Prof. Xinmin Zhan (project coordinator) attended the 3rd International Conference on Recent Advances in Pollution Control and Resource Recovery for the Livestock Farming Industry (LivestockWaste 2018) held in 26-28 July, 2018 in Xiamen City, China, and was invited to give a keynote speech. Prof. Zhan presented his thoughts on on-farm anaerobic digesters: Challenges facing on-farm anaerobic digestion. The challenges include: economic profitability, efficient use of biogas, digestate management, biosafety of digestate for land application, nutrient recovery technologies, and design and operation of on-farm digesters.
Prof. Liwen Xiao and Prof. Xinmin Zhan visited Tsinghua-Berkeley Shenzhen Institute
Prof. Liwen Xiao (Task 4 leader) and Prof. Xinmin Zhan (project coordinator) visited Tsignhua-Berkely Shenzhen Institute on the 24th July 2018. Both were invited to present their research. Prof. Liwen Xiao presented Investigation into the causes, impacts and measures to deal with algal blooms in Vartry Reservoirs. Prof. Liwen Xiao introduced the occurrence of diatom algal blooms in Vartry Reservoir since 2013, resulting in serious clogging of the slow sand filters in the water treatment plant and a reduction in the treatment capacity from 75 million litres to 40 million litres per day. His research team investigated three consecutive diatom bloom periods to understand the causes of the algal blooms. Their results indicate that rather than nutrient enrichment, the low zooplankton populations could be the cause of the blooms.
Prof. Xinmin Zhan presented NEO-GREEN concept for sustainable wastewater treatment. In his presentation, Prof. Zhan explained his thoughts on how to develop future wastewater treatment facilities which should be environmentally sustainable with energy and nutrient recovery. The major resource issues (water, food, energy) facing the world today are pushing the current wastewater treatment systems shifting to a new direction focusing on resources (energy, nutrient, water, etc.) recovery. This demands that future treatment technologies should harness potential energy in wastewater, incorporate nutrient (nitrogen and phosphorus) recovery and minimize waste sludge production whilst meeting increasingly stringent discharge permits. To address this need, Prof. Zhan proposes an innovative treatment system (i.e. NEO-GREEN), which is based on iron sulphides materials, for a viable next-generation wastewater treatment technology towards maximal resources recovery and minimal waste generation.
Tsinghua-Berkeley Shenzhen Institute (TBSI) is jointly established by Tsinghua University and University of California, Berkeley under the support of the Shenzhen Municipal Government. It is committed to exploring the cultivation mode in “university-government-enterprise” tripartite cooperation.
After presentation, Prof. Xiao and Prof. Zhan visited the environmental labs in the institute.
The Irish Division of the Microbiology Society recently hosted a conference entitled “Microbial Resources for Agricultural and Food Security”. The conference took place from the 21st to 23rd June 2017 in Belfast and was attended by a number of DairyWater researchers, Peter Leonard (NUI Galway), Beatriz Gil Pulido (UCC) and Dr. Niall O’Leary (UCC). The conference dealt with a number of concerning issues in both the agricultural and food sectors, which included the difficulties in nutrient removal and phosphorus recycling and recovery.
DairyWater researchers, Peter Leonard (NUI Galway), Dr. Niall O’Leary (UCC) and Beatriz Gil Pulido (UCC), during the poster session in Belfast
A number of emerging technologies to address these problems were central to many presentations. Peter spoke about IASBR technology, a novel system developed at NUI Galway, which offers a more economical and sustainable method of biological water treatment than what is currently employed within the industry. This technology is under investigation by the DairyWater project at both pilot- and laboratory-scale in order to determine its viability for use within the Irish dairy sector. Peter was able to report that the IASBR system has a promising future as initial testing has exhibited that the system has the capacity to remove over 95% of nitrogen, phosphorus and chemical oxygen demand on a wastewater and is capable of high strength dairy processing wastewater.
PhD student, Beatriz, presented a first approach on the microbial ecology of an IASBR system treating synthetic dairy wastewater. Molecular techniques were used to investigate the diversity of the bioreactor, where the results from a laboratory-scale trial, which was performed in 2015, were summarised in a poster presentation. The ecology of an IASBR was presented alongside its performance. Specific groups of bacteria were identified and linked to the optimal performance of the bioreactor (orthophosphate and ammonia removal efficiencies >90%) under one of the three aeration rates investigated during the trial.
As part of DairyWater Task 2, the researchers at NUI Galway have recently installed a pilot-scale IASBR (Intermittently Aerated Sequencing Batch Reactor) system at Aurivo Dairy Ingredients, Ballaghderreen, Co. Roscommon. An IASBR is a biological wastewater treatment system in which wastewater is completely mixed with the microorganisms in the system for the duration of the react phase. During this phase periods of non-aeration and aeration are cycled to maximise the removal capacity of the microbes present in the system. After the react phase, the circulation is stopped and the biomass will settle to the bottom of the unit allowing the treated water to be decanted from the top section of the system. The pilot-scale system, which is pictured below, has a working volume of 3000 litres, is running on a 12 hour cycle with a 4 day hydraulic retention time (i.e. 375 litres treated per cycle) and a 16 day solids retention time. Levels within the system are accurately regulated using a set of float switches and pumps.
In order to monitor the performance of the system, a refrigerated auto-sampler takes a daily sample of the treated effluent. These samples are collected weekly and transported to the environmental laboratory at NUI Galway for physico-chemical analysis. The removal rates for chemical oxygen demand (COD), total suspended solids (TSS), ammonia-nitrogen (NH4-N) and orthophosphate (PO4-P) from the Aurivo’s process wastewater are calculated based on the analysis of these samples. Initial results has exhibited that the system has great potential for the treatment of dairy processing wastewater as it has the capacity to remove up to 96.9% of COD, 99.8% of TSS ,99.6% of NH4-N and 99.9% of PO4-P.
The removal rates initially were quite unstable but this has since stabalised. For the majority of effluent samples analysed, the nutrient content was far below the EPA licence limits for the site. The next stages of the research involves improving the overall efficency of the system by maximising its treatment capacity and improving the effectiveness of the aeration rate.