Development of a Biochar-Based Laboratory- Scale Filter for Industrial Wastewater Treatment

Abstract

Abstract Biochar (BC) has lately emerged as a viable wastewater treatment agent. The invasive aquatic plant Pistia spp. was used in the present study to produce BC. Activated and non-activated BC samples were individually incorporated into a sand and gravel filter. Chemical and physical water quality parameters were measured in the experiment before and after treatment. The control filter was primarily developed using only sand and gravel. A brine shrimp lethality assay (BSLA) was carried out to evaluate the toxicity. The effect of particle sizes of BC (65-125mm and 125-250mm) and repeated treating process on treatment efficiency were carried out as optimization studies for activated BC filter. The filter unit containing activated Pistia spp. showed a higher treatment efficiency. BSLA revealed 100% mortality in raw wastewater and no mortality in activated BC treated water. The results of the optimization study revealed that, the BC integrated filter units could be used to treat wastewater for three consecutive cycles. The BC's small particle size (65-125mm) recorded the highest treatment. This particle size showed turbidity reduction by 99.72%. It was found that reduction of Total Phosphates, Ammoniacal Nitrogen, Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Nitrate (N-NO3−), Biological Oxygen Demand (BOD5) and Total Kjeldahl Nitrogen (TKN) by 97.82%, 91.49%, 88.38%, 88.18%, 87.44%, 84.38%, and 84.38% respectively. Hence, BC derived from Pistia spp. is a promising adsorbent for wastewater treatment. Findings of the study showed a long-term green wastewater treatment method that makes effective use of invasive aquatic plants.