Industrial Textile Wastewater Treatment Research Articles

Photocatalytic degradation of toxic basic blue 41 and reactive orange M2R dyes using green synthesized zinc oxide nanoparticles

Zinc oxide nanoparticles (Cm-ZnO NPs) were synthesized to eliminate organic dye pollutants from textile dye effluents. The present study reports Cucumis maderaspatanus L. leaves utilized as a green reducing/stabilizing agent for Cm-ZnO NPs synthesis. The nanoparticles underwent thorough analysis using techniques such as XRD, UV–vis, TEM, and FT-IR. Photocatalytic degradation of toxic basic blue 41 (BB41) and reactive orange M2R (ROM2R) dyes using Cm-ZnO NPs, showed a degradation rate of 97.69 % and 94.30 % respectively under optimized conditions. The kinetics of photocatalytic degradation of BB41 and ROM2R dyes followed first-order kinetics. The scavenger studies were conducted to identify the photogenerated reactive species involved in dye degradation. The singlet oxygen (1O2) and hydroxyl radicals (●OH) are mainly responsible for the degradation of BB41 and ROM2R dye respectively. LC-MS analysis was used to identify the photocatalytic degraded products, and ECOSAR software assessed their toxicity. The recyclability was performed up to four cycles and the stability of Cm-ZnO NPs was confirmed by XRD analysis. Thus, the as-synthesized Cm-ZnO NPs are suitable for industrial textile wastewater treatment.

The scope of alum coagulation-flocculation assisted by slaked lime for the treatment of industrial wastewater containing highly concentrated Acid Black 194 dye. Optimization, molecular weight distribution and toxicity analysis

This work evaluated the capacity of the alum coagulation-flocculation (C–F) process, assisted by slaked lime, for the treatment of industrial textile wastewater (ITWW) containing highly concentrated Acid Black 194 dye. By optimizing the operating conditions ([Alum] = 16.09 g/L, [Ca(OH)2] = 5.16 g/L) through experimental design, response surface methodology, and multi-objective optimization analysis, the C–F process removed 95 % of the dye, 63 % of the COD, 60 % of the TOC, and 94 % of the total Cr concentration, with a total operating cost of 5.99 USD/m3. This improved the biodegradability index (from 0.20 to 0.26), the COS parameter (from 0.14 to 2.46), and the toxicity of the effluent (LC50 for Artemia salina increased from 15.16 mg/L to 56.7 mg/L). The calcium hardness and total hardness were also reduced by 40 % and 44 %, respectively. The C–F supernatant was composed mainly of molecules with molecular weights less than and equal to 10 kDa. An LC-MS spectral analysis revealed the presence of four residual aromatic and recalcitrant compounds in the C–F supernatant, indicating that its further treatment is required before it can be safely discharged or recycled for industrial purposes. The alum C–F process, assisted by slaked lime, demonstrated greater performance, surpassing the individual processes in effectiveness and efficiency, and confirming their synergetic effect. The alum process alone (16.09 g/L) achieved a 37 % reduction COD and 91 % color removal, at a total cost of 4.49 USD/m3. The lime process alone (5.16 g/L) achieved a 37 % COD reduction and 64 % color removal, at a total cost of 1.36 USD/m3.

Comparative life cycle assessment of sequential chemical and electrochemical processes for the treatment of industrial textile wastewater

AbstractFenton-based processes, chemical and electrochemical, have attracted the interest of industrial and academic researchers for wastewater treatment. However, the deficiency of rigorous comparison between different methods, including assessment of their impact on the environment, has hindered their large-scale application. This study reports for the first time on the sustainability of raw textile wastewater treatment through two sequential processes, Coagulation-Flocculation-Fenton-Neutralization (CF-F-N) and Coagulation-Flocculation-Electro-Fenton-Neutralization (CF-EF-N), based on Life Cycle Assessment (LCA) approach. The CF-F-N and CF-EF-N were optimized at laboratory scale and compared through LCA, using the IPCC-2013 and ReCiPe-2016 midpoint and endpoint methods. The highest CO2 emissions relied on the wastewater primary treatment by CF. This due to the high amount of hazardous sludge generated and the technology necessary for its disposal (i.e., 16.89 kg CO2-Eq/FU for underground deposit in security cells or 47.52 kg CO2-Eq/FU for incineration) as well as the consumption of reagents required for the treatment (alum, 7.72 kg CO2-Eq/FU; and slaked lime, 5.56 kg CO2-Eq/FU). Regarding the sequential processes, the EF-N presented lower carbon footprint (CFP) than the F-N (14.74 kg CO2-Eq/FU vs. 20.74 kg CO2-Eq/FU). Electricity (87.02% of the total CFP) and reagents (88.63% of the total CFP) denoted the main environmental hotspot during the EF-N and F-N, respectively. The EF-N, compared to the F-N, had an inferior incidence in 14 of the 18 impact categories analyzed using the ReCiPe-2016 method at the midpoint level. This is the result of low consumption of reagents and auxiliary chemicals. The electricity was also found as main environmental hotspot of the EF-N. The ReCiPe-2016 method at the endpoint level showed that the EF-N resulted in lower environmental load in all impact categories. The economic performance (11.91 USD/m3 for CF-EF-N vs. 13.66 USD/m3 for CF-F-N) and LCA demonstrated the competitiveness of the electrochemical sequential process compared to the chemical one. The CF-EF-N can be considered more environmentally sustainable technology.

