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1.
Winery wastewater treatment: a critical overview of advanced biological processes.
Bolzonella, D, Papa, M, Da Ros, C, Anga Muthukumar, L, Rosso, D
Critical reviews in biotechnology. 2019;(4):489-507
Abstract
Wine production is one of the leading sectors of the food processing industry. The wine industry produces a large amount of wastewater characterized by a high strength in terms of organic pollution and large variability throughout the year. Most of the organic matter is soluble and easily biodegradable. On the other hand, nitrogen and phosphorous are lacking. The aerobic and anaerobic processes are largely applied for winery wastewater treatment because they can quickly react to changes in the organic loading. This review analyzes e applied biological systems, considering both aerobic and anaerobic processes, and different reactor configurations. The performances of different biological processes are evaluated in terms of operational conditions (organic loading rate and hydraulic retention time). Aerobic processes can guarantee chemical oxygen demand removal up to 98% for organic loading rates of some 1-2 kg of chemical oxygen demand m-3d-1 but requires good aeration systems to supply the required process oxygen. The management cost of these processes could be high considering the power density in the range 60-70 W m-3reactor and that nutrients should be added to support biomass growth. On the other hand, anaerobic processes are able to face high organic loads with low running costs, but COD removal is generally limited to 90%. Combination of the two treatment systems (anaerobic followed by aerobic) could reduce management costs and meet high discharge standards.
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2.
Bio-conversion of photosynthetic bacteria from non-toxic wastewater to realize wastewater treatment and bioresource recovery: A review.
Lu, H, Zhang, G, Zheng, Z, Meng, F, Du, T, He, S
Bioresource technology. 2019;:383-399
Abstract
Generating or recycling water and resources from wastewater other than just treating wastewater is one of the most popular trends worldwide. Photosynthetic bacteria (PSB) wastewater treatment and resource recovery technology is one of the most potential methods. PSBs are non-toxic and contain lots of value-added products that can be utilized in the agricultural and food industries. They are effective to degrade pollutants and synthesize useful biomass, thus realizing wastewater treatment, bioresource production, and eliminating waste sludge. If all the nutrients in wastewaters could be bio-converted by PSB, then pollutant reductions and economic benefits would be achieved. This review paper firstly describes and summarizes this technology, including PSBs classification, metabolism, and the market application. The feasibility, technical procedures, bioreactors, pollutant removal, and bioresource production are also summarized, compared and evaluated. Issues that concern the advantages and industrialization of this technologies at the plant scale are also discussed.
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3.
Advances in the technologies for studying consortia of bacteria and cyanobacteria/microalgae in wastewaters.
Perera, IA, Abinandan, S, Subashchandrabose, SR, Venkateswarlu, K, Naidu, R, Megharaj, M
Critical reviews in biotechnology. 2019;(5):709-731
Abstract
The excessive generation and discharge of wastewaters have been serious concerns worldwide in the recent past. From an environmental friendly perspective, bacteria, cyanobacteria and microalgae, and the consortia have been largely considered for biological treatment of wastewaters. For efficient use of bacteria‒cyanobacteria/microalgae consortia in wastewater treatment, detailed knowledge on their structure, behavior and interaction is essential. In this direction, specific analytical tools and techniques play a significant role in studying these consortia. This review presents a critical perspective on physical, biochemical and molecular techniques such as microscopy, flow cytometry with cell sorting, nanoSIMS and omics approaches used for systematic investigations of the structure and function, particularly nutrient removal potential of bacteria‒cyanobacteria/microalgae consortia. In particular, the use of specific molecular techniques of genomics, transcriptomics, proteomics metabolomics and genetic engineering to develop more stable consortia of bacteria and cyanobacteria/microalgae with their improved biotechnological capabilities in wastewater treatment has been highlighted.
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4.
Algae as a green technology for heavy metals removal from various wastewater.
Salama, ES, Roh, HS, Dev, S, Khan, MA, Abou-Shanab, RAI, Chang, SW, Jeon, BH
World journal of microbiology & biotechnology. 2019;(5):75
Abstract
Urbanization, industrialization, and natural earth processes have potentially increased the contamination of heavy metals (HMs) in water bodies. These HMs can accumulate in human beings through the consumption of contaminated water and food chains. Various clean-up technologies have been applied to sequester HMs, especially conventional methods including electrolytic technologies, ion exchange, precipitation, chemical extraction, hydrolysis, polymer micro-encapsulation, and leaching. However, most of these approaches are expensive for large-scale projects and require tedious control and constant monitoring, along with low efficiency for effective HMs removal. Algae offer an alternative, sustainable, and environmentally friendly HMs remediation approach. This review presents a state-of-the-art technology for potential use of algae as a low-cost biosorbent for the removal of HMs from wastewater. The mechanisms of HMs removal, including biosorption and bioaccumulation along with physical and chemical characterization of the algae are highlighted. The influence of abiotic factors on HMs removal and changes in algal biocomponents (including, carbohydrate, lipid, and protein) are discussed. Recent progresses made in the development of HMs-tolerant algal strains and the direction of future research toward the development of sustainable technology for advanced wastewater treatment and biomass production are covered.
