Effects of black soldier fly larvae (Diptera: Stratiomyidae) on food waste and sewage sludge composting.

With the rapid development of the economy and population, the improvement of life level, enormous organic wastes have been generated. Black soldier fly larvae (BSFL) treatment is an attractive management method as it provides a strategy for waste treatment while also generate biofertilizers. The aim of this study was to evaluate the BSFL processing residue quality through the physical and chemical parameters. The sewage sludge (T1) and food waste (T2) were employed with BSFL (7:1.2 ration on fresh weight basis) and without BSFL T3 and T4 was marked control and composted for 9 days. The results showed that the BSFL composting reduced the organic matter by 14.51-21.98% and the accumulation of volatile fatty acids by 10.12-28.50%. While BSFL composting greatly increased total kjeldahl nitrogen by 23.15% compared with T4, T1 remained essentially unchanged. The additive of BSFL was significantly increased the total phosphorous and potassium in T2, but T1 remained stable compared with control. These results showed that the BSFL could improve the quality of end product and promote the food waste degradation. The current study indicates that the BSFL management provides an environmentally relevant alternative with very convenience in food waste. Further research should focus on residue sanitation.

Liu T ，Awasthi MK ，Awasthi SK ，Duan Y ，Zhang Z ... -  《-》

Performance of black soldier fly larvae (Diptera: Stratiomyidae) for manure composting and production of cleaner compost.

The increasing number of livestock farms has led to a great deal of manure generation, and its improper treatment results in threats to the environment. Black soldier fly larvae (BSFL) have the potential to effectively convert manure into high-quality fertilizer. The aims of this investigation were to observe the organic matter transformation of different livestock manures and volatile fatty acids (VFAs), and to evaluate the end product quality. Three types of manure [chicken (T1), pig (T2), and cow (T3)] were inoculated with BSFL (1.2:7 ratio on fresh weight basis), three types without BSFL were used as control (T4, T5, and T6), and both were composted for 9 days. The results showed that the BSFL composting reduced the organic matter by 20.31-22.18% and the accumulation of VFAs by 25.58-80.08% as compared to the control. BSFL composting greatly decreased the nitrogen, by 6.08-14.37%. The employment of BSFL significantly increased the total phosphorous (TP), total Kjeldahl nitrogen (TKN), and total nutrients by 42.30-64.16%, 45.41-88.17%, and 26.51-33.34%, respectively. This study showed that employing BSFL could improve the quality of the product and the maturity degree of the composting. Therefore, the BSFL could be added as a high-efficiency transformation agent for converting organic manure into stable compost, especially in developing countries, where adopting technical devices for composting is expensive and difficult to manipulate.

Liu T ，Awasthi MK ，Chen H ，Duan Y ，Awasthi SK ，Zhang Z ... -  《-》

Conversion food waste and sawdust into compost employing black soldier fly larvae (diptera: Stratiomyidae) under the optimized condition.

The increasing number of food waste (FW) had led to an urgent methods to recycle, black soldier fly larvae (BSFL) was a potential quick waste manager. To assess the impact of BSFL on conversion FW and sawdust into compost via the parameters of maturity, nutrient transformation and volatile fatty acids (VFAs). Meanwhile, the artificial of FW contained noodles, cabbages, rice and pork. FW and sawdust were employed by BSFL (6.5:0.5:1.2 ratio on fresh weight basis) as T1 and without BSFL called control (T2), while moisture content for FW and sawdust was 86.57% and 5.98%. Results illustrated that BSFL declined the composting time and only 9 d. Compared with initial mixture materials, T1 decreased organic matter, total kjeldahl nitrogen and VFAs from 97.41 to 85.96%, 23.01 to 17.77 g kg-1 and 3.25 to 1.69 g kg-1, respectively. However, T1 increased the total phosphorous and total potassium in 3.8 folds and 5 folds. The value of pH and EC reached at 4.27 and 1100 μS cm-1, and the germination index attained to 70.69%. In addition, redundancy analysis was used to analysis the correlation between factors under composting employed with different additive ratio of BSFL. Therefore, BSFL played a vital role in FW and sawdust recycling, especially reduced composting time and made the final separation of larvae and substrate easily, saving labor costs.

