Waste Reduction Efficiency Research Articles

Synergy of machine learning and the Einstein Choquet integral with LOPCOW and fuzzy measures for sustainable solid waste management

<p>Solid waste management (SWM) protects public health, the environment, and limited resources in densely populated and urbanized countries such as Singapore. This work presents an advanced framework for optimizing SWM using advanced mathematical models and decision-making techniques, including the circular $ q $-rung orthopair fuzzy set (C$ q $-ROFS) for data, combined with the Choquet integral (CI) and logarithmic percentage change-driven objective weighting (LOPCOW) methods, enhanced by the aggregation operators (AOs) circular $ q $-rung orthopair fuzzy Einstein Choquet integral weighted averaging (C$ q $-ROFECIWA) and circular $ q $-rung orthopair fuzzy Einstein Choquet integral weighted geometric (C$ q $-ROFECIWG) aggregation operators. By conducting a systematic evaluation, these methods classified different alternatives to SWM, evaluating them according to criteria such as their environmental impact, cost-effectiveness, waste reduction efficiency, feasibility of implementation, health safety, and public acceptance. The operators C$ q $-ROFECIWA and C$ q $-ROFECIWG perform better than previous approaches in the effective management of multifaceted and dynamic SWM scenarios. The comparison study demonstrates that the integration of these operators with LOPCOW and the Choquet integral offers decision-making conclusions that are more reliable and sustainable. The study conducted in Singapore successfully finds the most feasible SWM alternatives and emphasizes the possibility of implementing more environmentally sustainable practices in the urban environment. This research offers practical insights for policymakers and emphasizes the need to improve and enhance these approaches to improve SWM in various urban environments.</p>

Evaluating the Influence of Nutrient-Rich Substrates on the Growth and Waste Reduction Efficiency of Black Soldier Fly Larvae

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.

Cultivating black soldier fly (Hermetia illucens) larvae on coconut endosperm and soybean curd residue: Impact on growth performance, waste reduction efficiency and larval nutritional composition

AbstractBlack soldier fly larva (BSFL), Hermetia illucens (L.) (Diptera: Stratiomyidae), presents an attractive waste management solution that not only addresses the issue of waste but also generates alternative proteins and fats. Substrate quality and pre‐treatment by fermentation may play a crucial role in waste reduction efficiency and larval quality. The aim of this study was to investigate the growth performance, waste reduction efficiency and nutritional composition of BSFL rearing using different ratios of coconut endosperm (CE) and soybean curd residue (SC) with pre‐treatment by self‐fermentation (F), fermentation with baker's yeast (Y) and without pre‐treatment (C). Seven‐day‐old larvae were randomly separated into 15 experimental groups with three replicates. The experiment ended when the prepupae appeared. Based on the results, the larvae fed a diet with a high percentage of fresh SC exhibited the highest weight and growth rate, whereas the shortest development time was observed in larvae reared on Y. Pre‐treatment of the substrate with fermentation proved effective in waste reduction. The nutritional composition of the larvae showed that the highest crude protein was produced in larva reared on fresh 100% SC, and the highest ether extract was found when fed CE at 100% with pre‐treatment with F or Y. In conclusion, it is recommended to employ a fresh diet with a high SC content to optimise protein production, whereas a high level of CE with F or Y may be performed to obtain a high ether extract content. However, incorporating yeast fermentation with an SC content exceeding 25% provided high efficiency in waste reduction. Therefore, the selection of the ratio between CE and SC and of pre‐treatment techniques depends on the producer's objective.

