RESUMEN

Industrial and urban modernization processes generate significant amounts of heavy metal wastewater, which brings great harm to human production and health. The biotechnology developed in recent years has gained increasing attention in the field of wastewater treatment due to its repeatable regeneration and lack of secondary pollutants. Pseudomonas, being among the several bacterial biosorbents, possesses notable benefits in the removal of heavy metals. These advantages encompass its extensive adsorption capacity, broad adaptability, capacity for biotransformation, potential for genetic engineering transformation, cost-effectiveness, and environmentally sustainable nature. The process of bacterial adsorption is a complex phenomenon involving several physical and chemical processes, including adsorption, ion exchange, and surface and contact phenomena. A comprehensive investigation of parameters is necessary in order to develop a mathematical model that effectively measures metal ion recovery and process performance. The aim of this study was to explore the latest advancements in high-tolerance Pseudomonas isolated from natural environments and evaluate its potential as a biological adsorbent. The study investigated the adsorption process of this bacterium, examining key factors such as strain type, contact time, initial metal concentration, and pH that influenced its effectiveness. By utilizing dynamic mathematical models, the research summarized the biosorption process, including adsorption kinetics, equilibrium, and thermodynamics. The findings indicated that Pseudomonas can effectively purify water contaminated with heavy metals and future research will aim to enhance its adsorption performance and expand its application scope for broader environmental purification purposes.

Asunto(s)

Metales Pesados , Pseudomonas , Contaminantes Químicos del Agua , Purificación del Agua , Pseudomonas/metabolismo , Pseudomonas/genética , Pseudomonas/aislamiento & purificación , Metales Pesados/metabolismo , Adsorción , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Aguas Residuales/microbiología , Aguas Residuales/química , Biodegradación Ambiental , Cinética , Modelos Teóricos

RESUMEN

A conventional activated sludge (CAS) system has traditionally been used for secondary treatment in wastewater treatment plants. Due to the high cost of aeration and the problem of sludge treatment, researchers are developing alternatives to the CAS system. A membrane bioreactor (MBR) is a technology with higher solid-liquid separation efficiency. However, the use of MBR is limited due to inevitable membrane fouling and high energy consumption. Membrane fouling requires frequent cleaning, and MBR components must be replaced, which reduces membrane lifetime and operating costs. To overcome the limitations of the MBR system, a microbial fuel cell-membrane bioreactor (MFC-MBR) coupling system has attracted the interest of researchers. The design of the novel bioelectrochemical membrane reactor (BEMR) can effectively couple microbial degradation in the microbial electrochemical system (MES) and generate a microelectric field to reduce and alleviate membrane fouling in the MBR system. In addition, the coupling system combining an MES and an MBR can improve the efficiency of COD and ammonium removal while generating electricity to balance the energy consumption of the system. However, several obstacles must be overcome before the MFC-MBR coupling system can be commercialised. The aim of this study is to provide critical studies of the MBR, MES and MFC-MBR coupling system for wastewater treatment. This paper begins with a critical discussion of the unresolved MBR fouling problem. There are detailed past and current studies of the MES-MBR coupling system with comparison of performances of the system. Finally, the challenges faced in developing the coupling system on a large scale were discussed.

Asunto(s)

Fuentes de Energía Bioeléctrica , Aguas del Alcantarillado , Membranas Artificiales , Electricidad , Reactores Biológicos

RESUMEN

This study examines the life cycle analysis of the manufacturing of 1 kg of green tea using various disposal techniques, including landfill procedure, incineration, and modification of green tea waste as an adsorbent for heavy metal removal. OpenLCA is used to produce the evaluation. To identify the objectives and scope, inventory analysis, effect, and interpretation, the assessment process corresponds to ISO 14044 of 2006. AGRIBALYSE version 3 is the database used to evaluate the environmental effects. A reference unit called a DALY is used to study the environmental impact. For the LCA of green tea, there were four main effect categories that were taken into consideration: human carcinogenic toxicity, human non-carcinogenic toxicity, global warming (human health), and fine particle creation. The outcome demonstrates that processing 1 kg of green tea waste has an environmental effect that is around 63% greater than incinerating it and roughly 58% higher than dumping it in a landfill. However the ecology is more affected by the adsorption process than by landfill and incineration of green tea waste. Even yet, if the preparation is done in bulk, the process can be improved by altering the adsorption of green tea waste.

RESUMEN

BACKGROUND: In this study the removal of Chromium (III) and Chromium (VI) ions are investigated via polymer enhanced ultrafiltration under important process parameters. This study proposes the use of unmodified starch as a novel polymer in the ultrafiltration process and its performance on the removal of chromium ions was compared with a commonly used polymer, polyethylene glycol. METHODS: The experiments were carried out at 1.5 bar and different pH values by using 10 kDa hollow fiber membrane operating in a cross-flow mode. RESULTS: The best chromium ions removal obtained approached 99% for Chromium (III) ion by unmodified starch at alkaline pH region and at pH 7 for Chromium (VI) ions retention by polyethylene glycol. Permeate flux behavior are fluctuated for both chromium ions tested at high metal ion concentrations. Low concentration of unmodified starch is applied to reduce gelatinization behavior. CONCLUSIONS: The findings suggest that binding of chromium ions by unmodified starch is related to granule structure which is probably a principal indicator of the non-ionic behavior of unmodified starch.