Manual Treatment of Urban Wastewater by Chemical Precipitation for Production of Hydroponic Nutrient Solutions (original) (raw)

Development of an ecologically sustainable wastewater treatment system

Water science and technology : a journal of the International Association on Water Pollution Research, 2008

The present study aimed mainly for the development of a wastewater treatment system incorporating enhanced primary treatment, anaerobic digestion of coagulated organics, biofilm aerobic process for the removal of soluble organics and disinfection of treated water. An attempt was also made to study the reuse potential of treated water for irrigation and use of digested sludge as soil conditioner by growing marigold plants. Ferric chloride dose of 30 mg/l was found to be the optimum dose for enhanced primary treatment with removals of COD and BOD to the extent of 60% and 77%, respectively. Efficient anaerobic digestion of ferric coagulated sludge was performed at 7 days hydraulic retention time (HRT). Upflow aerobic fixed film reactor (UAFFR) was very efficient in removals of COD/BOD in the organic loading rate (OLR) range of 0.25 to 3 kg COD/m(3)/day with COD and BOD removals in the range 65-90 and 82-96, respectively. Photo-oxidation followed by disinfection saved 50% of chlorine do...

Water Lettuce for Removal of Nitrogen and Phosphate from Sewage

The concept of using phytoremediation to treat wastewater has received a good recognition. Release of untreated domestic wastewater into the environment has negative influence on the environment. Phytoremediation (using aquatic plants) has good efficiency in removing pollutants in domestic effluents. It is economically beneficial, environment friendly and no energy is required in this treatment process. The main objective of this study was to determine the nutrient (nitrogen and phosphate) removal efficiency of water lettuce from sewage. Treatment was carried out using two plastic troughs of dimension 1m length, 0.3m width and 0.3m depth, one with water lettuce and the other as control unit. Sewage sample was analyzed for nitrate nitrogen, Ammoniacal nitrogen and phosphate. It was observed that water lettuce was capable of removing 83.3% nitrate nitrogen, 84.8% Ammoniacal nitrogen and 81.6% phosphate after 10 days of treatment. After treatment, the sewage water can be used for non-potable purposes.

Impact of Micronutrient Technique (MNT) for biosolids reduction in wastewater treatment plants

HKIE Transactions, 2022

Over the last two decades, the wastewater treatment industry has faced a recurring issue: an overwhelming amount of biosolid (sludge) yield, high power consumption and foul odour due to its anoxic treatment procedures. Engineers in China and Canada have experimented with a different approach, using facultative anaerobic digestion, called the Micronutrient Technique (MNT). This biochemical technique mixes essential growth elements, namely amino acids, vitamins, purine, pyrimidine and minerals, to create MNT mixtures for the WWTP industries. The specific MNT mixture is based on gas detection on-site, the principle of bacterial anoxic reaction. Dosage with MNT has enhanced bioremediation and degradation of pollutants. In the experiment and case studies, it was found that in typical city and some industrial WWTPs, MNT offered a low-cost alternative with encouraging sludge yield and odour control.