Growth performance, proximate composition and fatty acid profile of black soldier fly larvae reared on two grape pomace varieties

The black soldier fly (Hermetia illucens) is attracting increasing interest for its ability to convert low-value substrates into highly nutritious feed. This study aimed at evaluating grape pomace from two varieties (Becuet – B; Moscato – M) as rearing substrates for black soldier fly larvae (BSFL), focusing on the related effects on larval growth performance, proximate composition, and fatty acid profile. A total of six replicates per treatment, and 1 000 BSFL per replica, were used. Larval development was assessed by larvae weight, which was recorded eight times during the trial: the day after the beginning of the trial, and then on days 5, 8, 13, 15, 20, 22, and 27 (day in which the 30% of BSFL reached the prepupal stage). Production and waste reduction efficiency parameters, namely the growth rate, substrate reduction and substrate reduction index, were calculated. The two grape pomace varieties were analysed for their proximate composition and fatty acid profile; the same analyses were conducted on BSFL (30 larvae per replica) that were collected at the end of the trial (day 27). The growth rate of BSFL showed a higher value when the larvae were reared on B substrate (4.4 and 3.2 mg/day for B and M, respectively; P < 0.01). The rearing substrate did not significantly affect the proximate composition of BSFL. The percentage of total lipids (TL) in M-fed BSFL was significantly higher than in B ones. Total saturated (P < 0.001) and monounsaturated fatty acids (P < 0.05) were significantly higher in M-fed BSFL, while an opposite trend was observed for total branched-chain (P < 0.001) and total polyunsaturated fatty acids (P < 0.001). Interestingly, some conjugated linoleic acid (CLA) isomers [i.e., C18:2 c9t11(+t7c9+t8c10) and t9t11] were detected in low amounts in both rearing substrates (total CLA equal to 0.085 and 0.16 g/100 g TL in B and M substrate, respectively). Some CLA isomers (i.e., C18:2 c9t11, t7c9, and t10c12) were also found in BSFL, reaching a total CLA concentration equal to 2.95 and 0.052 g/100 g of TL in B-fed and M-fed BSFL, respectively. This study demonstrates that winery by-products from different grape varieties can significantly affect the development and lipid composition of BSFL. The CLA biosynthesis potential of BSFL opens newsworthy perspectives for a new valorisation of winery by-products to produce full-fat black soldier fly meal and black soldier fly oil enriched in specific fatty acids of potential health-promoting interest.

Bioconversion of organic wastes using black soldier fly

Experiment was conducted at Department of Entomology, University of Agricultural Science Dharwad, to evaluate feasibility to degrade organic wastes in laboratory condition. Organic wastes like Vegetable Waste (VW), Fruit Waste (FW), Unfed Crop Waste (UCW), Kitchen Waste (KW), VW + dung (3:1), FW + dung (3:1), UCW + dung (3:1), KW + dung (3:1) were added in tray with 700 maggots per tray. Organic wastes (feed) were supplied @ 220 mg/maggot/day and the total feed maintained was 500 g/tray which was sufficient for three days. Feed was supplied at three days interval up to 9th day and hence total feed used per tray was 1500 g. Results indicated that kitchen waste was significantly superior over the other treatments with high prepupal weight (317.97 mg/maggot), maximum bioconversion rate (14.56%) and high feed reduction rate (96.07%). The present study revealed that kitchen waste as feed for Black Soldier Fly, results in better pre pupal weight and higher waste reduction efficiency. Thus, the kitchen waste can be used for mass rearing of Black Soldier Fly to explore its potentiality as a bio agent for waste management.

Enhancing food waste reduction efficiency and high-value biomass production in Hermetia illucens rearing through bioaugmentation with gut bacterial agent

The black soldier fly (BSF) rearing technology has been a promising bioconversion method for food waste (FW) disposal. However, when used independently, it currently only achieves low efficiency and biomass transformation rates (BTR). This study screened and identified two strains of gut beneficial bacteria, Bacillus cereus and Bacterium YC-LK-LKJ45. The efficiency of a complex culture formulated by these strains was investigated, focusing on enhancing FW reduction and high-value biomass production during the rearing of BSF larvae. The coculture agent group (G1–10%, with two strains in 1:1 volume ratio at a 10 % dosage) exhibited higher larval yield (627.67 g·kg−1), BTR (47.90 %), FW reduction efficiency (80.67 %), and total protein and fat yield (261.99 g·kg−1and 46.24 g·kg−1) compared to the control and the monoculture agent group (which added a single gut beneficial bacteria agent, either Bacillus cereus or Bacterium YC-LK-LKJ45). The bacterial agent altered the richness and diversity of the gut microbial community of BSF, increasing the relative abundance of beneficial bacteria such as Bacillus, Oceano bacillus, and Akkermansia, while decreasing pathogenic bacteria, such as Acinetobacter and Escherichia-Shigella. Structural equation model quantification revealed that α-diversity (λ = 0.897, p < 0.001) and BTR (λ = 0.747, p < 0.001) are crucial drivers for enhancing high-value biomass during bioaugmentation rearing. This investigation provides a theoretical framework for the effective management of food waste using BSF, enhancing its decomposition and transformation into higher-value biomass.

