Pharmaceuticals residues in selected tropical surface water bodies from Selangor (Malaysia): occurrence and potential risk assessments

This study investigated the occurrence of nine pharmaceuticals (amoxicillin, caffeine, chloramphenicol, ciprofloxacin, dexamethasone, diclofenac, nitrofurazone, sulfamethoxazole, and triclosan) and to evaluate potential risks (human health and ecotoxicological) in Lui, Gombak and Selangor (Malaysia) rivers using commercial competitive Enzyme-Linked Immunosorbent Assay (ELISA) kit assays. Physicochemical properties of these rivers showed the surface samples belong to Class II of Malaysian National Water Quality Standards which requires conventional treatment before consumption. All the pharmaceuticals were detected in all three rivers except for triclosan, dexamethasone and diclofenac which were not detected in few of sampling locations in these three rivers. Highest pharmaceutical concentrations were detected in Gombak river in line of being as one of the most polluted rivers in Malaysia. Ciprofloxacin concentrations were detected in all the sampling locations with the highest at 299.88 ng/L. While triclosan, dexamethasone and diclofenac concentrations were not detected in a few of sampling locations in these three rivers. All these nine pharmaceuticals were within the levels reported previously in literature. Pharmaceutical production, wastewater treatment technologies and treated sewage effluent were found as the potential sources which can be related with pharmaceuticals occurrence in surface water samples. Potential human risk assessment showed low health risk except for ciprofloxacin and dexamethasone. Instead, ecotoxicological risk assessment indicated moderate risks were present for these rivers. Nevertheless, results confirmation using instrumental techniques is needed for higher degree of specificity. It is crucial to continuously monitor the surface water bodies for pharmaceuticals using a cost-effective prioritisation approach to assess sensitive sub-populations risk

Growth and development of black soldier fly (Hermetia illucens (L.), Diptera: Stratiomyidae) larvae grown on carbohydrate, protein, and fruit-based waste substrates

There has been a surge in interest in using food waste (FW) as an insect-rearing substrate in recent years. We examine the effect of protein-based food waste (leftover boneless chicken, LBC), carbohydrate-based food waste (overnight rice, OR), and fruit-based food waste (rotten banana, RB) on the following parameters: substrate reduction (SR), waste reduction index (WRI), bioconversion rate (BCR) and relative growth rate (RGR). BSFL reared on OR feed substrate had the highest biomass (0.23±0.01) g at d9 followed by RB (0.22±0.00) g and LBC (0.16±0.00) g. Larvae from OR-fed BSFL were the longest, averaging 20.53±0.46 mm in length on d12. The SR calculated for all feed substrates were as followed: RB (95.35 ± 0.33)% > OR (85.29 ± 0.80)% > LBC (83.17 ± 0.27)%. The WRI for control (C) and BSFL-fed on all feeds were in the following manner: (RBC:8.90±0.00 g days-1, RBBSFL:9.53±0.00 g days-1) > (ORC:7.35±0.00 g days-1, ORBSFL:8.53±0.09 g days-1) > (LBCC:6.90±0.00 g days-1, LBCBSFL: 8.32±0.03 g days-1). OR-fed BSFL showed the highest BCR (76.0±1.0) % and RGR (0.32±0.01) days-1. The FW’s self-composting (as in control) influenced the BSFL’s SR and WRI in all diets. Overall, the BSFL’s growth and development are affected by the nature, quality, and type of diet of the feed substrates

Evaluating the growth and development of black soldier fly (BSF) (Hermetia illucens (L.) (DIPTERA: STRATIOMYIDAE) larvae reared on different agricultural waste materials

The black soldier fly (BSL), Hermetia illucens (L.), is a beneficial insect that helps manage high concentrations of animal manure and other biosolids in tropical and warm-temperate areas. Bioremediation with black soldier fly larvae (BSFL) can turn biosolids into high-value biomass (proteins, oils, lipids, and chitin). This study explored the effects of three agricultural wastes as feedstocks for the growth and development of BSFL. A total of 1000 7-day-old BSFLs were reared separately in containers containing either palm kernel extract (PKE), soybean waste (SW), or coconut milk waste (CMW). The effect of feeding substrate on larval growth and development was determined for ten days by daily measurements of the BSFL’s length and weight. BSFL reared on PKE substrate resulted in the highest mean length (22.67±2.31 mm) and weight growth (0.27±0.02 g), followed by BSFL reared on SW (length: 18.67±1.53 mm; weight: 0.20±0.02 g) and CMW (length: 18.33±0.58mm; weight: 0.15±0.01 g). Bioconversion rate of BSFL was also found to differ across treatments; BSFL reared on PKE grows and converts substrates twice as fast as those fed on SW or CMW. This work then examines the effects of several SW:PKE ratios (20:80; 80:20; 30:70; 70:30 and 50:50) on BSFL growth. The weight (0.28±0.04 g) and length (22.67±2.52 mm) of BSFL were highest when SW:PKE ratio of 80:20 is used. High content of SW resulted in a significant increase in BSFL length (6.76%-15.25%) and weight (23.54%-64.71%). Therefore, it can be concluded that substrate feed type has a substantial effect on BSFL’s growth and development