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Critical loads of acidity and model predicted changes in forest growth in Sweden
1993
Svedrup, H. | Warfinge, P. (Lunds Tekniska Hoegskola (Sweden). Kemiska Inst.) | Rosen, K. | Melkerud, P.A.
Sewage Treatment by Kolkata’s Natural Wetland System
2024
I. Khan, D. Das Gupta and A. Gupta
The metropolis of Kolkata stands uniquely positioned to implement a natural sewage treatment paradigm through the utilization of waste stabilization ponds, specifically within the East Kolkata Wetlands (EKW). These shallow oxidation ponds harness solar irradiation and algae bacteria symbiotic processes to effectively treat incoming sewage. Concurrently, nutrient-rich effluents are assimilated through fish production, converting available nutrients into protein—a hallmark of nature-based treatment. A portion of raw sewage is used to cultivate a chunk of vegetables before treatment in fish ponds, and the reclaimed water after treatment is used for vegetable and paddy cultivation downstream. This investigation explains the delineation of a sewage flow system to EKW, a Ramsar-designated site. Substantively, it offers quantitative insights into the sewage volumes and quality undergoing treatment. The sewage flow is higher in the winter months (909.07 MLD) compared to the summer months (709.34 MLD). In general, the sewage from the Kolkata city flowing to the EKW is moderately polluted. Extensive scrutiny of sewage from pond inlets and outlets serves as a quantitative metric for evaluating treatment efficacy. EKW efficiently treats the sewage, demonstrating 59.1% Biological Oxygen Demand (BOD) removal and a 99.28% reduction in fecal coliform. The natural treatment system excels in removing ammoniacal nitrogen (80.38%) and phosphate (90%). The treated water’s quality along the EKW boundary, culminating at the Kulti Gong River discharge point, was systematically assessed. Analytical findings indicate that all measured concentrations in the treated water adhere to prescribed inland surface water discharge standards prescribed by the Central Pollution Control Board, India, barring a marginal elevation in BOD during winter. Evidently, the EKW system adeptly manages substantial sewage volumes, fostering efficient treatment while concurrently facilitating resource recovery through fish production, yielding economic dividends. Despite its substantial land footprint, preserving this inherently sustainable wastewater management paradigm is imperative.
Afficher plus [+] Moins [-]Effects of Rainfall Intensity, Kinetic Energy and Slope Angle to the Upslope, Downslope, and Lateral Slope Components of Splash Erosion in Hillslope Agriculture: A Case in Badiangan, Ajuy, Iloilo
2024
Shevanee Ruth G. dela Cruz and Ricardo L. Fornis
This study was conducted in Barangay Badiangan, Ajuy, Iloilo City, Philippines (11°10’N, 122°58’E) to determine the effects of rainfall intensity and other rainfall-derived parameters on the directional components of splash erosion in hillslopes. There are five experimental set-ups with slope angles ranging from 0% to 48% were tested under natural rainfall conditions using a modified splash collector. The data collected shows that kinetic energy, slope, and rainfall intensity have shown significant effects on splash erosion. The models obtained using regression analysis are 𝑄𝑄𝑑𝑑𝑑𝑑𝑑𝑑=0.0093(𝐾𝐾𝐾𝐾0.80) and 𝑄𝑄𝑡 𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡=0.060(𝐾𝐾𝐾𝐾0.107)(𝑆𝑆0.700)(𝐼𝐼200.700) . The model equation performance has been validated using the Standard Error of Estimates with values of 12 and 9.4 for splash detachment and splash transport, respectively. The constants used for kinetic energy in detachment and slope in transport align with the research by Quansah (1981) for sandy soil, which is similar (the characteristics) to the soil at our research site. Additionally, rainfall intensity, especially with a 20-min duration, generated the best model as it yielded the lowest SEE value for all cases.
Afficher plus [+] Moins [-]Enhanced Phenanthrene Biodegradation by Bacillus brevis Using Response Surface Methodology
2024
Kiran Bishnoi, Pushpa Rani and Narsi R. Bishnoi
The current investigation assessed the capability of a well-adapted and enriched bacterial strain known as Bacillus brevis for the biodegradation of phenanthrene. To enhance the removal efficiency of phenanthrene, employed Response Surface Methodology (RSM) in conjunction with a Box-Behnken design (BBD) model. The experiments were designed to explore the impact of pH (6.0 to 9.0), temperature (20 to 40°C), initial phenanthrene concentration (50 and 100 ppm), and incubation time (7 to 21 days) on biodegradation of phenanthrene. The highest level of phenanthrene biodegradation, approximately 55.0%, was achieved by Bacillus brevis when the optimal conditions were met as pH of 7.0, temperature 30oC, and initial phenanthrene concentration (70 ppm) after 21 days of incubation time. This study underscores the significance of employing statistical tools like RSM to enhance the microbial degradation of contaminants.
