Recikliranje ekspandiranog polistirena kao učinkovitog adsorbensa naftalena iz vodene otopine

Batch adsorption process factors [contact time (20–150 min), adsorbent dosage (0.5–1.5 g), adsorbate concentration (5–30 mg l–1), and agitation rate (100–250 rpm)] were optimised based on D-optimal Design under the Response Surface Methodology (RSM) of the Design-Expert Software (7.6.8) for the removal of naphthalene from aqueous solution using adsorbent developed from Acetylated Waste Expanded Polystyrene (AWEPs). The maximum adsorption capacity (5.6608 mg g–1) achieved was well fitted to Dubinin-Radushkevich Isotherm (R2 = 0.9949). The SSE (< 0.05) and ARE (< 4.0 %) indicated pseudo-second-order as the most suitable model. This research has demonstrated the effectiveness of the WEPs for the removal of naphthalene from the aqueous solution. This work is licensed under a Creative Commons Attribution 4.0 International License.Šaržni faktori procesa adsorpcije [vrijeme kontakta (20 – 150 min), doziranje adsorbenta (0,5 – 1,5 g), koncentracija adsorbata (5–30 mg l–1) i brzina miješanja (100–250 min–1)] optimizirani su na temelju D-optimalnog dizajna primjenom metodologije odzivne površine (RSM) programa Design-Expert (7.6.8) za uklanjanje naftalena iz vodene otopine pomoću adsorbenta razvijenog iz acetiliranog otpadnog ekspandiranog polistirena (AWEP). Ostvareni maksimalni adsorpcijski kapacitet (5,6608 mg g–1) dobro je prilagođen izotermi Dubinin-Radushkevich (R2 = 0,9949). SSE (< 0,05) i ARE (< 4,0 %) označili su pseudo-drugi red kao najprikladniji model. Ovo istraživanje pokazalo je učinkovitost WEP-a za uklanjanje naftalena iz vodene otopine. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Enhancing and upgrading biogas and biomethane production in anaerobic digestion: a comprehensive review

Anaerobic digestion (AD) processes can face operational challenges or flaws such as substrate structure and characteristics complexity, process complexity, low productivity, inefficient biodegradability, and poor stability, which suppresses or reduces biogas and biomethane production. As a result of the need to overcome these challenges/shortcomings and improve or enhance biogas and biomethane yield, process intensification methods have gained attention. There is some literature review on pretreatment and co-digestion as a means of improving AD performance; however, there is no systematic information on the various strategies required for improving AD performance and, in turn, increasing biogas/biomethane yield. The AD process produces biogas, a valuable renewable biofuel. Biogas is composed primarily of biomethane and other undesirable components such as carbon dioxide, oxygen, hydrogen sulphide, water vapour, ammonia, siloxanes, nitrogen, hydrocarbons, and carbon monoxide, which act as impurities or contaminants and tend to reduce the biogas specific calorific value while also causing various problems with machine operation. As a result, various technologies are used to improve raw biogas quality by removing contaminants during biogas transformation to biomethane. As a result, this paper provides a comprehensive review of the various systematic process intensification strategies used to overcome AD process challenges/shortfalls, improve or enhance biogas and biomethane production, and conventional and emerging or advanced technologies for biogas purification, cleaning, and upgrading

Quantification of Criteria Air Pollutants from Diesel Combustion on Ibadan Metropolitan City, Nigeria

The use of diesel as fuel by major industries in Ibadan Metropolis to run heavy duty generating set has increased drastically due the sporadic electricity supply by Electricity Distribution Company. The combustion of diesel results in the emission of Criteria Air Pollutants (CAPs), which are hazardous to human health. This study examined the consumption rate of diesel by the minor and major industries in Ibadan Metropolis between 2015 and 2019, while the Air quality implications were compared with the standards. The study was carried out in a three-step process (emission inventory, estimation of the rate of emission and dispersion modelling to predict the ground level concentration of the CAPs) for the industries within the period. The emission rate of for CO, NOx, PM, SOx and VOC is 77.132, 358.053, 25.170, 23.545 and 5.683 g/s, respectively and their corresponding predicted ground level concentration were 984.89, 4571, 321, 297 and 72.6 µg/m3. This research work will proffer information for the government in policy-making as regards the prompt and most effective method to control air pollution in near future for the citizens of Ibadan.Key words:     Diesel, combustion, Pollution,Emission, Criteria Air Pollutants, Air quality

Kinetic Modelling of Adsorptive Biodegradation of Anthracene onto Activated Carbon

The effect of adsorption on anthracene biodegradation in contaminated soil was studied by conducting kinetic batch tests in soil with varying degrees of commercial activated carbon (CAC) and in soil-free solution. The effect of CAC dose on the simultaneous adsorption-biodegradation of anthracene was evaluated. Adsorption-biodegradation model was adopted from the modification of a two-site kinetic numerical model by combining the elements of adsorption and biodegradation models and the validation of the model was carried out through the application of batch adsorption-biodegradation equilibrium and kinetic experimental data.  The Result obtained showed that the model predictions of the anthracene concentrations are in reasonable agreement with the experimental data. For simultaneous adsorption-biodegradation of anthracene by CAC, both adsorption rate coefficient and biodegradation rate coefficient increased with increased in CAC dose. The adsorption-biodegradation model is therefore a reasonable tool for simulating the adsorption-biodegradation behaviours of aromatic hydrocarbons in activated carbon.Keywords: Adsorption, Anthracene, Commercial Activated Carbon, Simultaneous Adsorption-Biodegradation

Decoding Anaerobic Digestion: A Holistic Analysis of Biomass Waste Technology, Process Kinetics, and Operational Variables

The continual generation and discharge of waste are currently considered two of the main environmental problems worldwide. There are several waste management options that can be applied, though anaerobic digestion (AD) process technology seems to be one of the best, most reliable, and feasible technological options that have attracted remarkable attention due to its benefits, including the generation of renewable energy in the form of biogas and biomethane. There is a large amount of literature available on AD; however, with the continuous, progressive, and innovative technological development and implementation, as well as the inclusion of increasingly complex systems, it is necessary to update current knowledge on AD process technologies, process variables and their role on AD performance, and the kinetic models that are most commonly used to describe the process-reaction kinetics. This paper, therefore, reviewed the AD process technologies for treating or processing organic biomass waste with regard to its classification, the mechanisms involved in the process, process variables that affect the performance, and the process kinetics. Gazing into the future, research studies on reduced MS-AD operational cost, integrated or hybrid AD-biorefinery technology, integrated or hybrid AD-thermochemical process, novel thermochemical reactor development, nutrient recovery from integrated AD-thermochemical process, and solid and liquid residual disposal techniques are more likely to receive increased attention for AD process technology of biomass wastes