Modified Septic Tank: Innovative Onsite Wastewater Treatment System

Abstract

This research documents two innovative designs of septic tanks used for onsite wastewater treatment. The designs were implemented and tested as part of a research project focused on innovative decentralized wastewater treatment solutions. The modified septic tanks were tested at different hydraulic loading rates for sufficient periods to effectively evaluate their performance. The two systems were designed with successive anaerobic and aerobic chambers and were differentiated between attached and suspended growth. The systems were operated at detention times of 4.3, 3.2, and 2.6 days. High removal of organic load was achieved under all loading criteria in both systems. Effluent BOD 5 concentration at lower and higher loading rates were found to be less than 15 and 25 mg/L, respectively, representing a removal rate of more than 95%. Nitrogen was also removed but at a lower rate. The highest TN removal was achieved (59%) in the attached growth system at the lowest loading rate. Although two logs of E. coli removal (99%) were achieved in all systems, E. coli numbers were high enough to necessitate further tertiary treatment. The modified septic tanks proved to be a cost-effective technology with low energy and O&M requirements.

Performance and kinetic modeling of modified attached-growth anoxic-oxic-anoxic reactor for onsite sanitation system treating septic tank effluent

“…The results of μ max and K B for TN removal in this study were higher than those of the NH 4 -N previous study of [10]. Additionally, the Stover-Kincannon model were also previously applied for evaluating kinetic coefficients for TN removal in the up-flow anoxic-aerobic sludge reactor, the bio-diatomite biofilm reactor, the up-flow aerobic-anoxic sludge bed reactor, the up-flow anaerobic sludge bed-anammox reactor, the anaerobic-aerobic reactor and combined anaerobic aerobic systems [13,17,24,33,34].…”

“…Based on the experimental results obtained for this study, the following conclusions can be drawn: The modified AG-AOAR could be effectively used as an effective on-site post-treatment system for removing COD, NH4 and TN concentrations in septic tank effluent. The maximum COD, NH 4 -N and TN removal efficiencies were obtained as 83.8, 91.4 and 66.1% at the OLR, NLR and NLR and HRT of 0.25 gCOD/(L-d), 0.05 gN/(L-d), 0.05 gNH 4 -N/(L-d) and 72 h, respectively.…”

“…Furthermore, the United Nations Sustainable Development Goals aim to provide clean water and sanitation (Goal 6) for more than 2.4 billion people currently being without proper sanitation [3]. Recently, there are numerous reports an upgrading performance of the onsite systems which normally focus on organics and solid removals, but high of total nitrogen (TN) were still found in the effluent [4]. Because the TN needs to be managed appropriately, the biological nutrient removal processes such as nitrification/denitrification have been applied for enhancing TN removal.…”

Strategy of Household Wastewater Management with Reduce, Reclaim and Reuse System (3R)

“…But it needs to be understood that the communal WWTPs that were sampled were the best WWTPs that were chosen purposively. According to [11], [63], [64], [65], [66], [67], that the septic tank is very good at maximum operation can reduce the BOD pollution load by 60%. The strategy to maximize the performance of WWTPs to reduce pollution load can be done by: carrying out maintenance of WWTP on a regular basis, operating WWTP continuously so that the microorganisms contained in the reactor as breeding decomposers are not disturbed, avoiding waste water flow into the WWTP network containing ingredients chemicals that can kill microorganisms, such as cleaning agents or anti-septic substances, avoid flowing into the WWTP network of hightemperature wastewater.…”

A modified upflow anaerobic sludge blanket reactor as an alternative for decentralized domestic wastewater treatment in developing countries

“…Therefore, there has been increased interest in the installation of decentralized wastewater treatment systems that employ a combination of onsite and/or cluster systems both in peri-urban and rural areas of small and medium-sized municipalities (Massoud et al 2009;Singh et al 2014;Chernicharo et al 2015). Abbassi et al (2018) state that in the USA alone, around 60 million people are connected to on-site wastewater treatment systems.…”