Organic Waste Removal Research Articles

Li/La and Cu modified ZnO semiconductor: Highly boosted of dielectric and sunlight-treatment of thiamethoxam and brilliant green contaminants

Solving the global environmental problem which related to the dissolved organic pollutants into water systems is an essential issue for human-health and aquatic life. This study represents the simple synthesis of new Li/La and Cu modified ZnO compositions as active photocatalysts and proper dielectric materials for electrical energy storage devices. The synthesized powders have one phase nature with hexagonal lattice indexed to ZnO structure. The field emission scanning electron microscopy (FESEM) clearly showed that (Li, La) modified ZnO powder consist of a mixture of particles having open hexagonal tube and spherical shapes. The FESEM picture of (Li, Cu, La) modified ZnO powder revealed lumps like cabbage shape mainly composed of pieces like sheets or papers. The purity and elemental composition were also verified by energy dispersive spectroscopy (EDS) analysis. The addition of (Li, La) and (Li, Cu, La) ions to ZnO semiconductor extremely improved the dielectric constant which is a benefit for application in solid state energy storage systems. (Li, Cu, La) modified ZnO sample is a suitable catalyst for removal of organic waste owing to its high response to visible light spectrum with measured band gap energy of 2.76 eV. The synergistic effect of Li+, Cu2+ and La3+ dopants induced high visible light photodegradation activities against thiamethoxam pesticide and brilliant green dye with measured efficiencies of 92 and 96 % after reaction time of 50 min, respectively. The high stability and mineralization properties of (Li, Cu, La) modified ZnO catalyst leads to the conclusion that this composition has a potential use in wastewater treatment.

Supercritical hydrothermal combustion: Basic principles, characteristics and applications and development in energy and environment

Supercritical hydrothermal combustion technology is a new homogeneous combustion technology with high potential in the fields of efficient removal of organic waste, clean utilization of conventional fossil energy, and efficient recovery of heavy oil. This manuscript reviews the literature related to supercritical hydrothermal combustion in recent years, and focuses on evaluating the current status of experimental and numerical simulation studies on the characteristics of supercritical hydrothermal combustion, as well as the latest progress in engineering. It is pointed out that the reduction of ignition temperature and extinction temperature is the key to promoting the application of supercritical hydrothermal combustion technology, and the consideration of the real-fluid effects and turbulence-reaction interactions can correctly reflect the combustion process. In addition, supercritical hydrothermal combustion technology, as a source of heat and reaction medium supply, can realize the efficient removal of highly concentrated organic wastewater, the clean combustion of coal and in-situ hydrogen production, as well as the thermal recovery of heavy oil by multi-thermal fluids. At present, supercritical hydrothermal combustion forced ignition technology, reactor design guidelines, and corrosion prevention of key equipment are still the focus of future research, which is of great significance to promote the application.

Metal oxide/chitosan composite for organic pollutants removal: A comprehensive review with bibliometric analysis

Organic pollutants are now a global concern because of their rapid increase following the rapid industrial growth. In tackling this problem, researchers have used chitosan that could act as adsorbing material. However, chitosan use in wastewater treatment requires further modification owing to its drawbacks of being susceptible to acidic environment and mechanically weak. Of many modifying approaches, metal-oxide embedment is perceived as promising because not only does it improve the chemical and physical properties of chitosan, but it also adds new features to the material such as being magnetic or photocatalytic. This present review describes the modification of chitosan through metal oxide embedment aiming to its utility in organic waste removal. Firstly, the definition of chitosan and the progress of its application in wastewater treatment are presented. Types of metal oxides, namely photocatalyst and magnetic iron oxide are also discussed. Embedment of metal oxides into chitosan could be done using methods such as sol-gel, high-energy ball milling, and spray-drying, where they affect the chemical and physical properties of the produced metal oxide/chitosan composites. Reported studies suggest a high percentage of organic pollutant removal, up to 100%. In addition to its removal ability, metal oxide/chitosan is also proven to be environmentally friendly and economical.

