Closing the phosphorus loop in England: The spatio-temporal balance of phosphorus capture from manure versus crop demand for fertiliser

Every year 90 million tonnes of housed livestock manures are produced in the UK. This is a valuable reservoir of global phosphorus (P) and a point in the cycle where it is vulnerable to being lost from the terrestrial system. Improved manure management for the effective reuse of phosphorus is vital to simultaneously tackle a major source of water pollution and reduce our dependence on imported fertilisers. This paper quantifies, for the first time, the spatial and temporal challenges of recycling the required amount of manure P from areas of livestock production to areas of crop production in eight regions of England. The analysis shows that England has a P deficit and therefore the capacity to fully utilise the manure P on arable land, but that uneven spatial distribution of livestock poses a significant challenge to closing the P loop in agriculture. Two of the eight regions were shown to have surplus manure P, with the remaining six regions having P deficits, indicating that an annual export of 4.7 thousand tonnes P (2.8 million tonnes manure) must take place from the west to the east of the country each year to balance P supply and demand. Moreover, housed manure production peaks between October and February, requiring an excess of 23.0 thousand tonnes P (15 million tonnes manure) to be stored until it can be used for crop fertilisation from March onwards. The results demonstrate the scale of the challenge in managing manure P in an agricultural system that has separated livestock production from crop production, a pattern that is echoed throughout the developed world. To overcome the spatial and temporal challenges, a logistical system is recommended that will balance the nutrient potential (nitrogen and P content and availability) and pollution potential (eutrophication, greenhouse gas emissions, particulates and nitrous oxide from transport) for cost-effective and environmentally compatible redistribution of manure P from areas of surplus to areas of deficit, when required.     

阳宗海表层沉积物磷、氟、硫的分布与污染状况

对阳宗海表层沉积物中磷、氟、硫的含量进行了调查,并用单指标标准指数法对污染水平进行了评价.结果表明,阳宗海表层沉积物磷、氟、硫含量的平均值依次为1 041 mg/kg、1 075 mg/kg、2 743 mg/kg.生活、生产污水、工业废气,以及机动船只、网箱养鱼等活动是阳宗海表层沉积物中磷、氟、硫的主要来源.磷、氟、...     

Four kinds of capping materials for controlling phosphorus and nitrogen release from contaminated sediment using a static simulation experiment

• Lanthanum modified bentonite (LMB) can effectively absorb phosphorus (P). • Water treatment plant sludge (WTPS) capping is effective for controlling P release. •Aluminum-based P-inactivation agent (Al-PIA) is an efficient P control material. •The P adsorbed by WTPS and Al-PIA is mainly in the form of NAIP. We determined the effects of quartz sand (QS), water treatment plant sludge (WTPS), aluminum-based P-inactivation agent (Al-PIA), and lanthanum-modified bentonite (LMB) thin-layer capping on controlling phosphorus and nitrogen release from the sediment, using a static simulation experiment. The sediment in the experiment was sampled from Yundang Lagoon (Xiamen, Fujian Province, China), which is a eutrophic waterbody. The total phosphorus (TP), ammonium nitrogen (NH₄⁺-N), and total organic carbon (TOC) levels in the overlying water were measured at regular intervals, and the changes of different P forms in WTPS, Al-PIA, and sediment of each system were analyzed before and after the test. The average TP reduction rates of LMB, Al-PIA, WTPS, and QS were 94.82, 92.14, 86.88, and 10.68%, respectively, when the release strength of sediment TP was 2.26–9.19 mg/(m²·d) and the capping strength of the materials was 2 kg/m². Thin-layer capping of LMB, WTPS, and Al-PIA could effectively control P release from the sediment (P<0.05). However, thin-layer capping of LMB, Al-PIA, and QS did not significantly reduce the release of ammonium N and organic matter (P > 0.05). Based on our results, LMB, Al-PIA, and WTPS thin-layer capping promoted the migration and transformation of easily released P in sediment. The P adsorbed by WTPS and Al-PIA mainly occurred in the form of NAIP.     

常绿-半常绿杨树对磷素的利用特性

缺磷是限制农林业产量的一个重要因子,传统的农林业生产主要通过施肥和土壤改良来满足植物对磷的需求,近年来人们开始发掘磷高效利用植物来替代传统方法提高磷的利用效率.A-65/27、A-65/31及A-61/186是目前世界上仅有的3个常绿杨树无性系,共同特点是容易扦插繁殖,造林成活率高,生长快,材质好.3个无性系的推广将极大地丰富南方用材林树种资源.为揭示磷素胁迫条件下常绿杨无性系对土壤中磷素的利用特性,通过沙培试验,设计5个磷素处理水平(磷的质量浓度依次是0.00、0.0310、0.0619、0.1239、0.1858 g·L~(-1)),进行不同磷素处理水平下常绿杨生长及生理生态特性的研究.结果表明:当磷的质量浓度为0.0619 g·L~(-1)时已经能满足常绿杨生长对磷的基本需求;磷素不足会明显的影响到常绿杨的生长.低磷胁迫下常绿杨高度、地径及生物量明显降低;低磷胁迫下光合速率也明显下降,通过对气孔导度及胞间二氧化碳浓度的变化趋势分析,导致光合速率下降的主要原因是非气孔限制因素,同步叶绿素荧光的测定表明光系统Ⅱ受到了一定的影响,这是非气孔限制因素之一.     

