Filter For Wastewater Treatment Research Articles

Polymeric Granules Supported Day–Night Photocatalyst-Based Filter for Wastewater Treatment

Polymeric Granules Supported Day–Night Photocatalyst-Based Filter for Wastewater Treatment

Pre-coating of stainless-steel mesh support material with wastewater treatment plant sludges in a dynamic membrane filtration process

This study focuses on wastewater treatment plant sludges to be deposited on large aperture meshes. In a column reactor that is filled with treatment plant sludges, a series of batch experiments were performed with varying sizes of stainless-steel mesh modules (75 to 300 μm) as a support media to form a dynamic membrane. Primary, secondary, and polyelectrolyte-added sludges were used both individually and in combination to investigate the performance (filterability, permeate quality, and dynamic layer formation ability) of the varying pore-size meshes at high fluxes. The results were superior when primary and secondary sludges were combined in the creation of a dynamic cake layer, as opposed to individual sludge usage. Mesh sizes were shown to have no effect on performance, providing turbidity of <10 NTU for a short duration (10 min) of filtration. Cake formation rates were calculated as 23.0 NTU/min, 19.48 NTU/min, 7.62 NTU/min, and 6.94 NTU /min for 100, 150, 200, and 300 μm support meshes, respectively. For the first time in literature, effluent water turbidity decreases to <5 NTU for 300 μm support mesh at high fluxes. Scanning electron microscope images showed that fibers that may originate from the primary sludge could enhance the formation of stable cake layer. This study is important for creating high-performing dynamic membrane filtration on large aperture meshes, which can be used as a cost-effective and reliable filter for wastewater treatment.

Pilot scale demonstration of an underground biological aerated filter for rural wastewater treatment in a protected area

The availability of land is one of the advantages of rural wastewater treatment. However, this advantage may be absent in protected areas. The objective of this study is to showcase pilot-scale wastewater treatment approaches specifically tailored to address challenges presented by these unique circumstances. The demonstration case presented here involves a rural campsite where ground works are restricted. A pilot-scale decentralized system that includes a rainwater recycling system for potable water production (2–3 m3/d) and an underground biological aerated filter for wastewater treatment was installed. The biological aerated filter was built under a parking area (a so-called Phytoparking® system) and did as such not use additional ground surface. The Phytoparking with an area of 44 m2 was operated for 7 months and a total of 220 m3 grey water and 127 m3 black water was treated. Good pollutants removal efficiency was achieved for total suspended solids (93 %), COD (93 %), NH4+-N (93 %), TP (99 %), E.coli (log reduction 4.3) and total coliforms (log reduction 2.4). The potential wastewater reuse is not only about technological concern but also social acceptable concern. Therefore, the campsite customers' acceptance level of this system and the reused water were surveyed by a questionnaire. Based on the results of the study's pollutant removal efficiency and questionnaire responses, it can be concluded that local and/or decentralized water treatment and reuse systems were perceived positively.

Modified Rice Husk Waste‐Based Filter for Wastewater Treatment: Pilot Study and Reuse Potential

AbstractThis study investigates a rice husk waste‐based filter (RHW‐BF) for the treatment of graywater (GW) and primary treated wastewater (PTW). The RHW‐BF comprises three layers: coarse sand, chemically modified rice husk (MRH), and gravel. Continuous runs (Run I, II, III) assessed chemical oxygen demand, total suspended solids, total dissolved solids, and turbidity removal. Run (I) for GW achieved high removal: 73.7 %, 73.4 %, 74.6 %, and 92.6 %. Subsequent runs showed decreasing efficiencies due to media saturation. Similar trends occurred for PTW, with Run (I) achieving significant removal: 70.3 %, 69.0 %, 44.2 %, and 90.2 %. MRH particles played a crucial role in sustainable pollutant removal. The study compares treated wastewater with the World Health Organization and Egyptian limits, demonstrating its suitability for reuse in irrigation, agriculture, or sewer discharge.