Design and synthesis of dual functional porphyrin-based COFs as highly selective adsorbent and photocatalyst

In this work, amide bonds linked 2D porphyrin-based covalent organic framework (Por-PD-COF) was designed and synthesized through condensation reaction between meso-tetrakis (p-carboxyphenyl) porphyrin (TCPP) and para-phenylenediamine (PD). Large surface area, abundant active sites and good stability of Por-PD-COF made it can quickly and efficiently absorb methylene blue (MB) selectively and remove it from aqueous solution. More importantly, in different mixture of organic dyes including RhB and MB, MB and MO, Por-PD-COF can selectively adsorb MB with a large adsorption capacity (328.57 mg·g−1), while a little MO and hardly RhB because of the unique charge selectivity and specific pore size. Especially in the mixture solution of MO and MB, compatitive adsorption appeared, MB can substitute the adsorbed MO on the active sites in the channel of Por-PD-COF. Furthermore, with the band gap narrow to 1.02 eV, Por-PD-COF could be used as efficient photocatalyst to degrade MB (99%, 180 min) directly under visible light irradiation, and can be reused for four times with almost no absorptive and photocatalytic capacity losing. The possible adsorption and photocatalytic mechanisms of Por-PD-COF were also proposed. As a result, with the uncomplicated preparation, effective and selective adsorption and reusability, Por-PD-COF was a promising specific adsorbent and photocatalyst for further application in specific organic molecules separation and organic waste removal from aqueous solution.

Liquid-gas phase transition enables microbial electrolysis cell to treat organic pollution and synchronously remediate nitrate-contaminated groundwater via hydrogenotrophic denitrification

Groundwater denitrification is challenged by a lack of electron donors and usually requires additional energy input or chemical agents. MEC can convert organic pollution into clean electron donor (hydrogen) through a gas-liquid phase transition. In this study, the MEC was combined with permeable bio-reactive barrier (PRB) as a hybrid system to achieved simultaneous organic waste removal, hydrogen production and groundwater remadition via long-distance hydrogenotrophic denitrification by biogas. The semi-hydrophobic PTFE-coated granular activated carbons (GAC) and hydrophilic GAC were filled as two kinds of biocarriers in PRBs, in which the hydrophobic PTFE surface coating improved hydrogen utilization. The PTFE-coated GAC maked the denitrification performance of PRB insensitive to hydrogen partial pressure within the tested range of 0.01–0.04 MPa and achieved effluent nitrate concentration of <20 mg L−1 within 12 h (The Water Quality Standard for Drinking Water Sources in China). The gas production in MECs was actively pumped to PRBs and spontaneously achieve negative pressure on the MEC side and positive pressure on the PRB side. The actively pumping of biogas induced negative pressure in MEC and positive pressure in PRB. The negative pressure improved current density by 18.6 ± 0.7% in MECs and the MEC-PRB hybrid system achieved a nitrate removal of 85.0 ± 0.8% in actual groundwater with an effluent concentration of 15.0 ± 0.8 mg L−1 at 72 h. This work demonstrated the feasibility of matching MEC and PRB as a novel hybrid system for organic pollution degradation and effective nitrogen removal in electron-donor-lacking groundwater.

Silver-Loaded Carbon and Phosphorous Co-Doped Boron Nitride Quantum Dots (Ag@CP-BNQDs) for Efficient Organic Waste Removal: Theoretical and Experimental Investigations.

In this paper, silver-loaded phosphorous and carbon co-doped boron nitride quantum dot (Ag@CP-BNQD) nanocomposites were synthesized using a co-precipitation method followed by a hydrothermal approach. The nanocomposites of Ag@CP-BNQDs were characterized by scanning electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and ultraviolet–visible spectrophotometry. The as-prepared Ag@CP-BNQDs were used for photocatalytic degradation of 10 common organic pollutants, including dyes, pharmaceuticals, and pesticides in aqueous solution under visible light irradiation. The high-performance photocatalysis of Ag@CP-BNQDs proved that Ag@CP-BNQDs is plasmonic and the n–p junction photocatalyst. Theoretical calculations were done to measure the crystals and electronic structures of Ag@CP-BNQDs. Theoretical results showed that loading of Ag behaves as plasmonic sensitizers and co-catalysts and provides extra bands, which make electron movement easier between valance and conduction bands. The mechanism of the charge separation enhancement was postulated. Our findings might deepen our understanding of how sensitizer surface modification works in photodegradation applications.