Research on color treatment of industrial textile wastewater using synthesized inorganic bentonite composite as an adsorbent

Vietnamese bentonite with poor quality had been purified before being modified with iron salts to create inorganic bentonite composite (Ben-C). This process increased the specific surface area to 221.83 m2g−1. The test showed that the reactive dye was rapidly adsorbed in about 1 h by the Ben-C and the adsorption efficiency reached its maximum value at a Ben-C content of 3 g/L. Ben-C had been used as an adsorbent for 6 types of textile industrial wastewater. Companies used different kinds of dyes and additives, so the color adsorption time of each wastewater was also different, ranging from 0.25 to 2 h. Adsorption efficiency tended to increase with adsorbent content, but the increased level depended on the type of wastewater. Wastewater color treatment was more effective when the adsorption process was carried out at a low temperature, 20–25 °C. The FTIR spectrum of wastewater also evaluated the effectiveness of wastewater color removal.

Industrial Textile Wastewater Treatment by Crossflow NF Membrane Filtration

Ineffective dyeing procedures frequently lead to the release of approximately 10–50% of the dye applied, which does not adhere to the fabric and is consequently discharged into the environment along with the effluent. This situation is undesirable both for potential recycling within the textile manufacturing process and because of its adverse environmental pollution effects. This study thoroughly examines nanofiltration (NF) membrane characteristics and their performance in textile wastewater treatment. Pristine NF membrane surfaces were revealing a web-like structure with well-defined pores predominantly in the membrane active region. This assessment confirms the membrane initial cleanliness, free from any external contaminants, which is vital for effective membrane-based filtration. Additionally, the study investigates how different feed flow rates affect water flux during NF membrane filtration. The results demonstrate a clear relationship, where the increasing flow rates boost water flux. This can be attributed to heightened cross-flow velocity and shear force on the membrane surface due to the increased water flux, minimizing external concentration polarization and reducing membrane fouling. The impact of feed flow rate on membrane separation efficiency is also examined, showing consistent efficiency at feed flow rates between 2 LPM and 5 LPM (approximately 80.8% to 82.22%). However, efficiency drops as the feed flow rate increases from 5 LPM to 6 LPM, likely due to increased pressure drop across the membrane, affecting separation efficiency.

Application of electrocoagulation process for the treatment of reactive blue 19 synthetic wastewater: Evaluation of different operation conditions and financial analysis

The aim of this study was to treat reactive blue 19 (RB 19) in solution by electrocoagulation (EC) process, using aluminum cathodes modified by zinc oxide nanoparticles (ZnO-NPs). Cyclic voltammetry methodology (CVM) was used to investigate the effect of coating aluminum electrodes with ZnO-NPs. The response surface methodology (RSM) based on central composite design (CCD) and analysis of variance (ANOVA) were used to evaluate and optimize the variables and the response, which was dye removal efficiency. The economic and energy analyses confirmed that this process was a promising method for pretreatment and treatment of industrial textile wastewater.