Afficher plus [+] Moins [-]Exploring the Adsorption Efficiency of Local Apricot Seed Shell as a Sustainable Sorbent for Nitrate Ion
2024
Mohd Ishaq, R. C. Chhipa, Anupama Sharma, Gh. Ali and Riyaz-ul Hussain
Locally available apricot seed shell as agro-waste was used for the preparation of adsorbents. The biochar was prepared at 370°C via pyrolysis and 80 mesh particle sizes were modified by 1N HCl. Nitrate adsorption and effect of co-ions from aqueous solution were studied under batch model using apricot seed shell powder (ASSP), apricot seed shell biochar (ASSB), and activated apricot seed shell biochar (AASSB). FTIR and pHPZC measurements were used to characterize the adsorbents. Based on the experimental findings, the optimum conditions follow pH 2, 0.3g dosage, initial concentration of 50 mg.L-1, and contact time of 90 min. The three forms of adsorbent exhibited good adsorption for nitrate. However, the maximum percentage removal of nitrate ions from the aqueous solution followed the order AASSB>ASSB>ASSP. The adsorption kinetic of nitrate ion was best fitted by pseudo 2nd order, and the parameters of adsorption isotherms elucidated favorable and improved sorption. This agro-waste could be used to develop sustainable adsorbents in water and wastewater treatment methods and has great potential to replace commercially available sorbents.
Afficher plus [+] Moins [-]Carbon Dioxide Adsorption by Variation in Operating Parameters of Sound Assisted Fluidization Using Coal Based Fine Activated Carbon
2024
A. P. Ganorkar and A. M. Langde
This research delves into the promising domain of CO2 capture through fine solid activated carbon adsorbent, offering a more energy-efficient alternative to traditional adsorption methods. The central challenge addressed here is the utility of cheaper CO2 adsorbent, fine powder materials whose properties can be precisely tailored via molecular-level fictionalization. Equally vital is selecting an optimal fluidizing column configuration that maximizes CO2 interaction with adsorption particles and enhances adsorption efficiency. The proposed solution is a fluidized bed column uniquely equipped with integrated acoustic vibrations to counteract interparticle forces common in fine powders. For adsorption evaluations, sound-assisted fluidized-bed experimentation on a laboratory size was set up. Adsorbent material activated carbon made up of coal underwent rigorous testing between a range of 20 Hz-200 Hz and 20 dB-135 dB. Results reveal the beneficial effects of acoustic enhancement of fluidization quality and adsorption efficiency, increased adsorption capacity, enhanced bed utilization, and accelerated adsorption rates. Extensive research has been conducted on the detailed effects of major operational variables on adsorption performance, notably frequency, sound intensity, and minimum fluidization velocity. The findings highlight the pivotal role of particle size with mean size 75 microns range as a determinant of adsorption capacity at 100 Hz and 125 dB. At the end of experimentation, the adsorbent considered for the experiment is compared to the study adsorption capacity at operating conditions. The research concludes with a discussion on the effects of influencing parameters for adsorption on employing sound vibrations using fluidization technique adsorption for CO2 capture.
Afficher plus [+] Moins [-]Research Insights into Punjab’s Stubble Burning Menace
2024
Ruchi Kohli, Anu Mittal and Amit Mittal
The current investigation endeavors to evaluate the prevalence of stubble burning in India, with a special focus on the state of Punjab. The study emphasizes the enormity of stubble burning by examining farm fire incidents, pollutant emissions, its detrimental impacts. It supports the effective management of crop residue along with proposing alternatives to stubble burning. The article conveys the message that stubble burning can result in deleterious effects on the environment, human health, crop growth, natural ecosystems, visibility, and physical infrastructure. The key solutions lie in education, functional literacy, a heightened awareness of environmental laws, rights and duties, stringent governance, and socially responsible public, promoting adherence to the National Green Tribunal’s guidelines for managing crop residue and enlightening farmers about the ill effects of stubble burning on animal, soil, human health, crop biodiversity, and climate change. The available data of districts of Punjab indicates the recent waning trend in stubble burning, thus heralding a positive indication of environmental preservation. Decreased stubble burning is the reward of untiring government initiatives, support and subsidies, awareness programs, advanced research and technology, and enforcement of stringent regulations combined with recognition of the deleterious environmental impacts of stubble burning. This research article indicates that there is still a need for efforts to be made to eliminate stubble burning altogether.
