Permeable pavements are a common solution for stormwater management. Porous areas in the pavements allow water to percolate into the subsurface layers, reducing surface runoff. However, it is common for substances to clog the voids, decreasing the porous area and permeability of the pavement system. This study examined the change in permeability over time at a site with two permeable pavement systems, the JW Eco-technology (JW) and pervious concrete (PC). Square frames SF-4 and SF-9 were used to perform falling-head and constant-head permeability tests, respectively. Results show that JW had a similar permeability across the test locations, 6.27-7.64 cm/s when using SF-4, and 0.95-1.00 cm/s when using SF-9. While the permeability at the center locations of PC showed no significant loss of permeability, there was a significant reduction of permeability on the corner and edge areas, where permeability ranged 0.28-1.73 cm/s using SF-4 and 0.14-0.36 cm/s using SF-9, suggesting the occurrence of clogging over time at corner locations. Furthermore, the measured values highlighted the measurement variability in permeability between the falling-head based method and the constant-head method, with measurements from SF-4 being approximately 6.2-7.6 and 2.0-5.7 times higher than those from SF-9 on JW and PC, respectively. In addition, as no current literature quantifies the relationship between permeability and extent of clogging for the JW Eco-technology pavement, evaluation of the proportionate change in permeability with respect to voids, or individual aqueducts, of JW pavement were investigated. While not a 1:1 linear relationship, data indicate that the permeability increased with an increase in non-blocked aqueducts. The JW pavement maintained more than 50% of its capacity when half of the aqueducts were fully blocked. Even when only one aqueduct was clear from clogging, the system had 36% (SF-4) and 19% (SF-9) of maximum permeable capacity.

Permeable pavements have the ability to reduce surface runoff by allowing water to infiltrate into the underlying soil. The potential of permeable pavements to assist in managing stormwater and improve water quality has gained attention as an option, other than conventional impermeable concrete for paving purposes. This study examined the permeability of three different pavement systems, including the JW Eco-technology pavement (JW), which has not previously been installed or studied in the U.S., standard impermeable concrete (IC), and pervious concrete (PC). Each pavement type was installed in triplicate. Devices based on the ASTM C1701/C1701M and ASTM C1781/C1781M constant-head methods, the National Center for Asphalt Technology (NCAT) falling-head permeameter, and two new square frames, SF-4 and SF-9, modified to fit the JW pavement, were utilized for permeability measurement on several locations of each pavement system. The results showed that the JW Eco-technology pavement had comparable permeability to the commonly used PC pavement in each method used. In addition, there was a strong correlation between the permeability measurements of NCAT method and SF-4, and between the ASTM standard and SF-9. The square frames used in this study showed their effectiveness and efficiency in performing permeability measurements. It was also found that the permeability obtained had a pronounced difference in values between the falling head and the constant head methods, with an average ratio ranging from 4.08–6.36.

Post-hydrothermal liquefaction wastewater (PHW) is a byproduct of the hydrothermal liquefaction (HTL) process. Previous research indicates that PHW is free of pathogens and contains nutrients needed for crop growth, but may contain metal(loid)s. This study evaluated the ability of differentially treated PHW for effective and safe hydroponic lettuce production. Water containing only hydroponic fertilizer (Source Water 1) had the highest total dry yield of all five treatments; 3.1 times higher than Source Water 2 (diluted PHW with sand filtration), 3.5 times higher than Source Water 3 (diluted PHW with sand + carbon filtration), 2.6 times higher than Source Water 4 (diluted and nitrified PHW with sand filtration), and 1.3 times higher than Source Water 5 (diluted PHW supplemented with hydroponic fertilizer). Findings also indicated that while PHW was below the US Department of Agriculture Foreign Agriculture Service maximum levels for cadmium, lead, and mercury in food, the concentration of arsenic was 1.6, 2.4, and 2.0 times higher than the maximum level for Source Waters 2, 3, and 4, respectively. There was no detectable E. coli or fecal coliforms in any of the treated PHW. While nitrogen was present in the raw PHW, only 0.03% was NO₃-N and NO₂-N. Diluted PHW supplemented with hydroponic fertilizer had lower lettuce yield than hydroponic fertilizer alone, indicating a potential non-nutrient inhibition of plant growth by PHW. Therefore, this research demonstrates that treated PHW does not pose a biological contamination risk for lettuce, but may entail levels of arsenic in edible leaf tissues that are in excess of safe levels. Additional treatment of PHW can benefit crop production by allowing crop utilization of a greater fraction of total nitrogen in the raw PHW.