Smouldering organic waste removal technology with smoke emissions cleaned by self-sustained flame

Smouldering is slow, low-temperature and flameless, and has been potentially regarded as an alternative for organic waste removal technology. However, as an incomplete combustion process, toxic smoke and pollution from the smouldering are significant concerns that limit its popularization. This work applies a newly developed smouldering-based waste removal technology to investigate the removal of coffee waste, wood waste, and organic soil (simulated sludge) via using a flame to clean smouldering emissions at different airflow velocities (3–24 mm/s). Once ignited from the top, the smouldering front first propagates downwards where a stable flame situated above could be piloted and sustained to purify the smouldering emissions until the smouldering front reached the bottom of the fuel bed. The efficiency of pollution mitigation was demonstrated by significantly lower CO and VOCs emission after purification by self-sustained flame. The equivalent critical mass flux of flammable gases required for igniting the smouldering emissions is 0.5 g/m2∙s, regardless of the fuel type. The smouldering temperature, propagation rate and burning flux all increase with the airflow velocity but are also slightly sensitive to the type of waste. This work enriches strategies for the clean treatment of smouldering emissions and promotes an energy efficient and environmentally friendly method for organic waste removal.

Optimization of schedules for early garbage collection and disposal in the megapolis

It is shown that due to the growth of waste generated by the metropolis, the processes of their removal and disposal must be more accurately accounted and controlled. If it is impossible to introduce “smart” control systems, it is proposed to search for reserves to increase the efficiency of the processes in their structure. A structural model of operations has been developed that can reduce time costs. The use of incomplete information on the accumulation and removal of garbage leads to unplanned mileage of trucks. In order to avoid unforeseen costs, it is proposed to use early garbage collection, which reduces the frequency of emptying containers. This leads to an increase in the number of truck arrivals to load, but eliminates unforeseen mileage due to inconsistencies in the loading forecast. It is shown that to effectively organize the work of garbage trucks on the transport network of the city, an active, shortest schedule of operations is required, which must be made for several periods. To develop an optimal cyclic schedule of garbage trucks, a method based on the ordering of mixed graphs is proposed. The mixed graph shows the set of garbage collection operations and the time relationships between their execution times. In order to develop an optimal schedule from such a graph, cycles must be removed from the graph. To do this, the “divide and conquer” method was used. The proposed algorithm for graph ordering is used to study the current garbage collection system. As a result of research, higher productivity of garbage trucks and timely removal of organic waste were achieved. The reduction of the weekly working time of 6 garbage trucks with the use of the 70 % container filling level reached 42 hours.

Sustainable Water Purification and Energy Generation Over Crystalline Chitosan Grafted Polyaniline Composite

The present research demonstrates the design and development of a dual-compartment water purification proto-plant for microbial degradation of organic waste using microbial fuel cell technology and adsorptive removal of inorganic pollutants present in sewage water using highly crystalline chitosan grafted polyaniline (CHIT-g-PANI) and rice husk derived adsorbent. The materials were characterized by UV–Vis, infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and relevant standard methods. The observed results revealed the highly crystalline, biocompatible, porous nature of CHIT-g-PANI as electrode materials for effective microbial degradation of organic wastes of sewage water for generating electricity and water purification. Thus, observed parameters were power density of 6.496 w/m2, sustainable usability for 20 days, and removal of organic waste by 97% from sewage water. Furthermore, the above partially treated water was passed through an adsorption chamber filled with rice husk-derived adsorbents, which removes the 84.5% inorganic impurities of its original concentrations.

Organic waste removal from pharmaceutical and textile effluents using composite adsorbent

Pharmaceutical and textile industries widely use inorganic and organic components which undergo different chemical and biochemical reactions with the ground water systems. The removal of organic wastes from effluents was carried out using a composite adsorbent. Four different samples were collected from the Gonoshasthaya Antibiotic Limted, Gonoshasthaya Pharmaceuticals Limited, Pakiza Dyeing and Printing Industries Limited and Bangladesh Dyeing and Finishing Industries Limited. Synthetic effluents of four types were prepared maintaining a similar chemical average of the collected samples. All the samples contained a high concentration of TDS, TSS, TS, COD and BOD5. The composite adsorbent performed excellently for all the samples. The concentrations of the components contained in the waste water were analyzed by UV-Visible spectrophotometer and High Performance Liquid Chromatography (HPLC). After the treatment, the decreasing trend of the absorbance and total peak area indicated that the significant amount of effluent materials were removed.&#x0D; Bangladesh J. Sci. Ind. Res.55(3), 197-206, 2020

Enhanced anaerobic fermentation of dairy manure by microelectrolysis in electric and magnetic fields