Optimizing bone and biomass co-torrefaction parameters: High-performance arsenic removal from wastewater via co-torrefied bone char

This study aimed to investigate bone char's physicochemical transformations through co-torrefaction and co-pyrolysis processes with biomass. Additionally, it aimed to analyze the carbon sequestration process during co-torrefaction of bone and biomass and optimize the process parameters of co-torrefaction. Finally, the study sought to evaluate the arsenic sorption capacity of both torrefied and co-torrefied bone char. Bone and biomass co-torrefaction was conducted at 175 °C–300 °C. An orthogonal array of Taguchi techniques and artificial neural networks (ANN) were employed to investigate the influence of various torrefaction parameters on carbon dioxide sequestration within torrefied bone char. A co-torrefied bone char, torrefied at a reaction temperature of 300 °C, a heating rate of 15 °C·min−1, and mixed with 5 g m of biomass (wood dust), was selected for the arsenic (III) sorption experiment due to its elevated carbonate content. The results revealed a higher carbonate fraction (21%) in co-torrefied bone char at 300 °C compared to co-pyrolyzed bone char (500–700 °C). Taguchi and artificial neural network (ANN) analyses indicated that the relative impact of process factors on carbonate substitution in bone char followed the order of co-torrefaction temperature (38.8%) > heating rate (31.06%) > addition of wood biomass (30.1%). Co-torrefied bone chars at 300 °C exhibited a sorption capacity of approximately 3 mg g−1, surpassing values observed for pyrolyzed bone chars at 900 °C in the literature. The findings suggest that co-torrefied bone char could serve effectively as a sorbent in filters for wastewater treatment and potentially fulfill roles such as a remediation agent, pH stabilizer, or valuable source of biofertilizer in agricultural applications.

Performance Evaluation of Two Series Vertical Flow Filters for Wastewater Treatment: A Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

Performance Evaluation of Two Series Vertical Flow Filters for Wastewater Treatment: A Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

Trickling filter systems for sustainable water supply: An evaluation of eco-environmental burdens and greenhouse gas emissions

Despite the global water crisis, the significant potential of trickling filter systems as a crucial auxiliary option for sustainable water supply has received insufficient attention. Therefore, this study presents the first-ever evaluation of the environmental impacts of trickling filter application in wastewater treatment, focusing on eco-environmental burdens. Additionally, the study explores greenhouse gas emissions, energy, and exergy footprints, providing novel insights into the environmental implications of using trickling filters for wastewater treatment. The study's findings indicate that the consumption of heat and electricity in trickling filters has significant environmental impacts, particularly on land use (93.24%), freshwater/marine eutrophication (∼81.98%), and human health (45.36%). The majority of the energy required for trickling filter operation is supplied by fossil fuels (96.02%), resulting in increased greenhouse gas emissions (65.58%). The exergy of trickling filters is highly efficient, accounting for over 95% of the system's energy. Mathematical modeling reveals that anaerobic digestion and secondary clarifier have the highest energy consumption, with contributions of 94.65% and 2.63%, respectively. Construction expenses account for almost 88% of the total cost, with anaerobic digestion (42.15%) and trickling filters (35.39%) being the most costly components. The cost of treating 1 m3 of wastewater is estimated at 0.52 $/m3. Sensitivity analysis demonstrates that electricity (14.66%) and heat (18.65%) significantly impact terrestrial ecotoxicity and land use, respectively. This study presents a framework for future investigations in this field.

Dynamic pore modulation of contracted carbon fiber filter for wastewater treatment: Filtration performance and in-situ regeneration mechanism

Antifouling and selectivity are the major challenges in membrane separation technologies. Inspired by membranes with tunable pore sizes in filtration systems, we propose a contracted carbon fibrous filter (CCF) with an inversed-triangle structure (ITS) using commercial carbon fibers that can control the filter pore size by adjusting the external force loading. By increasing the force loading on fibers, CCF pores shrunk from 2.02 to 0.98 µm, while maintaining a high rejection efficiency of kaolin particles (>99%) at a water flux ranging from 679.7 to 354.9 L m-2 h−1. The role of the ITS and the filtration mechanism of the carbon fibers was revealed via computational simulations and experimental results. Various cleaning strategies were explored to regenerate CCF performance after fouling. A mean flux recovery of 99.6% could be achieved during the nine-cycle filtration by adjusting the pore size combined with electrocleaning. Additionally, a removal mechanism for internal fouling was proposed. This study demonstrates that the novel CCF provides a simple and reliable strategy for wastewater filtration.

