The impact of COVID 19 on air pollution levels and other environmental indicators - A case study of Egypt.

The outbreak of coronavirus disease (COVID-19) not only affected health and economics, but also its effect extended to include other aspects, such as the environment. Using Egypt as a case study, this paper presents the impact of COVID-19 pandemic on air pollution levels by studying nitrogen dioxide (NO2), ozone (O3), particulate matter represented in absorbing aerosol index (AAI), carbon monoxide (CO), and greenhouse gas (GHG) emissions. The paper also highlights the impact of COVID-19 pandemic on other environmental indicators including environmental noise, medical and municipal solid wastes. The paper presents the Egyptian COVID-19 story from its different angles including the development of confirmed COVID-19 cases, containment measures from the government, the impact on the country's economy and the national energy consumption so as to effectively evaluate the effect on both the air pollution levels and the other studied environmental indicators. For the other environmental indicators, a strong link was observed between COVID-19 lockdown and the reduction in environmental noise, beaches, surface and groundwater pollution. For environmental noise, this has been confirmed by officially governmental announcements which reported that the level of environmental noise in Egypt was reduced by about 75% during the lockdown period. On the other hand, there are some negative effects, including an increase in medical solid waste (from 70 to 300 ton/day), municipal solid waste, as well as a less efficient solid waste recycling process. For air pollution levels, the data were obtained from National Aeronautics and Space Administration (NASA) and European Space Agency satellite data sets. The data for the lockdown period in 2020 have been extracted and compared to the corresponding months in the selected baseline period (2015-2019) to identify the effect that the lockdown period had on the air pollution levels in Egypt with focus on Cairo and Alexandria governorates. It was found that the AAI decreased by about 30%, the NO2 decreased by 15 and 33% over Cairo and Alexandria governorates, respectively, and that the CO decreased by about 5% over both governorates. In addition, the GHG emissions in Egypt were reduced by at least 4% during the pandemic. In contrast, ozone levels increased by about 2% over Cairo and Alexandria governorates. It can be concluded that the implemented containment measures during COVID-19 pandemic had resulted in both positive and negative environmental impacts. The positive environmental impacts are not sustainable and deterioration on them is expected to occur after the lockdown as it was before the pandemic. Therefore, stricter laws must be enacted to protect the environment in Egypt.

Zero-valent iron nanoparticles for methylene blue removal from aqueous solutions and textile wastewater treatment, with cost estimation.

Nanoscale zero-valent iron (nZVI) particles were investigated for the removal of methylene blue (MB) from aqueous solutions and the treatment of textile industry effluents. The nZVI material was characterized by XRD, TEM, EDS, FTIR, and SEM. It was demonstrated that several functional groups such as C-H, C = C, C-C, and C-O contributed to MB reduction. At initial MB concentration of 70 mg/L, the optimum pH was 6, achieving a removal efficiency of 72.1% using an nZVI dosage of 10 g/L, stirring rate of 150 rpm, and temperature of 30 °C within 30 min. The adsorption isotherm was described by the Langmuir model with monolayer coverage of 5.53 mg/g, and the Freundlich equation with multilayer adsorption capacity of 1.59 (mg/g)·(L/mg)1/n. The removal mechanisms of MB included reduction into colorless leuco-MB, precipitation as Fe(II)-MB, adsorption as ZVI-MB or FeOOH-MB, and/or degradation using •OH radicals. The synthesized nZVI particles were applied to reduce various organic and inorganic compounds, as well as heavy metal ions from real textile wastewater samples. The removal efficiencies of COD, BOD, TN, TP, Cu2+, Zn2+, and Pb2+ reached up to 91.9%, 87.5%, 65.2%, 78.1%, 100.0%, 29.6%, and 99.0%, respectively. The treatment cost of 1 m3 of textile wastewater was estimated as 1.66 $USD.

Viral outbreaks detection and surveillance using wastewater-based epidemiology, viral air sampling, and machine learning techniques: A comprehensive review and outlook.

