污泥改良沙土中重金属及营养元素的迁移转化

为探究城市污水厂离心脱水污泥改良沙土对重金属及营养成分迁移转化的影响,利用掺混量为15%的污泥改良沙土作为0—20 cm土层土壤,通过饱和淋洗的方式分析了重金属及营养成分在土层中含量及形态转化,揭示了土层中重金属及营养成分迁移转化规律。结果表明:从重金属总量来看,试验淋洗10次后,土壤表层Cu,Pb,Zn,Cr滞留率较高,分别为78.57%,78.72%,86.35%,76.61%,Ni滞留率较低,为40.37%。但随着淋融次数的增加,重金属都存在一定淋失或向下层土壤迁移的风险;从重金属形态来看,各重金属Ni,Zn,Cr,Cu,Pb活性系数（MF）分别为1.657,0.531,0.265,0.113,0,由此可以得出,Ni,Zn在土壤环境中性质不稳定,Cr,Cu性质较为稳定,Pb最为稳定;改良沙土中氮磷营养元素在淋洗后含量下降,氮的流失率为39.36%,磷的流失率为18.67%,氮素较磷素易发生流失,下层沙土氮提升量高于磷。     

低分子量有机酸对石灰性土壤有机磷组成及有效性的影响

为探索提高土壤磷素有效性的途径,采用室内培养的方法,研究不同有机酸对土壤速效磷含量及有机磷组分的影响。结果表明,添加有机酸后土壤速效磷含量发生显著变化,其中草酸处理下土壤速效磷含量显著高于其他处理,而柠檬酸和苹果酸对土壤速效磷含量具有抑制作用,其活化量为负值;随着培养时间的延长,速效磷含量缓慢降低。速效磷含量随着草酸浓度的升高而升高,随着苹果酸、柠檬酸浓度的升高而降低;有机酸处理后,土壤活性、中活性、中稳性有机磷升高,高稳性有机磷降低,这说明有机酸能促进土壤有机磷由有效性低的形态逐步向有效性高的形态转化,其中草酸的作用效果总体上较柠檬酸和苹果酸强。     

Integrative Soil Application of Humic Acid and Sulfur Improves Saline Calcareous Soil Properties and Barley Plant Performance

ABSTRACT

During the 2017 and 2018 seasons, two field experiments were conducted on newly reclaimed saline calcareous soil (7.13 dS m^?1, 16.9% CaCO₃) in the experimental farm of the Faculty of Agriculture, Demo, Fayoum Governorate, Egypt. The current work aimed at identifying the potential positive effects of applied humic acid (HA) and elemental sulfur (S) on some soil properties and barley plant performance. The results showed that the application of HA and/or S at different rates ameliorated the adverse effects of saline calcareous soil conditions and significantly reduced some chemical properties of the soil (e.g., pH, ECe, and CaCO₃%), while soil organic matter (OM%) and some nutrients (e.g., P, Fe, Mn, Cu, and Zn) contents were significantly increased. In addition, the contents of nutrients (e.g., P, Fe, Mn, Cu, and Zn) in barley plant and yielded grain, grain content of N and protein (%), and the performance (e.g., plant height, spike length, grain and straw yields, and weight of 1000-grain) of barley plant were significantly increased with the application of HA and/or S. The best results were obtained through the integrative application of 100 kg HA + 400 kg S ha^?1 to the tested saline calcareous soil. Therefore, the integrative soil application of 100 kg HA + 400 kg S ha^?1 can be recommended for the cultivation and sustainability of crop production in saline calcareous soil, in addition to rationalize the use of mineral fertilizers, which represent a surplus point for the sustainable agriculture system.     

蚯蚓活动对城市生活污泥重金属的影响

采用塑料温棚内垄式堆积污泥培养蚯蚓方式,研究了蚯蚓处理对污泥重金属的影响。结果表明,污泥经蚯蚓处理后,理化性质发生了显著的变化,污泥的pH值、有机质、总氮和总磷都有不同程度的降低;蚯蚓能吸收富集污泥中的重金属,其中对重金属Cd有较强的富集能力;蚯蚓处理使污泥中重金属含量均出现不同程度的下降,重金属Cr、Zn、Pb、Cd、Cu、Ni分别减少27.98%、31.46%、32.81%、13.85%、23.86%和22.92%。利用盆栽试验,研究了污泥施用于土壤后生菜体内重金属积累的情况,结果表明,生菜体内重金属Zn、Cu、Pb和Ni的含量为污泥处理高于蚓粪处理;Cr和Cd则分别为差异不显著和略有降低。     