Flame modified graphene oxide: Structure and sorption properties

The applications of graphene oxide (GO), advancing on its layered structure, such as selectively permeating membranes and sorption, heavily depend on changing/controlling the distance between the constituting layers. For the sorption, it is also critical to impede exfoliation of GO in solution to simplify the post-sorption separation. In this study, we demonstrate a new method for modifying the structure of solid graphite oxide. The method involves ultrafast passing of graphite oxide particles through a flame of a propane-oxygen gas burner. The resulted material (GOgts) retains the particulate morphology of the original graphite oxide, but has interlayer openings of varying width. The surface area of GOgts is increased 27 times, due to massive formation of narrow 3.5–6.0 nm sized pores. Chemically, GOgts retains the fine chemical structure of original GO with partial deoxygenation. State of the art HRTEM analysis reveals different structure of different GO layers, depending on their closeness to the formed openings. Some layers have large intact graphenic domains with the size of >30 nm. Finally, GOgts exhibits good sorption properties with respect to methylene blue, demonstrating higher sorption capacity, and faster kinetics than the original graphite oxide. Most importantly, in solution, GOgts particles do not disintegrate to single-atomic-layer sheets, affording simple separation of used GOgts from the purified water. The method of GOgts production is simple, scalable and can be used to create new filters for wastewater treatment. Methodologically, we perform HRTEM analysis of GO flake, comprising structurally different layers, with atomic resolution by applying selective Fourier filtering.

Gravity-driven rattan-based catalytic filter for rapid and highly efficient organic pollutant removal

Metal organic frameworks hold great promise as heterogeneous catalysts in sulfate radical (SO4∙-) based advanced oxidation. However, the aggregation of powdered MOF crystals and the complicated recovery procedure largely hinder their large-scale practical applications. It is important to develop eco-friendly and adaptable substrate-immobilized metal organic frameworks. Based on the hierarchical pore structure of the rattan, gravity-driven metal organic frameworks loaded rattan-based catalytic filter was designed to degrade organic pollutants by activating PMS at high liquid fluxes. Inspired by the water transportation of rattan, ZIF-67 was in-situ grown uniformly on the rattan channels inner surface using the continuous flow method. The intrinsically aligned microchannels in the vascular bundles of rattan acted as reaction compartments for the immobilization and stabilization of ZIF-67. Furthermore, the rattan-based catalytic filter exhibited excellent gravity-driven catalytic activity (up to 100 % treatment efficiency for a water flux of 10173.6 L·m−2·h−1), recyclability, and stability of organic pollutant degradation. After ten cycles, the TOC removal of ZIF-67@rattan was 69.34 %, maintaining a stable mineralisation capacity for pollutants. The inhibitory effect of the micro-channel promoted the interaction between active groups and contaminants, increasing the degradation efficiency and improving the stability of the composite. The design of a gravity-driven rattan-based catalytic filter for wastewater treatment provides an effective strategy for developing renewable and continuous catalytic systems.

Fate of biofilm activity in cascade aerating trickling filter for wastewater treatment: Comparison of two types of indigenous support media

Cascade aerating trickling filters (CATF) with two indigenous and novel support media [date palm fiber, (DPF) and maize cob (MC)] were operated to treat domestic wastewater. The biomass, nitrification rate (NR), oxygen uptake rate (OUR) and cultural characteristics of biofilms were measured to investigate microorganism activity and biodiversity. However, the attached biomass on MC (4760 gVSS/m3) was obviously found more than the DPF (1460 gVSS/m3). Huge biomass may decrease the activity of biofilm in CATF. It was also observed that the nitrifying bacteria grow easily on MC surface due to its lower NR (4.2 mg N gVSS/m3) than DPF (5.3 mg N gVSS/m3). Similarly, the OUR of MC media was found higher than DPF media that indicated the improved metabolic activities and microbial growth in the biofilm. At filtration velocities of 4, 8, and 12 m/hr, the biofilm biomass increased with increasing filtration velocity, reaching 2105, 4817, and 6247 mgVSS/m2 respectively. At a filtration velocity of 12 m/hr, the highest biofilm density was 39 mg/cm3. Biomass and thickness of Biofilm were lowest at the filtration velocity of 8 m/hr due to the low influent loading rate. Both the CATFs showed good capability of COD removal, nitrification and denitrification.

