Wastewater

About: Wastewater is a research topic. Over the lifetime, 92512 publications have been published within this topic receiving 1256590 citations. The topic is also known as: waste water.

Anaerobic Codigestion of Municipal Wastewater Treatment Plant Sludge with Food Waste: A Case Study.

Abstract: The aim of this study was to assess the effects of the codigestion of food manufacturing and processing wastes (FW) with sewage sludge (SS), that is, municipal wastewater treatment plant primary sludge and waste activated sludge. Bench scale mesophilic anaerobic reactors were fed intermittently with varying ratio of SS and FW and operated at a hydraulic retention time of 20 days and organic loading of 2.0 kg TS/m3·d. The specific biogas production (SBP) increased by 25% to 50% with the addition of 1%–5% FW to SS which is significantly higher than the SBP from SS of VS added. Although the TS, VS, and tCOD removal slightly increased, the biogas yield and methane content improved significantly and no inhibitory effects were observed as indicated by the stable pH throughout the experiment. Metal screening of the digestate suggested the biosolids meet the guidelines for use as a soil conditioner. Batch biochemical methane potential tests at different ratios of SS : FW were used to determine the optimum ratio using surface model analysis. The results showed that up to 47-48% FW can be codigested with SS. Overall these results confirm that codigestion has great potential in improving the methane yield of SS.

Laboratory Development of Permeable Reactive Mixtures for the Removal of Phosphorus from Onsite Wastewater Disposal Systems

Abstract: Laboratory batch and column studies were conducted to develop permeable reactive mixtures to remove phosphorus from the effluent of onsite wastewater disposal systems. Mixtures can be placed in situ, as horizontal or vertical reactive barriers in sediments receiving wastewater discharge, or can be used in single pass, self-contained treatment modules in alternative treatment systems. Reactive mixtures composed of silica sand, high calcium crushed limestone, and readily available metal oxides were tested to evaluate phosphorus attenuation. Iron/calcium oxides, produced from steel manufacturing, and fine-grained activated aluminum oxide outperformed other oxides tested during batch experiments. These materials removed greater than 99% of PO4 from a 10 mg/L PO4−P solution within 1 h of contact. Long-term attenuation capacities of the mixtures were assessed by continually loading bench-scale columns with a 3.3 mg/L PO4−P solution, at representative groundwater flow rates. A column containing 50 wt % silica sa...

Production of hydrogen from domestic wastewater in a pilot-scale microbial electrolysis cell.

Abstract: Addressing the need to recover energy from the treatment of domestic wastewater, a 120-L microbial electrolysis cell was operated on site in Northern England, using raw domestic wastewater to produce virtually pure hydrogen gas (100 ± 6.4 %) for a period of over 3 months. The volumetric loading rate was 0.14 kg of chemical oxygen demand (COD) per cubic metre per day, just below the typical loading rates for activated sludge of 0.2-2 kg COD m(-3) day(-1), at an energetic cost of 2.3 kJ/g COD, which is below the values for activated sludge 2.5-7.2 kJ/g COD. The reactor produced an equivalent of 0.015 LH(2)L(-1) day(-1), and recovered around 70 % of the electrical energy input with a coulombic efficiency of 55 %. Although the reactor did not reach the breakeven point of 100 % electrical energy recovery and COD removal was limited, improved hydrogen capture and reactor design could increase the performance levels substantially. Importantly, for the first time, a 'proof of concept' has been made, showing that this technology is capable of energy capture as hydrogen gas from low strength domestic wastewaters at ambient temperatures.