ULTRASOUND-ASSISTED ADSORPTION HG (II) USING KAOLIN ADSORBENTS MODIFIED WITH ANIONIC SURFACTANT

This study aims to test the reservoir wastewater containing domestic waste using a modified kaolinite adsorbent with Alkyl Benzene Sulfonate surfactant using ultrasonic technology (KM). First, the adsorbent to be used is characterized using several different techniques such as SEM analysis, and FTIR and the calculation of the efficiency of the adsorbent concerning contact time with wastewater. Meanwhile, the wastewater tested was tested for the effect of contact time on TDS and PH. The results of the analysis show that the maximum waste reduction efficiency occurs in modified kaolin (KM), where adsorption occurs faster than in unmodified natural kaolin (PK). The maximum percentage is 84, 21% for metal removal efficiency using modified kaolin at a contact time of 45 minutes and a weight of 1.8 g of adsorbent, while kaolin without modification has an efficiency of 62.47% at a contact time of 80 minutes and a weight of 1.8 g of adsorbent. The contact time test on the TDS value of wastewater that has been adsorbed with KM shows that the TDS value is getting lower over time, which indicates the Hg (II) ion has been dispersed and fused so that the Hg (II) metal in the water is reduced. The use of the adsorption method with the help of ultrasonic technology is proven to be more efficient in accelerating the removal of Hg (II) ions by increasing the surface dispersion of the adsorbent with metal ions in water. The contact time test on the TDS value of wastewater that has been adsorbed with KM shows that the TDS value is getting lower over time, which indicates the Hg (II) ion has been dispersed and fused so that the Hg (II) metal in the water is reduced. The use of the adsorption method with the help of ultrasonic technology is proven to be more efficient in accelerating the removal of Hg (II) ions by increasing the surface dispersion of the adsorbent with metal ions in water. The contact time test on the TDS value of wastewater that has been adsorbed with KM shows that the TDS value is getting lower over time, which indicates the Hg (II) ion has been dispersed and fused so that the Hg (II) metal in the water is reduced. The use of the adsorption method with the help of ultrasonic technology is proven to be more efficient in accelerating the removal of Hg (II) ions by increasing the surface dispersion of the adsorbent with metal ions in water.

Use of fermented spent coffee grounds as a substrate supplement for rearing black soldier fly larvae, Hermetia illucens (L), (Diptera: Stratiomyidae).

Spent coffee grounds (SCG), an increasingly abundant waste product with environmental disposal problems, has been used as a dietary supplement for many animals and have the potential to be used as a dietary supplement for black soldier fly (BSF) larvae; however, its effective use is still under scrutiny. To date, no studies have considered the use of SCG after microbial fermentation (fSCG) and its effects on BSF life history. A mixture of fruit and vegetable pulp residue supplemented with one of six different fSCG percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) were provided as a diet substrate in order to evaluate the effect of the fSCG quantity on BSF growth, yield, and conversion ability. The addition of fSCG to the pulp diet prolonged larval development times, while 100% fSCG affected the larval survival rate and resulted in a male-biased adult sex ratio. The 20-40% fSCG and 40-60% fSCG treatments supported the largest prepupal and mature larval sizes, respectively. The highest waste reduction efficiency and feed conversion rate by BSF larvae was found with 20% fSCG, similar to the control (0% fSCG). From the short rearing time, high yield, and high bioconversion efficiency, a 20% fSCG supplementation of the mixed pulp was recommended for rearing BSF larvae. These data are valuable for coffee by-product waste management in urban areas.