An Artificial Neural Network for Simulation of an Upflow Anaerobic Filter Wastewater Treatment Process

The purpose of this work was to develop a problem-solving approach and a simulation tool that is useful for the specification of wastewater treatment process equipment design parameters. The proposition of using an artificial neural network (ANN) numerical model for supervised learning of a dataset and then for process simulation on a new dataset was investigated. The effectiveness of the approach was assessed by evaluating the capacity of the model to distinguish differences in the equipment design parameters. To demonstrate the approach, a mock dataset was derived from experimentally acquired data and physical effects reported in the literature. The mock dataset comprised the influent flow rate, the bed packing material dimension, the type of packing material and the packed bed height-to-diameter ratio as predictors of the calorific value reduction. The multilayer perceptron (MLP) ANN was compared to a polynomial model. The validation test results show that the MLP model has four hidden layers, each having 256 units (nodes), accurately predicts calorific value reduction. When the model was fed previously unseen test data, the root-mean-square error (RMSE) of the predicted responses was 0.101 and the coefficient of determination (R2) was 0.66. The results of simulation of all 125 possible combinations of the 3 mechanical parameters and identical influent wastewater flow profiles were ranked according to total calorific value reduction. A t-test of the difference between the mean calorific value reduction of the two highest ranked experiments showed that the means are significantly different (p-value = 0.011). Thus, the model has the capacity to distinguish differences in the equipment design parameters. Consequently, the values of the three mechanical feature parameters from the highest ranked simulated experiment are recommended for use in the design of the industrial scale upflow anaerobic filter (UAF) for wastewater treatment.

Density Effect of Eisenia sp. Epigeic Earthworms on the Hydraulic Conductivity of Sand Filters for Wastewater Treatment

Inside sand filters, as inside other microporous substrates, several invertebrates create temporary burrows that impact on water movement through the filter. Lumbricids Eisenia fetida and Eisenia andrei live under a wide range of environmental conditions and have a high reproduction rate so they are good candidates for ecological engineering tests. We assessed the impact of these species at different densities (0, 100, 500, 1000 g m−2) on the hydraulic conductivity of small-sized experimental filters made of columns filled with filter sand classically used for sanitation mixed with 5% organic matter. The hydraulic conductivity was recorded every 7 days over 37 days in non-saturated conditions. On day 23, 40 g of peat bedding was added at the column surfaces to simulate a surface clogging organic matter pulse input. Columns with an earthworm density equal or superior to 500 g m−2 revealed the highest hydraulic conductivities during the first 21 days. At these densities, the hydraulic conductivity was also restored in less than 7 days after the addition of the surface organic matter, showing the influence of the earthworm species on the resilience capacity of the hydraulic conductivity. It was also highlighted that the hydraulic flow was dependent on the lumbricid densities with an optimal density/effect around 500 g m−2 in this specific substrate composition. This study showed that the feeding habits and burrowing activity of both Eisenia species significantly enhanced the hydraulic flow in a sandy substrate, providing a sustainable solution to limit the clogging of the substrate similar to the one used in filters to treat wastewater.

Investigations on influences of MWCNT composite membranes in oil refineries waste water treatment with Taguchi route

Most of the ‘oil refineries’ severally pollutes the water resources by depleting their untreated waste water like cooling water, storm water and unsanitary sewage water. These wastewaters are to be treated with high care to protect the human, pebbles, plants, fish and other water animals and from harmful effects. The present study focused to treat the oil refinery wastewater by means of Multi wall carbon nanotube (MWCNT) coated Polyvinylidene Fluoride (PVDF) membrane. The main objectives are: to increases the life of filter, reduce the percolation flux and reduce the formation of antifouling in the filter by using MWCNT composite membrane in it. Different process parameters of the proposed water treatment process, like diameter of MWCNT (15 nm, 20 nm, 25 nm and 30 nm), operating pressure (3 bar, 4 bar, 5 bar and 6 bar), pH value (3, 5, 7 and 9) and temperature (25 °C, 30 °C, 35 °C and 40 °C) temperature. Taguchi statistical technique is employed for designing experiments and for optimizing the process parameters of wastewater treatment process of an oil refinery. The proposed filter for wastewater treatment exhibited appreciable performance in removal rate of Percolation flux, percentage of chemical oxygen demand removal and percentage of total carbolic rejection as 27.2 kg/m2h, 78.51% and 95.33% respectively.

