Decline of phosphorus, copper, and zinc in anaerobic swine lagoon columns receiving pretreated influent

Land application of both anaerobic lagoon liquid and sludge can increase nutrient accumulation beyond the soils assimilative capacity and become a threat to water quality in regions with intensive, confined swine production. In a 15-month meso-scale column study, we evaluated the effect of manure pretreatment on the reduction of total suspended solids (TSS), total phosphorus (TP), soluble reactive P (SRP), and total copper (Cu) and zinc (Zn) in swine lagoons using (i) enhanced solid-liquid separation (SS) and (ii) solid-liquid separation plus biological nitrogen treatment with nitrification-denitrification (SS + NDN). A conventional anaerobic lagoon treatment was included as a control. A mass flow balance revealed that with both pretreatments the net mass input of TP, Cu, and Zn in the lagoon columns declined 80 to 100 % when compared to the control. Even though both pretreatments significantly reduced P in the inflow, TP and SRP were negatively correlated (r = -0.51 to -0.87) with TSS in the liquid fraction because of the dissolution of P from sludge into the overlying lagoon liquid. On the other hand, the removal of solids by both pretreatments effectively reduced Cu and Zn concentrations in the lagoon liquid, and their concentrations were positively correlated (r = 0.79 to 0.90) with TSS. The decline in mass accumulation of TP, Cu, and Zn in sludge as a result of the reduction of input solids can help minimize both the frequency of sludge removal for lagoon maintenance and the land area for its disposal.(AU)

Recovery of ammonia from anaerobically digested manure using gas-permeable membranes

Nitrogen (N) can be recovered from different types of wastewaters. Among these wastewaters, anaerobically digested swine manure (digestate) has the highest N content in ammonia form (NH3). It is desirable to reduce N in digestate effluents to safely incorporate them in arable soil in N vulnerable zones (NVZ) and to mitigate NH3 emissions during N land application. Additional benefit is to minimize inhibition of the anaerobic process by removing NH3 during the anaerobic digestion process. This work aimed to apply the gas-permeable membrane technology to evaluate ammonia (NH3) recovery from high-ammonia digested swine manure. Anaerobically digested swine manure with NH4+ content of 4,293 mg N L1 was reduced by 91 % (to 381 mg N L1) during the 32-day experiment. Although the results showed a total N recovery efficiency of 71 %, it is possible to increase this recovery efficiency to > 90 % by adjusting the area of the membrane system to match the high free ammonia concentration (FA) in digested swine manure. Moreover, final digestate pH and alkalinity were kept around 8.1 and 8,923 mgCaCO3 L1, which are convenient for the anaerobic process or incorporation in arable soil when the process is finished.

Decline of phosphorus, copper, and zinc in anaerobic swine lagoon columns receiving pretreated influent

Land application of both anaerobic lagoon liquid and sludge can increase nutrient accumulation beyond the soils assimilative capacity and become a threat to water quality in regions with intensive, confined swine production. In a 15-month meso-scale column study, we evaluated the effect of manure pretreatment on the reduction of total suspended solids (TSS), total phosphorus (TP), soluble reactive P (SRP), and total copper (Cu) and zinc (Zn) in swine lagoons using (i) enhanced solid-liquid separation (SS) and (ii) solid-liquid separation plus biological nitrogen treatment with nitrification-denitrification (SS + NDN). A conventional anaerobic lagoon treatment was included as a control. A mass flow balance revealed that with both pretreatments the net mass input of TP, Cu, and Zn in the lagoon columns declined 80 to 100 % when compared to the control. Even though both pretreatments significantly reduced P in the inflow, TP and SRP were negatively correlated (r = -0.51 to -0.87) with TSS in the liquid fraction because of the dissolution of P from sludge into the overlying lagoon liquid. On the other hand, the removal of solids by both pretreatments effectively reduced Cu and Zn concentrations in the lagoon liquid, and their concentrations were positively correlated (r = 0.79 to 0.90) with TSS. The decline in mass accumulation of TP, Cu, and Zn in sludge as a result of the reduction of input solids can help minimize both the frequency of sludge removal for lagoon maintenance and the land area for its disposal.

Recovery of ammonia from anaerobically digested manure using gas-permeable membranes

Nitrogen (N) can be recovered from different types of wastewaters. Among these wastewaters, anaerobically digested swine manure (digestate) has the highest N content in ammonia form (NH3). It is desirable to reduce N in digestate effluents to safely incorporate them in arable soil in N vulnerable zones (NVZ) and to mitigate NH3 emissions during N land application. Additional benefit is to minimize inhibition of the anaerobic process by removing NH3 during the anaerobic digestion process. This work aimed to apply the gas-permeable membrane technology to evaluate ammonia (NH3) recovery from high-ammonia digested swine manure. Anaerobically digested swine manure with NH4+ content of 4,293 mg N L1 was reduced by 91 % (to 381 mg N L1) during the 32-day experiment. Although the results showed a total N recovery efficiency of 71 %, it is possible to increase this recovery efficiency to > 90 % by adjusting the area of the membrane system to match the high free ammonia concentration (FA) in digested swine manure. Moreover, final digestate pH and alkalinity were kept around 8.1 and 8,923 mgCaCO3 L1, which are convenient for the anaerobic process or incorporation in arable soil when the process is finished.(AU)

Chemical phosphorus removal: a clean strategy for piggery wastewater management in Brazil.

The intensive production of animal protein is known to be an environmental polluting activity, especially if the wastewater produced is not managed properly. Swine production in Brazil is growing, and technologies to manage all pollutants present in the wastewater effluent are needed. This work presents a case of study of phosphorus (P) removal from piggery wastewater using Ca(OH)2, and demonstrates the feasibility of this strategy for P management. The effluent of a swine manure treatment plant was treated with Ca(OH)2. According to the addition of Ca(OH)2 the pH of the effluent ranged from 8.0 to 10.0. Different conditions of sludge dewatering were evaluated, and the chemical composition of sludge was investigated. Ion chromatography analysis of effluent samples showed that 92% of total P (TP) was present as soluble P (SP) whereas 75% of SP species were present as phosphate. The efficiency of P removal was typically 90% at pH 8.5 and higher than 98% at pH 10.5. The sludge was separated by sedimentation, centrifugation or filtration and dried. The TP content of dried sludge was 9.3% (w/w). X-ray diffraction analysis of the dry sludge showed the presence of amorphous compounds of Ca and P, which is an indication that the sludge obtained from the swine manure treatment has a potential for application as biofertilizer.