Diet Composition Influences Growth Performance, Bioconversion of Black Soldier Fly Larvae: Agronomic Value and In Vitro Biofungicidal Activity of Derived Frass

In recent years, the larval stage of Hermetia illucens, commonly known as the black soldier fly (BSFL), has been used to promote the circularity of the agri-food sector by bioconverting organic waste into larval biomass which has been used as a livestock feed. A secondary byproduct of this process is frass that can be used as an organic fertilizer. This study compared two different plant-based diets on frass characteristics as well as larval performance, nutritional composition, and waste reduction efficiency. A fruit/vegetable/bakery waste-based diet supplemented with brewery waste (FVBB) was compared to a control Gainesville (GV) reference diet and fed to BSFL under standard conditions. The results demonstrated that NPK and some of the macro and micronutrients in both frasses are comparable to commercially available organic fertilizers. It was shown that microorganisms present in frass from the two diets inhibit the mycelial growth of several plant pathogens through the production of antifungal and/or anti-oomycetes compound(s) (antibiosis). This diet also had a positive effect on individual larval mass (162.11 mg), bioconversion rate (13.32%), and larval crude lipid (35.99% of dry matter) content. The BSFL reared on this diet reduced feedstock dry matter by 67.76% in a very short time (10 days), which is a promising solution for food waste management.

Effect of Feeding Rate on Growth Performance and Waste Reduction Efficiency of Black Soldier Fly Larvae (Diptera: Stratiomyidae).

Malaysia like many other developing countries is facing the challenge of poor waste management. This research was conducted to determine the effect of black soldier fly (BSF) larvae in decomposing food waste, palm oil waste, fish waste and yard waste. The development time and waste reduction efficiency of four different organic materials were evaluated. In this study, BSF larvae were fed with all four types of waste at five feeding rates of 0.25, 0.50, 1.00, 1.50 and 2.00 g larva−1 day−1 with three replicates per feeding rate until the larvae reached the pre-pupae stage. During the study, larval development time, larval mortality, pre-pupae weight and waste reduction indexes (WRI) were determined. Food waste and yard waste achieved the highest WRI of 4.43 ± 0.06 and 0.71 ± 0.01, respectively at the feeding rate of 0.50 g larva−1 day−1 while palm oil waste and fish waste attained the highest WRI values at feeding rates of 1.00 g larva−1 day−1 (1.89 ± 0.02) and 0.25 g larva−1 day−1 (3.75 ± 0.24), respectively. The results showed that both variables significantly influenced the bioconversion process, but waste reduction efficiency was the most influential element.

Household waste reduction efficiency of Hermetia illucens larvae

Waste management with limited resource input under minimum space is the need of the hour. Black Soldier Fly (BSF)/Hermetia illucens is a fly prevailing and flourishing in our tropical climatic condition and is a miracle insect since it can solve a multitude of global problems like waste management, animal feed production and energy production. This fly is highly reputed in converting low quality biomasses in to high protein, high energy larvae meal. In this study we are assessing the quantity of BSF larvae produced from food waste and the waste reduction efficiency of the BSF larvae. Four kilograms of food waste was kept in a modified bin with 6 replicates and the development of the larvae was through natural breeding. The study revealed that from the above said quantity, an average of 0.567kg of BSF larvae can be produced per bin and average waste reduction efficiency was 73.81%.

