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Performance Evaluation of Different Soil Media by Batch-Operated Pilot-Scale Horizontal Subsurface Flow Constructed Wetlands for Wastewater Treatment
2023
Kumar Swarnakar, Arvind | Bajpai, Samir | Ahmad, Ishtiyaq
Constructed wetland systems (CWs) are low-cost natural treatment systems for various types of influents. Although mainly the natural wetlands are soil-based, the constructed wetlands have been traditionally built using aggregate media. The performance of four types of available soils in Chhattisgarh was studied as the filter media in the horizontal subsurface flow-constructed wetland (HSFCW). Fourteen pilot-scale CW units with different soil types (entisol, vertisol, alfisol, inceptisol, and stone aggregate) and plant types (Canna indica and Typha latifolia) were used to treat domestic wastewater (WW). One set of each soil base reactor was planted with Canna indica and Typha latifolia, and one was kept blank (unplanted). All soils and plants are easily available.The reactors received primary wastewater in batch loads with WW loading for six hours to maintain aerobic conditions. The residence time of WW was 48 hours, and the applied hydraulic loading rate (HLR) was based on soil and aggregate. According to the findings, the planted HSFCW was more effective than the unplanted system. The results show that the wetland constructed on the treatment efficiency of the soil base has excellent potential to treat WW, with both plants.
Показать больше [+] Меньше [-]Assessment of some Heavy Metals and Health Risks in Water and Shrimps from a Polluted Mangrove Swamp, Niger Delta, Nigeria
2023
Davies, Davies, Ibienebo Chris | Anyanwu, Emeka
The heavy metal concentrations of water and shrimp (Penaeus monodon) from Isaka Bundu swamp, Niger Delta were evaluated between January and June 2022. The non-carcinogenic health risk assessment was used to assess the water's suitability for recreation and the shrimps for consumption. Five heavy metals (Pb, Cu, Cd, Ni, and Zn) were assessed in both media using standard methods and compared with national and international standards. The Chronic daily intake (CDI) for Cd and Cu (in children) exceeded their respective reference doses while hazard quotients (HQs) for Cd and Cu (in children) and all the hazard indices were greater than 1 in the water. All the target hazard quotients (THQs) and total hazard index (THIs) were lower than 1 in the shrimps. The heavy metal concentrations, CDIs, HQ/THQs and HI/THIs were higher in the more impacted stations 1 and 3. Based on the heavy metal concentrations and health risk assessment, the waters of the Isaka Bundu swamp are unsafe for recreational purposes. However, shrimps are safe for human consumption. The high concentrations of heavy metals in the water influenced the concentrations in the shrimps. Anthropogenic activities in the area contributed to the heavy metal concentrations in the environment. The results also showed that the children were more prone to adverse health impacts.
Показать больше [+] Меньше [-]Status, Health Effects and Remediation Techniques of E-waste – A Review
2023
Guin, Shailu | Deswal, Surinder
The annual global generation of e-waste is estimated to be 59.08 million tonnes (7.37 kg per capita), out of which the major chunk is being processed in informal sector using primitive and hazardous methods in developing countries due to cheap labour, less stringent laws and regulatory policies. Despite the fact the annual global value of e-waste industry being about USD 62.5 billion that provides employment to millions in developing countries, the unstructured/informal operations in e-waste sector had and have been causing hazardous health issues in human and environment along with unlawful activities. Many studies have been reported on wide array of interrelated aspects and issues of e-waste, but only few studies have reviewed potential remediation techniques that can take care of the increasing e-waste and its sustainable management. Therefore, disposal and remediation techniques for polluted sites have been the key concerns in the field of environmentally sustainable management (ESM) of e-waste. The present review revealed that of all the classic and hybrid remediation techniques, the biological remediation techniques being eco-friendly and cost effective needs to be explored for metal removing from contaminated environment. The review also concludes the imminent necessity of ESM by framing and implementing regulations and laws essentially incorporating Extended Producer Responsibility (EPR) in developing countries. The review of Indian scenario suggests the scope of startups for the sustainable recycling of e-waste to achieve healthy environment, employment and economic opportunities.
Показать больше [+] Меньше [-]A Review on Global Pesticide Use and Food Contamination: African Perspective
2023
Adebisi, Fagbohun | Dauda, Mary | Anjorin, Toba
Pesticide application has increased globally with increasing demand for food, and modernized Agriculture as a result of an explosion in the world’s population growth, especially in developing nations in Africa, Asia, and South America. However, pesticides have helped to improve productivity, protect the nutritive integrity of food crops, and ensure year-round food supplies worldwide. The production and consumption of pesticides persisted from one decade to another until the ecosystem started to suffer from its adverse effects on the environment and human health. Previous investigations revealed that pesticides found entry into the human food chain. In response to these problems, researchers all over the world have conducted several kinds of research on pesticide applications, and their residual contamination in food. This review crosses from the past to present researches on the usage of pesticides, their accumulation in food, and possible methods of their reduction as highlighted by researchers over many years. There is a need for continuous monitoring of pesticide residue profile in soil, crop produce, and animal products in developing countries so that it will not exceed maximum residue limits (MRLs).
