Environmental Health Engineering and Management Journal
Volume:11 Issue: 3, Summer 2024

Ultrafiltration plants are increasingly used for producing high-quality water. The research aimed to compare two compact piping units employed as pretreatment systems to enhance surface water quality. The aim was to achieve the specified average values of feed water quality necessary for ultrafiltration (UF) plants, as per the requirements of the UF manufacturer. The units were intended for use in a water treatment plant with a capacity of 5000 m3/day, where the influent water’s total suspended solids (TSS) ranged from 130 to 160 mg/L.

The initial unit implemented plate settler technology to facilitate sedimentation, whereas the subsequent unit adopted filtration. Both piping systems were assessed for their efficacy in conforming to stipulated water quality standards alongside the corresponding economic considerations.

Both piping units effectively achieved the mandated water quality standards, albeit at disparate costs. In this specific case study, the sedimentation units incurred an initial expense of 191 800 Egyptian pounds (LE) (equivalent to $6209.5), whereas the filtration units necessitated an initial investment of 471 680 LE ($15 270.5). Additionally, both the initial outlay and ongoing operational expenses of the sedimentation units were inferior to those of the filtration units.

Based on the study results, the use of sedimentation units proved to be more cost-effective. Despite meeting the required water quality standards, the sedimentation units had lower initial and operational costs than the filtration units. Therefore, it is recommended to use sedimentation units as the pretreatment system in this water treatment plant to achieve the desired water quality while optimizing costs.

SARS-CoV-2, the causative agent of the COVID-19 pandemic, spreads through both direct and indirect pathways. Among the latter, surface contamination is a significant concern due to the virus’s prolonged viability on surfaces. There is ongoing discussion over the impact of environmental surface contamination, especially in light of the introduction of novel viral types. The present study aimed to examine the extent of environmental surface contamination across different hospital wards and evaluate the effectiveness of disinfectants in inactivating the virus.

The samples were collected from critical areas in a hospital, both pre-disinfection (n = 40) and post-disinfection (n = 17), using reverse transcription-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2.

The findings indisputably confirm the presence of SARS-CoV-2 on swab samples from frequently-touched surfaces. Notably, 10 samples were virus-positive before disinfection, highlighting persistent viral contamination in vital hospital zones.

This study underscores the critical role of environmental surface contamination in SARSCoV-2 transmission, particularly in healthcare settings. Detecting the virus on frequently-handled surfaces underscores the urgent need for rigorous and frequent surface disinfection. Effective surface disinfection remains a rapid, straightforward, and practical strategy to mitigate virus transmission to healthcare workers and patients. These findings hold significant implications for infection control, particularly amid emerging virus variants. They emphasize the need to maintain stringent hygiene and disinfection practices within healthcare facilities to combat the spread of COVID-19.

Congo red (CR), a harmful dye present in water, requires effective removal methods. This study investigated the utilization of dry green pea husk (DGPH) and its charcoal (CGPH) as economical and eco-friendly adsorbents.

Various factors, including contact time, pH, adsorbent dosage, initial concentration, and temperature, were investigated to assess their impact on the adsorption process. Also, different models (isotherms, kinetics, and thermodynamics) were compared to describe the adsorption phenomenon.

Equilibrium adsorption was achieved within 30 minutes for both adsorbents. The optimum pH for CR removal was determined to be 2. The adsorption capacity decreased by increasing the adsorbent dosage, whereas it increased by increasing the initial dye concentration. The Langmuir isotherm model demonstrated the best fit for DGPH, while the Freundlich model exhibited the best fit for CGPH. The pseudo-second-order model displayed a superior fit for both adsorbents. To assess the spontaneity and feasibility of the adsorption process, thermodynamic parameters including enthalpy, entropy, and Gibbs free energy were computed. The results indicated that the adsorption of CR on DGPH was endothermic and favorable at lower temperatures, whereas the adsorption on CGPH was exothermic and favorable at higher temperatures. The negative values of Gibbs free energy for the CGPH adsorbent confirmed the spontaneous nature of the adsorption process.

The study establishes that green pea husk and its charcoal are effective and environmentally friendly alternatives for the removal of CR from water.

