A new strategy for obtaining highly concentrated phosphorus recovery solution in biofilm phosphorus recovery process

Recovery of phosphorus(P)from wastewater is of great significance for alleviating the shortage of P resources.At present,the P recovery process is faced with the problem of excessive organic carbon consumption when obtaining a P-concentrated recovery solution.This study proposed a new strategy to obtain a more highly concentrated P recovery solution with minimal carbon consumption by strengthening the P storage capacity of the biofilm.A biofilm sequencing batch reactor(BSBR)process was modified to treat synthetic wastewater.The effect of the dissolved oxygen(DO)concentration on the P storage capacity of the biofilm was investigated at DO concentrations of DO 3.5 mg/L(P_(L))and DO 6.5 mg/L(P_(H)).The results showed a maximum P storage of 101.2 and 149.6 mg-P/g-mixed liquid suspended solids under the two conditions.Strengthening the P storage capacity of the biofilm resulted in a net increase in the P recovery rate,which was as high as 66.96%in a harvesting cycle,and total soluble P>220 mg/L in the P recovery solution was successfully achieved.Meanwhile,the carbon cost of P recovery in the BSBR was reduced to 41.57 g-chemical oxygen demand/gP,and the carbon utilization efficiency was enhanced.To highlight the new strategy,the P recovery performance of the BSBR was given and the relationship between P content and anaerobic P release was discussed.In addition,the changes in the microbial communities under P_(L) and P_(H) conditions were analyzed.

Biological conversion pathways of sulfate reduction ammonium oxidation in anammox consortia

For over two decades,sulfate reduction with ammonium oxidation(SRAO)had been reported from laboratory experiments.SRAO was considered an autotrophic process mediated by anammox bacteria,in which ammonium as electron donor was oxidized by the electron acceptor sulfate.This process had been attributed to observed transformations of nitrogenous and sulfiirous compounds in natural environments.Results obtained differed largely for the conversion mole ratios(ammonium/sulfate),and even the intermediate and final products of sulfate reduction.Thus,the hypothesis of biological conversion pathways of ammonium and sulfate in anammox consortia is implausible.In this study,continuous reactor experiments(with working volume of 3.8L)and batch tests were conducted under normal anaerobic(0.2<DO<0.5 mg/L)/strict anaerobic(DO<0.2 mg/L)conditions with different biomass proportions to verify the SRAO phenomena and identify possible pathways behind substrate conversion.Key findings were that SRAO occurred only in cases of high amounts of inoculant biomass under normal anaerobic condition,while absent under strict anaerobic conditions for same anammox consortia.Mass balance and stoichiometry were checked based on experimental results and the thermodynamics proposed by previous studies were critically discussed.Thus anammox bacteria do not possess the ability to oxidize ammonium with sulfate as electron acceptor and the assumed SRAO could,in fact,be a combination of aerobic ammonium oxidation,anammox and heterotrophic sulfate reduction processes.

OpenKG Chain:A Blockchain Infrastructure for Open Knowledge Graphs

The early concept of knowledge graph originates from the idea of the semantic Web,which aims at using structured graphs to model the knowledge of the world and record the relationships that exist between things.Currently publishing knowledge bases as open data on the Web has gained significant attention.In China,Chinese Information Processing Society of China(CIPS)launched the OpenKG in 2015 to foster the development of Chinese Open Knowledge Graphs.Unlike existing open knowledge-based programs,OpenKG chain is envisioned as a blockchain-based open knowledge infrastructure.This article introduces the first attempt at the implementation of sharing knowledge graphs on OpenKG chain,a blockchain-based trust network.We have completed the test of the underlying blockchain platform,and the on-chain test of OpenKG’s data set and tool set sharing as well as fine-grained knowledge crowdsourcing at the triple level.We have also proposed novel definitions:K-Point and OpenKG Token,which can be considered to be a measurement of knowledge value and user value.1,033 knowledge contributors have been involved in two months of testing on the blockchain,and the cumulative number of on-chain recordings triggered by real knowledge consumers has reached 550,000 with an average daily peak value of more than 10,000.For the first time,we have tested and realized on-chain sharing of knowledge at entity/triple granularity level.At present,all operations on the data sets and tool sets at OpenKG.CN,as well as the triplets at OpenBase,are recorded on the chain,and corresponding value will also be generated and assigned in a trusted mode.Via this effort,OpenKG chain looks forward to providing a more credible and traceable knowledge-sharing platform for the knowledge graph community.