Sustainable treatment of textile wastewater

The reduced natural waters and the large amount of wastewater produced by textile industry necessitate an effective water reuse treatment. In this study, a combined two-stage water reuse treatment was established to enhance the quality and recovery rate of reused water. The primary treatment incorporated a flocculation and sedimentation system, two sand filtration units, an ozonation unit, an ultrafiltration (UF) system, and a reverse osmosis (RO) system. The second treatment included an ozonation unit, a sand filtration unit, and UF and RO systems. The color removal rate increased with the increasing ozone dosage, and the relational expression between the ozone dosage and color removal rate was fitted. Ozonation greatly reduced the color by 92.59 and 97.27 times during the primary and second ozonation stages, respectively. RO had the highest removal rate. The combined processes showed good performance in water reuse treatment.

An effluent treatment technique adapted to the dyes must eliminate them completely in order to avoid the formation of more dangerous by-products than the initial compounds and more particularly to prevent the formation of carcinogenic products. Conventional methods of treatment do not meet this expectation.

The objective of this study is the development of a new biological approach which is more suitable in terms of cost-effectiveness, pollutant removal efficiency, and recyclability and inexpensive, effective, and eco-friendly (biodegradable) for the treatment of effluents of the textile industry. To our knowledge, this is the first report on the textile effluent treatments using peptides. This technology will be based on the best binding affinity of textile dyes on peptides synthesized via a solid-phase peptide synthesis (SPPS) technique.

The objective of this study was development of a new biological method for the treatment of textile industry effluents, which is cheaper, more profitable, and eco-friendly. This method is essentially based on the synthesis of dye-fixing peptides. The use of peptides synthesized via a solid-phase synthesis to fix a reference textile dye like “Cibacron blue” (CB) and the performance analysis of binding assays were the main objectives of this study. For this reason, two peptides P1 (NH2-C-G-G-W-R-S-Q-N-Q-G-NH2) and P2 (NH2-C-G-G-R-R-Y-Q-P-D-S-NH2) binding with the CB dye were synthesized by the solid-phase peptide synthesis (SPPS) technique. The obtained results showed significant fixation yields of CB-peptides of 91.5% and 45.9%, respectively, and consequently, their interesting potential as a tool for a new biochemical method in the pollution prevention of textile wastewater.

Environmental  management  projects  require  economic  integrated  approach  including  the  combination  of  in–process, in–plant and end–of–pipe treatment modules to comply with environmental regulations.

The main objectives of this study to management and control of liquid and solid wastes in the industry as well as find a sustainable solution for the textile industrial wastewater in order to comply with the National Regulatory Standards governed by the ministerial decree for wastewater discharge into public sewage network to protect the environment as well as selecting the wastewater streams that need to be treated prior to its discharge, identifying  the  different  possible  treatment  trains  for  the  wastewater,  conducting  treatability  analysis  for investigating  the  feasibility  of  each  of  the  identified  trains,  selecting  the  most  suitable  treatment  train,  and developing  the  basic  design  for  the  selected  treatment  train.

The  study  is  conducted  through  very  precise characterization of the wastewater produced from the final effluent during the working shifts and application of appropriate  treatment  options  for  the  end-of-pipe  using  different  treatment  techniques  in  order  to  protect water resources from contamination.

The study investigates the performance of chitosan and microorganism towards treatment of textile wastewater by using aeration & flocculation process. Chitosan is found from chitin by deacetylation. Flocculation and the process are done using Jar test experiment. The effect of dosage, reduction of COD, reduction of BOD and color of textile wastewater is studied. The results obtained found that chitosan is very effective for reduction of COD, BOD and color.

This article presents a new approach, which is an intersection of advanced primary and secondary water treatment solutions, to meet challenge of to meet the challenges faced by the textile industry.

Electrocoagulation is one of the emerging water treatment solutions capable of handling the varying wastewater characteristics of textile industry effluent. This advanced technology utilizes the advantages and functions of conventional flotation, coagulation, and electrochemistry in water and wastewater treatment to optimize contaminant removal in an environmentally sustainable and cost efficient way.Electrocoagulation is one of the emerging water treatment solutions capable of handling the varying wastewater characteristics of textile industry effluent. This advanced technology utilizes the advantages and functions of conventional flotation, coagulation, and electrochemistry in water and wastewater treatment to optimize contaminant removal in an environmentally sustainable and cost efficient way.

This specialized solution provides companies with new and existing wastewater treatment systems the opportunity to optimize their current treatment process, adding dependability, reducing operating & maintenance cost, sludge disposal costs, and the mitigation of environmental concerns relating to toxic non biodegradable solids sludge disposal.

Advanced electrocoagulation water treatment solutions can provide value in several aspects of the textile wastewater treatment process. These aspects include primary pretreatment to remove/reduce non biodegradable, toxic compounds and color prior to a biological process or as a polishing pretreatment for specific contaminants such as colloidal organics, minerals, or microbiological contaminants prior to ultrafiltration (UF) or reverse osmosis desalination (RO) systems.