Special attention should be given to the seepage in dams since it may cause failure. Seepage is not considered in the total risk factor calculated using the International Commission of Large Dams (ICOLD), the United States Bureau Reclamation (USBR) while the description of the dam seepage condition is given a weightage in the Brazilian method.

Haditha Dam, Iraq, was constructed on varying degrees of limestone beds of the Euphrates and Ana formations. Therefore, seepage from the dam should be continuously monitored and accurately measured. In the present study, a methodology was proposed to overcome the problem of inconsistent seepage data. The inconsistent seepage rates can be replaced by the predicted seepage rates obtained from SEEP/W model.

The predicted seepage rates for different water levels in the reservoir of Haditha Dam were found in association (R2 = 0.96). In addition, the value of mean absolute error (MAE) for the model accuracy was found to be 0.0106. According to the Brazilian index, the weightage for the seepage condition of Haditha dam was in the second category and equal to 3.

For Haditha Dam, the seepage data cannot be used in the dam risk assessment since it was inconsistent with gaps, and it can be replaced by the consistent predicted seepage rates predicted by SEEP/W model. Generally, the aging and other dam problems result in increasing seepage rate. This highlights the importance of efficient management that follows resilient monitoring and surveillance programs that ensure dam safety.

Nowadays, one of the most serious environmental concerns is the appropriate management and disposal of municipal waste, which can lead to significant environmental consequences. This study aimed to examine the determinants of source waste separation behavior (SWSB) among high school students applying the theory of planned behavior (TPB).

In this descriptive study that was performed in 2022 via an online survey, 689 questionnaires were completed by students in 10 randomly selected high schools in Abhar, Iran. The data were analyzed by IBM SPSS Amos version 23. To assess the predictive determinants of SWSB, a structural equation model (SEM) was used.

Subjective norm was found to be the best predictor of high school students’ source waste separation (SWS) intention. The TPB had a prediction power of 68% and 74% for predicting waste separation from the source intention and behavior, respectively.

According to the results of this study, subjective norm has the greatest impact on separation intentions (regression weight = 0.550; SE = 0.08; CR = 6.863; and P < 0.0001). Educational administrators are suggested to pay special attention to the role of significant others, such as teachers, parents, and peers in their planning to improve waste separation behavior at the source in schools.

Research on the relationship between bioaerosols and particulate matter (PM) concentrations is necessary, especially in hospitals where airborne bioaerosols can facilitate disease transmission. This study aimed to investigate the relationship between PM (PM2.5 and PM10) and bioaerosols, as well as the factors influencing them (temperature and humidity), in the air of liver transplant operating rooms (LTOR) at Imam Khomeini Hospital in Tehran.

Bioaerosol samples (32 samples) were collected using the passive sampling method, employing open-door plates containing culture medium, during June and July of 2019. PM samples were obtained concurrently with bioaerosol samples using the GM8803 air quality detector, during four one-hour periods. Simple linear regression analysis was performed to determine the relationship between bioaerosol and PM concentrations.

It was revealed that the average concentrations of PM2.5 and PM10 were 17.8 (SD = 2.2) and 27.0 (SD = 2.6) μg/m3, respectively. Additionally, the average concentrations of bacterial and fungal bioaerosols were 2132 (SD = 837) and 550 (SD = 189.4) CFU/m2.h, respectively. Linear regression analysis demonstrated a strong correlation between bacterial bioaerosols and PM concentrations, whereas the relationship with fungal bioaerosols was relatively weaker.

The findings of this study indicate that the indoor air in LTOR exhibits a higher level of microbial contamination than the recommended guidelines for high-risk environments. To improve the air quality in LTOR, it is recommended to implement periodic microbial monitoring, ensure the proper functioning of ventilation systems, and pay attention to their maintenance and operation.

Dukku and Kalgo rivers in Kebbi, Nigeria, provide essential ecosystem services such as drinking and domestic water, fishing, and farming. However, the safety of these rivers in terms of microplastic pollution has not been investigated. This study aimed to characterize and determine the concentration and associated risks of microplastics in both rivers.

