Agricultural wastes such as rice straw, sugar beet, and sugarcane bagasse have become a critical environmental issue due to growing agriculture demand. This study aimed to investigate the valorization possibility of sugarcane bagasse waste for activated carbon preparation. It also aimed to fully characterize the prepared activated carbon (BET surface area) via scanning electron microscope (SEM) and in terms of surface functional groups to give a basic understanding of its structure and to study the adsorption capacity of the sugarcane bagasse-based activated carbon using aqueous methylene blue (MB). The second main objective was to evaluate the performance of sugarcane bagasse-based activated carbon for indoor volatile organic compounds removal using the formaldehyde gas (HCHO) as reference model in two potted plants chambers. The first chamber was labeled the polluted chamber (containing formaldehyde gas without activated carbon) and the second was taken as the treated chamber (containing formaldehyde gas with activated carbon). The results indicated that the sugarcane bagasse-based activated carbon has a moderate BET surface area (557 m²/g) with total mesoporous volume and microporous volume of 0.310 and 0.273 cm³/g, respectively. The prepared activated carbon had remarkable adsorption capacity for MB. Formaldehyde removal rate was then found to be more than 67% in the treated chamber with the sugarcane bagasse-based activated carbon. The plants’ responses for this application as dry weight, chlorophyll contents, and protein concentration were also investigated. Implications: Preparation of activated carbon from sugarcane bagasse (SCBAC) is a promising approach to produce cheap and efficient adsorbent for gas pollutants removal. It may be also a solution for the agricultural wastes problems in big cities, particularly in Egypt. MB adsorption tests suggest that the SCBAC have high adsorption capacity. Formaldehyde gas removal in the plant chambers indicates that the SCBAC have potential to recover volatile gases. The results confirmed that the activated carbon produced from sugarcane bagasse waste raw materials can be used as an applicable adsorbent for treating a variety of gas pollutants from the indoor environment.

The cement industry is prospering in the Middle East countries, especially in Egypt due to the presence of raw materials, as well as increasing population growth in the region and increasing cement demand. Without activating and applying the regulations and laws, which enforced by local government to ensure compliance with national and international standards upon this industry, the increase of cement factories and complementary units in the region may damage air quality and threaten the ecosystems. This paper deals with the monitoring of the ambient pollutants surrounding 21 cement factories during the 2017 year: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and particulate matter (TSP, PM10, and PM2.5) emitted from the cement production processing. Air pollutants around the cement plants were determined using appropriate sampling techniques according to international standard methods. Results indicated that particulate matter concentrations were higher than all permissible guidelines for ambient air quality. Carbon monoxide concentrations of all sites were lower than permissible limits, while recorded gases concentrations (NO2, SO2, O3) in some sites were comply with those limits. High concentrations of particulate matter at all sites could be attributed to the applied processes for cement production, such as raw materials mining, transportation, blending, quarrying, preparation, and stockpiles. Moreover, kilns operation, clinker cooling, and milling processes were responsible for gases and particulates emission operations. The results indicated also that exhaust emissions were attributed to the type of fuel used and coal is responsible for the production of most pollutants while natural gas produced the least amount of pollution. The use of clean fuel with ideal combustion techniques and the application of interlocking mechanisms to all processes are recommended for the cement manufacturers in Egypt to reduce adverse emissions to the environment.

Acute and chronic health problems are expected due to exposure to high levels of formaldehyde. The aim of the current study was to evaluate the outdoor and indoor levels of formaldehyde in Cairo in order to assess the carcinogenic and non-carcinogenic risks as a result of exposure to formaldehyde. Formaldehyde concentrations were measured outdoors and indoors at five residential sites in Cairo, Egypt. The samples were taken during the day (8 AM to 6 PM) and at night (8 PM to 6 AM) for 10 hours during winter and summer seasons of 2018/2019. Chronic daily intakes (CDI), cancer risk (R) and hazard quotient (HQ), were estimated to assess health risks from exposure to formaldehyde. Outdoor average concentrations of formaldehyde at the selected sites were 24.6 and 22.8 µg/m³ in summer and winter, respectively, which exceeded the value of 15 ppb (18.3 µg/m3) set as an indicator for urban environment. Indoor HCHO concentrations are still far lower than the effective short-term exposure levels of HCHO between 0.5 and 1 ppm (0.62-1.23 mg/m3) which could lead to irritation of throat, nose and eyes. Newly apartments with newly furnished can be a stronger source for formaldehyde emissions than the ambient sources.The I/O ratios of formaldehyde were above one which demonstrated that the sources in the indoor environment are prevalent at the investigated sites.The outdoor cancer risk values did not exceed the “alarm level” (R > 1 × 10–4) for formaldehyde, while in living rooms and kitchens they exceeded the “alarm level” by 30% and 55% in winter and summer, respectively. The results indicated that the levels of airborne and inhaled formaldehyde in Cairo residences should not be underestimated. The current study can help regulatory agencies to establish guidelines for formaldehyde concentration in indoor air.