Turning calcium carbonate into a cost-effective wastewater-sorbing material by occluding waste dye

Background, aim, and scope  

Over the years, organic pollution in the environment has aroused people’s concern worldwide, especially persistent organic pollutants (POPs). Particularly in developing countries, plenty of concentrated organic wastewaters treated noneffectively are discharged into aquatic environments from chemical, textile, paper-making, and other industries to seriously threaten the surface and drinking water. The conventional wastewater treatment techniques are often helpless due to high cost with multilevel processing. Adsorption as an efficient method is often applied to the treatment of wastewater. The aim of this work is to develop an eco-friendly and cost-effective wastewater-sorbing material with weak acidic pink red B (APRB) and calcium carbonate (CaCO₃) by reusing highly concentrated dye wastewater.     

Formation of shaped barium sulfate-dye hybrids: waste dye utilization for eco-friendly treatment of wastewater

Purpose

Owing to the present complexity and difficulty of concentrated dye wastewater treatment, this work aimed to synthesize a reproducible waste-sorbing material for the treatment of wastewater by forming the dye-conjugating complex hybrid.

Methods

The inorganic/organic hybridization was applied to prepare the objective material by immobilizing waster dye-Mordant blue 9 (MB) with barium sulfate (BaSO₄). The composition and pattern of the formed material were determined by spectrometry and characterized by SEM and XRD, and their formation process was clarified. The adsorption of cationic dye-basic blue BO (BB) and copper ion was investigated..

Results

The hybrid of MB alone into growing BaSO₄ formed the pineapple-like particles while that of the MB/BB-conjugating complex was the rhombus material. The adsorption of BB on the MB–BaSO₄ hybrid was probably attributed to ion-pair equilibrium and that of Cu²⁺ may result from the complexation. The treatment of dye and heavy metal wastewaters indicated that the MB hybrid material removed 99.8% BB and 97% Cu²⁺ and the dye-conjugating hybrid with growing BaSO₄ 100% MB, 99.5% BB, and 44% Cu²⁺.

Conclusion

The waste MB–BaSO₄ hybrid material is efficient to treat cationic dye and Cu²⁺ wastewater. The dye-conjugating hybridization method is the first to be advanced for in situ wastewater treatment, and it showed a combined effect for the removal of both organic dyes and heavy metals.     

Simulation of the influence of industrial wastewater on a municipal sewage treatment plant—a case study

Purpose  

Industrial wastewater flow caused operational difficulties in the wastewater treatment plant in Debrecen, Hungary. Bioaugmentation was successfully applied to maintain effluent quality in the periods when wastewater of high starch content was accepted, but, at the end of 2008, the nitrification capacity of the plant decreased considerably due to improperly pre-treated pharmaceutical wastewater.     

RO/NF membrane treatment of veterinary pharmaceutical wastewater: comparison of results obtained on a laboratory and a pilot scale

Background  

Emerging contaminants (ECs) are commonly derived from industrial wastewater, which is often a consequence of an inadequate treatment of the latter. Improperly pretreated pharmaceutical wastewater could cause difficulties in operations of wastewater treatment plants while incomplete elimination of ECs during the processing might result in their appearance in drinking water.     

The role of cytochromes P450 and peroxidases in the detoxification of sulphonated anthraquinones by rhubarb and common sorrel plants cultivated under hydroponic conditions

Background, aim and scope  

Sulphonated anthraquinones are precursors of many synthetic dyes and pigments, recalcitrant to biodegradation and thus not eliminated by classical wastewater treatments. In the development of a phytotreatment to remove sulphonated aromatic compounds from dye and textile industrial effluents, it has been shown that rhubarb (Rheum rabarbarum) and common sorrel (Rumex acetosa) are the most efficient plants. Both species, producing natural anthraquinones, not only accumulate, but also transform these xenobiotic chemicals. Even if the precise biochemical mechanisms involved in the detoxification of sulphonated anthraquinones are not yet understood, they probably have cross talks with secondary metabolism, redox processes and plant energy metabolism. The aim of the present study was to investigate the possible roles of cytochrome P450 monooxygenases and peroxidases in the detoxification of several sulphonated anthraquinones.     

