Pilot study of cold-rolling wastewater treatment using single-stage anaerobic fluidized membrane bioreactor

Applications of submerged and staged membrane systems for pollutant removal from effluents and mechanism studies - a review

Membrane based filtration is one of the promising technologies for rehabilitation of wastewater streams for reuse and recycle. Many advancements have emerged with the use of novel materials and innovative integrated technologies. The present investigation focuses on the treatment methods based on submerged and stages systems of membranes for water purification. Ceramic, polymeric and mixed matrix type of membranes fabricated for specific type of effluents, their modification methods for accelerating the rejection efficiency, permeability, durability, stability and antifouling properties are detailed in this review. Graphene oxide is the most considered membrane material for adsorption purposes as it exhibits larger surface area, abundant functional groups contain oxygen and has good supply of ligands which is responsible in metal adsorption as it enhances electrostatic interaction by bonding metal ions with graphene oxide nanosheets. Energy derivation in terms of biogas production was also reported in some integrated methods. In many cases, embedded nanomaterial matrices yielded maximum efficiencies in both the submerged and staged operations. However, submerged type of membranes are reported more than the staged type due to simpler configuration with relatively lesser equipment, operational and maintenance issues. In treatment of a low strength wastewater, aluminum oxide based membrane in fluidized bed assembly was reported to yield promising results with reduced power requirement.

The dosage-effect of biochar on anaerobic digestion under the suppression of oily sludge: Performance variation, microbial community succession and potential detoxification mechanisms

This study investigated the dosage-effect of biochar on the suppressed mesophilic digestion of oily sludge (OS) containing naphthalene (recalcitrant compound) and starch (easily bioavailable substrate). Methanogenesis was inhibited in control with OS, where biomethane yield (63.33 mL/gVS) was obviously lower than theoretical yield (260.55 mL/gVS). With adding optimal dose of biochar (0.60 g/gVS OS), the highest CH₄ yield (138.41 mL/gVS) was 2.19 times of control. Meanwhile, the efficiencies of hydrolysis, acidogenesis and acetogenesis were significantly enhanced. However, excessive biochar (4.80 g/gVS OS) caused negative effects with methanogenic efficiency diminished by 32.5% and lag phase prolonged by 5.72 h. Dissolved organic matter (DOM) analysis showed that humic acid-like and fulvic acid-like components percentages of fluorescence regional integration were decreased because of the adsorption of biochar. In addition, biochar mediating interspecies electron transfer selectively enriched electroactive fermentation bacteria (Clostridium and Bacteroides) and acetoclastic Methanosaeta, which was responsible for promoting mesophilic digestion performance. The functional genes related to metabolism and environmental information processing were potentially activated by biochar. Above results indicate that moderate biochar application may mitigate the bio-toxicity suppression of OS, which help to provide a promising pathway for reinforcing oily wastes bio-treatment.

A comprehensive review on application of bioreactor for industrial wastewater treatment

In the recent past, wastewater treatment processes performed a pivotal role in accordance with maintaining the sustainable environment and health of mankind at a proper hygiene level. It has been proved indispensable by government regulations throughout the world on account of the importance of preserving freshwater bodies. Human activities, predominantly from industrial sectors, generate an immeasurable amount of industrial wastewater loaded with toxic chemicals, which not only cause dreadful environmental problems, but also leave harmful impacts on public health. Hence, industrial wastewater effluent must be treated before being released into the environment to restrain the problems related to industrial wastewater discharged to the environment. Nowadays, biological wastewater treatment methods have been considered an excellent approach for industrial wastewater treatment process because of their cost-effectiveness in the treatment, high efficiency and their potential to counteract the drawbacks of conventional wastewater treatment methods. Recently, the treatment of industrial effluent through bioreactor has been proved as one of the best methods from the presently available methods. Reactors are the principal part of any biotechnology-based method for microbial or enzymatic biodegradation, biotransformation and bioremediation. This review aims to explore and compile the assessment of the most appropriate reactors such as packed bed reactor, membrane bioreactor, rotating biological contactor, up-flow anaerobic sludge blanket reactor, photobioreactor, biological fluidized bed reactor and continuous stirred tank bioreactor that are extensively used for distinct industrial wastewater treatment.

Membrane processes

This literature review provides a review for publications in 2018 and 2019 and includes information membrane processes findings for municipal and industrial applications. This review is a subsection of the annual Water Environment Federation literature review for Treatment Systems section. The following topics are covered in this literature review: industrial wastewater and membrane. Bioreactor (MBR) configuration, membrane fouling, design, reuse, nutrient removal, operation, anaerobic membrane systems, microconstituents removal, membrane technology advances, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include the following: Biological Fixed-Film Systems, Activated Sludge, and Other Aerobic Suspended Culture Processes, Anaerobic Processes, and Water Reclamation and Reuse. This publication might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants.