Microplastics were extracted from water samples through filtration and analyzed using spectroscopy and microscopy.

Significant concentrations of microplastics were detected in both rivers. Dukku River samples showed concentrations ranging from 125.00 to 160.30 particles/liter, while Kalgo River ranged from 119.30 to 134.70 particles/liter. Both rivers predominantly contained microplastic fibers and fragments, with fibers comprising the highest percentages (61% in the Dukku River and 56% in the Kalgo River). Microplastics in Kalgo River were predominantly sized between 0 and 100 μm, whereas in Dukku River, sizes ranged from 500 to 1000 μm. Polyamide was the dominant polymer, constituting 50% in the Dukku River and 42.50% in the Kalgo River, followed by polyethylene (34% in the Kalgo River and 25.60% in Dukku River), and polyvinyl alcohol (24.40% in Dukku River and 23.50% in Kalgo River). The predominant risk level posed by these polymers was level III (moderate risk), although polyamide posed a level IV risk (high risk). The pollution load index (PLI) for both rivers exceeded one, indicating a high risk.

Microplastic pollution in these rivers poses ecological and health risks. Identifying and mitigating sources of microplastic entry into the rivers is crucial to reducing exposure levels.

The growing use of treated wastewater in farming has raised concerns about the potential impacts on public health.

This study assessed the levels of the heavy metals lead (Pb), cadmium (Cd), and arsenic (As) in plants watered in greenhouse settings using both well water and synthetic wastewater. Synthetic wastewater with As at concentrations of 0.1, 0.2, and 0.4 mg/L, Pb at 1, 3, and 5 mg/L, and Cd at 0.01, 0.03, and 0.05 mg/L, as well as well water were used to irrigate radish, coriander, and grass. In the end, 144 vegetable samples were gathered, and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to determine the heavy metal concentrations in the samples. Risk assessment for consumers was determined based on the measured levels of heavy metals in the vegetables.

Even though the concentrations of heavy metals in the wastewater were within the limits for irrigation, the risk assessment showed that consumption of vegetables irrigated with treatment wastewater could pose risks to individuals’ health. The maximum concentration of Pb in radish leaves was observed at the Pb concentration of 5 mg/L, and the maximum concentration of As in cress irrigated with As effluent at the As concentration of 0.02 mg/L.

The consumption of vegetables containing Pb can pose a significant non-carcinogenic risk to consumers. However, well water may also be dangerous in the long run. Therefore, it is important to ensure about food safety when using treated wastewater for irrigation.

The escalating production and utilization of plastics, driven by their distinctive properties, have significantly contributed to environmental pollution. One of these pollutants is microplastic (MP), which is present in many food products, such as tea bags. The primary objective of this study was to investigate the presence and characteristics of MPs in tea bags from five different brands in Iran.

For this study, 30 tea bags from five different brands in Iran were selected for sampling. The unaltered tea bags (with tea) were placed in 100 mL of ultrapure water at a temperature of 95 °C for 5 minutes, representing an alternative approach involving tea bag sampling with tea and without rinsing. Subsequently, the samples were subjected to quantitative analysis using a scanning electron microscope (SEM) and qualitative analysis using a micro-Raman spectrometer.

All brands exhibited MP contamination, with an average abundance of 518 459 items per individual tea bag. Fibers were the predominant form of MPs, primarily falling within the 10–50 μm size range. Polymer analysis identified cellulose acetate (CA), nylon, polyethylene terephthalate (PET), and polyethylene (PE) as the prevalent types, with CA and nylon as the most frequent ones. The estimated daily intake (EDI) of MPs was calculated at approximately 17,282 items/kg-BW/day for children consuming 100 ml of tea daily and 14,813 items/kg-BW/day for adults consuming 400 mL of tea daily.

This study underscores tea bag consumption as a significant route of MP exposure for humans and the environment, posing potential risks and implications.

Heavy metals (HMs) in the environment threaten food safety and human health. In this study, the health risks of HMs caused by the consumption of commonly consumed vegetables in the central part of Mazandaran province were evaluated.