REMOVAL OF HG(II) METAL IONS USING KAOLIN ADSORBENTS MODIFIED WITH ANIONIC SURFACTANT AND EFFICIENT ULTRASONIC ASSISTED

This study reported the reduction of metal Hg(II) from water using natural kaolinite (NK) based adsorbents compared with modified kaolinite adsorbents with Hexadecyl trimethyl ammonium bromide anionic surfactants using ultrasonic technology (SMK). These adsorbent samples were characterized using several different techniques such as FTIR, X-RD and AAS analysis. The adsorption capacity is influenced by variables such as the contact time and adsorben dosage. The results of the analysis reported that the maximum waste reduction efficiency occurs in modified kaolin (SMK), where adsorption occurs faster than natural kaolin (NK). The maximum persentation is 94.57% for metal removal efficiency using modified kaolin at the contact time of 45 minutes and the dose of adsobene 1.4 g, while kaolin without modification is 73.83% of efficiency at the contact time of 60 minutes the adsobent dose was 1.4 g. The use of the adsorption method with the help of ultrasonic technology is proven to be more efficient in accelerating the removal of Hg2+ ions by increasing the surface dispersion of the adsorbent with metal ions in water. The adsorption kinetics model that is suitable for calculating the adsorption capacity of the adsorbent in the removal of Hg2+ ions using unmodified kaolin is pseudo-second-order models.

Growth Performance, Waste Reduction Efficiency and Nutritional Composition of Black Soldier Fly (Hermetia illucens) Larvae and Prepupae Reared on Coconut Endosperm and Soybean Curd Residue with or without Supplementation.

Simple SummaryBlack soldier fly (BSF, Hermetia illucens) larvae have a high potential to convert organic waste into high-value products. However, the growth performance, waste reduction efficiency, and chemical composition of BSF larvae are greatly influenced by the rearing substrate. This study focused on investigating the growth performance, waste reduction efficiency, and nutritional composition of BSF larvae reared on different ratios of coconut endosperm (C) and soybean curd residue (S), with or without supplementation, compared to standard diets (Gainesville: G and starter chicken diet: CK). The results showed that BSF larvae fed CK has the highest larval weight, followed by those fed coconut endosperm and soybean curd residue at a ratio of 20:80 (C20S80), and coconut endosperm and soybean curd residue at a ratio of 50:50 (C50S50) without supplementation. The greatest waste reduction efficiency was observed in the G, C50S50, and C20S80 groups without supplementation. The highest crude protein content in larvae was presented in the G and C20S80 groups followed by the CK and C50S50 groups. Therefore, equal proportions of C and S without supplementation is likely the best formulation for growth performance, waste reduction efficiency, and nutritional composition of BSF larvae when compared with standard diets.Black soldier fly (BSF, Hermetia illucens) larvae are considered as insects with a high potential to convert organic waste into high-value products. The objective of this study was to investigate the growth performance, waste reduction efficiency, and nutritional composition of BSF reared on different ratios of coconut endosperm (C) and soybean curd residue (S), with or without supplementation, compared to standard diets (Gainesville: G and starter chicken diet: CK). Seven-day-old larvae were randomly divided into eight experimental groups (G, CK, and three different ratios of C and S with or without supplementation) with three replicates with an equal weight of larvae. The supplement contained calcium, phosphorus, amino acids, and a mineral–vitamin premix which was formulated to correlate with CK. Each replicate was terminated, measured, and evaluated when 40% of larvae had reached prepupal stage. The highest larval weight gain was presented in BSF fed CK, followed by those fed coconut endosperm and soybean curd residue at a ratio of 20:80 (C20S80), and coconut endosperm and soybean curd residue at a ratio of 50:50 (C50S50) without supplementation (numbers after C and S represent their percentage in the formulation; p < 0.001). Harvesting was delayed in the BSF fed C80S20 with and without supplementation (p < 0.001). The number of total larvae and prepupae was not significantly different between groups (p > 0.05). The greatest waste reduction efficiency was observed in the G, C50S50, and C20S80 groups without supplementation (p < 0.001). All groups with supplementation had a higher proportion of ash in both larvae and prepupae compared to non-supplemented groups (p < 0.001), but lower growth performance. The highest percentage of crude protein in larvae was presented in the Gainesville and C20S80 groups followed by the CK and C50S50 groups (p < 0.001). Equal proportions of C and S without supplementation are suggested as a rearing substrate. However, growth performance was lower than for CK; therefore, further studies could investigate cost-efficient techniques to promote this parameter.