The degradation rate of lignocellulose and methane (CH4) content must be improved through anaerobic fermentation process engineering in order to promote the proper operation of anaerobic organic waste removal without secondary pollution and low cost. The present study investigates mesophilic anaerobic fermentation of dairy manure (DM) under weak magnetic and low operation voltage (0.3–0.8 V). The results showed that the effect of electric and magnetic fields (EMF) can significantly enhance the fermentation, and improve the CH4 content of biogas and accelerate the degradation rate of lignocellulose. Fe-C microelectrolysis intensified the anaerobic fermentation of DM, the highest CH4 content was 87%, the cellulose degradation rate was 36%, increased by 125%, and the lignin degradation rate was 23%, increased by 203%, under loading 0.5 V voltage and weak magnetic field. Metagenome sequence results showed that EMF and Fe-C microelectrolysis can not only promote the microbial diversity, but also increase the abundance of functional microorganisms at various stages. This finding provides theoretical support and foundation for the extraordinary efficiency degradation of lignocellulose and the electric and magnetic regulation of anaerobic fermentation microorganism system.

Polychaetes as Potential Risks for Shrimp Pathogen Transmission

Polychaetes comprise the benthic meiofauna of the soft-bottom intertidal zone and of shrimp ponds in coastal areas. While polychaetes provide benefits to the shrimp farming industry as (i) natural food in traditional shrimp ponds, (ii) nutrient regenerators through bioturbation and removal of organic waste in the sediment through feeding, and (iii) feed supplement to enhance maturation of shrimp brooders, the conditions present in aquaculture ponds may increase the opportunity for polychaetes to transfer pathogens to shrimp through the food chainThere is growing concern that internationally traded polychaetes, which are fed to shrimp brooders, are potential vectors for the transmission of other shrimp pathogens. The detection of the aetiological agents of two newly emerging diseases of shrimp in polychaetes, Enterocytozoon hepatopenaei (EHP) and Vibrio parahaemolyticusAHPND causing hepatopancreatic microsporidiosis (HPM) and acute hepatopancreatic necrosis disease (AHPND), respectively, suggests that these worms can be a host or/and passive carrier of these pathogens. This review discusses the benefits of polychaetes to shrimp farming, the risk of shrimp pathogen transmission by polychaetes at the pond, hatchery and global level, and calls for closer observation on shrimp pathogens in polychaetes used as shrimp feed.

Enhancement of power generation by microbial fuel cells in treating toluene-contaminated groundwater: Developments of composite anodes with various compositions

This work develops microbial fuel cells (MFCs) with composite anodes that combine conductive coke (CC) and conductive carbon black (CCB) to improve the performance of those MFCs in treating toluene-contaminated groundwater. The effect of the combination ratio (CRCCB:CC) of the composite anode with various ratios of CCB to CC on MFC performance was evaluated. The results demonstrate that the time required (tr) for the MFC with CR1:3 to remove all toluene was half of that required by other MFCs except for that with CR1:9. Additionally, CR1:3 is associated with the highest power density (PDmax) of 72 mW/m2, which is 1.24–2.78 times higher than those obtained using other CRs or a single-material anode (CC) except for CCB, owing to the high conductivity of the latter. Cyclic voltammetry (CV) yields oxidized-reduced current peaks of CR1:3 that are 1.44–2.89-fold as high as those obtained using other CRs, suggesting that the composite anode with CCB or CC at an optimal ratio accelerates the oxidation-reduction reactions, favoring the removal of organic waste. This work establishes the feasibility of using a composite anode to improve the removal of toluene and the generation of electricity by MFCs.

Green synthesis of CuO nanomaterials and their proficient use for organic waste removal and antimicrobial application