Climate change is a well-known phenomenon all over the globe. The influence of projected climate change on agricultural production, either positive or negative, can be assessed for various locations. The present study was conducted to investigate the impact of projected climate change on rice’s production, water demand and phenology for the state of Bihar, India. Furthermore, this study assessed the irrigation water requirement to increase the rice production by 60%, for the existing current climate scenario and all the four IPCC climate change scenarios (RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5) by the 2050s (2050–2059). Various management practices were used as adaptation methods to analyze the requirement of irrigation water for a 60% increase in rice production. The climate data obtained from the four General Circulation Models (GCMs) (bcc_csm1.1, csiro_mk3_6_0, ipsl_cm5a_mr and miroc_miroc5) were used in the crop growth model, with the Decision Support System for Agrotechnology Transfer (DSSAT) used to simulate the rice yield, phenological days and water demand under all four climate change scenarios. The results obtained from the CERES-Rice model in the DSSAT, corresponding to all four GCMs, were ensembled together to obtain the overall change in yield, phenology and water demand for 10 years of interval from 2020 to 2059. We investigated several strategies: increasing the rice’s yield by 60% with current agronomic practice; increasing the yield by 60% with conservation agricultural practice; and increasing the rice yield by 30% with current agronomic practice as well as with conservation agricultural practices (assuming that the other 30% increase in yield would be achieved by reducing post-harvest losses by 30%). The average increase in precipitation between 2020 and 2059 was observed to be 5.23%, 13.96%, 9.30% and 9.29%, respectively, for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5. The decrease in yield during the 2050s, from the baseline period (1980–2004), was observed to be 2.94%, 3.87%, 4.02% and 5.84% for RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5, respectively. The irrigation requirement was predicted to increase by a range of 39% to 45% for a 60% increase in yield using the current agronomic practice in current climate scenario and by 2050s with all the four climate change scenarios from the baseline period (1980–2004). We found that if we combine both conservation agriculture and removal of 30% of the post-harvest losses, the irrigation requirement would be reduced by 26% (45 to 19%), 20% (44 to 24%), 21% (43 to 22%), 22% (39 to 17%) and 20% (41 to 21%) with current climate scenario, RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 conditions, respectively. This combination of conservation practices suggests that the irrigation water requirement can be reduced by a large percentage, even if we produce 60% more food under the projected climate change conditions.

Hydrothermal liquefaction aqueous phase (HTL-AP) is a waste product from a thermochemical process where wet biomass is converted into biocrude oil. This nutrient-rich wastewater may be repurposed to benefit society by assisting crop growth after adequate treatment to increase inorganic nitrogen, especially NO₃⁻. This study aims to increase HTL-AP inorganic nitrogen, specifically NH₃/NH₄⁺ and NO₃⁻, through fungal remediation for further use in hydroponic systems. Trametes versicolor, a white-rot fungus known for degrading a range of organic pollutants, was used to treat a diluted (5 %) HTL-AP for 9 days. No fungal growth was observed, but T. versicolor activity was suspected by laccase activity throughout cultivation time. NO₃⁻-N and NH₃/NH₄⁺-N increased by 17 and 8 times after three days of fungal treatment, which was chosen as the appropriate time for HTL-AP fungal treatment as it resulted in the highest concentration of NO₃⁻-N. The addition of nitrifying bacteria to the fungal treatment resulted in a twofold increase in NO₃⁻-N concentration compared to the fungal treatment alone, indicating an enhancement in treatment efficacy. COD decreased by 51.33 % after 24 h, which may be related to the fungus’ capacity to reduce the concentration of organics in the wastewater; nonetheless, COD increased in the following days, which may be related to the release of fungal byproducts. T. versicolor shows promise as a potential candidate for increasing inorganic nitrogen in HTL-AP. However, future studies should primarily address HTL-AP toxicity, reducing NH₃/NH₄⁺-N while increasing NO₃⁻-N, and hydroponics crop production after fungal treatment.

Recycling post-hydrothermal liquefaction wastewater (PHWW) may allow the use of nutrients in the aqueous phase that may otherwise go unused. PHWW is an attractive option for use as fertilizer in systems like crop production. However, there are potential contaminants in the PHWW that may inhibit crop growth or pose a food safety risk. This study investigated the concentrations of heavy metals and nutrients in the PHWW, as well as the presence of indicator pathogens. In addition, four different water treatment methods were used: (1) dilution of raw PHWW, (2) sand filtration after dilution, (3) sand and carbon filtration after dilution, and (4) reverse osmosis after dilution. Our results indicate that the concentrations of cadmium, lead, and arsenic in raw PHWW were well below the maximum recommended concentrations set by the US Environmental Protection Agency (US EPA) for Water Reuse. In addition, the treatment methods in this study achieved percent removals ranging from 82–100% for cadmium, 99–100% for mercury, 75–99.5% for lead, and 71–99% for arsenic. Nitrogen in raw PHWW was predominantly in the total N form, preventing it from being accessible to plants. After nitrification was induced, the concentration of NO₃ + NO₂ increased by 1.75 mg/L in the untreated 5% PHWW mixture, but remained unchanged or decreased for all other treatments and mixtures. There were no E. coli or coliform colonies detected in the raw PHWW, or in any PHWW mixtures. All PHWW mixtures with and without treatment are within US EPA guidelines for metals for irrigation water reuse. However, fertilizer supplementation may be required for PHWW to be suitable for crop production, as the low concentrations of NO₃ + NO₂ may prove challenging for growing crops.