Assessment of biological trickling filter systems with various packing materials for improved wastewater treatment

Abstract

Attached growth processes for wastewater treatment have significantly been improved during recent years. Their application can be extended to sustainable municipal wastewater treatment in remote locations and in developing countries for the purpose of organic matter (biochemical oxygen demand, BOD) removal and pathogenic decontamination. The aim of this study is to assess selected packing media for biological trickling filters (BTFs) and to develop a simplified model for describing the capacity of BOD removal in BTFs. In this work, BTFs with four different media viz., rubber, polystyrene, plastic and stone have been investigated at two temperature ranges of 5-15°C and 25-35°C. The average removal of both chemical oxygen demand and BOD was higher than 80 and 90% at temperature ranges of 5-15 and 25-35°C, respectively. The geometric mean of faecal coliforms in BTF using polystyrene, plastic, rubber and stone as filter media was reduced by 4.3, 4.0, 5.8 and 5.4 log10, respectively, at a low temperature range of 5-15°C. At a higher temperature range of 25-35°C, the faecal coliform count was reduced by 3.97, 5.34, 5.36 and 4.37 log10 from polystyrene, plastic, rubber and stone media BTF, respectively. Simplified model was developed and used to estimate the optimal BOD loading rates (Bvd) for designing robust BTF systems, with appropriate filter media. It has been concluded that highly efficient BTFs can be designed using various filter media, which may be capable of treating organic loading rates of more than 3 kg BOD/m3 day. These types of BTFs can be applied for the BOD and microbial contaminants removal of wastewater for potential reuse in developing countries.

Experimental Study on Maize Cob Trickling Filter-Based Wastewater Treatment System: Design, Development, and Performance Evaluation

“…3 and 4, respectively. This is because the anaerobic zone was destroyed using proper flushing, by which the aerobic zone was maintained in the outer portion of the slime layer [39][40][41][42]. Therefore, in the present study after 40 days of MCTF-WWT system operation, 85-90% of COD and BOD removal efficiencies were yielded.…”

Removing Organic Matter and Nutrients from Swine Wastewater after Anaerobic–Aerobic Treatment

“…According to Metcalf and Eddy [22], a steady operating state in trickling filters is usually reached in about four weeks of continuous operation, although other authors have observed that the steady state for COD removal can occur anywhere from three days to seven weeks [33,34]. Naz et al evaluated different media in a trickling filter, and observed that the highest COD removal efficiency was obtained by stone (93.4%), outperforming plastic (89.4%), polystyrene (86.3%), and rubber (81.9%) [13].…”

Identification and Elucidation of the Designing and Operational Issues of Trickling Filter Systems for Wastewater Treatment

“…The thickness and shape of the biofilm is influenced by several environmental factors such as the type of pollutant, packing material used, ambient air and wastewater temperature, humidity, moisture content, system design, and configuration of the treatment system [13,23,137]. Wijeyekoon et al [112] reported that organic loading influenced biofilm internal microstructure as with the increased organic load that produced a compact biofilm layer with lower porosity.…”

“…Mixing of industrial wastewater in influent during VOC degradation Anaerobic conditions in the system Try to neutralized the TF influents by using buffer materials for, e.g., calcium carbonate and dolomite Use nutrient solution, for example Ca(OH) 2 , NaOH, NaHCO 3 , and urea [13,126,129] Biofilm/Slime layer Improper media selection Uneven nutrients supply Uneven aeration High organic and hydraulic loading rates Uneven sloughing Weather Conditions Control the slime layer thickness by sloughing process Create aerobic conditions by maintaining optimum oxygen transfer rate Use good filter media that support microbial growth Use a chemical addition like ferric chloride and polymers to enhanced the growth of the slime layer and also trickling filter efficiency Use optimum oxygen levels for proper growth of bio-film Optimum amounts of nutrient solutions can be applied for microbial growth Increase the DO level of influent by recirculating the effluent Optimize the organic loading rate to maintain bio-film structure [13,23,80,[136][137][138][139][140][141][142][143] effect in TF systems. It was also observed that biofilm thickness also fluctuates seasonally and the thickness was increased in winter and decreased in summer [13,79].…”

“…The key consideration and hindrance in selection of a suitable treatment system is the cost, energy, trained human resources, system compatibility, and operational complications [15]. The right choice of an appropriate and workable technology is very important because of the [19] Membrane Bioreactor Wastewater COD, MLSS, MLVSS, ammonium nitrogen, phosphate-phosphorus, and TOC [20] Bioremediation (Constructed Wetlands) Municipal wastewater BOD 5 , COD, and nutrients (nitrogen and phosphorus) [21] Constructed Wetlands Domestic wastewater TSS, TDS, SO 4 -2 , PO 4 -3 , NO 3 , NO 2 bacterial counts and fecal pathogens [22] Trickling Biofilter System Municipal wastewater Ammonium nitrogen, BOD 5 , COD, and pathogen [23] Bio-Sorption Synthetic wastewater NH 4 + [24] Anaerobic Reactor and Fenton's Process Textile wastewater Color, COD, and turbidity [25] Constructed Wetlands Industrial wastewater EC, turbidity, COD, TSS, TDS, TS, nitrates, ammonia, phosphates, heavy metals (i.e., Cd, Ni, Hg, and Pb) [26] Bio-Sorption Textile wastewater COD, TDS, TSS, and color [27] Bio-Remediation Textile wastewater. BOD, COD, TOC, and cytotoxicity [28] Advanced Oxidation Processes Municipal wastewater BOD, COD, turbidity, conductivity, pH, and fecal coliform [29] Fixed Biomass and Sand Column Reactor Municipal wastewater Odor, alkalinity, pH, turbidity, BOD 5 , COD, TDS, TSS, EC, PO 4 , SO 4 , NO 3 , NO 2 , and DO [30] Membrane Bioreactor Synthetic wastewater Nutrients [31] Hybrid Constructed Wetland (HCW) Domestic wastewater NO 3 , NO 2 , BOD 5 , COD, SO 4, PO 4 , and pathogenic [32] Fixed Biofilm Reactor Municipal wastewater…”