The german textile industry is challenged by the introduction of new governmental regulations in the field of textile wastewater management. This causes a large cost for water compared to other European countries. Even some economic experts see Germany seriously endangered as a place of textile productions, however there are opportunities with the development of high performance clean tecnologies as a result of government regulations. In particular the required separate treatment of selected wastewater of different finishing processes has some good perspectives since specialized wastewater techniques can be applied efficiently.

Ozonation being sludge-free method to decompose dyestuff, finishing products, and other organic materials is of increasing imporatnce because of the limited space of disposal of sludges. Other advantage of ozone treatment are the improvement of biodegrability, reduction of aromatic and halogenated compunds and also significant decrease of chemical oxygen demand. The ozonation of textile wastewaters in combination with inexpensive biological processes has a major role to play in the future. Partial replacement of coagulation/percipitation can be expected.

The textile wastewaters (TWWs) are one of the major sources of environmental pollution, due to the presence of various recalcitrant dyes. It is estimated that about 300,000 t of synthetic dyes are discharged in TWWs every year worldwide. Thus, untreated or incompletely treated TWWs cause harm to aquatic and terrestrial life. To avoid the negative impacts associated to the discharge of TWWs into the natural ecosystems, effective dye remediation processes are being developed.

Current methods of removing dyes from TWWs are generally regarded to be complex, expensive and energy demanding processes. Therefore, bioremediation of TWWs using microbial consortia has appeared as an emerging alternative for textile dyes removal. This chapter provides an updated literature on the application of microbial consortia in the treatment of TWWs, focusing on the mechanisms involved in dye biodegradation and the main interactions established between the consortia members and their influence on dye removal efficiencies.

The aim of this article is to demonstrate the technical and economic feasibility of an integrated process for microbial treatment of dye(s) containing wastewater from textile effluent that evaluates the efficiency and effectiveness to meet the dye(s)’ maximum contaminant level. It covers the whole process of microbial treatment methods that are adopted for dye removal to make an eco-friendly system. The purpose of this treatment technology includes process modifications and engineering approaches. It comprises existing technologies with new advanced technologies at all stages of the process.

Apart from evaluating the reliability of technologies for small and large systems to make the system cost-effective, it also demonstrates the potential of genetically engineered microorganisms for their dye removing potential and feasible economics. 

In the early 1960’s, the Japanese company Nihon Chlorella was the first to make microalgae commercially available. Since then, the microalgae cultivation at industrial scale has grown and diversified significantly. Among the microalgae applications, bioremediation of textile wastewater is one the most promising technologies due to the simultaneous benefits: microalgae cultivation using textile wastewater as culture medium (bioremediation and CO2 mitigation) followed by microalgae lipid application (biodiesel production). Therefore, the aim of this work is to explore the potential business opportunities in using microalgae for bioremediation and wastewater treatment.

The study concludes that compared to physicochemical methods (ozonation, electrochemical destruction, activated carbon), biological methods (bioremediation using microalgae) show advantages in terms of cost effectiveness, easy scale up and mainly the potential to simultaneously carried out the bioremediation, CO2 mitigation and biosynthesize high-added value molecules. In addition, there is no consensus on the best microalgae cultivation system.

Microalgal biodiesel has emerged as an environment friendly alternative to the existing fossil fuels. The commercial production of this biodiesel is still challenging due to several technical and economic issues, which span from mass cultivation of microalgae to the biodiesel production. Mass cultivation is the most critical step in terms of water and nutrient requirement. Industrial wastewater such as textile wastewater (TWW) is a cheap source for water, which additionally contains necessary nutrients (phosphate, nitrates, micronutrients etc.) and organic dyes (potential carbon source) for algae cultivation. The application of microalgae for biodiesel production employing a single objective strategy is not sustainable.

Microalgae can be effectively employed to bioremediate TWW (dyes and nutrients removal) and to produce biodiesel from grown microalgae. This process integration (bioremediation-biodiesel production) can potentially improve biodiesel production and wastewater treatment. However, this process coupling needs to be thoroughly investigated to identify and optimize critical process factors (algal species, cultivation and harvesting methods, bioremediation mechanism etc.).

This study has reviewed the status of TWW as potential source of water and nutrients, role of different algal species in the bioremediation of TWW, different cultivation systems, harvesting and biodiesel production methods. It also suggests future research and development challenges for coupled textile wastewater treatment and microalgal biodiesel production.

In textile reactive dyeing, dyed fabrics have to be rinsed in the wash-off step several times to improve color fastness. Thus, the multiple rinsing processes drastically increase the freshwater consumption and also generate massive waste rinsing effluents. This paper addresses an innovative alternative to recycle the waste effluents to minimize freshwater consumption in the wash-off step. Accordingly, catalytic ozonation with a highly effective catalyst has been applied to remedy the waste rinsing effluents for recycling.