Industrial textile wastewater treatment using Neolamarckia cadamba NFC filter paper via cross-flow filtration system

This study investigated the potential use of Neolamarckia cadamba as nanofibrillated cellulose (NFC) filter paper for treating industrial textile wastewater via the cross-flow filtration system. Response surface methodology (RSM) was employed to optimize the system and create a predictive model to evaluate the performance of the NFC filter paper. Experimental results from the central composite design (CCD) showed that a high value of colour removal efficiency of 90.56 % and an optimum value of normalized flux of 0.7397 were achieved at pH 6.5 with 100 % of initial feed concentration of the textile wastewater and 60:40 cellulose dosage ratio of the NFC filter paper. Optimisation and verification experiments were conducted under the optimal conditions determined. The formation of a cake layer in the two stages of the membrane fouling mechanism under the optimum operational condition was revealed using model fitting according to Wiesner and Aptel equations and confirmed via Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) analyses. Water quality in terms of colour, pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and turbidity was monitored to determine if the treated wastewater met the discharge limits. The findings of this study demonstrated the potential of using the NFC filter paper for industrial textile wastewater treatment and provided valuable insights for optimising the operating parameters of filter papers.

Wastewater treatment using recyclable agar-graphene oxide biocomposite hydrogel in batch and fixed-bed adsorption column: Bench experiments and modeling for the selective removal of organics

Hydrogel biocomposite using graphene oxide and agar biopolymer (agar-GO) was synthesized to treat textile wastewater through fixed-bed adsorption. After characterization, batch experiments were conducted to evaluate the pH effect in the adsorption process, adsorption isotherms, and kinetics for four cationic dyes – Nile Blue A (NB), Methylene Blue (MB), Malachite Green (MG) and Basic Fuchsin (BF). Adsorption equilibrium isotherms were fitted to Freundlich, Langmuir and Sips models, and kinetic data were adjusted to Driving Force models, and Fickian Diffusion equation. Fixed-bed experiments were carried out, and the adsorption capacities on a dry basis were 226.46 mg·g−1 (NB), 79.51 mg·g−1 (MB), 58.25 mg·g−1 (MG), 38.11 mg·g−1 (BF). LDF model was fitted with the experimental breakthrough curves. The column packed with the agar-GO hydrogel was tested for the treatment of synthetic textile wastewater. Color and total organic carbon (TOC) were evaluated and there was an indication of the adsorbent selectivity for the separation of the dyes, which can facilitate dye recovery. Agar-GO proved to be a viable and eco-friendly alternative, since a small amount of material was used to treat over 6 L of wastewater, being most of the composite biodegradable. Moreover, the material exhibited remarkable regenerative capacity, proving its effectiveness for applications in industrial textile wastewater treatment.

Construction and implementation of floating wetpark as effective constructed wetland for industrial textile wastewater treatment

Fimbristylis dichotoma, Ipomoea aquatica, Pluchea tomentosa and their co-plantation (consortium FIP) autonomously degrade Orange 3R. Consortium FIP showed 84% removal of Orange 3R within 48 h, which is a higher dye elimination rate than individual plant systems. Oxidoreductase enzymes like tyrosinase (76%), varatryal alcohol oxidase (85%), lignin peroxidase (150%), riboflavin reductase (151%), laccase (171%), NADH-DCIP reductase (11%) and azo reductase (241%) were expressed in consortia FIP during Orange 3R degradation. UV–vis spectroscopy, enzyme activities, HPTLC, FTIR and GC-MS confirmed mineralization of Orange 3R into its metabolites. Microscopic investigation of root tissue revealed the harsh effect of dye on root tissues. Toxicity assessment on the HepG2 cell line demonstrated the toxic nature of Orange 3R, which gets reduced after phyto-treatment with consortia FIP. Floating wetpark of consortia FIP was found more efficient for the treatment of industrial textile waste and accomplished 87%, 86%, 75%, 49% and 46% removal of COD, BOD, color, TSS and TDS of effluent.

Investigation of fouling mechanism in membrane distillation using in-situ optical coherence tomography with green regeneration of fouled membrane

Membrane distillation (MD) has the potential to expand its application from desalination to wastewater treatment by developing a in-situ membrane fouling and wetting detection system. In this study, advanced in-situ 3D optical coherence tomography (OCT), coupled with model simulation, was used to reveal the fouling mechanisms in real-time during MD treatment of industrial textile wastewater. Additionally, an ultrasonic cleaning operation was conducted to control fouling and regenerate the fouled membrane. Two commercial membranes, polyvinylidene fluoride (C-PVDF) and polytetrafluoroethylene (C-PTFE), were applied in dye wastewater treatment by MD, where the C-PTFE membrane achieved 99.9% dye removal. 3D-OCT images indicated that the foulant attachment on the C-PTFE membrane was much looser than on the C-PVDF membrane, owing to its pattern shaped surface morphology and higher hydrophobicity as explained through mathematic modeling. Average water flux was maintained above 31.38 ± 0.19 LMH for 24 h MD operation with the C-PTFE membrane and a water recovery rate of 73.2 ± 0.26% was attained by using the in-line ultrasonic operation.