Показать больше [+] Меньше [-]Treatment of Fish Processing Wastewater by Alum and PAM: A Comparative Study on Turbidity, COD, BOD, and Rheological Properties
2023
AL Riyami, Hanan Ahmed Said | Al Dawery, Salam Kadhim | Reddy, Sreedhar | Ahmed, Anwar
This research article compares the efficacy of using alum and poly aluminum chloride (PAM) for the treatment of fish processing wastewater. This study aims to determine the effectiveness of each treatment method in reducing turbidity, COD), BOD, and altering the rheological properties of the wastewater. Batch mode coagulation and flocculation experiments were conducted using lab scale jar test apparatus. The findings indicate that both alum and PAM can significantly reduce turbidity and COD. The highest turbidity removal efficiency of 93% was achieved with alum at a dose of 200 mg/L, while PAM achieved a maximum turbidity removal efficiency of 86% at a dose of 100 mg/L. Alum and PAM achieved the highest BOD5 and COD removal efficiencies at a dosage of 200 mg/L and pH 7.0. However, the removal efficiencies varied at different pH values and dosages. Alum and PAM have significant effect on the rheological properties of fish processing wastewater. The viscosity of settled residual sludge after chemical coagulation is more compared to untreated fish processing wastewater due to aggregation of suspended particles to form larger flocs. This would improve the settling properties of the coagulated sludge. The study concludes that both alum and PAM can be viable options for treating fish processing wastewater, with Alum showing a slight edge over PAM in certain aspects.
Показать больше [+] Меньше [-]Enhanced Microbial and Total petroleum hydrocarbon degradation in Crude-Oil Polluted Soils using Agro-Wastes
2023
Bessong Agbor, Reagan | Eyogor Edu, Ndem | Ndarake Asuquo, Eno | Akpang Ivon, Etta | Alain Inah, Simon | Bebia, Obase-Etta
Bioremediation has become a trending and developing field in environmental restoration through the use of micro-organisms to utilize and reduced the concentration and toxicity of various chemical pollutants. This study is on bioremediation of hydrocarbon-polluted soils using some agricultural wastes. Ninety (90) plastic buckets were filled with 4kg each of the composite soil. The soil contained in the plastic buckets was spiked with 250ml crude oil, except in the unpolluted plastic buckets (0%) crude oil. The agro-wastes (plantain stem sap, bush mango peels, and fruited pumpkin husk powder) in single and combined forms were applied after 14 days soil pollution. The amendments were applied as follows: Pristine control (0% agro-wastes), crude-oil control (0% agro-wastes), 150g, 250g, and 350g of the agro-wastes. Soil samples were collected at 90 days for soil microbial counts and the total hydrocarbon content of the soil. Data collected were subjected to 2-way ANOVA. The result showed that the microbial population in the crude-oil polluted soil amended with different agricultural wastes significantly increased (p<0.05) the total heterotrophic and crude oil utilizing bacterial and fungal counts in the soils and the increase in microbial population result in a significant reduction in total hydrocarbon content (THC) of the soils. The reduction in the THC of the soil was treatment dependent. It is, therefore concluded that based on the efficiency of these agro-wastes in enhancing microbial degradation, further studies should be carried out on the enzyme activities and production of bio-surfactant from the wastes to shorten the degradation time.
Показать больше [+] Меньше [-]Feasibility of Production of PET/ZIF-8 Polymer Media to Remove Particles from the Air Stream Compared to HEPA Filter
2023
Kazemi, Meghdad | Kalantary, Saba | Abbasi, Ali Reza | Rahimi Foroushani, Abbas | Golbabaei, Farideh
Polyethylene terephthalate (PET) and Zeolitic Imidazolate Framework-8 (ZIF-8) were used to investigate the feasibility of producing electrospun PET/ZIF-8 polymer media in removing particles from the air stream to compare with the HEPA filter. To make PET/ZIF-8 media, concentrations of 0.5, 1, 2.5, and 5 wt.% of ZIF-8 were dissolved in PET20% solutions, and dispersed for 10 min. Then, PET/ZIF-8 media was produced with an ESDP30 model electrospinning device. The efficiency and pressure drop of nanofiber media were measured with a respiratory mask and filter test device. The FTIR, XRD and SEM analysis were carried out to obtain the characteristics of nanofibers. The overall XRD pattern and its peaks were in reasonable agreement with previous findings that confirmed the structure of ZIF-8. The FTIR spectra of the obtained materials confirm that the chemical bond structure corresponds to that reported for ZIF-8. In total, The PET/ZIF-8(1%) media efficiency, pressure drop, the average diameter of nanofibers, and the quality factor were 100%, 320 Pa, 171.18±37.91 nm and 0.0143 Pa-1, respectively, which was better than other electrospun PET/ZIF-8 media and HEPA filters. According to the results, with an increase in the weight percentage of Zif-8 (>5 wt.%) in the structure of PET/Zif-8 media, due to the increase in the viscosity of the solution jet, the diameter of the produced nanofibers increased and the efficiency of the electrospinning medium decreased.
