A pilot scale trickling filter with pebble gravel as media and its performance to remove chemical oxygen demand from synthetic brewery wastewater

Evaluating the performance of a biotrickling filter for the treatment of wastewaters produced by a company manufacturing beer was the aim of this study.A pilot scale trickling filter filled with gravel was used as the experimental biofilter.Pilot scale plant experiments were made to evaluate the performance of the trickling filter aerobic and anaerobic biofilm systems for removal of chemical oxygen demand(COD) and nutrients from synthetic brewery wastewater.Performance evaluation data of the trickling filter were generated under different experimental conditions.The trickling filter had an average efficiency of(86.81±6.95)% as the hydraulic loading rate increased from 4.0 to 6.4 m3/(m2·d).Various COD concentrations were used to adjust organic loading rates from 1.5 to 4.5 kg COD/(m3·d).An average COD removal efficiency of(85.10±6.40)% was achieved in all wastewater concentrations at a hydraulic loading of 6.4 m3/(m2·d).The results lead to a design organic load of 1.5 kg COD/(m3·d) to reach an effluent COD in the range of 50–120 mg/L.As can be concluded from the results of this study,organic substances in brewery wastewater can be handled in a cost-effective and environmentally friendly manner using the gravel-filled trickling filter.

Atmospheric emission characterization of a novel sludge drying and co-combustion system

A novel system combining sludge drying and co-combustion with coal was applied in disposing sludge and its atmospheric emission characteristics were tested. The system was composed of a hollow blade paddle dryer, a thermal drying exhaust gas control system, a 75 tons/hr circulating fluidized bed and a flue gas cleaning system. The emissions of NH3, SO2, CH4 and some other pollutants released from thermal drying, and pollutants such as NOx, SO2 etc. discharged by the incinerator, were all tested. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans （PCDD/Fs） in the flue gas from the incinerator were investigated as well. The results indicated that the concentrations of NOx and SO2 in the flue gas from the incinerator were 145 and 16 mg/m^3, respectively, and the I-TEQ concentration of 2,3,7,8-substitued PCDD/Fs was 0.023 ng I-TEQ/Nm^3. All these values were greatly lower than the emission standards of China. In addition, there was no obvious odor in the air around the sludge dryer. The results demonstrated that this drying and co-combustion system is efficient in controlling pollutants and is a feasible way for large-scale treatment of industrial sludge and sewage sludge.

Bioavailability of wastewater derived dissolved organic nitrogen to green microalgae Selenastrum capricornutum,Chlamydomonas reinhardtii,and Chlorella vulgaris with/without presence of bacteria

Effluent dissolved organic nitrogen（DON） is problematic in nutrient sensitive surface waters and needs to be reduced to meet demanding total dissolved nitrogen discharge limits.Bioavailable DON（ABDON） is a portion of DON utilized by algae or algae ＋ bacteria,while biodegradable DON（BDON） is a portion of DON decomposable by bacteria.ABDON and BDON in a two-stage trickling filter（TF） wastewater treatment plant was evaluated using three different microalgal species,Selenastrum capricornutum,Chlamydomonas reinhardtii and Chlorella vulgaris and mixed cultured bacteria.Results showed that up to80% of DON was bioavailable to algae or algae ＋ bacteria inoculum while up to 60% of DON was biodegradable in all the samples.Results showed that C.reinhardtii and C.vulgaris can be used as a test species the same as S.capricornutum since there were no significant differences among these three algae species based on their ability to remove nitrogen species.