Environmental Health Engineering and Management Journal
Volume:10 Issue: 4, Autumn 2023

Electrocoagulation is becoming a promising eco-friendly wastewater treatment technique. It is a low-cost wastewater treatment method suitably applied for various wastewater effluent characteristics. Nevertheless, there are different kinds of electrocoagulation; comparison among them in terms of nutrient removal is investigated in the present research. This study analyzed nitrate (NO3-) and phosphate (PO43-) removal potential of the sono-alternative and direct-current electrocoagulation process.

Batch reactor and sono-direct current (SDC)/sono-alternative current (SAC) electrocoagulation cell were employed to investigate NO3- and PO43- removal efficiency from domestic effluents. The data gathered from laboratory experiments were analyzed using response surface methodology (RSM). ANOVA was used to examine the interaction effects of diverse parameters in terms of NO3_ and PO43- removal from domestic wastewater effluents.

At extreme experimental conditions, the percentage of NO3- and PO43- removal attained with sono-direct current electrocoagulation (SDCE) and sono-alternative current electrocoagulation (SACE) were 96.5%, 96.2% and 96.8%, 96.5, respectively. The SACE was more successful in eliminating NO3-and PO43- than the SDCE process. The appearance of resistant oxide coating on the cathode and the appearance of corrosion on the anode due to oxidation processes in the case of SDCE were identified as principal factors highly affecting NO3- and PO43- removal efficiency.

With optimum process efficiency, experimental findings show that the SACE process is more capable of NO3- and PO43- removal than the SDCE process.

The environmental conditions potentially predispose the northern part of the Persian Gulf to the occurrence of dust storms. Outdoor PM2.5 and their water-soluble ions in Bushehr port were studied from December 2016 to September 2017.

A total of 46 outdoor PM2.5 samples were collected by high-volume air sampler and eight water-soluble ions, including Ca2 + , Mg2 + , Na + , K+ , F-, Cl-, NO3-, and SO42- in PM2.5 were also measured by ion chromatography (IC).

The 24-hour average concentration of PM2.5 was in the range of 22.09 to 292.45 μg/m3. The mean concentration of water-soluble ions in PM2.5 was in the range of 0.10 ± 0.14 to 6.76 ± 4.63 μg/m3.The major water-soluble ions were the secondary inorganic aerosols (SO42- and NO3-), which accounted for nearly 41% of total water-soluble ions in PM2.5. The total water-soluble ions level of PM2.5 in winter was higher than that in spring and summer. The positive matrix factorization (PMF) model showed that the source contributions of PM2.5 were in the order of dust (55.8%), sea salt (17.1%), secondary sulfate (11.8%), industries (7%), vehicular emission (4.7%), and secondary nitrate (3.7%).

According to the results, dust and sea salt are the main sources of water-soluble ions in PM2.5 in Bushehr port, which should attract much attention.

Removing natural organic substances from drinking water sources is necessary to prevent the formation of toxic and carcinogenic disinfection by-products (DBPs). The nano-photocatalytic oxidation process to remove these substances is easier, faster, cheaper, and more efficient than other methods.

This study investigated the efficiency of the TiO2/UV nano-photocatalytic process in removing humic acid (HA) and fulvic acid (FA) from aqueous solutions. Batch tests were performed to investigate the effect of various parameters such as contact time (15, 30, 45, 60, and 75 minutes), initial pH (4, 7, and 9), initial HA and FA concentration (0.5, 1, 2, 5, and 7 mg/L-1), TiO2 dose (5, 10, 15 and 20 mg/L-1), and different UV irradiation (8 W and 16 W) for the removal of HA and FA from aqueous solutions using TiO2/UV at room temperature (20 ± 3 °C). The equilibrium adsorption data and the standard parameters were evaluated. Data were analyzed using SPSS version 25.