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5.
Biological nitrogen removal from wastewater using sulphur-driven autotrophic denitrification.
Cui, YX, Biswal, BK, Guo, G, Deng, YF, Huang, H, Chen, GH, Wu, D
Applied microbiology and biotechnology. 2019;(15):6023-6039
Abstract
Biological denitrification process in mainstream wastewater treatment often needs dosing supplemental electrons, consequently adding a remarkable operating cost. Organic carbon compounds are nowadays the most intensively used electron sources in full-scale wastewater treatment, corresponding with the well-understood carbon-nitrogen biogeochemistry for heterotrophic denitrification process. In the twenty-first century, the low-carbon technology is on calling to reduce the carbon footprint and relieve climate changing threatens. Autotrophic denitrification is highly recommended for mainstream wastewater treatment. The reduced-sulphur compounds (such as sulphide, elemental sulphur, and thiosulphate) could be utilised as electron donors, to drive sulphur cycle reactions to reduce nitrate and nitrite to dinitrogen gas. Based on the literature review and our own research experiences, this paper presents our perspectives on sulphur-driven autotrophic denitrification. It particularly focuses on the functional enzymes, sulphur bioreactors, and influential operating factors. Overall, this paper provides new insights on sulphur-nitrogen biogeochemistry and application as a low-carbon technology for nitrogen removal during municipal wastewater treatment.
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6.
Impact of engineered nanoparticles on microbial transformations of carbon, nitrogen, and phosphorus in wastewater treatment processes - A review.
Wu, S, Wu, H, Button, M, Konnerup, D, Brix, H
The Science of the total environment. 2019;:1144-1154
Abstract
Concern regarding the potential negative impacts of released engineered nanoparticles (ENPs) on pollutant removal performance of wastewater treatment systems has received booming attention in recent years. However, the conclusions drawn from different studies often lead to fragmented overall knowledge, some of which are even contradictory. This scenario shows the necessity for a comprehensive review of the interactions of ENPs in wastewater treatment systems, particularly on the impacts of ENPs on microbial processes of carbon (C), nitrogen (N), and phosphorus (P) removal in water treatment systems. This review introduced the impact of 6 often reported ENPs in 5 types of treatment systems. We found that exposure to most of the investigated ENPs at low concentrations doesn't adversely influence the growth of the heterotrophic microbes, which are responsible for organic matter removal. The impacts of ENPs on various microbial nitrogen transformation processes have been investigated. Dosing of ENPs often causes acute microbial nitrogen removal inhibition at various concentrations, but does not influence long-term operation due to microbial adaption. No significant negative effects on biological phosphorus removal in different wastewater treatment processes have been reported after both short-term and long-term exposure (except copper nanoparticles). Environmentally relevant concentrations of ENPs have been reported to enhance the photosynthetic capacity of wetland plants, whereas chronic inhibition to photosynthesis was found in exposure to high concentrations of ENPs. Inhibition effects are often overestimated in pure cultivated toxicity test assays compared to testing with artificially prepared wastewater containing various ingredients or with real wastewater. Potential ligands in real wastewater can bind with ENPs and lower their dissolution. Some challenges exist regarding detection and quantification techniques of ENPs at environmental concentrations, modeling of engineered nanomaterial release on a worldwide scale, and inhibitory mechanisms to microbial transformations.
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7.
Dye Removal from Water and Wastewater Using Various Physical, Chemical, and Biological Processes.
Piaskowski, K, Świderska-Dąbrowska, R, Zarzycki, PK
Journal of AOAC International. 2018;(5):1371-1384
Abstract
Synthetic dyes or colorants are key chemicals for various industries producing textiles, food, cosmetics, pharmaceutics, printer inks, leather, and plastics. Nowadays, the textile industry is the major consumer of dyes. The mass of synthetic colorants used by this industry is estimated at the level of 1 ÷ 3 × 105 tons, in comparison with the total annual consumption of around 7 × 105 tons worldwide. Synthetic dyes are relatively easy to detect but difficult to eliminate from wastewater and surface water ecosystems because of their aromatic chemical structure. It should be highlighted that the relatively high stability of synthetic dyes leads to health and ecological concerns due to their toxic, mutagenic, and carcinogenic nature. Currently, removal of such chemicals from wastewater involves various techniques, including flocculation/coagulation, precipitation, photocatalytic degradation, biological oxidation, ion exchange, adsorption, and membrane filtration. In this review, a number of classical and modern technologies for synthetic dye removal from industry-originated wastewater were summarized and discussed. There is an increasing interest in the application of waste organic materials (e.g., compounds extracted from orange bagasse, fungus biosorbent, or green algal biomasses) as effective, low-cost, and ecologically friendly sorbents. Moreover, a number of dye removal processes are based on newly discovered carbon nanomaterials (carbon nanotubes and graphene as well as their derivatives).