Copper oxide (CuO) nanomaterials (NMs) of different size and morphology were synthesized by Chemical precipitation, Microwave irradiation and Hydrothermal method and characterized by TEM, BET, FTIR, XRD and EDX analysis. As synthesized CuO NMs were utilized for elimination of harmful dyes viz. Direct Red 81 (DR-81) and Coomassie Brilliant blue R-250 (BBR-250) and pathogenic bacteria (Staphylococcus aureus). Owing to their morphology, smaller size and relatively high surface area (40.320 m2 g−1), CuO NMs prepared by chemical precipitation method were observed to show better adsorption capacity for both the dyes (68.70 (DR-81) and 73.04 (BBR-250) mg g−1). The influence of different experimental conditions was studied by the methodical assessments of various parameters such as pH, adsorbent dose, concentration and contact time. Moreover, different adsorption isotherms and pseudo-second order kinetic model were applied to understand the adsorption mechanism. Langmuir model was found to be best fit thus confirming the monolayer adsorption process. To ensure the practical utility of CuO NMs for organic waste removal, the adsorption studies were performed in the presence of different inorganic ions and real water samples. In addition, recovery of the dye and NMs were also carried out effectively by simple method, thus avoiding the secondary pollution. CuO NMs were observed to exhibit significant antibacterial activity against the human pathogenic bacteria. These studies demonstrated that synthesized CuO NMs showed good adsorption efficiency for the removal of harmful dyes and antimicrobial activity against the pathogenic bacteria, which vary as a function of size and surface area.

Liquid crystal display electrode assisted bio-reactor for highly stable and enhanced biofilm attachment for wastewater treatment – A sustainable approach for e-waste management

Existing conventional attached growth wastewater systems are greatly hampered by long start-up times, frequent biofilm sloughing and/or erosion which lead to poor or inconsistent performance. In this study, a novel electrically bound biofilm process has been developed, and its efficacy in achieving an improved bacterial adhesion for the removal of organic waste has been demonstrated. An electrically bound biofilm reactor (EBBR) was developed, consisting of a conductive nematic liquid crystal electrode (NLCE) as the anode, obtained from an inutile desktop monitor. Three metal electrodes, namely, Al, Cu and Pt were evaluated as candidate cathodes. Electric potential and choice of the cathode were chosen as the two optimization parameters for enhancing biofilm attachment. At the optimized condition (corresponding to 1 V and Pt-NLCE electrode combination), enhanced biofilm attachment was observed, with reduction in suspended solids up to 79.3% and a bio degradation rate of 71.2%, within a reaction time of 28 h. The presence of active functional groups and chromophores (containing CN, NH2 and CO functional groups) were confirmed using Cyclic Voltammetry (CV), Fluorescence spectroscopy, Raman and Fourier transform infrared (FTIR) spectroscopy. High biofilm stability (over 120 h) and rapid start-up times (of the order of few hours) were observed, which can be attributed to (a) the presence of these functional groups on NLCE, and (b) electrostatic attractive forces in the EBBR, unlike in conventional attached growth systems. Enhanced biofilm attachment combined with rapid start-up times paves way for a sustainable approach towards future wastewater treatment efforts.

The role of polychaeteNereis diversicolorin bioremediation of wastewater and its growth performance and fatty acid composition in an integrated culture system withHuso huso(Linnaeus, 1758)

This study was undertaken to evaluate the role of polychaete Nereis diversicolor in bioremediation of waste water and its growth performance and fatty acid composition in an integrated culture system with great sturgeon, Huso huso. Three treatments consisting of N. diversicolor fed with H. huso waste (FNW), N. diversicolor fed with fish feed waste (NW), and fish waste without the worm (FW) were considered at water temperature of 23°C for 8 weeks. The obtained results demonstrated that N. diversicolor in the flow-through system could grow via feeding with the fish waste water. The pure production and survival rate of harvested Nereis in NW treatment were significantly higher than those of FNW treatment (p < .05). However, no significant difference was observed in specific growth rate and weight gain between these two treatments (p > .05). The highest removal efficiency of waste water including total nitrogen (56%), total phosphorus (53%), NO2-N (91%), NH3-N (35%), PO4-P (47%), BOD5 (60%) were seen in FNW treatment. Also, the highest additional efficiency of NO3-N occurred in FW (37%) treatment. Certain fatty acids specifically 20:5 ω3 (eicosapentaenoic acid [EPA]) and 22:6 ω6 (docosahexaenoic acid [DHA]) were also abundant in Nereis, and analysis revealed some differences due to the diet. These results demonstrated that the promotion of growth by cultured Nereis can enhance the decomposition rate of organic matter in enriched sediment and minimize negative effects in fish farms. These results also suggest that the use of N. diversicolor is an excellent potential candidate for an integrated aquaculture and nutrient recycling including the removal of organic wastes.