Physiological parameters of plants as indicators of water quality in a constructed wetland

Introduction  

Increasing demand for water has stimulated efforts to treat wastewater for reuse in agriculture. Decentralized facilities for wastewater treatment became popular as a solution to remote and small communities. These systems mimic natural wetlands, cleaning wastewater as they flow through a complex of filter media, microbial fauna, and vegetation. The function of plants in constructed wetlands (CWs) has not been fully elucidated yet.     

Combined biological processing and microfiltration in the treatment of unhairing wastewater

Introduction  

The unhairing step, a part of the beamhouse process, is particularly polluting, generating an alkaline wastewater with high concentrations of organic and inorganic matter. The aim of this study was to evaluate the treatment of this industrial wastewater using a combination of biological and microfiltration processes.     

Wet air oxidation and catalytic wet air oxidation for dyes degradation

Background, aim, and scope  

Textile industry produces wastewater which contributes to water pollution since it utilizes a lot of chemicals. Preliminary studies show that the wastewater from textile industries contains grease, wax, surfactant, and dyes. The objective of this study was to determine the treatment efficiency of the nickel catalysts supported on hydrotalcites in three-dye model compounds and two types of wastewater.     

Microbial dynamics in a sequencing batch reactor treating alkaline peroxide mechanical pulp and paper process wastewater

Background, aim, and scope  

For many years, highly concentrated wastewater generated from the pulp and paper industry has become the focus of much concern worldwide. The objectives of this study were to determine the treatment efficiency of the alkaline peroxide mechanical pulp (APMP) process wastewater using a sequencing batch reactor (SBR) and analyze the microbial dynamics of the wastewater treatment system using the random amplified polymorphic DNA (RAPD) method.     

Characterization of tannery sludge activated carbon and its utilization in the removal of azo reactive dye

Introduction  

The removal of azo Reactive Red 31(RR31) from synthetic dye solution using tannery sludge-developed activated carbon (TSC) was investigated.     

Uptake and distribution of metals by water lettuce (<Emphasis Type="Italic">Pistia stratiotes</Emphasis> L.)

Background, aim and scope  

Water quality impairment by heavy metal contamination is on the rise worldwide. Phytoremediation technology has been increasingly applied to remediate wastewater and stormwater polluted by heavy metals.     

Image analysis application for the study of activated sludge floc size during the treatment of synthetic and real fishery wastewaters

Background, aim, and scope  

Fishery wastewater treatment can be compromised due to seasonal production. The use of sequencing batch reactors is not completely successful, despite flexibility being one of the principal advantages. Most research on activated sludge is performed using synthetic wastewater to ensure a stable and constant feed. The current work compared biomass morphology and settling ability using image analysis of synthetic and real fishery wastewaters, with and without NaCl addition.     

Influence of soluble microbial products (SMP) on wastewater disinfection byproducts: trihalomethanes and haloacetic acid species from the chlorination of SMP

Introduction  

Effluent organic matter from biological wastewater treatment plants is composed of degradation products and soluble microbial products (SMP). Protein, polysaccharide, humic acid, and DNA were major biomolecules of SMP. Little is known about the effects of SMP as microbially derived precursors on disinfection byproduct formation and speciation in biologically treated wastewater. In addition, there has never been any attempt to directly chlorinate the major biomolecules of SMP.     

Structural elucidation of main ozonation products of the artificial sweeteners cyclamate and acesulfame

Purpose  

The two artificial sweeteners cyclamate (CYC) and acesulfame (ACE) have been detected in wastewater and drinking water treatment plants. As in both facilities ozonation might be applied, it is important to find out if undesired oxidation products (OPs) are formed.     

Application of central composite face-centered design and response surface methodology for the optimization of electro-Fenton decolorization of Azure B dye

Purpose

The aim of this work was to improve the ability of electro-Fenton technique for the remediation of wastewater contaminated with synthetic dyes using a model azo dye such as Azure B.

Methods

Batch experiments were conducted to study the effects of main parameters, such as dye concentration, electrode surface area, treatment time, and voltage. In this study, central composite face-centered experimental design matrix and response surface methodology were applied to design the experiments and evaluate the interactive effects of the four studied parameters. A total of 30 experimental runs were set, and the kinetic data were analyzed using first- and second-order models.

Results

The experimental data fitted to the empirical second-order model of a suitable degree for the maximum decolorization of Azure B by electro-Fenton treatment. ANOVA analysis showed high coefficient of determination value (R ²?=?0.9835) and reasonable second-order regression prediction. Pareto analysis suggests that the variables, time, and voltage produce the largest effect on the decolorization rate.