The efficiency of this process in optimal conditions (pH: 4, anatase TiO2: 10 mg/L-1, irradiation time: 60 min, UV = 16 W) for removing humic and fulvic (initial HA concentration: 2 mg/L-1 and initial FA concentration: 5 mg/L-1) was 89% and 92%, respectively. The analysis of the experimental isotherm data showed that in the adsorption process of HA and FA on TiO2/UV, the Langmuir isotherm and the first-order reaction had the best fit with the experimental data.

TiO2/UV nano-photocatalytic process is suitable for the photo-degradation and removal of HA and FA in aqueous solutions.

This study assessed the effect of various agitation timings on bioethanol production from cassava peels (CP) using separate hydrolysis and co-fermentation (SHCF) technique.

The milled CP was divided into three groups each of 20 g and subjected to two-stage hydrolysis carried out at 100 oC for 60 min and 50 minutes, respectively. Experimental layouts were Sample 1 (B1) [0 hours i.e., no shaking], Sample 2 (B2) [3 hours shaking with an electric shaker at 200 rev/min-1], and Sample 3 (B3) [6 hours shaking at 200 rev/min-1]. Fermentations were carried out at 30 oC for 72 days. Data were analyzed using descriptive statistics, one–way ANOVA, and New Duncan’s multiple range test at P = 0.05.

The TSS and pH readings of the treatment groups before and after fermentation were: B1 – TSS (27.15 ± 0.15, 17.25 ± 0.07 oBx), pH (5.50 ± 0.00, 4.53 ± 0.04); B2 – TSS (27.32 ± 0.08, 14.78 ± 0.12 oBx), pH (5.50 ± 0.00, 4.74 ± 0.06); and B3 – TSS (27.17 ± 0.07, 10.24 ± 0.08 oBx), pH (5.50 ± 0.00, 4.77 ± 0.05) (P < 0.05). The mean fermentation efficiency (FE) and ethanol productivity (EP) were B1 (15.17 ± 0.07%, 0.122 ± 0.001 gL-1h-1), B2 (15.70 ± 0.18%, 0.126 ± 0.002 gL-1h-1), and B3 (18.80 ± 0.14%, 0.151 ± 0.001 gL-1h-1) (P < 0.05). All treatment groups attained the maximum ethanol yields at 72 hours of fermentation (P < 0.05). Agitation at 200 rev/min-1 for 6 hours gave the optimal FE (%), EP, and ethanol yield.

The established condition improved the Bioethanol quality and yield of CP. Thus, optimizing bioethanol production from CP would help enhance sustainable biofuel production without affecting food security.

Several aquaculture industries in underdeveloped nations use fossil fuel-powered generators to produce electricity. This pattern has raised greenhouse gas emissions as well as the price of aquaculture products.

To address this issue, this study contains a bi-objective model that optimizes the parametric settings of waste-to-energy (WTE) plants for aquaculture firms: Levelized cost of energy and power expenses for reverse logistics. The best values for these objectives were created using a genetic algorithm and goal programming.

Four planning periods were taken into account during implementation, and actual data were gathered from a Nigerian aquaculture company. The electricity costs from biodiesel ranged from N0.7541 per kW to N0.7628 per kW, respectively. Reverse logistics has energy costs ranging from N6 329 492.10 to N7 121 015.53. The proposed model produced average values for several WTE parametric parameters, including a 1.69 million kg hydrogen gas, a 59.16% hydrogen gas compression efficiency, and an 83.39% electricity conversion efficiency. Furthermore, the system had logistics’ minimum and maximum fractions of 0.18% and 21%, respectively.

Our findings demonstrated how WTE parametric parameters impact the aquaculture industry’s electrical power unit.

Awareness, knowledge, and attitude towards waste management, environmental factors of waste disposal sites and citizens’ as well as waste generators’ behaviors should be considered for implementing a waste segregation plan at the source.

The statistical population of this cross-sectional study includes 150,000 households living in Kerman. The sample size is calculated as 444 individuals using a stratified sampling method considering a 15% withdrawal probability. The correlation between Kerman citizens’ demographic data (age,gender, mean income, and household head’s educational level) and behavioral patterns (knowledge and awareness, attitude and behavior) regarding waste management and environmental factors of waste disposal sites was evaluated using SPSS software.