Показать больше [+] Меньше [-]Catalytic Conversion of Carbon Dioxide by Metal-Organic Frameworks: an Effective Approach for CO2 Utilization
2023
Tayebi, Leila | Rahimi, Rahmatollah | Akbarzadeh, Ali Reza
Due to the increase in carbon dioxide emission, there is a need for achieving efficient ways to reduce CO2 harmful effects. There are several strategies to mitigate atmospheric CO2 concentration. The catalytic cycloaddition of carbon dioxide with epoxides to provide cyclic carbonates employing metal-organic frameworks is a promising method for this purpose. Herein the application of two porous porphyrinic MOFs (Co-PMOF and Cu-PMOF) as catalysts in CO2 conversion was investigated. These MOFs demonstrated good crystallinity and porosity, providing them with two promising platforms to study CO2 conversion reactions. These heterogeneous porphyrin-based MOFs are catalytically efficient towards the chemical conversion of CO2 under moderate conditions because these MOF matrices contain a high density of active Lewis acidic and basic sites for activating CO2 and epoxide compounds. These MOFs exhibited high catalytic efficiency for the chemical fixation of CO2 at ambient temperature and solvent-free conditions. The reactions formed the proportionate cyclic carbonates in good yields. These products are valuable compounds in a variety of chemical fields.
Показать больше [+] Меньше [-]Dust Emission Calculation and Forecasting using CALPUFF and GCM models
2023
Tamjidi, Mahsa | Abbaspour, Madjid | Rashidi, Yousef | Mirzahosseini, Alireza
Dust is an important atmospheric phenomena that occurs in spring and summer in many regions, including Iran and its neighboring countries. Considered one of the most important challenges of the last century, this phenomenon occurs on a global scale in arid and semi-arid regions. Because of changes in climate and vegetation as well as progressive processes of soil erosion and the disturbances resulting from them, the sensitivity of regions to rapid erosion will have important reactions on the region's climate and desertification. Therefore, the current research investigated the concentration and distribution of fine dust under the influence of meteorological parameters using the GCM climate model and attempted to determine the effect of climate change on the concentration of the relevant pollutant in the coming years. In this study, the CALPUFF model considered the temporal and spatial effects of weather conditions on the transfer, transformation, and removal of atmospheric pollutants. The emission rate of the PM10 pollutant was estimated. The results indicated that the increase in greenhouse gas emissions and changes in climate variables in the near future will cause the distribution of suspended particles one of the important pollutants to increase significantly. The results also revealed a significant relationship between the degradation of air quality and the trend of air warming during the period 2046-2065.
Показать больше [+] Меньше [-]A Preliminary Study on the Water Quality from two Estuaries in Madura Island, East Java, Indonesia
2023
Fitrihidajati, Herlina | Purnomo, Tarzan | Rachmadiarti, Fida | Ambarwati, Reni | Yolanda, Rofiza
The water quality in the western part of Madura Island is currently faced with a severe threat due to pollution. Therefore, this study aimed to investigate the water quality from Bancaran and Kwanyar estuaries, Madura Island, using the physicochemical approaches. A total of eight physiochemical parameters such as salinity, temperature, pH, DO, CO2, BOD, Pb, and Cd were investigated at three sampling stations of each estuary on 15 June 2022 and 19 December 2022 to identify the potential environmental factors controlling the water quality for effective monitoring and management of these estuaries. The results showed that temperature (25–29.5ºC), pH (7.47–7.8), DO (2.45–4.57 ppm), CO2 (0.5–10.4 ppm), BOD (1.86–9.99 mg.L-1) and Pb (–0.55 to –0.31 mg.L-1) differed significantly (P < 0.01), while salinity (0.2–2.90‰) and Cd (0.02–0.05 mg.L-1) did not exhibit significant differences (P > 0.05). Pearson’s correlation indicated significant positive correlations between salinity and Pb, as well as Cd and Pb. According to the principal component analysis (PCA), salinity and BOD were related to the Kwanyar estuary, while the other parameters were associated with the Bancaran estuary. This preliminary investigation showed a decline in the water quality of these estuaries, specifically from DO measurement. Although low DO levels occur naturally, the continuous occurrence will affect the living organisms in the water that plays an important role in the aquatic environment. Therefore, continuous monitoring of these estuaries is needed to provide better information and for protection as well as sustainable use of water resources.
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