Loose nanofiltration membrane with highly-branched SPEI/PEI assembly for dye/salt textile wastewater treatment

Salt accumulation is inevitable in the conventional textile wastewater treatment, which hardly realize the effectively remove of dye and recover of water. Loose nanofiltration (NF) membrane with highly hydrophilic surface and loose structure has been demonstrated as an optimal choice for efficient dye/salt separation. This study develops a loose NF membrane via the layer-by-layer (LbL) assembly of highly-branched sulfonated polyethyleneimine (SPEI)/polyethyleneimine (PEI) and mussel-inspired post-crosslinking. Different molecular weights of highly-branched SPEI are synthesized. Effects of LbL assembly and cross-linking process, SPEI molecular weight and crosslinker type are investigated systematically. It is found that the membrane prepared with the assembly of SPEI10k/PEI and crosslinked by catechol exhibits low roughness (Ra = 3.56 nm), high hydrophilicity (WCA = 44.07°) and negatively-charged membrane surface (ζ = −16.39 mV). As a result, the membrane achieves an ultrahigh permeability (~ 36.89 LMH/bar), excellent dyes retention (> 99.37% to Congo red), as well as low rejection to salts (2.47% to NaCl). The novel loose NF membrane developed in this work therefore shows a promising prospect in practical industrial textile wastewater treatment.

A continuous mode reactor design for industrial textile wastewater treatment through catalytic ozonation

A rapid catalytic process with low energy requirements gives catalytic ozone the potential to treat industrial textile wastewater in a full-scale application. However, until today, this catalytic ozone technology remains energy-consuming and, as a consequence, expensive. Thus, to overcome the bottleneck related to energy needs, this research aims to design a continuous mode reactor design to treat industrial textile wastewater through catalytic ozone, which integrated solar power plants (PLTS). In this work, a constant mode reactor design combined with an integrated sensor is investigated for industrial textile wastewater. Combining the autonomous and continuous removal of the impurities makes this continuous mode reactor excellent for the treated wastewater on the industrial textile scale.

Microscopic Analysis of Activated Sludge in Industrial Textile Wastewater Treatment Plant

Abstract The relationship between a quality of activated sludge microbiota and wastewater treatment plant (WWTP) operational stability has been defined in the past few decades. However, this dependence is not so clear in the case of industrial wastewater treatment. In this article, a very specific example of industrial textile wastewater treatment plant (ITWTP) is analyzed. Textile effluents are well known as highly contaminated wastewater containing many biodegradable compounds. Microscopic analysis included flocs morphology examination, attempts to evaluate the Sludge Biotic Index (SBI), and identification of dominant filamentous microorganisms. Routine operational control of ITWTP covered pH, temperature, redox potential, dissolved oxygen and COD measurements. The average ecosystem existing in the described ITWTP differed significantly compared to municipal WWTPs. The flocs were smaller and irregular. Filamentous bacteria did not cause foaming although filaments index reached 4. Nostocoida limicola I dominated with significant amounts of type 0041 and type 021N. The evaluation of SBI was impossible as the most of protozoan was in the form of cysts. The overall microbiota diversity correlated with COD removal in activated sludge unit of ITWTP.

Autotrophic nitrogen removal for decentralized treatment of ammonia-rich industrial textile wastewater: process assessment, stabilization and modelling

Digital textile printing (DTP) is a game-changer technology that is rapidly expanding worldwide. On the other hand, process wastewater is rich in ammoniacal and organic nitrogen, resulting in relevant issues for discharge into sewer system and treatment in centralized plants. The present research is focused on the assessment of the partial nitritation/anammox process in a single-stage granular sequencing batch reactor for on-site decentralized treatment. The technical feasibility of the process was assessed by treating wastewater from five DTP industries in a laboratory-scale reactor, in one case investigating long-term process stabilization. While experimental results indicated nitrogen removal efficiencies up to about 70%, complying with regulations on discharge in sewer system, these data were used as input for process modelling, whose successful parameter calibration was carried out. The model was applied to the simulation of two scenarios: (i) the current situation of a DTP company, in which wastewater is discharged into the sewer system and treated in a centralized plant, (ii) the modified situation in which on-site decentralized treatment for DTP wastewater is implemented. The second scenario resulted in significant improvements, including reduced energy consumption (− 15%), reduced greenhouse gases emission, elimination of external carbon source for completing denitrification at centralized WWTP and reduced sludge production (− 25%).

