Yorkshire Forward

About: Yorkshire Forward is a(n) other organization based out in Leeds, United Kingdom. It is known for research contribution in the topic(s): Chemical oxygen demand & Wastewater. The organization has 3 authors who have published 3 publication(s) receiving 427 citation(s).

Treatment of tannery wastewater by chemical coagulation

Abstract: The objective of this study was to develop a treatment system that can effectively reduce the concentration of pollutants in tannery wastewater to environmentally acceptable levels and that can greatly reduce the cost of discharging the effluents. Aluminium sulphate and ferric chloride were used as a coagulant in the process. The influence of pH and coagulant dosages on the coagulation process was studied and conditions were optimised corresponding to the best removal of organic matters, suspended solids as well as chromium. The COD and chromium were removed mainly through coagulation: 38–46% removal of suspended solids, 30–37% removal of total COD from settled tannery wastewaters and 74–99% removal of chromium at an initial concentration of 12 mg/l can be achieved by using the optimum coagulant dosage (800 mg/l) in the optimum pH range (around 7.5). Ferric chloride produced better results than aluminium sulphate. The initial chromium concentrations and pH values of the wastewater had a great effect on chromium removal efficiency. Low chromium concentrations and high pH produced a more effective result on chromium removal than high chromium concentrations and low pH. Higher dosages did not significantly increase pollutant removal and were not economical. Coagulation combined with centrifugation improved the removal efficiency of suspended solids (70%). A high degree of clarification is attained as indicated by an excess of 85–86% colour removal. The results provide useful information for tannery wastewater treatment.

Public Procurement and Supply Management Strategies

Abstract: This article develops several frameworks for the analysis of supply strategies employed for public sector contracts on the basis of a review of the literature on public procurement and supply manag...

Anaerobic treatment of olive mill wastewater and piggery effluents fermented with Candida tropicalis.

Abstract: Olive mill wastewater (OMW) contains high concentrations of phenolic compounds that are inhibitory to many microorganisms making it difficult to treat biologically prior to discharge in waterways. The total mono-cyclic phenol reduction in OMW in this study was carried out by aerobic pre-treatment using the yeast Candida tropicalis in a 18 L batch reactor at 30 °C for 12 days followed by anaerobic co-digestion. A COD removal of 62% and a reduction in the total mono-cyclic phenol content by 51% of the mixture was achieved in the aerobic pre-treatment. Pig slurry was added as co-substrate to supplement the low nitrogen levels in the olive mill wastewater. Subsequent anaerobic treatment was carried out in a 20 L fixed-bed reactor at 37 °C and HRT between 11 and 45 days. After a long start-up period, the OLR was increased from 1.25 to 5 kg COD m−3 day−1 during the last 30 days, resulting in subsequent increase in overall COD removal and biogas production, up to maximum values of 85% and 29 L biogas L reactor − 1 da y − 1 , respectively. Methane content of the biogas produced from the anaerobic digestion ranged between 65% and 74%.