A critical review on advances in the practices and perspectives for the treatment of dye industry wastewater

New batch electro-coagulation process for treatment and recovery of high organic load and low volume egg processing industry wastewater

This study systematically reviews greenhouse gas (GHG) emissions reduction strategies in wastewater treatment industry from a system engineering perspective. It highlights the lack of comprehensive assessments across the wastewater treatment industry, incorporating both wastewater treatment plants (WWTPs) and sludge management, to understand the full GHG emissions landscape. Suitable processes and technologies for GHG control have been identified, which emphasizes the importance of on-site N2O emission control, operational efficiency, energy source shifts, and increased sludge incineration. Through life cycle assessment (LCA) evaluation, plant-wide models exhibited the best performance of GHG emission control from operational stages, while technologies recovering energy from both wastewater and sludge can greatly mitigate 25–100 % GHG emissions. The paper also suggests hydrothermal processes, especially wet oxidation as preferable to avoid GHG emissions from sludge management, urging future research toward multi-technology integration and collaborative management strategies for effective GHG mitigation.

The wastewater treatment industry is an energy-intensive industry and one of the main sources of high warming potential greenhouse gases （GHG） such as CH4 and N2O. The GHG reduction in this industry is an important part of achieving global climate goals. In 2019, there were 4 359 urban wastewater treatment plants in China, with a total wastewater treatment volume of 63.26 billion m3, ranking first in scale worldwide. From 2009 to 2019, the energy consumption, GHG emissions, and GHG emissions intensity of wastewater treatment in China increased by 161.78%, 193.55%, and 41.54%, respectively. Faced with the new situation, new tasks, and new requirements of the collaborative promotion of carbon reduction, pollution reduction, green expansion, and growth, water pollutant reduction needs to be coordinated with GHG reduction. To this end, the sources and trends of energy consumption and GHG emissions in the wastewater treatment industry were identified, and the situation and challenges to GHG reduction in this industry were analyzed. The results indicated that the wastewater treatment industry in China has been facing problems such as a lack of carbon emission-related standards, insufficient energy self-sufficient technology reserves, lack of coordination between wastewater treatment levels and carbon emissions control, and inadequate infrastructure and operation and maintenance management. Based on this, it is necessary to accelerate the top-level design of GHG reduction in the wastewater treatment industry； strengthen the research and development, verification, demonstration, and integrated application of disruptive technologies； expand the natural-based solution as a technological supplement； innovate refined management in the wastewater treatment industry； and ultimately promote the reconstruction of the wastewater treatment industry.

Trends in dye industry effluent treatment and recovery of value added products

Removal of metals from wastewaters by mineral and biomass-based sorbents applied in continuous-flow continuous stirred tank reactors followed by sedimentation

Nowadays, the extraction of textile dyes from the wastewater in industry becomes an environmental worldwide issue. Water contamination is a big threat of not only for state of the environment but human body causes some chronic diseases. Textile dyes are worn to several types of products by fabrication, for paper, leather, plastic and some products, used in human daily life. Despite of containing various hazardous chemicals into textile dyes, it is necessary to be discharged from effluents of waste-water of industry through treatment as quick as possible. A number of technologies of different processes are effectively carried out for the treatment of industrial waste water by removal of colors. A variety of textile dyes is having different chemical structure with different properties dealing with the activity of industrial reaction. By reviewing of effects of textile dyes such as toxicity and mutagenicity, bacteria and organism embedded a prologue of the expulsion of metals to the environment. Certainly, for the dominion of textile dyes removal, adsorption can be regarded as effective method used by activated carbon, bentonite clay as adsorbent for the wastewater treatment in industry. Predominantly, it is a critical review of literature conferred the removal of textile dyes for the treatment of industrial wastewater by using techniques, technologies, adsorbents thoroughly. Certainly, Adsorption is the sole and ultimate approach for removal of textile dyes through the industrial wastewater treatment. This literature shows the feasibility of minimum cost adsorbent in term of maximum outcome of industrial wastewater treatment for textile dyes removal.

Petroleum industry is one of the fastest growing industries, and it significantly contributes to economic growth in developing countries like India. The wastewater from a petroleum industry consist a wide variety of pollutants like petroleum hydrocarbons, mercaptans, oil and grease, phenol, ammonia, sulfide, and other organic compounds. All these compounds are present as very complex form in discharged water of petroleum industry, which are harmful for environment directly or indirectly. Some of the techniques used to treat oily waste/wastewater are membrane technology, photocatalytic degradation, advanced oxidation process, electrochemical catalysis, etc. In this review paper, we aim to discuss past and present scenario of using various treatment technologies for treatment of petroleum industry waste/wastewater. The treatment of petroleum industry wastewater involves physical, chemical, and biological processes. This review also provides scientific literature on knowledge gaps and future research directions to evaluate the effect(s) of various treatment technologies available.