Adsorptive and photocatalytic activity of Fe3O4-functionalized multilayer graphene oxide in the treatment of industrial textile wastewater.

Multilayer graphene oxide (mGO) was synthesized and functionalized via co-precipitation method to produce magnetic Fe3O4-functionalized multilayer graphene oxide nanocomposite (MmGO). Photocatalytic properties of MmGO were investigated in the photodegradation of raw textile wastewater samples. Fourier-transformed infrared spectroscopy revealed Fe-O vibrations, characterized by the band shift from 636.27 to 587.25 cm-1 on MmGO. X-ray diffraction confirmed the successful oxidation of graphite by the (002) peak at 10° and indicated the presence of Fe3O4 on MmGO surface by the peaks at 2θ 35.8° (311), 42.71° (400), 54.09° (511), and 62.8° (440). There was no detection of coercivity field and remnant magnetization, evidencing a material with superparamagnetic properties. Then, the textile effluent was treated by heterogeneous photo-Fenton (HPF) reaction. A 22 factorial design was conducted to evaluate the effects of MmGO dosage and H2O2 concentration on HPF, with color and turbidity removal as response variables. The kinetic behavior of the adsorption and HPF processes was investigated separately, in which, the equilibrium was reached within 60 and 120 min, for adsorption and HPF, respectively. Pseudo-second-order model exhibited the best fit, with COD uptake capacity at equilibrium of 4094.94 mg g-1, for chemical oxygen demand. The modeling of kinetics data showed that the Chan and Chu model was the most representative for HPF, with initial removal rate of 95.52 min-1. The removal of organic matter was 76.36% greater than that reached by conventional treatment at textile mills. The presence of Fe3O4 nanoparticles attached to MmGO surface was responsible for the increase of electron mobility and the enhancement of its photocatalytic properties. Finally, MmGO presented low phytotoxic to Cucumis sativus L. with a RGI of 0.53. These results bring satisfactory perspectives regarding further employment, on large scale, of MmGO as nanocatalyst of textile pollutants.

Scalable Ti3C2Tx MXene Interlayered Forward Osmosis Membranes for Enhanced Water Purification and Organic Solvent Recovery.

The design of nanosheets interlayer between the substrate and polyamide layer has attracted growing attention to improve the performance of thin-film composite membranes. However, the membrane size is limited by current fabrication methods such as vacuum filtration. Herein, a high-performance MXene (Ti3C2Tx) interlayered polyamide forward osmosis (FO) membrane is fabricated based on a combination of a facile and scalable brush-coating of MXene on nylon substrates and the interfacial polymerization process. The as-prepared FO membrane shows high water permeability of 31.8 L m-2 h-1 and low specific salt flux of 0.27 g L-1 using 2.0 mol L-1 sodium chloride as the draw solution. This is attributed to the adjustment of substrate properties and the polyamide layer by coating of MXene as well as the facilitation of water transportation by the interlayer distances between Ti3C2Tx. The membrane also exhibits a good organic solvent forward osmosis performance with high ethanol flux as 9.5 L m-2 h-1 and low specific salt flux of 0.4 g L-1 using 2.0 mol L-1 lithium chloride as the draw solution. Moreover, the MXene interlayered FO membrane demonstrates a feasible application in real seawater desalination and industrial textile wastewater treatment. This work presents an effective approach to fabricating nanomaterials interlayered FO membranes with superior performance for both desalination and organic solvent recovery.