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8.
The Impact of Climate Change on Raw and Untreated Wastewater Use for Agriculture, Especially in Arid Regions: A Review.
Faour-Klingbeil, D, Todd, ECD
Foodborne pathogens and disease. 2018;(2):61-72
Abstract
Climate change is one of the major challenges of our time that pose unprecedented stress to the environment and threats to human health. The global impacts of climate change are vast, spanning from extreme weather events to changes in patterns and distribution of infectious diseases. Lack of rainfall associated with higher temperatures has a direct influence on agricultural production. This is compounded by a growing population forecasted to expand further with increasing needs for food and water. All this has led to the increasing use of wastewater worldwide. In this review, we more specifically discuss the use of untreated wastewater in agriculture in the Middle East and North Africa (MENA) countries, the most arid region in the world. This presents challenges for agriculture with respect to water availability and increasing wastewater use in agri-food chain. This in turn exerts pressures on the safety of food raised from such irrigated crops. Current practices in the MENA region indicate that ineffective water resource management, lack of water quality policies, and slow-paced wastewater management strategies continue to contribute to a decline in water resources and an increased unplanned use of black and graywater in agriculture. Radical actions are needed in the region to improve water and wastewater management to adapt to these impacts. In this regard, the 2006 WHO guidelines for the use of wastewater contain recommendations for the most effective solutions. They provide a step-by-step guide for series of appropriate health protection measures for microbial reduction targets of 6 log units for viral, bacterial, and protozoan pathogens, but these need to be combined with new varieties of crops that are drought and pest resistant. More research into economic local treatment procedures for wastewater in the region is warranted.
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9.
A comprehensive review of phosphorus recovery from wastewater by crystallization processes.
Peng, L, Dai, H, Wu, Y, Peng, Y, Lu, X
Chemosphere. 2018;:768-781
Abstract
The presence of phosphorus (P) in discharged wastewater can lead to water pollution events and eutrophication. Given the increasing consumption of phosphate (PO43-) rocks, wastewater containing large quantities of P is deemed as a potential source of P recovery. Crystallization of P is an ideal way to recover P because of its simple design, ease of operation, high efficiency, and limited environmental impact. This paper provides a comprehensive review of P recovery by crystallization processes with respect to the mechanisms involved, operational parameters that influence the quality of the crystal, and available seed materials for inducing crystallization. Various operational parameters including pH, molar ratio of participating ions, mixing intensity, reactor type, and seeding conditions, were detailedly investigated. Different kinds of seeds were reviewed critically with regard to their principal properties, application, and long-term prospects. Crystallized products with a high P content can be used directly as slow-release fertilizers for agricultural production, and some test methods have been developed to determine their efficiency as a fertilizer and to evaluate their availability for plants. Further, the feasibility of P recovery by crystallization was evaluated in terms of economic benefits and environmental sustainability. This work serves as a basis for future research of P recovery by crystallization processes and responses to the increasingly stringent problems of eutrophication and the growing depletion of P resources.
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10.
Pepper mild mottle virus: A plant pathogen with a greater purpose in (waste)water treatment development and public health management.
Symonds, EM, Nguyen, KH, Harwood, VJ, Breitbart, M
Water research. 2018;:1-12
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Abstract
An enteric virus surrogate and reliable domestic wastewater tracer is needed to manage microbial quality of food and water as (waste)water reuse becomes more prevalent in response to population growth, urbanization, and climate change. Pepper mild mottle virus (PMMoV), a plant pathogen found at high concentrations in domestic wastewater, is a promising surrogate for enteric viruses that has been incorporated into over 29 water- and food-related microbial quality and technology investigations around the world. This review consolidates the available literature from across disciplines to provide guidance on the utility of PMMoV as either an enteric virus surrogate and/or domestic wastewater marker in various situations. Synthesis of the available research supports PMMoV as a useful enteric virus process indicator since its high concentrations in source water allow for identifying the extent of virus log-reductions in field, pilot, and full-scale (waste)water treatment systems. PMMoV reduction levels during many forms of wastewater treatment were less than or equal to the reduction of other viruses, suggesting this virus can serve as an enteric virus surrogate when evaluating new treatment technologies. PMMoV excels as an index virus for enteric viruses in environmental waters exposed to untreated domestic wastewater because it was detected more frequently and in higher concentrations than other human viruses in groundwater (72.2%) and surface waters (freshwater, 94.5% and coastal, 72.2%), with pathogen co-detection rates as high as 72.3%. Additionally, PMMoV is an important microbial source tracking marker, most appropriately associated with untreated domestic wastewater, where its pooled-specificity is 90% and pooled-sensitivity is 100%, as opposed to human feces where its pooled-sensitivity is only 11.3%. A limited number of studies have also suggested that PMMoV may be a useful index virus for enteric viruses in monitoring the microbial quality of fresh produce and shellfish, but further research is needed on these topics. Finally, future work is needed to fill in knowledge gaps regarding PMMoV's global specificity and sensitivity.