The roles of bacteria in resource recovery, wastewater treatment and carbon fixation by microalgae-bacteria consortia: A critical review

Biological treatment of industrial waste is a widely practiced technique that generates comparatively less environmentally hazardous waste than other chemical treatment processes. Wet milling of maize generates huge amount of wastewater (5 m3/ton) of low pH with organic matter and nutrients. Anaerobic methanogenic and aerobic bacteria are mostly highly sensitive to low pH. The treatment of wastewater causes huge cost of chemical neutralization or hydraulic recirculation for maintaining neutral pH. In the present study, different microbial consortia isolated from cow dung, active sludge from an anaerobic reactor for treatment of industrial wastewater, and leaf debris from benthic soil were screened for tolerance against low pH and for potential of chemical oxygen demand (COD) removal in order to find out an alternative microbial population for industrial water treatment at low pH. The most effective consortia found from leaf debris were further investigated for optimal operation. The microscopic analysis of leaf debris sludge showed abundance of Gram‐negative methanococci, which was found tolerant to low pH in plate culture method. On further investigation for COD removal from starch industry effluent, they were found to be most effective at pH 5 with highest COD removal rate of 70% and lowest biomass generation of 81%. Hence, it was concluded that the low pH‐tolerant methanogen bacteria, enriched from leaf debris sludge, is highly beneficial for anaerobic treatment of wastewater from several industries including corn starch industry by reducing cost of operation for neutralization to neutral pH and through reducing excess waste sludge production by the treatment system.

Cationic tamarind kernel polysaccharide (Cat TKP): A novel polymeric flocculant for the treatment of textile industry wastewater

This current issue covers the use of green adsorbents, green solvents, or any green processes and technologies for the purification of drinking water and wastewater. It addresses the research and innovations, as well as the engineering and management practices, for water purification and resource restoration and recovery, thus inspiring the new generation in respect to wastewater treatment and its management through green and sustainable methods.

Planning the centralization level in wastewater collection and treatment: A review of assessment methods

Biosolids (BS) are organic dry matter produced from wastewater treatment plants (WWTPs). The current yearly worldwide production of BS is estimated to be around 100–125 million tons and is expected to continuously increase to around 150–200 million tons by 2025. Wastewater treatment industries across the globe strive to achieve a green and sustainable manufacturing base for the management of enormous amounts of municipal BS, which are rich in nutrients and organic dry matter along with contaminants. The management of these organic-rich wastes through environmentally friendly recovery technologies is a major challenge. The need to improve waste biomass disposal by biological development and develop more economically viable processes has led to a focus on the transformation of waste resources into value-added products (VAP). This paper assesses the leading disposal methods (based on volume and contaminant reduction) and reviews the state of biotechnological processes for VAP recovery from municipal wastewater sludge (untreated solid waste residual) and BS (stabilized solid waste which meets criteria for its use in land). A review of the anaerobic and aerobic digestion processes is presented to provide a holistic overview of this growing research field. Furthermore, the paper also sheds light on the pollutant reduction and resource recovery approaches for enzymes, bioflocculants, bioplastics, biopesticides, and biogas as a mean to represent BS as a potential opportunity for WWTPs. However, only a few technologies have been implemented for VAP resource recovery and a shift from WWTPs to waste resource recovery facilities is still far from being achieved.

The substantial volume of wastewater generated by the leather industry, laden with high levels of pollutants, poses a significant environmental threat. Without proper treatment, the discharge of such wastewater could have severe and detrimental effects on the environment. The treatment of wastewater in the leather industry is pivotal for mitigating environmental impacts and represents a cornerstone of sustainable environmental management. The industry not only minimizes its environmental impact but also aligns with and contributes to various sustainable development goals (SDGs). The industry’s commitment to responsible practices is demonstrated by employing diverse methods such as BOD, chlorides, COD, Cr (III), heavy metals, sulfates, and TDS. This includes adsorption, biochemical/biological treatment, chemical precipitation, Electro-coagulation, Fenton oxidation, hybrid processes, ozonation, electro-oxidation, photo-catalytic ozonation, and physical treatment. Moreover, a sustainable approach involves the recovery of valuable substances from the treated wastewater. The solid waste generated, particularly after chromium removal, contains minerals such as phosphorus (P) and potassium (K), which are categorized into 4R (reduce, reuse, recycle, and recover) dimensions. Integrating advanced wastewater treatment methods and resource recovery processes in the leather industry not only helps mitigate environmental impacts but also aligns with broader sustainability objectives, embodying a responsible and forward-thinking approach to wastewater management. Combining effective wastewater treatment in the leather industry is a cornerstone of sustainable environmental management. The emphasis on recovering valuable substances and repurposing solid waste underscores a holistic and responsible approach toward resource utilization. This comprehensive strategy indeed reflects a commitment to environmental stewardship and sustainability in the leather industry.

Revisiting China's domestic greenhouse gas emission from wastewater treatment: A quantitative process life-cycle assessment