Conclusion

Optimum conditions suggested by the second-order polynomial regression model for attaining maximum decolorization were dye concentration 4.83?mg/L, electrode surface area 15?cm², voltage 14.19?V, and treatment time of 34.58?min.     

Winter accumulation of acidic pharmaceuticals in a Swedish river

Purpose  

In this study, seasonal variations in the concentration profile of four analgesics and one lipid regulator were monitored on their way from a wastewater treatment plant (WWTP) effluent, along a river, and into a lake.     

Equilibrium, kinetic and thermodynamic studies on the biosorption of reactive acid dye on Enteromorpha flexuosa and Gracilaria corticata

Purpose

Biosorption is an emerging, eco-friendly and economical method for treating the wastewater effluents. Compared to many other biological materials, algae biomass proved to be the better biosorbent due to the presence of cell wall polymers in them.

Methods

Algal biomasses namely Enteromorpha flexuosa and Gracilaria corticata were dried, crushed and used as biosorbents. Ponceau S, a diazo dye was used as a model adsorbate for the biosorption studies. The biosorbents were characterized by Scanning Electron Microscopy, FT-IR and zero point charge. Batch studies were performed by varying pH, biosorbent dosage and initial dye concentrations. Adsorption isotherms, kinetic and thermodynamic analyses were carried out. The effect of electrolytes was also studied. Batch desorption studies were also carried out using various reagents.

Results

Isotherm data were tested with Langmuir and Freundlich isotherm models and the results suggested that the Freundlich isotherm fitted the data well. Kinetic studies were performed with varying initial dye concentrations and the data were incorporated with pseudo first-order and pseudo second-order kinetic equations and was found that the studied biosorption processes followed pseudo second-order kinetic equation. Thermodynamic parameters were evaluated at three different temperatures 293?K, 300?K and 313?K. About 95% of the dye could be desorbed from both the biosorbents.

Conclusion

Both the algal biomasses had heterogeneous surfaces and followed pseudo second-order chemical kinetics. Thermodynamic parameters proved that the biosorption by both the biomasses were spontaneous, feasible and endothermic processes. Desorption studies proved the worth of the algal biomasses as biosorbents in industrial level.     

Influence of operational parameters (sludge retention time and hydraulic residence time) on the removal of estrogens by membrane bioreactor

Introduction  

This paper deals with the removal of two natural estrogens, estrone (E1) and 17β-estradiol (E2) and a synthetic one 17α ethinylestradiol (EE2) from wastewater in a laboratory-scale membrane bioreactor (MBR).     

Whole effluent assessment of industrial wastewater for determination of BAT compliance. Part 2: metal surface treatment industry

Background, aim and scope  

Toxicity testing has become a suitable tool for wastewater evaluation included in several reference documents on best available techniques of the Integrated Pollution Prevention and Control (IPPC) Directive. The IPPC Directive requires that for direct dischargers as well as for indirect dischargers, the same best available techniques should be applied. Within the study, the whole effluent assessment approach of OSPAR has been applied for determining persistent toxicity of indirectly discharged wastewater from the metal surface treatment industry.     

Enhanced degradation of azo dye alizarin yellow R in a combined process of iron–carbon microelectrolysis and aerobic bio-contact oxidation

Purpose

With the aim of enhanced degradation of azo dye alizarin yellow R (AY) and further removal of the low-strength recalcitrant matter (LsRM) of the secondary effluent as much as possible, our research focused on the combination of aerobic bio-contact oxidation (ABO) with iron/carbon microelectrolysis (ICME) process.

Materials and methods

The combined ABO (with effective volume of 2.4?l) and ICME (with effectively volume of 0.4?l) process were studied with relatively short hydraulic retention time (HRT) of 4 or 6?h.

Results

At the HRT of 6?h with the reflux ratio of 1 and 2, the AY degradation efficiency in the final effluent was >96.5%, and the total organic carbon (TOC) removal efficiency were 69.86% and 79.44%, respectively. At the HRT of 4?h and the reflux ratio of 2, TOC removal efficiency and AY degradation efficiency were 73.94% and 94.89%, respectively. The ICME process obviously enhanced the total AY removal and the generated micromolecule acids and aldehydes then that wastewater backflow to the ABO where they were further biodegraded.

Conclusion

The present research might provide the potential options for the advanced treatment azo dyes wastewater with short HRT and acceptable running costs.