Liu T ，Awasthi SK ，Qin S ，Liu H ，Awasthi MK ，Zhou Y ，Jiao M ，Pandey A ，Varjani S ，Zhang Z ... -  《-》

Manure pretreatments with black soldier fly Hermetia illucens L. (Diptera: Stratiomyidae): A study to reduce pathogen content.

This study aim was to investigate the influence of black soldier fly larvae (BSFL) Hermetia illucens L. (Diptera: Stratiomyidae) on pathogenic bacteria (PB) survival in the chicken manure (CM), pig manure (PM), cow manure (COM) and sewage sludge (SS) compost. Three kinds of manure [chicken (T2), pig (T4) and cow (T6)] and SS (T8) were inoculated with BSFL (1.2:7 ratio on fresh weight basis) and without BSFL (T1, T3, T5 and T7) was used as control and experiment lasted for 9 days. The results indicated that BSFL amendment 90-93% of PB abundances (RAs) was significantly mitigate in CM and COM (T2 and T6), and 86-88% in PM and SS compost. However, relatively greater abundance of PB was recorded in the T4 and T8 treatments. Most of the PB belong to Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes phylum and their community composition varied from phylum to species levels among the all treatments. The PB composition was significantly altered by BSFL amendment and also important role play to enhance in compost quality. Interestingly, Bacillus and Clostridium were significantly very less abundant present in BSFL applied treatments, but considerably higher population of these bacterial genus and its associated species were identifies from control or without BSFL applied treatments. Overall, without BSFL blended-all three kinds of manure-composts have comparatively greater PB abundance than with BSFL applied treatments, as the PB species Listeria_monocytogenes_FSL_R2-503, Staphylococcus_aureus_M0406, Bacillus_anthracis, Listeria_ivanovii, Staphylococcus_aureus_C0673, Salmonella Bacillus_cereus_VD115, Mycobacterium_tuberculosis_FJ05194 and Pseudomonas_aeruginosa has relatively greater RAs, followed by Bartonella_bacilliformis_Ver075; Bordetella_pertussis_2356847; Brucella_melitensis_ADMAS-G1; Klebsiella_pneumoniae_LCT-KP182 and Corynebacterium_jeikeium_K411 respectively. Thus, chicken manure composting with BSFL addition is efficient technology for the organic waste recycling and conversion of sanitized matured compost with significantly less abundance of pathogenic bacteria.

Awasthi MK ，Liu T ，Awasthi SK ，Duan Y ，Pandey A ，Zhang Z ... -  《-》

Process efficiency and ventilation requirement in black soldier fly larvae composting of substrates with high water content.

In order to transition from a linear to a circular economy in the organic waste management sector, more of the elements in waste need to be recycled. Use of black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) larvae (BSFL) for organic waste treatment has potential to harvest more complex molecules than conventional methods. Many organic waste substrates have high water content (>80%), but the impact on BSFL treatment efficiency of substrate water contents >80% is not known. This study evaluated the impact of high water content food waste on BSFL composting efficiency in terms of waste-to-biomass conversion ratio, material reduction, larval survival and the ventilation required for enabling dry separation of larvae from residue. In total, six water contents ranging from 76% to 97.5% were evaluated in two experimental trials. It was found that increasing water content reduced biomass conversion ratio and survival rate of the larvae, from 33.4% of volatile solids (VS) and 97.2% survival in 76% water to 17.5% of VS and 19.3% survival in 97.5% water. Furthermore, we found that the ventilation requirement for achieving dry separation of larvae from residue could be modelled by estimating the amount of water that would need to be removed, taking into account the water bound in the larvae, and knowing the specifics of the ventilation set-up of the modelled system. The findings could have implications on the waste management sector interested in implementing BSFL treatment, as the findings demonstrate that it is possible to treat wet substrates (such as fruit and vegetable wastes) without any pre-treatment other than grinding and attain an adequately dry residue for enabling dry separation of the larvae from the residue.

Lalander C ，Ermolaev E ，Wiklicky V ，Vinnerås B ... -  《-》