Potential of Catalytic Ozonation in Treatment of Industrial Textile Wastewater in Indonesia: Review

Industrial textile wastewater is one of the most heavily polluting in Indonesia. Wastewater from industrial textile contains organic contamination that is very difficult to remove pollutants that remaining even though it has been through the usual wastewater treatment unit installed and bio refractory in nature. Toxic organic compounds discharged from the textile industry, such as colored dyes, heavy metals, and various chemicals, will hurt the environment. These contaminants have been proven toxic to the biotic environment, such as mutagenic, which can increase the incidence of cancer and endocrine disruptor effects. Removal of contaminants from industrial textile wastewater is currently one of the most critical subjects in water pollution prevention. Applications of catalytic ozonation treatment initially, powder catalysts have been employed, and later, the use of activated carbon materials in more advanced catalyst structures reported, and more sophisticated types of catalyst equipment namely carbon nanotube, and nanoparticles. In-depth research on the combination of ozonation and catalytic research of industrial textile wastewater treatment has the potential to become a well-developed approach to treatment industrial textile wastewater. This review provides process principles and characteristics, including the use of various catalysts, variations in reactor design, and application catalytic ozonation in synthetic textile wastewater and real industrial textile wastewater outlined and discussed. Include future research directions of the treatment of industrial textile wastewater in to clean water with drink quality.

Assessment of the optimized treatment of indigo-polluted industrial textile wastewater by a sequential electrocoagulation-activated carbon adsorption process

Wastewater collected from a local jean manufacturing plant was treated using an electrocoagulation process (EC) coupled with activated carbon (AC) adsorption. The process variables were optimized using multivariate regression coupled with nonlinear programming with nonlinear restrictions to achieve the lowest possible cost while keeping a high enough degradation rate for chemical oxygen demand (COD), color, and turbidity to fulfill the Colombian environmental regulation requirements. Under optimal conditions (pH = 5.4, σ =2 mS/cm, j =14 mA/cm2, and t = 11 min) color, COD, and TOC removals of 95%, 63%, and 51%, respectively, were achieved. The biodegradability index also increased from 0.13 to 0.29, whereas toxicity tests showed a remaining toxicity of 45%. A kinetic study was conducted for the EC process. The activated carbon (AC) adsorption process was successfully used to completely remove toxicity, while further increasing color, COD, and TOC removals to 96%, 72%, and 61%, respectively. The conditions for the AC adsorption process (20 g/L of AC and 1 h) were determined by experimental adsorption isotherms and kinetic studies. The optimized EC/AC process led to an effluent satisfying the Colombian regulations and seems technologically viable with lower costs than other similar process that were reported in previous works.

A novel dual-layer, gas-assisted electrospun, nanofibrous SAN4-HIPS membrane for industrial textile wastewater treatment by direct contact membrane distillation (DCMD)

In this work, a dual-layer nanfibrous SAN4-HIPS membrane has been fabricated via the gas-assisted electrospinning, and employed for industrial textile wastewater treatment by direct contact membrane distillation (DCMD). The obtained results showed that the new membrane is robust and able to remove the contaminants, remarkably, with almost 99.28 %, 97.93 %, and 100 % reductions for COD, BOD and color, respectively. However, a flux decline of up to 42.58 % was observed after 48 h DCMD process. Concerning the rejection results, it can be concluded that the flux decline is mainly caused by the membrane fouling rather than the partial pore wetting as the membrane remained hydrophobic after the 48-h experiment. The surface contact angle reduced from 143.2° to 121.5°. Foulants accumulation on the membrane surface can increase the mass transfer resistance of vapor molecules. This can considerably reduce the productivity. The obtained results were also compared with the literature on the other MD processes, as well as the conventional pressure-driven membrane processes. Further studies on enhancing the membrane surface properties are required to control and reduce the fouling tendency caused by the contaminants in the industrial textile wastewater. This is of crucial for the long-term DCMD performance.

Treatment of Industrial Textile Wastewater in Biological Aerated Filters – Microbial Diversity Analysis

Investigated herein was the biodegradation of highly contaminated textile wastewater on a laboratory scale, with biological aerobic filters as a single treatment and in combination with the coagulation/flocculation process. Among the three support materials tested (Intalox saddles, ceramsite and beach shavings), the highest organic carbon compound removals (above 60% measured as COD and TOC) and steady operation were obtained for ceramsite. Effective and stable biological treatment was possible thanks to the development of biofilm of high bacterial and fungal diversity. The biodiversity of microflora was estimated on the basis of metagenomic analysis. The coagulation process with PAX 18 was effective in total phosphorus depletion (94%), while the coagulant Epoly CRD enabled up to 99% colour removal. The best results were obtained after the combined treatment, in which biodegradation was followed by coagulation (PAX 18). Such a combination enabled the removal of 98% of BOD5, 87% of COD, 88% of TOC, 48% of the total nitrogen, 98% of the total phosphorus, 98% of toxicity (towards Vibrio fisheri) and above 81% of colour.