Waste management service is inefficient in peri-urban and rural areas where biowaste is a major component of the household waste produced. Biowaste recycling using black soldier fly larvae (BSFL) at source can reduce the burden on the authorities and add economic value to a yet underutilized resource. This study evaluated the practicability of BSFL bin use at the household level to handle kitchen biowaste by placing three bins per house after 15 days interval of larval feeding. It was found that 50% of the households contacted cooperated well to continue the experiment. A set of instructions for handling BSFL bins based on reasons of agreement and disagreement was developed and shared. Key parameters to evaluate waste treatment performance and larval development were waste dry matter weight reduction (89.66%, SD 6.77%), volumetric reduction (81.3%, SD 4.8), final prepupal dry weight (69 mg/larvae, SD 7.1), biomass conversion rate (12.9%, SD 1.7), metabolism (77.3%, SD 6.0) and residue (10.4%, SD 6.8). On average, 87.7% (SD 9.1) of waste was actually digested, with 16.6% (SD 2.2) efficiently converted into biomass. Initial moisture content of waste was found to be more significant for achieving greater waste dry weight reduction as compared with the feeding rate. Source separation of biowaste and cooperation between households and authorities may lead to successful implementation of BSFL-assisted biowaste bins.

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a b s t r a c tThe study was based on the wastewater quality of the four drains (Outfall, Gulshan-e-Ravi, Hudiara and Babu Sabu) entering into river Ravi in Lahore, Pakistan. Pollution parameters were analyzed including pH, dissolved oxygen, biological oxygen demand (BOD), chemical oxygen demand (COD), turbidity, electrical conductivity (EC), total suspended solids, nitrates, phosphates, sulfates and fecal coliform. All parameters of drains exceeded the permissible level of wastewater standards. Hudiara drain showed the highest pollution load in terms of COD: 429.86 t/d while in Babu Sabu drain, highest pollution load was calculated in terms of BOD: 162.82 t/d. Lab-scale treatment (oxidation ponds) was designed to treat the wastewater of the Babu Sabu drain, through combination of different algae species, namely Chaetomorpha sutoria, Sirogonium sticticum and Zygnema sp. Two different size ponds (horizontal and vertical), and three different concentration of algal samples (25, 50 and 75 g/3 L) were selected for 6 d retention time. Percentage removal efficiencies of parameters in vertical and horizontal ponds, that is, turbidity: 62.12%, 69.79%; EC: 79.3%, 83%; BOD: 86.6%, 88.5%; COD: 79.72%, 83.01%; FC: 100%, 100%; nitrates: 89.6%, 89.8%; sulfates: 96.9%, 97%; phosphates: 85.3%, 86.3% and TOC: 75.6%, 79% were observed, respectively. Maximum reduction was observed after day 6 in the 50 g/3 L algae setup in horizontal pond due to large surface area. Results concluded that algae-based treatment is the most energy efficient and cost-effective in improving water quality in drains.

The availability and continuous supply of black soldier fly larvae (BSFL) is crucial for efficient operation of a BSF biowaste recycling facility. Its rearing performance was for the first time investigated in Pakistan under outdoor ambient weather conditions. Comparison of the findings with the BSF rearing performance of Indonesia’s facility highlights the life stages needing special attention. In Pakistan, mean BSF emergence, hatching and survival rate of 58.8% (SD 15.2), 44.5% (SD 21.8) and 91.4% (SD 1.68) were achieved respectively. A positive significant correlation was found between the number of emerged flies and prepupae ( R = 0.75) and the number of eggs produced and hatched ( R = 0.92). On average, BSF took 49.5 days (SD 3.20) to complete one life cycle (LC) under ambient temperature and relative humidity (RH) between (22–35 °C) and (24.7–89.3%) respectively. The mean duration of eclosion, pre-oviposition, egg hatching, larval feeding and pupation was 15.6 days (SD 1.6), 3.5 days (SD 0.5), 3 days (SD 0.6), 22 days (SD 2.5), 3.8 days (SD 1.2) respectively. In Pakistan, the LC duration was longer with a smaller number of eggs/fly, lower BSF emergence and hatching rates as compared to Indonesia. BSF tolerated the semiarid weather conditions of Pakistan, successfully developed into all instars and completed all LCs under observation. It is suggested to provide controlled environmental conditions at the nursery stage to improve BSFL rearing performance for sustainable biowaste management.

Black Soldier Fly Larvae (BSFL) (Hermetia illucens) waste treatment process is a promising solution for reclaiming organic waste which is up to 50% of municipal waste produced in the developing countries. BSFL operational guidelines issued by EAWAG Switzerland recommend 5-10 cm thick waste layers for the treatment process requiring large space especially for treating huge quantities of waste. This study explored performance of BSFL waste treatment process for waste feeding layers with thickness between 10-100 cm on a pilot scale in Pakistan. The key parameters analyzed were, waste layer thickness and 50% thickness reduction with time, dry matter waste weight reduction and volume reduction which indicated degree of waste treatment. Furthermore, larval weight gain, bio conversion rate (BCR), residue and metabolism were also calculated. Waste layer thickness reduction varied between 68.9 (SD 0.75)-96.7 % (SD 0.65), waste dry weight reduction 45.2 (SD 5.20)-96.5% (SD 0.20) and volume reduction was found to be between 64.0 (SD 3.46) and 87.9% (SD 2.61) for layers with thickness of 10-100cm. Final larval weight and bioconversion rate ranged between 0.031-0.047 g and 6.01% and 9.94% respectively in different layers. Metabolized waste was more than the residue in all samples except the one with 90cm waste layer thickness. This study confirmed that space foot print of BSFL treatment process can be decreased using waste layers with higher thickness than the widely practiced 10 cm thickness.