The Sonoco Plant at Stainland, Halifax processes recycled paper, pulps it and make cardboard tubes. The plant uses large amount of water which results in waste effluent that requires treating before it can be discharged to sewer or reused in the process.
The Effluent Treatment Plant comprises a DAF and activated sludge plant. The plant generally performs well but frequently suffers from filamentous bacteria outbreaks in the activated sludge plant which cause operation and performance issues.
Aquability OPS Ltd performed an assessment of the treatment plant as a whole and provided recommendations for improving and optimising plant operation and performance, and determined the design requirements for a replacement fine bubble aeration system.
Yorkshire Water’s 35,000 PE Denaby WWTP was built in 2008 and combined flows from Denaby, (population 6,500). Burcoft (population 11,400) and Mexborough (population 17,600). The treatment plant includes primary settlement, an anoxic tank, four activated sludge lanes and two final settling tanks.
The plant treats a flow to full treatment of up to 215 l/s and has final effluent consent requirements of 25 mg/l BOD (or 70% removal), 125 mg/l COD (or 75% removal) and 9 mg/l ammonia on a 95%ile spot sample basis, which is discharged to the River Don.
Since it was built the plant has suffered from microthrix growth and associated operational and performance issues for around six months of the year. In 2017 Aquability OPS Ltd was engaged by Yorkshire Water to determine the cause of the issues and identify and implement a solution. The changes made by Aquability have resulted in the plant achieving robust and reliable operation and performance, and to date the microthrix has not returned.
Aquability OPS Ltd modified and optimised the failing Jet Tech SBR’s at the one million PE Saltend WWTP at Hull. The plant now consistently achieves it’s effluent consent with a 20% reduction in total power consumption.
Yorkshire Water’s 34,000 PE Beverley WWTP was upgraded in 1999 to include a new nitrifying tertiary treatment process which consisted of two rectangular CASS SBR basins.
The Beverley WWTP treats a flow to full treatment of up to 291l/s utilising primary tanks, trickling filters, humus tanks and CASS SBR’s. The final effluent consent requirements are 25mg/l BOD (or 70% removal), 125 mg/l COD (or 75% removal) and 10mg/l ammonia on a 95%ile spot sample basis, which is discharged to the River Hull.
Over the last few years the plant has suffered from operational and performance issues. In 2016 Aquability OPS Ltd was engaged by Yorkshire Water to determine the root cause of the problems and to implement a solution to improve operation and performance.
Aquability provided the following services:
Revised SBR control philosophy
Jar testing and sampling and analysis
Primary tank chemical dosing trials
The changes made by Aquability have had a significant effect on plant performance and process reliability resulting in the plant achieving its best ever environmental performance. Chemical dosing is not required following the optimisation of the SBR’s.