Sludge Granulation During Anaerobic Treatment Of Pre-Hydrolysed Domestic Wastewater

ABSTRACT The objective of this study was to evaluate the efficiency of electrocoagulation in the removal of Escherichia coli from domestic and urban wastewaters and to determine the effects of the main operational parameters on the process. An electrocoagulation reactor with aluminum and iron electrodes was built for this purpose. A factorial design was applied, where amperage, treatment time, and pH were considered as the factors and E. coli percent removal was the response variable. After 20 min of treatment, >97% removal efficiency was achieved. The highest E. coli removal efficiency achieved was 99.9% at a neutral pH of 7, amperage of 3 A, and treatment time of 60 min. However, the removal efficiency of close to 99% was also achieved at natural wastewater pH of 8.5. The statistical analyses showed that the three tested factors significantly affected the E. coli removal percentage (p < 0.05). These results indicate that electrocoagulation has a high disinfection power in a primary reactor in removing water con[1]taminants as well as simultaneously removing pathogenic microorganisms when compared to biological treatment processes. This represents an additional benefit, because it will considerably reduce the use of chlorine during the final disinfection stage.

Abstract : The robustness of reverse osmosis (RO) against polar organic micropollutants (MPs) was investigated in pilot-scale drinking water treatment. Experiments were carried in hypoxic conditions to treat a raw anaerobic riverbank filtrate spiked with a mixture of thirty model compounds. The chemicals were selected from scientific literature data based on their relevance for the quality of freshwater systems, RO permeate and drinking water. MPs passage and the influence of permeate flux were evaluated with a typical low-pressure RO membrane and quantified by liquid chromatography coupled to high-resolution mass spectrometry. A strong inverse correlation between size and passage of neutral hydrophilic compounds was observed. This correlation was weaker for moderately hydrophobic MPs. Anionic MPs displayed nearly no passage due to electrostatic repulsion with the negatively charged membrane surface, whereas breakthrough of small cationic MPs could be observed. The passage figures observed for the investigated set of MPs ranged from less than 1%e25%. Statistical analysis was performed to evaluate the relationship between physicochemical properties and passage. The effects of permeate flux were more pronounced for small neutral MPs, which displayed a higher passage after a pressure drop.

Abstract: Waste water treatment issues have been a growing problems these days. Its treatment is becoming must in this Industrial world. Nanoparticles have a great potential to be used in waste water treatment. Some of the unique characteristics of it having high surface area can be used efficiently for removing toxic metal ions, disease causing microbes, inorganic and organic solutes from water. The different classes of nanomaterials also have the authority to be efficient for water treatment like metal-containing nanoparticles, carbonaceous nanomaterials and zeolites. The review includes recent development in nanotechnology for water and wastewater treatment. The paper covers nanomaterials that enables the applications, advantages and limitations as compared to existing processes. Nanotechnology has led to various efficient ways for treatment of waste water in a more precise and accurate way on both small and large scale.