A viral outbreak is a global challenge that affects public health and safety. The coronavirus disease 2019 (COVID-19) has been spreading globally, affecting millions of people worldwide, and led to significant loss of lives and deterioration of the global economy. The current adverse effects caused by the COVID-19 pandemic demands finding new detection methods for future viral outbreaks. The environment's transmission pathways include and are not limited to air, surface water, and wastewater environments. The wastewater surveillance, known as wastewater-based epidemiology (WBE), can potentially monitor viral outbreaks and provide a complementary clinical testing method. Another investigated outbreak surveillance technique that has not been yet implemented in a sufficient number of studies is the surveillance of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in the air. Artificial intelligence (AI) and its related machine learning (ML) and deep learning (DL) technologies are currently emerging techniques for detecting viral outbreaks using global data. To date, there are no reports that illustrate the potential of using WBE with AI to detect viral outbreaks. This study investigates the transmission pathways of SARS-CoV-2 in the environment and provides current updates on the surveillance of viral outbreaks using WBE, viral air sampling, and AI. It also proposes a novel framework based on an ensemble of ML and DL algorithms to provide a beneficial supportive tool for decision-makers. The framework exploits available data from reliable sources to discover meaningful insights and knowledge that allows researchers and practitioners to build efficient methods and protocols that accurately monitor and detect viral outbreaks. The proposed framework could provide early detection of viruses, forecast risk maps and vulnerable areas, and estimate the number of infected citizens.

Techno-economic estimation of electroplating wastewater treatment using zero-valent iron nanoparticles: batch optimization, continuous feed, and scaling up studies.

Electroplating manufacturing processes release industrial effluents that comprise severe levels of heavy metals into the environment. This study investigated the utilization of nanoparticles of zero-valent iron (nZVI) for the treatment of electroplating wastewater industry containing multiple heavy metal ions. In batch experiments using Cu2+ as a single solute, the optimum operating condition was pH 7.3, nZVI dosage 1.6 g/L, time 36 min, temperature 30 °C, and agitation speed 180 rpm, achieving almost 100% Cu2+ removal efficiency. The adsorption mechanisms were illustrated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FTIR) spectrometer. Moreover, continuous-feed experiments were performed to treat real electroplating wastewater industry via adsorption and sedimentation processes. The system attained removal efficiencies of 91.3% total suspended solids (TSS), 68.3% chemical oxygen demand (COD), 94.2% nitrogen (N), 98.5% phosphorus (P), 66.7% Cr6+, 91.5% Pb2+, 83.3% Ag+, 80.8% Cu2+, 17.4% Ni2+, 47.1% Mn2+, 54.6% Zn2+, 94.7% Fe3+, 100.0% Al3+, and 42.1% Co2+. The removal mechanisms included reduction of Men+ to Me(n-x)+/Me0 by the Fe0 core, adsorption to the oxide shell as Me(OH)x and Me-Fe-OOH, oxidation of Men+ to Me(n+z)+, specific surface bonding, and sequential steps of electron transfer and precipitation. The total cost, including amortized and operating expenses for scaling up the adsorption system, was 4.45$ per m3 of electroplating wastewater. Graphical abstract.

Applying the three R's: Reduce, reuse, and recycle in the chemical industry.

Pollution prevention (P2) assessment was conducted by applying the three R's, reduce, reuse, and recycle, in a chemical industry for the purpose of reducing the amount of wastewater generated, reusing paint wastewater in the manufacture of cement bricks, recycling cooling water, and improving water usage efficiency. The results of this study showed that the annual wastewater flow generated from the paint manufacturing can be reduced from 1,100 m3 to 488.4 m3 (44.4% reduction) when a high-pressure hose is used. Two mixtures were prepared. The first mixture (A) contains cement, coarse aggregate, fine aggregate, Addicrete BVF, and clean water. The second mixture (B) contains the same components used in the first mixture, except that paint wastewater was used instead of the clean water. The prepared samples were tested for water absorption, toxicity, reactivity, compressive strength, ignitability, and corrosion. The tests results indicated that using paint wastewater in the manufacture of the cement bricks improved the mechanical properties of the bricks. The toxicity test results showed that the metals concentration in the bricks did not exceed the U.S. EPA limits. This company achieved the goal of zero liquid discharge (ZLD), especially after recycling 2,800 m3 of cooling water. The total annual saving could reach $42,570 with a payback period of 41 days. IMPLICATIONS: This research focused on improving the water usage efficiency, reducing the quantity of wastewater generated, and potentially reusing wastewater in the manufacture of cement bricks. Reusing paint wastewater in the manufacture of the bricks prevents the hazardous pollutants in the wastewater (calcium carbonate, styrene acrylic resins, colored pigments, and titanium dioxide) from entering and polluting the surface water and the environment. We think that this paper will help to find the most efficient and cost-effective way to manage paint wastewater and conserve fresh water resources. We also believe that this paper provides a rich agenda for future research in water conservation and industrial wastewater reuse subjects.