Afficher plus [+] Moins [-]Microbes Breaking Down Plastic: Insights for Sustainable Waste Management
2024
C. J. Patel, R. H. Kansagara, D. V. Modi, N. J. Dudhat, K. H. Sojitra and D. M. Babaria
This research investigates the microbial degradation of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) plastics by Bacillus sp., Proteus sp., Pseudomonas sp., and Salmonella sp. The study employs a systematic approach, isolating microorganisms from plastic-contaminated soil and subjecting them to a series of biochemical tests for identification. The research evaluates the weight loss of LDPE and HDPE over two months, revealing varying degrees of degradation among the bacterial strains. Results suggest a potential greater susceptibility of HDPE to microbial degradation. Scanning Electron Microscopy (SEM) analysis provides high-resolution images of the plastic surface, indicating structural changes and biofilm formation during degradation. The findings highlight the unique enzymatic capabilities of each strain and underscore the significance of SEM in elucidating microbial interactions with plastics. The study prompts discussions on optimization, synergistic effects, and the identification of key enzymes in plastic degradation, emphasizing the importance of microbial strategies for waste management. Overall, this research contributes valuable insights into the potential of bacterial strains for addressing plastic pollution challenges.
Afficher plus [+] Moins [-]Performance Evaluation of Advanced Wastewater Treatment Technologies in Herbal Processing and Extraction Industry
2024
Avinash Kumar Sharda, Varinder S. Kanwar and Ashok Sharma
Due to enormous quantities with hazards and complexity in nature is a big challenge for effective treatment of wastewater from pharmaceutical processes including herbal extraction through conventional methods of distillation. The situation is further aggravated in countries facing high rising population, urbanization, and industrialization resulting in the generation of industrial wastes. The study has been carried out in the herbal extraction industry by conducting stage-wise sampling of ETP based on the conventional method and further coupled with ozonation as an advanced treatment to comply with regulatory standards. Additionally, the same process was studied that implementing the best available technology (BAT) by providing ETP with advanced technology modules such as MBR (membrane bioreactor) + RO + O3 has not only resulted in compliance with standards but also reuse of treated wastewater into the process and utilities has been proved to be techno-economically a viable and sustainable option. Modifying existing aeration tanks and advanced oxidation through ozone injection post-biological treatment has resulted in COD and BOD reduction of 96.42% and 99.0% respectively. Whereas in the case of MBR + RO + O3, the values of pH, BOD, COD, TSS, and sulfide have been observed as 8.32, 2.0 mg.L-1, 14.0 mg.L-1, 1.0 mg.L-1 and 0.0 mg.L-1 respectively and 98% recovery of treated effluent, thus saving 44 KL.day-1 of freshwater resulting into significant financial benefits of Rupees 12.59 acs annually, which otherwise was outsourced through tankers.
Afficher plus [+] Moins [-]Characteristics, Abundance and Polymer Type of Microplastics in Anadara granosa (Blood Clam) from Coastal Area of Palopo City
2024
Abd. Gafur Rahman, Muhammad Farid Samawi and Shinta Werorilangi
Plastic waste in marine waters will undergo a degradation process that breaks down large plastic pieces into smaller particles called microplastics. The abundance of microplastics, caused by their small size (<5mm) can be easily indirectly consumed by aquatic animals. Anadara granosa is one of the bivalves that is quite vulnerable to microplastic contamination because it has the nature of a filter feeder which means it can sift particles and organic matter around it. The purpose of this study was to determine the characteristics, abundance, and types of microplastic polymers in blood clams (A. granosa). The results of microplastic observations made on 60 blood clams were 153 microplastic particles identified from 47 individuals (78%) of contaminated blood clams with an average microplastic abundance of 0.591 ± 0.083 item/gr. Fiber-type microplastics are the most dominant form found and blue is the most dominant color found in the sample. Based on the average abundance of microplastics in Anadara granosa in the coastal area of Palopo City, it is lower than several studies that have been conducted previously. Fourier Transform-Infra Red was conducted to determine the type of polymer in microplastics. Three types of polymers were found in the Anadara granosa samples polyethylene terephthalate (PET), polystyrene, and polyester. The three types of polymers have effects on human health such as respiratory problems, skin irritation, and genotoxicity. Action is needed to prevent microplastic pollution in Palopo City’s rivers before microplastic pollution becomes more severe in the future.
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