Overview of biologically digested leachate treatment using adsorption

Biological process is effective in treating most biodegradable organic matter present in leachate; however, a significant amount of ammonia, metals and refractory organic compounds may still remain in this biologically digested leachate. This effluent cannot be released to receiving bodies until the discharge limit is met. Several physical/chemical processes have been practiced as post-treatment to remove the remaining pollutants including coagulation–flocculation, oxidation and adsorption. Adsorption is often applied in leachate treatment as it enhances removal of refractory organic compounds. This chapter will focus on works related to adsorption as one of the commonly used methods to treat biologically digested leachate further down to acceptable discharge limit

Overview of biologically digested leachate treatment using adsorption

Biological process is effective in treating most biodegradable organic matter present in leachate; however, a significant amount of ammonia, metals and refractory organic compounds may still remain in this biologically digested leachate. This effluent cannot be released to receiving bodies until the discharge limit is met. Several physical/chemical processes have been practiced as post-treatment to remove the remaining pollutants including coagulation–flocculation, oxidation and adsorption. Adsorption is often applied in leachate treatment as it enhances removal of refractory organic compounds. This chapter will focus on works related to adsorption as one of the commonly used methods to treat biologically digested leachate further down to acceptable discharge limit

Wastewater Treatment: Current and Future Techniques

Recently, national and international effluent standards have become more stringent, posing a significant challenge in the water treatment industry. Accordingly, treatment techniques with minimal energy consumption and maximal performance are urgently required for wastewater and water treatments. This topic was investigated from both technical and environmental perspectives to improve water and wastewater treatment techniques and enhance the quality of water bodies. This Special Issue (SI) has attracted investigations by researchers worldwide, including those from Australia, the United States, Finland, Turkey, South Africa, Oman, China, Japan, Malaysia, and Pakistan. In this SI, research and review articles propose and discuss efficient water and wastewater treatment techniques. We hope that the readers of Water can learn about new aspects of wastewater treatment using physicochemical, biological, and hybrid techniques. Finally, we hope that this SI will contribute to the United Nations’ Sustainable Development Goal 6, which is to ensure a secure water supply globally through cost‐efficient technologies

Organic matter removal of landfill leachate using integrated electrocoagulation-ultrasonic method

The utilization of hybrid treatment technologies has been recognized as one of the treatment methods conducted to enhance the efficiency of wastewater treatment due to the various challenges such as the high concentration of pollutants and the limited ability of a single treatment process. Leachate from Pulau Burung Sanitary Landfill (PBSL) has been categorized as poor biodegradability leachate and it is composed of high dissolved organic matter, inorganic components, and toxic substances. In this study, an integrated treatment between electrocoagulation (EC) and ultrasonic (US) was introduced to evaluate the effectiveness of the hybrid treatment process in landfill leachate treatment of organic matter removal in terms of COD compared with a single treatment with different operating conditions of voltage, treatment time, and distance of electrode. Other than that, the effect of the control factors on the weight loss of electrodes was also investigated. The maximum COD reduction from both single EC and combined EC-US methods have achieved the same best operating condition which are potential of 10 V, treatment time of 25 min, and electrode distance of 2 cm, but the combined EC-US treatment (61.13%) provide better removal of COD compared with the treatment process of a single EC method (37.51%). On the other hand, the highest weight loss of the electrode was observed at the anode (Al-21.60%) with the same operating conditions for the best removal efficiency in the EC-US process. It is found that the cathode (Fe) experienced a slight increase in the final weight of the electrode due to the hydrolyzation reaction. Hence, this research work demonstrated that the utilization of combined EC-US treatment significantly enhanced the removal of COD from leachate compared with the single EC method

Advanced treatment of poultry slaughterhouse wastewater using electrocoagulation and peroxidation: Parametric analysis and process optimization

In this research, electrocoagulation-intensified peroxidation using an aluminum electrode was studied as a post-treatment method for poultry slaughterhouse wastewater (SWW) with 4 operational variables (pH, current density, contact time, and H2O2 dosage). Optimization was carried out using response surface methodology. Analysis of variance was used to analyze the experimental data, and a second-order model was created to test the effects of process parameters on treatment performance. The optimum conditions were chosen as follows: pH 5.83, 0.18 g/L H2O2 dosage, 58.60 min contact time, and current density of 4.21 mA/cm2. The compatibility of the predicted optimum conditions has been verified by experimental data. As a result of the experiments performed under optimum conditions, COD, TSS, and color removals were found to be 97.89%, 99.31%, and 98.56%, respectively. The difference between experimental and predicted values was found to be less than 0.86%. The final treated effluent met the discharge standards determined by the World Bank, EU, US, and Malaysian Department of Environment. Under optimum conditions, the cost of treating 1 cubic meter of SWW was calculated as 3.02 MYR ($ 0.68)

Risk assessment of nitrate transport through subsurface layers and groundwater using experimental and modeling approach

Landfills are one of the main point sources of groundwater pollution. This research mainly aims to assess the risk of nitrate (NO-3) transport from the unlined landfill to subsurface layers and groundwater using experimental results and the SESOIL model. Samples from 12 groundwater wells downstream of the landfill were collected and analyzed in 2008, 21 years after the landfill construction. The average NO-3 concentration in the wells was 54 mg/L, slightly higher than the World Health Organization (NO-350 mg/L) standards. SESOIL model was used to predict the NO-3 concentration at the bottom of the unsaturated zone. Results indicated that the current mean NO-3 concentration at the bottom of the unsaturated zone is 75 mg/L. the model predicted that the level of NO3 will increased up to 325 mg/L within 30 years. Accordingly, the NO-3 concentration in groundwater wells near the landfill area is expected to gradually increase with time. Although the current risk associated with the NO-3 level might not be harm to adults, however, it might pose severe risks to both adults and infants in the near future due to NO-3 leaching. Urgent mitigation measures such as final cell cover (cap), lining system and vertical expansion should be considered at the landfill to protect the public health in the area. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group