Ayed Amr, Sarah Jaradat, Hatim AlKhatib, Imad Hamadneh, Lama Hamadneh, Hamadallah Hodali, Moroug Zeadeh, and Mohammad Shahein. Prev Nutr Food Sci 2022;27:457-63. https://doi.org/10.3746/pnf.2022.27.4.457

The aim of this study was to synthesize two cellulose-based hydrogel/nanohydroxyapatite composites and to investigate their effect on the growth and quality of lettuce, Lactuca sativa L.. of the var. Locarno RZ85-81 in terms of nitrate content under greenhouse conditions. The first composite was synthesized from commercial sources of cellulose and nanohydroxyapatite (SHGH), while the second composite was synthesized from cellulose extracted from cypress and laboratoryprepared nanohydroxyapatite (CHGH). Both composites were loaded with two nitrogen fertilizers (KNO3 and (NH4)2SO4), separately at three different rates (50, 75 and 100 kg nitrogen/he). Growth parameters in terms of fresh weight (FW), plant height, number of leaves were measured at harvest, whereas nitrate content in inner and outer leaves was measured after harvest. Results indicated that CHGH significantly increased FW (147g and 151g), plant height (20cm and 22cm), number of leaves (25 and 22) at the rates of 75%, and 100%, respectively for (NH4)2SO4. In addition, it reduced the nitrate content in the outer leaves (0.73mg/g FW, 0.73mg/g FW and 29mg/g FW) at the rates of 50%, 75%, and 100%, respectively for KNO3 and the inner leaves (0.01mg/g FW and 0.07mg/g FW) at the rates 75% and 100% of KNO3, respectively. In conclusion, the newly developed green CHGH was superior to SHGH in enhancing growth and reducing nitrate content in lettuce.

Potato is a widely consumed staple crop prone to postharvest deterioration and quality loss. Biodegradable edible coatings offer an eco-friendly alternative to conventional packaging for extending shelf life. This study evaluated the effectiveness of whey protein concentrate (WPC) based coatings, with and without chitosan, in maintaining potato quality under different storage conditions and durations. Tubers were treated with WPC coating (WC1) or WPC–chitosan coating with additives (WC2) and stored at room temperature (RT, 24 °C), refrigeration (RF, 4 °C), or incubator (IC, 20 °C) for up to 48 days. Dry matter (DM), firmness (FR), and total soluble solids (TSS) were determined every 8 days. DM ranged between 17.3–20.7%, FR between 5.6–8.1 N, and TSS between 3.4–5.3 °Brix. Storage period (SP) had the strongest influence, with DM peaking after 16–24 days, FR gradually decreasing, and TSS dropping sharply after 32 days. Coating did not significantly affect DM, but WC2 improved FR retention while slightly lowering TSS. RF best preserved FR and TSS, whereas RT and IC accelerated quality loss. Overall, WPC-based coatings, particularly WC2, provide a biodegradable and effective strategy to reduce postharvest losses, maintain potato quality, and support sustainable food preservation.

This secondary-data integrated assessment combines national wastewater treatment records, two national sludge reports, Jordanian regulatory criteria, published agronomic evidence, engineering scenarios, and a previously prepared spatial screen. The present national context includes 33 municipal wastewater treatment plants (WWTPs), but the analytical sources cover different historical plant sets. The 2020 GIZ report surveyed 29 operating WWTPs and reported sludge-quality data for 25 plants, comprising 28 plant-stage records. The 2014 USAID strategy covered 28 WWTPs, with metal data for 9 plants and six nutrient samples from 3 plants. In the GIZ records, mean concentrations were 3.44 mg Cd kg⁻¹, 7.93 mg Pb kg⁻¹, 603.79 mg Zn kg⁻¹, and 111.86 mg Cu kg⁻¹ dry solids. Maximum concentration-to-limit ratios were 1.00 for Cd, 0.103 for Pb, 0.525 for Zn, and 0.377 for Cu. USAID nutrient samples averaged 3.93% total N, 1.71% total P, and 0.71% total K. GIZ estimated 101,533–108,719 t dry solids yr⁻¹ in 2020 and 128,540–149,332 t yr⁻¹ in 2035. USAID produced lower estimates of 50,947 and 72,418 t yr⁻¹ for the same years, showing major model uncertainty. The source spatial screen mapped 10,150.28 km², including 745.62 km² of protected rangeland reserves. Excluding those reserves leaves 9404.66 km² for further regulatory and field screening. The results support controlled reuse based on batch testing, pathogen reduction, nitrogen and phosphorus budgets, and long-term soil monitoring.

The excessive use of conventional NPK fertilizers can reduce nutrient use efficiency due to nutrient losses, emphasizing the need for controlled-release fertilizer systems. This study aimed to prepare and evaluate olive pomace-derived biochar (BC) as a carrier for nitrogen–phosphorus–potassium (NPK) fertilizer and assess its effects on nutrient release and lettuce performance. Biochar was produced by pyrolysis at 400 °C and loaded with NPK fertilizer. The BC/NPK composite was characterized using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), nutrient-release behavior was evaluated in deionized water and soil. The cumulative nutrient release reached 64% in deionized water and 91% in soil. Under greenhouse conditions, BC/NPK applied at 100% and 75% NPK rates increased lettuce fresh weight, plant height and leaf number to 163.33 and 183.67 g, 23.00 and 23.67 cm, 34 and 36, respectively. Moreover, BC/NPK reduced nitrate accumulation in lettuce leaves, with nitrate concentrations decreasing in outer leaves to 10 and 0.73 mg g⁻¹ and in inner leaves to 2 and 1.33 mg g⁻¹ at the 100% and 75% rates, respectively. These findings demonstrate that olive pomace-derived BC/NPK is a promising slow-release fertilizer capable of improving crop performance while supporting sustainable nutrient management and agricultural waste valorization.