Background: The black soldier fly (Hermetia illucens) has emerged as a promising tool in sustainable waste management, owing to its larvae’s ability to efficiently convert organic waste into valuable biomass. Objective: This study investigates the impact of various substrate compositions on the growth, waste reduction efficiency, and bioconversion rate of black soldier fly (BSF) larvae (Hermetia illucens). The aim is to optimize feeding strategies to enhance the effectiveness of BSF larvae in sustainable waste management and protein production. Methods: A controlled experiment was conducted over a 20-day period, using four different substrate types: 100% sludge, 75% sludge + 25% chicken feed, 25% sludge + 75% chicken feed, and 100% chicken feed. Each treatment had three replicates with 100 larvae each. Larval growth metrics, including weight and width, were recorded bi-daily. The waste reduction efficiency and bioconversion rate were calculated based on the remaining substrate weight and larval biomass, respectively. Elemental analysis was performed to determine the impact of substrate type on the accumulation of various elements in the larvae. Results: Significant differences were observed in larval growth, waste reduction efficiency, and bioconversion rates across the different substrates. The 100% chicken feed substrate led to the highest larval growth (M = 0.0881 g/day, SD = 0.0042) and bioconversion rate (M = 7.52%, SD = 0.34), while the 100% sludge substrate achieved the highest waste reduction rate (M = 86.2%, SD = 2.15). ANOVA tests indicated that substrate composition significantly affected these outcomes (p < 0.05). Elemental analysis showed substantial variations in the concentrations of calcium, cadmium, and nickel among the substrates, with the 100% sludge substrate having the highest nickel accumulation (M = 0.2763 ppm, SD = 0.023), significantly different from the other treatments (p < 0.001). Conclusions: The results demonstrate that substrate composition is crucial for optimizing BSF larvae growth and waste reduction efficiency. Nutrient-rich substrates, such as chicken feed, significantly enhance bioconversion rates and larval biomass production, although careful consideration of elemental accumulation, especially heavy metals, is essential for safe application in animal feed.

Antiscalants are organic polymers widely used for scale inhibition in seawater desalination. While they are susceptible to biodegradation, they provide nutrients for bacterial cell growth and energy for the microbes that assimilate and degrade them. This paper shows the biodegradability of three commercial antiscalants (polyacrylate—CA, polyphosphonate—PP, and carboxylated dendrimers—DN) applied in seawater reverse osmosis desalination (SWRO) as well as analyzing the antiscalant’s effects on microbial diversity using microbial cultures grown in seawater, under semi-continuous batch conditions. Nutritional uptake and contribution of the antiscalants to microbial growth were investigated by measuring DOC, TDN, NO₃⁻, NO₂⁻, PO₄⁻, NH₄⁺, and TP of the filtered samples of the incubated batch, twice a month, for twelve months. The microbial community was estimated by 16S rRNA sequencing. The main changes in the microbial communities were determined by the incubation period. However, bacterial orders of the antiscalant treatments differed significantly from the control treatment, namely Planctomycetales, Clostridiales, Sphingobacteriales, Rhodobacterales, and Flavobacteriales, and other unclassified bacterial orders, which were found in various relative abundances dependent on incubation times. The results showed the PP antiscalant to be the least biodegradable and to have the least effect on the bacterial community composition compared to the control. This result emphasizes the need to reassess the suitability criteria of antiscalants, and to further monitor their long-term environmental effects.

Leachate generated from landfills contains many toxic contaminants, such as dissolved organics, inorganic salts, ammonia, and heavy metals, which impact the surrounding environmental systems. This study characterized the AL-Mufarrihat Sanitary Landfill (MSL) leachate in Al-Medinah Al-Munawwarh...

This study evaluated the effect of deficit irrigation (DI) using treated wastewater TWW on the vegetative productivity and quality of greenhouse-grown eggp

Aerobic composting is a cost-effective option for managing sewage sludge and organic waste. The performance of aerobic composting of sludge mixed with locally available organic materials was evaluated under protected, non-temperature-controlled conditions, and potential management options for the resulting products were assessed. Three mixtures were evaluated in two separate runs: sludge and olive mill pomace (1S:1J), sludge with olive mill pomace, manure, and plant waste (3S:3J:2M:2W), and sludge with manure (1S:1M). Pile temperatures reached only 30–40 °C and did not attain the thermophilic range required for reliable sanitization. From the initial to final sampling, organic matter decreased by 5.2–29.8% in the first run and 25.0–42.9% in the second run. Nitrogen changed by +31.1% to +200.8% in the first run and −51.8% to +48.9% in the second run. Phosphorus changed by +80.2% to +217.5% in the first run and −33.0% to +81.9% in the second run. Selected trace elements also showed treatment-specific numerical changes, including a 131.1% increase in Fe and a 72.6% decrease in Zn in 1S:1M during the first run. All measured potentially toxic elements remained below the cited regulatory limits. Microbiological compliance varied by treatment and run, and one second-run mixture contained 9.4 × 10³ MPN/g total fecal coliforms, above the reported Class 1 limit. These results show useful nutrient characteristics but do not demonstrate consistent sanitization or unrestricted agricultural suitability. Additional process control and microbiological verification are required before reuse.

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.