Application of collected shells as a bioremediator for fish pond effluent

Abstract

The increasing pollution caused by effluent from fish ponds is a significant environmental concern, particularly in aquaculture. This study evaluates the use of snail and crab shells as bioremediators to treat fish pond effluent. Snail and Crab shells were purchased from local seafood markets and a snail farm, washed, dried, and homogenized by grinding to a small particle size. 100 g each of the shells was measured and introduced into 10 L of plastic rubbers designated as control (no treatment), Treatment 1 (snail shells), Treatment 2 (crab shells), and Treatment 3 (a combination of both). Fish pond effluent was collected from a nearby fish pond and filled into the plastic at 8.5 L. Physical and chemical parameters (Total Hardness (TH), Total Alkalinity (TA), pH, calcium, chloride, Dissolved Oxygen (DO), BOD, COD, temperature, and Electrical Conductivity (EC) of the effluent water were measured three times weekly for 21 days. The Results indicate that Treatments 2 and 3 significantly improved water quality compared to the control and Treatment 1. T2 and T3 had greater reductions in BOD (1.26 and 1.24 mg/L, respectively) and COD, along with increases in TH, TA, and calcium content, demonstrating the effectiveness of crab shells in particular. T1 exhibited moderate improvements but was less effective than T2 and T3. Additionally, physical observations showed that T2 and T3 produced biofilms and microbial activity, which disappeared by Day 10. The study concludes that shell-based bioremediation is a sustainable, eco-friendly method for improving aquaculture effluent quality. Further research is recommended to optimize this technique for larger aquaculture systems and explore its economic feasibility.