Purification of wastewater of industrial enterprises from phenols by modified energy waste

With the development of engineering and technology, industrial enterprises have an increasing impact on the environment. One of the problems of our time is the pollution of water bodies with industrial toxic waste. Innovative in the field of environmental protection are methods of using inexpensive adsorbents for wastewater treatment, where cost factors play a major role. For quite a long time, an urgent task has been the development of inexpensive adsorbents that can be alternative to those existing at wastewater treatment facilities. Inexpensive alternative adsorbents can be obtained from a wide range of raw materials that are abundant, cheap, and highly absorbent. The article discusses the possibility of purification of industrial wastewater from phenols of oil refining industries on the example of LLP Aktobe Oil Refining. In the treatment of industrial wastewater, the method of adsorption treatment is widely used, which allows not only to purify from pollutants to maximum permissible concentrations (maximum permissible concentrations), but is also cost-effective when introduced. Economic efficiency is characterized by the use of industrial waste as adsorption materials, which in turn show high cleaning efficiency and resolve the issue of disposal of production waste. In this work, energy waste is used as an adsorption material - carbonate sludge from the chemical water treatment of the Aktobe TPP. To achieve a high degree of purification from pollutants, a modified carbonate sludge was obtained, which is used as an adsorption material in filters. A method for obtaining modified carbonate sludge from chemical water treatment is considered. A basic technological scheme of wastewater treatment from phenols has been proposed, a sorption filter for wastewater treatment with a filler - modified carbonate sludge has been selected and calculated. To implement the technology of purification of wastewater from phenols, the economic efficiency and the prevented environmental harm were calculated using the example of the enterprise LLP Aktobe Oil Refining. The technology of regeneration of waste carbonate sludge is considered. The heat effects of combustion of spent carbonate sludge as a fuel material are calculated using the example of Aktobe TPP.

Hybrid constructed wetlands integrated with microbial fuel cells and reactive bed filter for wastewater treatment and bioelectricity generation.

The present study aimed to develop a pilot-scale integrated system composed of anaerobic biofilter (AF), a floating treatment wetland (FTW) unit, and a vertical flow constructed wetland coupled with a microbial fuel cell (CW-MFC) and a reactive bed filter (RBF) for simultaneously decentralized urban wastewater treatment and bioelectricity generation. The first treatment stage (AF) had 1450 L and two compartments: a settler and a second one filled with plastic conduits. The two CWs (1000 L each) were vegetated with mixed plant species, the first supported in a buoyant expanded polyethylene foam and the second (CW-MFC) filled with pebbles and gravel, whereas the RBF unit was filled with P adsorbent material (light expanded clay aggregate, or LECA) and sand. In the CW-MFC units, 4 pairs of electrode chambers were placed in different spacing. First, both cathode and anode electrodes were composed of graphite sticks and monitored as open circuit. Later, the cathode electrodes were replaced by granular activated carbon (GAC) and monitored as open and closed circuits. The combined system efficiently reduced COD (> 64.65%), BOD5 (81.95%), N-NH3 (93.17%), TP (86.93%), turbidity (94.3%), and total coliforms (removal of three log units). Concerning bioenergy, highest voltage values were obtained with GAC electrodes, reaching up to 557 mV (open circuit) and considerably lower voltage outputs with closed circuit (23.1 mV). Maximum power densities were obtained with 20 cm (0.325 mW/m2) and 30 cm (0.251 mW/m2). Besides the electrode superficial areas, the HRT and the water level may have influenced the voltage values, impacting DO and COD concentrations in the wastewater.

