This literature review investigated the efficacy of both unmodified and modified biochars as an adsorbent for phosphorus (P) capture from waste streams. The review focused on critical design aspects including the maximum phosphate removal adsorption capacities, influence of pH, coexisting ions, and pyrolytic conditions on P adsorption. The adsorption mechanisms, including electrostatic interactions, ion exchange, and complexation, were elucidated to provide insights into the underlying processes. The review revealed that the maximum phosphate removal adsorption capacity was influenced by factors such as the biochar type, surface properties, pyrolytic conditions, and presence of hydroxyl (–OH), carboxyl (–COOH) functional groups. The pH of the solution was identified as a crucial parameter affecting the efficiency of phosphate adsorption. Coexisting ions, notably carbonate anions, exhibited negative impacts on the phosphate removal process. Furthermore, this review discusses the characterization techniques used to assess biochar properties and adsorption mechanisms. Challenges related to biochar scalability, regeneration, stability, and metal leaching are addressed. Moreover, this review explored agricultural applications of P-laden biochar and found P-enriched biochar holds promise as a slow-release fertilizer for soil enrichment. This review highlights the role of biochar in promoting sustainable P management by integrating its application in wastewater treatment and agricultural reuse.

Phosphorus (P) is a valuable, nonrenewable resource in agriculture promoting crop growth. P losses through surface runoff and subsurface drainage discharge beneath the root zone is a loss of investment. P entering surface water contributes to eutrophication of freshwater environments, impacting tourism, human health, environmental safety, and property values. Soluble P (SP) from subsurface drainage is nearly all bioavailable and is a significant contributor to freshwater eutrophication. The research objective was to select phosphorus sorbing media (PSM) best suited for removing SP from subsurface drainage discharge. From the preliminary research and literature, PSM with this potential were steel furnace slag (SFS) and a nano-engineered media (NEM). The PSM were evaluated using typical subsurface drainage P concentrations in column experiments, then with an economic analysis for a study site in Michigan. Both the SFS and generalized NEM (GNEM) removed soluble reactive phosphorus from 0.50 to below 0.05 mg/L in laboratory column experiments. The most cost-effective option from the study site was the use of the SFS, then disposing it each year, costing $906/hectare/year for the case study. GNEM that was regenerated onsite had a very similar cost. The most expensive option was the use of GNEM to remove P, including regeneration at the manufacturer, costing $1641/hectare/year. This study suggests that both SFS and NEM are both suited for treating drainage discharge. The use of SFS was more economical for the study site, but each site needs to be individually considered.

Wastewater produced during the wine-making process often contains an order of magnitude greater chemical oxygen demand (COD) concentration than is typical of domestic wastewater. This waste stream is also highly variable in flow and composition due to the seasonality of wine-making. The recent growth of small-scale wineries in cold climates and increasing regulations present a need for low-cost, easily-operable treatment systems that do not require large amounts of land, yet maintain a high level of treatment in cool temperatures. This research investigates the use of a subsurface vertical flow constructed wetland (SVFCW) to treat winery wastewater. In this study, clinoptilolite, tire chips, and a nano-enhanced iron foam were used to enhance bench-scale gravel cells to adsorb ammonia, nitrate, and phosphorus, respectively. The treatment systems, without nitrogen adsorption media, performed well, with >99% removal of COD and 94% removal of total nitrogen. Treatment systems with the nitrogen adsorption media did not enhance nitrogen removal. Equilibrium was reached within two weeks of start-up, regardless of prior inoculation, which suggests that microbes present in the winery wastewater are sufficient for the start-up of the wastewater treatment system; therefore, the seasonality of winery wastewater production will not substantially impact treatment. Operating the treatment systems under cool temperatures did not significantly impact COD or total nitrogen removal. Further, the use of nano-enhanced iron foam exhibited 99.8% removal of phosphorus, which resulted in effluent concentrations that were below 0.102 mg/L P.

The United States produces significant quantities of waste biomass from wastewater treatment, food production, food services, and landscape and wood debris. This waste contains essential resources, including water, carbon, and nutrients. Conversion of carbon to energy and recovery of nutrients and water have the potential to reduce the use of scarce resources, protect the environment, and save funds. Several established, demonstrated technologies that convert wastes to resources are available and are reviewed in this paper. Included are anaerobic digestion, direct combustion, biodiesel production, ethanol production, and particulate phosphorus and organic nitrogen separation using ultrafiltration, ammonia stripping, and reverse osmosis. Thermochemical technologies include pyrolysis, torrefaction, and gasification. Unlike solar, wind, hydrological (dams and pumped storage), and closed-loop geothermal renewable energy technologies, the transportation of biomass can be energy intensive. Therefore, a holistic evaluation of complexity, costs, and benefits of converting wastes to resources is mandatory to ensure a net-positive energy value and environmental protection. Several tools described in this paper are available to aid stakeholders when considering biomass waste-to-resource projects. Many of these tools have long been in practice and have been extensively covered in technical and popular literature. As interest in renewable energy resources increases, new tools are being developed to address the challenges posed by biomass projects. This paper discusses tools that combine waste biomass inventories with a geographic information system mapping platform and cost-benefit analysis that return environmental, economic, and financial assessments of selected feedstocks that can be used in planning, siting, and financing a biomass-to-energy project.

A treatability study was conducted to determine the potential of white rot fungi to remediate soil from a Superfund site that had been contaminated with DDT. A tiered approach was utilized, starting with simple laboratory studies to screen the potential of white rot fungal strains to degrade DDT and culminating with a soil pan study that simulated land farming. Results from early tiers of the study indicated that Phanerochaete sordida had the best potential for remediating the soil. In the soil pan study, the fungus ultimately grew very well after second inoculation. However, the good growth did not translate to higher DDT removal compared to removal in pans that were not inoculated. ¹⁴[DDT] fate studies indicated the small amount of removal that did occur for both fungal inoculated and non‐inoculated conditions could be partially attributed to incorporation into humic material. Addition of a surfactant to the soil enhanced the removal of DDT in both inoculated and non‐inoculated soil. Consequently, under simulated land fanning conditions, this strain of fungus was not successful in remediating this soil.