Anaerobic digestion is a worldwide technology for the treatment of organic waste streams with clear environmental benefits including generation of methane as renewable energy. However, the need to improve process feasibility of existing applications as well as to expand anaerobic digestion to a range of new substrates has raised interest on several intensifications techniques. Among them, the supplementation of inorganic and biological additives has shown good results at improving digesters performance. This manuscript presents a comprehensive review about recent advances in the utilization of inorganic and biological additives. On the one hand, reviewed inorganic additives comprise: (i) macro- (e.g. P, N and S) and micro- (e.g. Fe, Ni, Mo, Co, W and Se) nutrients supplements, (ii) ashes from waste incineration, (iii) compounds able to mitigate ammonia inhibition, and (iv) substances with high biomass immobilization capacity. Among them, iron (Fe 0 and Fe(III)) has shown particularly promising results, which have been mainly related to their action as electron donor/acceptor and cofactor of key enzymatic activities. On the other hand, reviewed biological additives include: (i) the dosage of microbial inocula with high hydrolytic or methanogenic activity (bioaugmentation), and (ii) the addition of enzymes able to facilitate particulate organic matter solubilization.

The role of additives on anaerobic digestion: a review

Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.

/pdf/total-value-of-phosphorus-recovery-32gase9ckg.pdf

Total Value of Phosphorus Recovery

Electrodialysis Desalination for Water and Wastewater: A Review

Limits in resource availability are driving a change in current societal production systems, changing the focus from residues treatment, such as wastewater treatment, toward resource recovery. Biotechnological processes offer an economic and versatile way to concentrate and transform resources from waste/wastewater into valuable products, which is a prerequisite for the technological development of a cradle-to-cradle bio-based economy. This review identifies emerging technologies that enable resource recovery across the wastewater treatment cycle. As such, bioenergy in the form of biohydrogen (by photo and dark fermentation processes) and biogas (during anaerobic digestion processes) have been classic targets, whereby, direct transformation of lipidic biomass into biodiesel also gained attention. This concept is similar to previous biofuel concepts, but more sustainable, as third generation biofuels and other resources can be produced from waste biomass. The production of high value biopolymers (e.g., for bioplastics manufacturing) from organic acids, hydrogen, and methane is another option for carbon recovery. The recovery of carbon and nutrients can be achieved by organic fertilizer production, or single cell protein generation (depending on the source) which may be utilized as feed, feed additives, next generation fertilizers, or even as probiotics. Additionlly, chemical oxidation-reduction and bioelectrochemical systems can recover inorganics or synthesize organic products beyond the natural microbial metabolism. Anticipating the next generation of wastewater treatment plants driven by biological recovery technologies, this review is focused on the generation and re-synthesis of energetic resources and key resources to be recycled as raw materials in a cradle-to-cradle economy concept.

/pdf/resource-recovery-from-wastewater-by-biological-technologies-1i28a8v00y.pdf

Resource Recovery from Wastewater by Biological Technologies: Opportunities, Challenges, and Prospects

Technologies to recover nitrogen, phosphorus, and potassium from waste streams have undergone accelerated development in the past decade, predominantly due to a surge in fertilizer prices and stringent discharge limits on these nutrients. This review provides a critical state of art review of appropriate technologies which identifies research gaps, evaluates current and future potential for application of the respective technologies, and outlines paths and barriers for adoption of the nutrient recovery technologies. The different technologies can be broadly divided into the sequential categories of nutrient accumulation, followed by nutrient release, followed by nutrient extraction. Nutrient accumulation can be achieved via plants, microorganisms (algae and prokaryotic), and physicochemical mechanisms including chemical precipitation, membrane separation, sorption, and binding with magnetic particles. Nutrient release can occur by biochemical (anaerobic digestion and bioleaching) and thermochemical treatm...

/pdf/technologies-to-recover-nutrients-from-waste-streams-a-1px0pf2bli.pdf

Technologies to Recover Nutrients from Waste Streams: A Critical Review

Platforms for energy and nutrient recovery from domestic wastewater: A review.

Nucleation and growth kinetics of struvite crystallization

Nutrient recovery from wastewater through pilot scale electrodialysis

https://espace.library.uq.edu.au/view/UQ:363292/UQ363292_OA.pdf

Chirag M. Mehta

Papers

Technologies to Recover Nutrients from Waste Streams: A Critical Review

Platforms for energy and nutrient recovery from domestic wastewater: A review.

Nucleation and growth kinetics of struvite crystallization

Nutrient recovery from wastewater through pilot scale electrodialysis

Low pH anaerobic digestion of waste activated sludge for enhanced phosphorous release