The carbon aerogel (CA) hosted bimetallic hybrid material was fabricated and used as the catalyst in the degradation of residual dyes in the waste rinsing effluents by ozonation treatments. The results indicate the participation of the catalyst significantly enhanced the removal percentage of chemical oxidation demand by 30%. In addition, it has been validated that waste effluents had been successfully reclaimed after catalytic ozonation. They could be additionally reused to reduce freshwater consumption in the wash-off step, but without sacrificing the color quality of corresponding fabrics in terms of color difference and colorfastness.

This study may be the first to report the feasibility of catalytic ozonation in minimization of freshwater consumption in the wash-off step in textile reactive dyeing

Textile industries use large amounts of water in the processes of dyeing and processing of textile fibers, generating high volumes of wastewater containing dyes, surfactants, inorganic ions, wetting agents, among others. The main environmental impact of these effluents is related to the absorption of light into the water, which interferes with the photosynthesis of plants and algae. Therefore, it is relevant to have environmental planning aimed at the reuse of the water, increased removal of dyes, as well as reducing losses in the dyeing.

In this work, studies were undertaken to propose control measures so as to introduce the concepts of Cleaner Production (CP) in the textile sector. Data was collected in a company located in the catchment area of the river Doce, in Minas Gerais, and established the association of the relative advantages of conventional coagulation/flocculation with the combined use of Advanced Oxidation Processes (AOP). The proposed measures entail a decrease in the volume and characteristics of the refractory sludge generated and the possibility of recirculation of treated effluent. The need to develop pilot-scale experiments was identified, including monitoring of the acute toxicity of treated effluents.

This study evaluates the feasibility of water minimization and wastewater reuse for a wool finishing textile mill. The evaluation process is based upon a detailed analysis on water use, process profile and wastewater characterization, indicating a potential for 34% reduction in water consumption and for 23% of wastewater recovery for reuse.

Wastewater reuse requires treatment and results in a remaining wastewater stream with stronger characteristics and consequently more costly to treat. The feasibility includes technical considerations for appropriate treatment alternatives and related cost factors for water consumption, treatment for reuse and for discharge either to sewer or to receiving media.

This article makes an attempt to review the various waste minimisation techniques and possibilities that are available for the textile industry. The strategies and technologies discussed apply to all types of wastes such as hazardous materials, non-hazardous materials, water, energy, raw materials, all waste emissions, and other resources.

Some of the prominent techniques discussed include source reduction of waste, reducing water and chemical consumption, energy conservation, solid waste generation minimization and more.

US-based SeaChange Technologies has put a new spin on the clean-up of textile effluent from dyeing and finishing with a new way to treat wastewater and sludge using vortex separation in a one-step process.Funded by Fashion for Good, the North Carolina start-up has recently completed a 3- month pilot-scale trial with Indian textile giant Arvind using its patented cyclonic separation technique to clean wastewater streams and highly concentrated sludge to reduce both chemical discharge and overall greenhouse gas emissions in the dyeing process.

One of the textile industries in Penang, Malaysia is experiencing high  concentration  of  COD  and  colour  in  the  final  effluent  after  biological  treatment  exceeding  the  standard  discharge  limit.  The  purpose  of  the  present  study was to investigate the suitability of using activated carbon (AC), limestone (LS)  and  mixture  of  both  (LS:AC)  as  low  cost  media  for  the  post-treatment  of  treated  effluent.  The  physico-chemical  treatment  adopted  in  this  study  is  preferred  over  the  other  methods  because  of  its  simplicity,  easy  maintenance  and  quality  control.  The result showed that limestone  and  activated  carbon  mixture  provides alternative medium for removing COD and colour at a much lower cost as compared with activated carbon.

This work involved the treatment of industrial wastewater from a nylon carpet printing plant which currently receives no treatment and is discharged to sea. As nylon is particularly difficult to dye, acid dyes are required for successful coloration and cause major problems with the plant's effluent disposal in terms of color removal. Granular activated carbon Filtrasorb 400 was used to treat a ternary solution of acid dyes and the process plant effluent containing the dyes in a fixed-bed column system.

Presented in this paper is a low-carbon assessment for wastewater treatment by a constructed wetland as ecological engineering. Systems accounting by combining process and input–output analyses is applied to track both direct and indirect GHG emissions associated with the wastewater treatment. Based on the detailed assessment procedures and the embodied GHG emission intensity database for the Chinese economy in 2007, the GHG emissions embodied in both the construction and operation stages of a pilot constructed wetland in Beijing are investigated in detail, with parallel calculations carried out for a cyclic activated sludge plant as a typical conventional wastewater treatment system for comparison.

With the overall embodied GHG emissions taken into account, the constructed wetland is shown to be remarkably less carbon intensive than the conventional wastewater treatment system, and the contrast in GHG emission structure is also revealed and characterized. According to the results, the ecological engineering of the constructed wetland is considered to be favorable for achieving the low-carbon goal.