In this study, 42 vegetable samples were analyzed for concentration of HMs, and estimated daily intake (EDI), target hazard quotients (THQ), hazard index (HI), and target carcinogenic risk (TCR) were calculated.

The mean content of lead (Pb), cadmium (Cd), and zinc (Zn) in the studied areas were obtained 28.45, 0.26, and 79.20 mg/kg, respectively. The concentration of Pb, Cd, and Zn in the studied vegetables was found to be 1.76 ± 0.2, 0.09 ± 0.07, and 11.53 ± 1.20 mg/kg, respectively. The EDI average of Pb, Cd, and Zn in adults was 0.0064, 0.0003, and 0.0412 mg/kg day−1; and in children were 0.0099, 0.0005, and 0.0686 mg/kg day−1, respectively. The present study showed that the THQ for Pb in all vegetables consumed by children faces much higher risks than adults. The TCR for Pb in total vegetables was less than 10-4 and for Cd was identified as more than 10-4 in some vegetables in the adults and the children’s population.

The concentration of Cd and Zn in the soil and related vegetables is less than the permissible limit, but the amount of Pb in the vegetables is higher than the permissible limit. Therefore, continuous care and monitoring of agricultural soils in these areas, such as the proper use of chemical fertilizers, pesticides, and treated wastewater sludge, is necessary.

Following an extensive examination of various biofiltration packing materials within a typical bioreactor (a biofilter) is aiming to remove hydrogen sulfide (H2S) in the raw biogas.

Both biochar (pre- and post-pyrolysis at 400, 500, and 600 °C) and cellular concrete (CLC) waste, representing organic and inorganic packing materials, respectively, displayed remarkable removal efficiency (RE) performance under dynamic conditions. Nevertheless, the physical and chemical properties of these packing materials play a crucial role in absorbing and trapping H2S for further filtration from the raw biogas. Key evaluations encompass chemical compositions, porosity, and specific surface area, aligning with contemporary research methodologies (e.g., XRF, Walkley-black, Kjeldahl, BET, T-plot), as analyzed in this study.

Subsequently, the modification of these physicochemical properties aimed to demonstrate continued interactions of iron (III) oxide (Fe2O3) with H2S for chemical modification of CLC waste, and enhance the specific surface area of biochar from 12, 22, and 24 m2/g to 235, 433, 475 m2/g, and for porosity from 0.01, 0.42, and 0.025 cm3/g to 0.096, 4, 0.24 cm3/g, respectively, for physical modification of biochar samples after pyrolysis at 400, 500, and 600 °C.

In the end, improving the possibility of getting better RE from a laboratory-scale biofilter is possible by modification of the most effective physical (adding KOH to biochar and increasing porosity by 9 times, specific surface area by 19 times) and chemical (adding Fe2O3 to CLC waste) properties of the environment-friendly packing materials.

An essential component of environmental sustainability and sanitation is the management of dry toilets, especially waste disposal. Understanding the composition of the brown water from dry toilets, putting the proper composting technique in place, and guaranteeing safe disposal and reuse procedures are all necessary to handle the waste successfully. It has been discovered that brown water, sometimes known as feces, can be used for brick-making, fuel, fertilizer, and other purposes.

This review focuses on dry toilet technology, management processes, and sanitation systems in Ethiopia and other underdeveloped nations. It utilizes secondary information and searches from Google scholars, Library catalogs, and Researchers to comprehend dry sanitation systems, including their implementation, use, and maintenance. Keywords used in the search include “in-situ treatment,” “fecal sludge treatment,” “fecal slurry management,” and “brown water treatment.”

The review used a total of 108 articles and books, agricultural research, and reports on the feces’ physical, chemical, and biological characteristics. It also discussed risks associated with the mismanagement of feces, including parasitic diseases in exposed humans. The main aim of the review was to develop an understanding of brown water uses, composition, and management and select the proper method of composting with dry toilets.

Dry toilets in developing countries are utilized for ecological sanitation and agriculture, with feces potentially used as fertilizer. Utilizing feces as fertilizer is a sustainable, eco-friendly, and environmentally responsible practice that can increase productivity while maintaining a clean environment.