Determining the Black Soldier fly larvae performance for plant-based food waste reduction and the effect on Biomass yield

Management of Municipal solid waste in low-income countries with high population densities such as India has always been a strenuous task. With perpetual advancements, there are many available technologies dealing with waste management such as incineration, pyrolysis and landfill operations. But such technologies are often accompanied with some limitations (operational and maintenance problems) and have negative environmental impacts. In this regard, continuous efforts are currently spent to develop the sustainable technologies for coping with the problems of waste management. Confronted with such problems, BSF larval composting has emerged as a green approach for waste management which outshines the various current technologies. However, it is not widely explored and therefore in the present study, BSF larval treatment efficiency has been tested against different types of food waste treatments viz., mix food waste (T1), restaurant waste (T2), fruit waste (T3), and vegetable waste (T4). We have also evaluated the Biomass Conversion Ratio (BCR) of BSF larvae. The waste reduction efficiency was found to be 72% for T1 followed by T3 and T2 whereas the efficiency was least for T4 corresponding to lower BCR comparatively. BCR obtained for T1 treatment was almost 25% which was exceptionally high in comparison to other published studies. The highest waste reduction efficiency and the BCR values for T1 may be attributed to appropriately balanced food nutrition and C/N ratio Therefore, it may be concluded that substrate type and its nutritional value strongly determines the growth and development of larva influencing the waste ingestion rate.

Comparative evaluation ofHermetia illucens larvae reared on different substrates for red tilapia diet: effect on growth and body composition

Black soldier fly larvae (BSFL;Hermetia illucens) can be a very beneficial source of protein to replace fishmeal for fish feed, but little is known about the impact of their growing substrate on the performance and nutritional composition of the fish consuming them. In this study, BSFL were reared on two different substrates; palm oil decanter cake (DC) and coconut pulp (CP) for 35 days before processing and including them in tilapia diet with 50% inclusion level. The weight and length of the BSFL as well as waste reduction efficiency was observed. The fish were assigned to three different diets, namely DC50 (50% BSFL from DC), CP50 (50% BSFL from CP) while 100FM (100% fishmeal) is treated as a control. The fish performance, feed efficiency and nutritional composition of their body after 4-weeks of feeding trial were observed. The results indicate that BSFL cultured in DC obtained higher body weight gain but less efficient in reducing waste compared to those cultured in CP. The utilisation of 50% inclusion level of BSFL cultured in DC for tilapia diet improves growth and feed efficiency. However, the inclusion of all experimental diets has a less pronounced effect on protein and ash body composition; although fish fed with CP50 has the least lipid body composition compared to other treatments. The experiment demonstrated that replacement of fishmeal by BSFL cultured in different substrates would influence the performance of fish consuming it. Results of the present study will offer an optimal solution, especially for large-scale commercial BSFL cultivation.

From a Food Safety Prospective: The Role of Earthworms as Food and Feed in Assuring Food Security and in Valuing Food Waste.

The Sustainable Development Goals are a set of global goals that provide a framework for shared action. These goals also include the reduction of food waste and the definition of sustainable solutions to achieve food security. In this context, the aim of the study was to describe all phases of a pilot earthworm rearing project started in September 2017 and concluded in December 2017, together with a risk analysis carried out in order to evaluate if earthworms can represent a safe and sustainable protein source for human consumption and/or animal nutrition. The conversion rate, that in this study is more appropriately identified as the “waste reduction efficiency,” was also calculated in order to define the extent to which earthworm rearing can contribute to the objective of reducing fruit and vegetable waste (FVW). The results showed that earthworms can bio-convert 3750 kg of FVW in three months producing 1050 kg of compost and 82 kg of fresh earthworms with minimal environmental impact showing good waste reduction efficiency. Moreover, the risk analysis conducted on earthworm rearing highlighted a microbiological hazard after the freeze-drying phase. The critical control point was therefore identified, and, in order to guarantee the total food safety of the finished product, corrective action was taken consisting in the implementation of heat treatment—sterilization at 121 °C for 20 min. The results of microbiological analyses carried out on the earthworm meal after the sterilization treatment showed that the treatment guarantees microbiological safety for the consumer and ensures a balanced approach in relation to two main topics—public health and food-borne diseases. In conclusion, earthworm meal is a concentrate of valuable nutrients useful for human and animal nutrition and can also transform fruit and vegetable waste into a resource.