Perylene pigment wastewater treatment by fenton-enhanced biological process

Polycyclic aromatic hydrocarbons (PAHs) are regarded as priority pollutants owing to their toxic, mutagenic and carcinogenic characteristics. Perylene is a kind of 5-ring PAH with biological toxicity, and classified as a class III carcinogen by the World Health Organization (WHO). Nowadays, some of its derivatives are often used as industrial pigments. Hence, urgent attention is highly needed to develop new and improved techniques for PAHs and their derivatives removal from the environment. In this study, Fenton oxidation process was hybridized with the biological (anaerobic and aerobic) treatments for the removal of perylene pigment from wastewater. The experiments were carried out by setting Fenton treatment system before and between the biological treatments. The biological results showed that COD removal efficiency reached 60% during 24 h HRT with an effluent COD concentration of 1567.78 mg/L. After the HRT increased to 48 h, the COD removal efficiency was slightly increased (67.9%). However, after combining Fenton treatment with biological treatment (Anaerobic-Fenton-Aerobic), the results revealed over 85% COD removal efficiency and the effluent concentration less than 600 mg/L which was selected as the better treatment configuration for the biological and chemical combined system. The microbial community analysis of activated sludge was carried out with high-throughput Illumina sequencing platform and results showed that Pseudomonas, Citrobacter and Methylocapsa were found to be the dominant genera detected in aerobic and anaerobic reactors. These dominant bacteria depicted that the community composition of the reactors for treating perylene pigments wastewater were similar to that of the soil contaminated by PAHs and the activated sludge from treating PAHs wastewater. Economic analysis results revealed that the reagent cost was relatively cheap, amounting to 10.64 yuan per kilogram COD. This study vividly demonstrated that combining Fenton treatment with biological treatment was efficient and cost-effective.

Recent advancement on biological technologies and strategies for resource recovery from swine wastewater

Swine wastewater is categorized as one of the agricultural wastewater with high contents of organics and nutrients including nitrogen and phosphorus, which may lead to eutrophication in the environment. Insufficient technologies to remove those nutrients could lead to environmental problems after discharge. Several physical and chemical methods have been applied to treat the swine wastewater, but biological treatments are considered as the promising methods due to the cost effectiveness and performance efficiency along with the production of valuable products and bioenergies. This review summarizes the characteristics of swine wastewaters in the beginning, and briefly describes the current issues on the treatments of swine wastewaters. Several biological techniques, such as anaerobic digestion, A/O process, microbial fuel cells, and microalgae cultivations, and their future aspects will be addressed. Finally, the potentials to reutilize biomass produced during the treatment processes are also presented under the consideration of circular economy.

Biological treatment of DMSO-containing wastewater from semiconductor industry under aerobic and methanogenic conditions

This study evaluated biological treatment of dimethyl sulfoxide (DMSO)-containing wastewater from semiconductor industry under aerobic and anaerobic conditions. DMSO concentration as higher as 1.5 g/L did not inhibit DMSO degradation efficiency in aerobic membrane bioreactor (MBR), while specific DMSO degradation rate at different initial DMSO-to-biomass (S₀/X₀) ratios from batch tests seemed to follow the Haldane-type kinetics. According to the microbial community analysis, Proteobacteria decreased from 88.2% to 26% as influent DMSO concentration increased, while Bacteroidetes, Parcubacteria, Saccharibacteria increased. Within the Bacteroidetes class, Flavobacterium and Laribacter genus significantly increased from less than 0.05%-26.8% and 13.4%, respectively, which might both be related to the DMS degradation. Hyphomicrobium and Thiobacillus, known as aerobic DMSO and DMS degraders, instead, decreased at higher DMSO conditions. Under methanogenic conditions, batch results implied DMSO concentrations higher than 3 g/L could be inhibitory, while DMSO and COD removal achieved 100% and 93%, respectively, using a pilot-scale anaerobic fluidized bed membrane bioreactor (AFMBR) with influent DMSO below 1.5 g/L. Results of terminal restriction fragment length polymorphism (TRFLP) analysis targeting on mcrA functional gene revealed that Methanomethylovorans sp. was dominant in AFMBR after 54 days of operation, indicating its importance on degrading DMS and mathanethiol (MT).