obtained results revealed that the equilibrium data have good and reasonable fitness and agreement with the Langmuir isotherm models. The highest adsorption capacity of ARM was 1.79423925mg/g. The maximum percentage of removal was found to be about 71% at ambient temperature.

Water contamination with nitrates is a serious problem due to the detrimental effects of nitrates on both human life and the global ecosystem; therefore, it is essential to remove nitrates using efficient methods. Accordingly, various methods have been used to treat nitrate-containing solutions, but recent studies focused on electrocoagulation (ELE) as it produces high quality water at low cost and it is environmentally friendly. However, passive layers are growing on the aluminum anodes after short time of treatment, which substantially affects the efficiency of ELE. In this investigation therefore, ultrasonic filed was used to remove these passive layers, and consequently improves the efficiency of ELE. This new method, ultrasonic-assisted ELE (U-ELE), was used to remove nitrates from water under various operational conditions. In particular, the impacts of water initial pH (WIP) (4.0-8.0), applied current densities (ACD) (6.0-9.0 mA/cm2), flow rates (FR) (60-100 ml/min), and initial nitrate concentrations (INC) (100-200 mg/L), which were optimized using the Central Composite Design (CCD). The ultrasonic irradiation time (UT) has been kept at 10 minutes for all experiments. The best possible removal of nitrate using only ELE method was about 77% at WIP of 6, UT of 10 minutes, FR of 40 ml/min, INC of 150 mg/l and ACD of 7.5mA/cm2. However, it was found that exerting ultrasonic for 10 minutes, U-ELE method, has increased nitrates removal to 87.80% under the same conditions of ELE treatment.