A Review of the Use of Black Soldier Fly Larvae, Hermetia illucens (Diptera: Stratiomyidae), to Compost Organic Waste in Tropical Regions.

Hermetia illucens (L., 1758) is a fly of the family Stratiomyidae frequently found in tropical zones. Adult flies are not considered pathogens as they are incapable of biting and feeding thus not transmitting sicknesses to humans. The larval stage feeds off organic matter and offer a rich protein source naturally consumed by animals. The use of black soldier fly (BSF) larvae to treat organic waste is growing around the world. This is especially true for tropical low- and middle-income countries as their favourable climate conditions mean that the BSF technology has significant potential to solve existing problems associated with a poorly developed sanitation infrastructure. In this study, we evaluate the feasibility, benefits and limitations of implementing BSF projects in tropical regions using Belem, in Brazil, as a case study. Black soldier fly prepupae, arising from the waste reduction process, can be used as animal feed. It therefore offers potential to promote regional development, create jobs and dispose of organic waste locally. Legal requirements as outlined in the Brazilian National Policy on Waste offer further incentives. However, more studies are needed to compare BSF waste reduction efficiency and prepupae yield to other technologies such as traditional composting and vermiculture, which can inform the decision-making for implementation of organic waste treatment facilities.

Effect of rearing substrate on growth performance, waste reduction efficiency and chemical composition of black soldier fly (Hermetia illucens) larvae.

Wastes can be used as rearing substrate by black soldier fly (BSF) larvae, the latter being exploitable as a protein source in animal feed. This research aimed to assess the influence of four rearing substrates (Trial 1 (organic wastes): a mixture of vegetable and fruit (VEGFRU) vs. a mixture of fruits only (FRU); Trial 2 (agro-industrial by-products): brewery (BRE) vs. winery (WIN) by-products) on BSF larvae development, waste reduction efficiency and nutritional composition. If respectively compared to FRU and WIN, VEGFRU and BRE larvae needed less time to reach the prepupal stage (22.0, 22.2, 20.2 and 8.0 days of trial, respectively) and had higher protein content (229.7, 257.3, 312.9 and 395.7 g kg-1 dry matter). The waste reduction index ranged from 2.4 (WIN) to 5.3 g d-1 (BRE). BRE larvae showed the lowest saturated and the highest polyunsaturated fatty acid proportions (612.4 and 260.1 g kg-1 total fatty acids, respectively). Vegetable and fruit wastes and winery by-products can be used as rearing substrates for BSF larval mass production. Brewery by-products led to very promising larval performance and nutritional composition. However, given BRE limited availability, low BRE dietary inclusion levels could be used with the purpose of increasing larval performance. © 2018 Society of Chemical Industry.

Integrated Electroplating System Modeling and Simulation for Near Zero Discharge of Chemicals and Metals

The optimality of design and operation of an electroplating system determines largely coating quality, productivity, and waste reduction efficiency. Industrial practice shows that, in a usual operation, the solution loss from an electroplating unit through drag-out can be as high as 30% of overall consumption. This has dramatically increased operating cost as well as waste treatment cost. On the other hand, plating quality in terms of coating thickness on workpieces is always a concern in plants. To improve the economic and environmental performance, a key step is to have a deep understanding of the system. Model-based simulation has proven to be a cost-effective approach along this venue. This paper introduces a fundamental-based general modeling methodology for characterizing an integrated electroplating system that consists of a plating unit and a solution recovery subsystem. The methodology allows detailed system analysis and complete process information integration, which will be crucial for optimal design and operation of a closed-loop electroplating for prevention of plating solution loss and assurance of coating thickness on workpieces. A case study on an alkali zinc electroplating system will demonstrate the efficacy of the model-based design and operation approach.

Vermicomposting of household biowaste using Eisenia fetida: Evaluation of waste reduction efficiency and coexistent microbial community structure

Vermicomposting of household biowaste using Eisenia fetida: Evaluation of waste reduction efficiency and coexistent microbial community structure