Search

AbstractPakistan is a developing country and its population is growing rapidly. The trend towards economic growth and satisfying the needs of the growing population is increasing daily. For this purpose, industrial activities, vehicle emissions, and household-related activities pollute the atmospheric environment and release different types of toxic gases. Particulate matter assessments (PM2.5 and PM10) were reviewed in different cities of Pakistan. Respectively, the PM2.5 evaluation was carried out in 15 cities, while the PM10 concentration was in 18 cities in Pakistan. According to the review, the highest concentrations of PM2.5 were 302, 211.97, 88, 163.63, 113.09, 110.81, 110.81, 139.43, 126.97, 107.68, 109.81, 172, 150, 66, 354, 43.9, 2305 µg/m3 in Lahore, Faisalabad, Karachi, Gujranwala, Multan, Vehari, Bahawalnagar, Okara, Pakpattan, Jehlum, Sargodha, Peshawar Quetta, Islamabad, Haripur, Mingora, and Mardan (Jalala). Specifically, the highest concentration of PM10 were 301, 568, 638, 160.5, 200, 384.15, 301.38, 311.61, 700 µg/m3 in Lahore, Faisalabad, Peshawar, Charsada, Karachi, Gujranwala, Multan, Rawalpindi, and Quetta. Only, these cities are the most polluted in the whole country and the concentration of PM2.5 was above the normal range those prescribed by the National Environmental Quality Standred (NEQS). Commonly, the main problem is the suspended particulate matter (PM2.5 and PM10) in the atmosphere. The increasing level of pollution leads to different types of problems such as respiratory problems, eye irritation, throat infections, asthma, and cancer, and it also increases the level of death ratio in the country. The main reason for PM is the burning of solid waste near cities; industrial emission, vehicular emission, lack of proper green belt and solid waste management are the main reasons for atmospheric pollution. Given the existing state of the air, urgent action is required to address the low air quality. [ABSTRACT FROM AUTHOR]

This article describes the production of eucalyptus wood waste biochar (EWB) and its use in the adsorptive removal of naphthalene (Nap) from vehicle wash wastewater (VWW). EWB was produced by carbonizing the waste eucalyptus wood at a high temperature in a nitrogen atmosphere. The produced EWB was chemically activated by being subjected to 1 M HCl in order to increase its effectiveness. The EWB was described using pertinent instrumental techniques such as surface area analysis, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Nap adsorption from aqueous solutions through EWB was examined using batch adsorption tests. As adsorption parameters, initial EWB concentration, contact time, pH, temperature, and adsorbent dose were all examined. Under ideal conditions, the adsorption efficiency was computed and the Nap contents were determined using a UV spectrometer. The optimal conditions for the highest adsorption of Nap from VWW on the EWB adsorbents were found to be an initial concentration of 30 ppm, contact time of 90 min, temperature of 60°C, adsorbent dose of 0.30 g, and 5 pH. Kinetic and isotherm models were applied to evaluate the adsorbent capacity to bind Nap. The kinetic study shows that the adsorption of Nap onto EWB is controlled by pseudo-second-order kinetics. The results of the experiment demonstrated that the Langmuir isotherm model offered the best fit for the data. The values of thermodynamic parameters such as entropy (Î"S°), Gibb's free energy (Î"G°) and enthalpy (Î"H°) show that the adsorption process is spontaneous and exothermic in nature. The trial results revealed that the highest adsorption at optimum condition for Nap from VWW was 98.65% (qe = 141.52 mg/g). The performances of certain commercial adsorbents utilized in practice were also compared with the results. This analysis showed that the new EWB has a significant potential (>95%) for removing and recovering Nap from industrial effluent. [ABSTRACT FROM AUTHOR]