Bacterial community analysis of an industrial wastewater treatment plant in Colombia with screening for lipid-degrading microorganisms

The operation of wastewater treatment technologies depends on a combination of physical, chemical and biological factors. Microorganisms present in wastewater treatment plants play essential roles in the degradation and removal of organic waste and xenobiotic pollutants. Several microorganisms have been used in complementary treatments to process effluents rich in fats and oils. Microbial lipases have received significant industrial attention because of their stability, broad substrate specificity, high yields, and regular supply, as well as the fact that the microorganisms producing them grow rapidly on inexpensive media. In Colombia, bacterial community studies have focused on populations of cultivable nitrifying, heterotrophic and nitrogen-fixing bacteria present in constructed wetlands. In this study, culture-dependent methods, culture-independent methods (TTGE, RISA) and enzymatic methods were used to estimate bacterial diversity, to monitor temporal and spatial changes in bacterial communities, and to screen microorganisms that presented lipolytic activity. The dominant microorganisms in the Wastewater Treatment Plant (WWTP) examined in this study belonged to the phyla Firmicutes, Proteobacteria and Bacteroidetes. The enzymatic studies performed indicated that five bacterial isolates and three fungal isolates possessed the ability to degrade lipids; additionally, the Serratia, Kosakonia and Mucor genera presented lipase-mediated transesterification activity. The implications of these findings in regard to possible applications are discussed later in this paper. Our results indicate that there is a wide diversity of aerobic Gram-negative bacteria inhabiting the different sections of the WWTP, which could indicate its ecological condition, functioning and general efficiency.

Innovative strategy with potential to increase hemodialysis efficiency and safety

Uremic toxins are mainly represented by blood urine nitrogen (BUN) and creatinine (Crea) whose removal is critically important in hemodialysis (HD) for kidney disease. Patients undergoing HD have a complex illness, resulting from: inadequate removal of organic waste, dialysis-induced oxidative stress and membrane-induced inflammation. Here we report innovative breakthroughs for efficient and safe HD by using a plasmon-induced dialysate comprising Au nanoparticles (NPs)-treated (AuNT) water that is distinguishable from conventional deionized (DI) water. The diffusion coefficient of K3Fe(CN)6 in saline solution can be significantly increased from 2.76, to 4.62 × 10−6 cm s−1, by using AuNT water prepared under illumination by green light-emitting diodes (LED). In vitro HD experiments suggest that the treatment times for the removals of 70% BUN and Crea are reduced by 47 and 59%, respectively, using AuNT water instead of DI water in dialysate, while additionally suppressing NO release from lipopolysaccharide (LPS)-induced inflammatory cells.

Designed synthesis of hematite-based nanosorbents for dye removal

We report the design and synthesis of two hematite (α-Fe2O3)-based nanomaterials based on effective hydrothermal conversion of chemically metastable K1.33Mn8O16 nanowires (KWs) in Fe(NO3)3 aqueous solution. Insights are gained into the functions of sodium dodecyl benzene sulfonate (SDBS) and the mechanisms for generating large quantities of α-Fe2O3 hollow structures (FHSs) and K1.33Mn8O16@α-Fe2O3 heterostructured nanowires (KFHWs) in solution phase. The controllable growth dynamics allows convenient control over the morphology and production of the hematite-based nanostructures. Adsorption experiments indicate that the resulting hematite-based materials are powerful nanosorbents for swift removal of Congo red from wastewater at room temperature. The adsorption kinetics and adsorption isotherm are also investigated and the findings indicate that the as-prepared KFHW and FHS hold great potential as environmentally friendly filter materials for water purification and organic waste removal.

Mariculture for bacterial and organic waste removal: a field study of sponge filtering activity in experimental farming

Culture experiments in the field were performed on western Mediterranean populations of Ircinia variabilis and Agelas oroides. To evaluate culture and filtering performances among polluted and unpolluted sites in shallow waters, farming experiments were carried out in a harbour, a small tourist nautical base and a pristine biotope. Sponge explants were cultured onto nylon ropes, and in situ clearance rate tests were performed on farmed sponges to assess filtering ability under diverse farming conditions. At the harbour site, sponge survival and growth were similar to that observed in the two unpolluted sites until early summer, when a rapid increase in explant mortality occurred in response to extreme variations in environmental conditions. Filtering experiments revealed high retention and clearance rates of I. variabilis and A. oroides at all sites. The highest rates were observed at the polluted site, reflecting the optimal metabolic performance of explants in the first phase of culture under stressful conditions. Our results highlight the feasibility of sponge microcosms and the ability of I. variabilis and A. oroides to clear large volumes of water of organic and bacterial loads in polluted sites.