青山水库底泥磷释放与库区水体磷浓度的关系

通过对青山水库底泥磷释放特性的实验结果分析,对照库区水体浓度监测的数据,确定了库区各测点底磷释放量与水体浓度之间的关系,进而为库区环境总量控制与各支流的分配计算提供了依据。同时也为防止水库的进一步富营养化,进而改善水质提供了新的思路。     

Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag

Removal kinetics of phosphorus through use of basic oxygen furnace slag (BOF-slag) was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial pH, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant (k_obs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial pH, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage. A linear dependence of k_obs on total removed phosphorus (TRP) was established with k_obs = (3.51 ± 0.11) × 10^− 4 × TRP. Finally, it was suggested that the Langmuir–Rideal (L–R) or Langmuir–Hinshelwood (L–H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.     

电子受体类型对聚磷污泥胞外聚合物的影响研究

采用3种电子受体(硝氮、亚硝氮、氧),在SBR反应器中分别驯化了具有稳定除磷能力的聚磷污泥。对比研究了不同聚磷污泥胞外聚合物(EPS)的组分与含量,结合三维荧光光谱对EPS中有机物质进行分析。研究表明,以硝氮、亚硝氮为电子受体的聚磷污泥EPS平均浓度较为接近,分别为115.6mg/gVSS、133.5 mg/gVSS,由厌氧段至缺氧段,EPS总浓度有所下降。以氧为电子受体聚磷污泥的EPS平均浓度相对较高,为194.5 mg/gVSS,由厌氧段至好氧段,EPS总浓度略有升高。不同聚磷污泥的EPS组分均以胞外蛋白为主,占EPS总量的53%~65%,多糖与核酸占EPS总量28%~34%、5%~7%。三维荧光光谱显示3种聚磷污泥EPS均具有芳香结构蛋白质、可溶性代谢物的荧光峰,另外,以硝氮为电子受体的聚磷污泥还具有明显的腐殖酸类物质的荧光峰。研究结果表明电子受体对聚磷污泥EPS的组分、浓度、有机质类别有一定的影响。     

Effect of organic matter on phosphorus recovery from sewage sludge subjected to microwave hybrid pretreatment

Microwave (MW) hybrid processes are able to disrupt the flocculent structure of complex waste activated sludge, and help promote the recovery of phosphorus as struvite. In this study, to optimize struvite yield, (1) the characteristics of matter released in MW-hybrid treatments were compared, including MW, MW-acid, MW-alkali, MW-H₂O₂, and MW-H₂O₂-alkali. The results showed that selective release of carbon, nitrogen, phosphorus, Ca^2 +, and Mg^2 + achieved by sludge pretreatment using MW-hybrid processes. MW-H₂O₂ is the recommended sludge pretreatment process for phosphorus recovery in the form of struvite. The ratio of Mg^2 +:NH₄⁺-N:PO₄^3 −-P was 1.2:2.9:1 in the supernatant. (2) To clarify the effects of organic matter on struvite recovery, the composition and molecular weight distribution of organic matters were analyzed. Low molecular weight COD was found to facilitate the removal rate of NH₄⁺-N and PO₄³-P via crystallization, and the amorphous struvite crystals (< 1 kDa) from the filtered solutions had high purity. Therefore, the present study reveals the necessity of taking into consideration the interference effect of high molecular weight organic matters during struvite crystallization from sewage sludge.     

Removal kinetics of phosphorus from synthetic wastewater using basic oxygen furnace slag

Removal kinetics of phosphorus through use of basic oxygen furnace slag(BOF-slag)was investigated through batch experiments. Effects of several parameters such as initial phosphorus concentration, temperature, BOF-slag size, initial p H, and BOF-slag dosage on phosphorus removal kinetics were measured in detail. It was demonstrated that the removal process of phosphorus through BOF-slag followed pseudo-first-order reaction kinetics. The apparent rate constant(kobs) significantly decreased with increasing initial phosphorus concentration, BOF-slag size, and initial p H, whereas it exhibited an opposite trend with increasing reaction temperature and BOF-slag dosage.A linear dependence of kobson total removed phosphorus(TRP) was established with kobs=(3.51 ± 0.11) × 10- 4× TRP. Finally, it was suggested that the Langmuir–Rideal(L–R)or Langmuir–Hinshelwood(L–H) mechanism may be used to describe the removal process of phosphorus using BOF-slag.     

化学沉淀法除磷和生物法除磷的比较

对化学沉淀法除磷和生物法除磷的机理作了较详细的阐述，并就两者在除磷效果，污泥产量，污泥处置，除磷费用方面进行了比较。结果表明，两种方法磷的去除率比较接近，总费用没有明显差别，其优点是，生物法除磷污泥产量少，而化学沉淀法除磷操作简便。