Examining the variables indicates that attitude, environmental factors, behavior, awareness, and knowledge have the highest mean and standard deviation, respectively. The highest mean score of awareness and knowledge was observed among individuals who earned 40 million IRR and higher income (2.55 ± 0.24) and those who had a PhD degree (2.63 ± 0.27). The results show that one unit increase in the score of awareness and knowledge, attitude and environmental factors could increase the mean behavior score.

Teaching the households waste-related environmental issues and how to properly separate recyclable waste as well as providing correct information regarding the current (COVID-19 period) and future plans and policies of the waste management organization, and developing suitable motivational mechanisms could improve the performance level of a society.

The widespread presence of organic dyes in the various industries’ effluent such as paper, textile, and clothing has led to significant environmental pollution. Titanium oxide (TiO2) nanoparticles immobilized on zeolite (ZSM-5) were investigated under UV light for activation of peroxymonosulfate (PMS) for photocatalytic degradation of Orange II (OII) dye in aqueous solutions.

In this study, the photocatalyst used was prepared by immobilizing different amounts of TiO2 nanoparticles on ZSM-5. Characterization analyses including X-ray diffractometer (XRD), Fourier transform infrared (FTIR), BET, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were performed on the synthesized samples. Then, the effect of various parameters, such as TiO2 nanoparticles loading onto the ZSM- 5, pH, contact time, dye concentration, and TiO2/ZSM-5 dosage, is investigated for the removal of OII as a model molecule under the UV irradiation with 15 W power.

The highest removal percentage of OII dye (97.44%) was obtained in the optimal operating conditions of pH = 3, the initial dye concentration = 5 ppm, amount of TiO2/ZSM-5 = 10 mg/L, amount of PMS = 50 mg/L, and reaction time = 120 minutes. The Langmuir–Hinshelwood kinetics model fitted with the experimental data.

The obtained results of this research showed that PMS can be used as a suitable oxidant activated with ZSM-5/TiO2 nanocomposite in OII degradation in different water environments, by optimizing the effective operating factors.

The health and productivity of the land across the Sahel are in declension due to desertification. This has lowered the quality of ecosystem services and has led to a vicious cycle of drought, famine, poverty, and insecurity in the region. As one of the flagship interventions of the UN’s decade (2020-2030) of ecosystem restoration to tackle desertification and respond to climate change, there are mixed reactions to the successes of the Great Green Wall (GGW) in Nigeria due to the failure of the Sustainability of Policy Instrument.

A two-round Delphi reached consensus on 42 sub-indicators under 14 indicators as indicated by Kendell’s (W = 0.509, P = 0.001) and high correlation between rounds (rho = 0.959, P = 0.001). The indicators were then deployed to assess the GGW in a questionnaire (n = 401) via a multi-stage sampling, and their performance was weighted using principal component analysis (PCA).

“Proportion of land reclaimed” was recorded as the highest-performing indicator due to the multifaceted afforestation program covering fodder and wood lot areas, while “dune fixation” has the least performance due to the lack of employment of ecological engineering tools. The findings showed that the presence of local jobs is not significant in raising the livelihood status above the poverty line.

To meet the 2030 timeline, there is a need to scale up the implementation of the GGW and support the desert frontline states (DFS) with alternative energy to reduce the rate of deforestation.

Leachate, a highly contaminated liquid, is produced by separating wastes and introducing moisture into the waste layers. Biological toxicity evaluation is a method that may be used to analyze the toxicity of leachate to organisms and plants. Sorghum bicolor was employed in this study to evaluate the acute toxicity of raw leachate and landfill leachate.

Leachate was collected from different locations within the refuse that was collected and mixed in a sampling container. The physiochemical characteristics of the leachate were analyzed in both raw leachate and landfill leachate. Germination rate, root weight, and root length were measured 24, 48, and 72 hours after planting for leachate dilutions of 25%, 50%, 75%, and 100%, respectively.