Adsorption and catalytic degradation of Tartrazine in aqueous medium by a Fe-modified zeolite

Azo dyes, as Tartrazine (T), are one of the rawest materials in food, pharmaceutical and textile industries. Many dyes are difficult to degrade due to their complex structure and xenobiotic properties. Although adsorption is considered an effective, efficient, and economic method for water purification, degradation of organic pollutant like synthetic dyes by using advanced oxidation processes (AOPs), as Fenton process, has become increasingly significant during last decades. However, as Fenton process requires ferrous salt for the oxidation reaction to take place, the iron sludge formed after the reaction, has to be removed before discharging. A novel composite material, which is referred to as iron-loaded natural zeolite (NZ-A-Fe), was used for the removal of Tartrazine (T) from water through the combined adsorption and heterogeneous catalysis. Since the adsorption step determines the rate in heterogeneous catalytic processes, its study becomes necessary for understanding the degradation mechanism. The suitability of Langmuir and Freundlich isotherms to the equilibrium data was investigated in the solid-liquid system. The equilibrium adsorption capacity (qe) increases with the increase of the initial concentration of T. The pseudo-second-order model can well describe the adsorption process of T on NZ-A-Fe, where k2 = 0.246 g(mg.min)−1is the rate constant for adsorption process. Degradation kinetics can be described using the classical pseudo-first order. Tartrazine degradation was high between 90 and 95% for [H2O2] /[T] = 37 for [T] = 10 mg/L. The novelty of this work is the simultaneous adsorption and Fenton degradation using a supported catalyst NZ-A-Fe that facilitates the design of filters for wastewater treatment.

Biomass Production and Removal of Nitrogen and Phosphorus from Processed Municipal Wastewater by Salix schwerinii: A Field Trial

In many Baltic regions, short-rotation willow (Salix spp.) is used as a vegetation filter for wastewater treatment and recycling of valuable nutrients to upsurge bioeconomy development. In this context, a four-year field trial (2016–2019) was carried out near a wastewater treatment plant in eastern Finland (Outokumpu) to investigate the effect of the processed wastewater (WW) on biomass production as well as the nutrients uptake capability (mainly N and P) by a willow variety (Salix schwerinii). Results indicated that WW irrigation expressively increased the willow diameter growth and biomass yield around 256% and 6510%, respectively, compared to the control treatment site (without WW). The willow was also able to accumulate approximately 41–60% of the N and 32–50% of the P in two years (2018–2019). Overall, willow showed a total 20% mortality rate under WW irrigation throughout the growing periods (2017–2019) as compared to control (39%). The results demonstrate that willow has the potential to control eutrophication (reducing nutrients load) from the wastewater with the best survival rate and can provide high biomass production for bioenergy generations in cold climatic conditions.

Modeling-based performance evaluation of novel cascade cum trickling filter wastewater treatment system

Modeling-based performance evaluation of novel cascade cum trickling filter wastewater treatment system

Novel and multifunctional adsorbent fabricated by Zeolitic imidazolate framworks-8 and waste cigarette filters for wastewater treatment: Effective adsorption and photocatalysis

Cellulose based aerogels for water purification have attracted intensive attentions due to the high porosity and biodegradability. However, the low adsorption capacity and poor adsorption efficiency restrain its practical application in this field. In this work, we synthesized a series of zeolitic imidazolate framworks-8 (ZIF-8) decorated waste cellulose aerogels through a facile blending method using waste cigarette filters and NaOH/urea as cellulose resources and a green solvent, respectively. These results showed that ZIF-8 can improve the thermal stability and increase the specific surface area of cellulose aerogels effectively. Furthermore, the highest specific surface area for as-prepared waste cellulose/ZIF-8 aerogels reached to 1035 ​m2 ​·g−1. They exhibited a high adsorption capacity of 10.31 ​mg ​·g−1 and a strong photocatalytic activity for methylene blue, which can degrade methylene blue completely within 2 ​h under UV light. In addition, these waste cellulose/ZIF-8 aerogels had a good recycle-ability, and the degradation rate can maintain above 84% after 5 cycles. Thus, as-prepared waste cellulose/ZIF-8 aerogels can be applied in water purification as multifunctional adsorbents with good adsorption-photocatalytic performance.