Raw leachate had greater concentrations of metals (Fe, Zn, Cu, Mn, Cr, Cd, and Pb), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), nitrate, ammonia, and phosphate, as well as a more acidic pH (< 6), as compared to landfill leachate. The results showed that landfill leachate had a lower potential for toxicity than raw leachate, with seed-germination rates of 0.1 and 0 in the presence of 75% landfill leachate after 48 and 72 hours, respectively, as opposed to 0.3 and 0.1 in the presence of raw leachate.

The findings show that raw leachate can include higher concentrations of metals and organic compounds, which can be one of the causes of Sorghum seed phytotoxicity. Waste leachate management is one of the most important pillars of environmental protection, and it should be taken into consideration by the right authorities.

In recent years, new findings on the relationship between human health and air pollutants have emerged, underscoring the necessity for appropriate site selection of air monitoring stations.

This analytical-cross-sectional study aimed to compare the concentration levels of PM10 and PM2.5, as measured by weight method, with data collected from an air quality monitoring station (AQMS) in Tehran. Initially, data were collected from the Tarbiat Modares AQMS. The accuracy of this data was then evaluated using a high-volume sampler and Grimm dust monitor situated approximately 200 meters away from the Tarbiat Modares station. The study period was between June 2017 and October 2017, and the frequency of sampling was every six days according to the instructions.

The results revealed that the average concentration levels of PM10, as measured during the sampling period by the high-volume sampler, the Grimm device, and the air quality measurement station, were 143.54 ± 33.84, 70.95 ± 7.06, and 110.06 ± 27.08 μg.m-3, respectively. The highest daily concentration of PM10 was recorded by the high-volume sampler device at 197.12 μg.m-3.

This study found a weak correlation between the aerosol concentration data obtained from the monitoring station and those obtained from the Grimm device and the high-volume sampler. Therefore, it is crucial to ensure the quality control and assurance of data collected from monitoring stations for accurate decision-making and planning.

Many countries undertake development activities that utilize resources from the environment. In the Democratic Republic of the Congo (DRC), the Congolese Environmental Agency is supervised by the Ministry of Environment and Sustainable Development to undertake an environmental assessment of all projects that pose risks to the environment. The present study conducted a critical review of the country’s existing environmental assessment legislation, identifying strengths and weaknesses in the Environmental and Social Impact Assessment (ESIA) system.

A literature survey was done in the Google Scholar, Taylor & Francis, and Elsevier databases, which were also guided by the PRISMA. All full-text articles included in the study were written or translated (using online translation software) into the English language, and also, reported on environmental impact assessment as well as legislation. A textual examination of the included literature was done. A set of adapted analytical criteria was used to critically review the ESIA system in the DRC. The results were discussed, and recommendations were given.

It was found that the decree was not effective and efficient for the ESIA study. Some of the key limitations of the ESIA decree included the lack of scoping in the entire ESIA process, alternatives that were limited in scope, fees and charges that were not explicitly stated in the legislation, and the lack of public participation at some stages.

The ESIA system in the DRC is ineffective and needs revision to improve its effectiveness.

The exposure to toxic metals is a major global health concern due to their stability, bioaccumulation, and high toxicity. These metals can be transmitted to the fetus through the placenta and exposure can last throughout life. This systematic review focused on the potential risks of arsenic (As) in breast milk to newborns and infants.

Multiple keywords, such as “human milk” and “breast milk”, associated with “toxic metal”, “heavy metal” or “arsenic” were used to search related databases. Of the 151 articles found, 45 studies were eligible for qualitative review, and 34 were included in the meta-analysis.

The lowest and highest levels of arsenic were found to be 0.04 ± 0.70 and 27.75 ± 28.30 μg/L, respectively. The overall pooled average concentration (95% CI) of arsenic in breast milk was 0.11 (95% CI: 0.11, 0.12). The results indicated that infants who consume breast milk are within a safe limit for cancer risk.

The exposure to significant metals is associated with disease development. Therefore, ongoing knowledge creation through mental acts and continuous observation is necessary to better understand the effects of heavy metals in future studies.