Nutrient Availability in a Calcareous Soil Amended with Different Types of Biomass Ash

An incubation experiment was conducted to evaluate the effects that three types of biomass ash, each applied at two doses, exert on the nutrient availability in a calcareous soil. The application of the ash from dry olive cake or greenhouse vegetable wastes significantly increased soil ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extractable phosphorus (P), potassium (K), sodium (Na), copper (Cu) and zinc (Zn) as well as exchangeable and non-exchangeable K and Na. Wood ash was effective only for increasing soil ABDTPA-extractable Zn and Cu. By contrast, the three types of biomass ash hardly increased soil ABDTPA-extractable Fe or Mn. The high content in carbonate of the soil appears to minimize the potential of the ash to increase the micronutrients availability, which shortened with longer incubation time. Soil ABDTPA-extractable heavy metals were not detected in the different treatments tested. Other parameters of the soil, as pH and organic carbon, were scarcely affected by the ash, while conductivity and dehydrogenase activity increased.     

沈抚灌区土壤重金属污染健康风险初步评价

采用现场采样及室内测试方法对沈抚灌区农田土壤中Cu、Hg、Ni和Cd等重金属的含量进行了测定分析,利用污染指数法对灌区土壤环境质量进行了评价,并应用美国环保局推荐的健康风险评价模型对灌区土壤重金属通过土壤摄食途径所引起的健康风险作了初步评价。结果表明,灌区土壤中重金属的平均浓度范围分别为Cu：22．1～40．8mg·kg^-1,Hg：0．036-0．310mg·kg^-1,Ni：29．8～44．4mg·kg^-1,Cd：0．145～0．956mg·kg^-1。4种重金属浓度平均值大小为Ni〉Cu〉Cd〉Hg;土壤中Cu、Hg、Ni和Cd所引起的成人和儿童的平均个人风险均低于可接受水平10^-6,且在这两类调查人群中,健康风险大小顺序均为Cd〉Ni〉Hg〉Cu;儿童比成人更易受到土壤重金属的影响,致癌风险是成年的3倍;灌区土壤环境质量环境评价结果显示,灌区土壤重金属污染处于轻微水平。     

Mineralizable Nitrogen of Organic Wastes and Soil Chemical Changes under Laboratory Conditions

This study looks at the ability of organic wastes from different sources to efficiently promote chemical attributes and enhance nitrogen (N) concentrations in an Oxisol Ustox with a sandy texture. This experiment was performed in a randomized design using wastes from pulp mill sludge, petrochemical complex, sewage treatment plant, dairy factory sewage treatment plant, and pulp fruit industry, on 10 different days. Results showed that addition of the wastes to the soil amended their chemical attributes. The different characteristics of the organic wastes seem to have influenced the N mineralization rates during the 112 days. There was a close relationship between the N mineralization and organic waste C/N ratio: blank soil (SP) (Nma = 3.17) < Treated pulp mill sludge (PMS) (Nma = 30.49, C/N 63.6:1) < Organic compost from the fruit pulp industry (FPW) (Nma = 67.6, C/N 11.9:1) < Treated urban sewage sludge (USS) (Nma = 76.22, C/N 7.2:1) = Petrochemical complex sludge (PS) (Nma = 84.0, C/N 7.7:1) < Treated dairy industry sewage sludge (DSS) (Nma = 102.17, C/N 8.4:1).     

南昌市城市污泥重金属形态分布及其生物活性研究

对南昌市青山污泥和纸厂污泥Hg,Ni,Cd,Cr,Zn,As,Cu,Pb的形态分布及其生物活性和迁移性进行了调查研究。结果表明,运用Tessier连续提取法,污泥中Hg,Ni,Cd,Cr,Zn,As,Cu,Pb的各形态含量之和与其总量非常接近,对Pb提取率为92.5%～94.6%,对Cr为90.1%～90.3%,表明该形态分析方法的结果是合理的。2种城市污泥中Ni,Cu,Zn,As,Cd,Pb,Cr,Hg的形态分布有很大的差别,且这些重金属的不同形态也存在较大的差异。青山污泥重金属生物活性系数的大小顺序是:HgNiAsCdCuCrZnPb;迁移能力的顺序为:HgNiCdCrZnAsCuPb。纸厂污泥重金属生物活性系数的大小顺序是:CrHgCuCdNiZnAsPb,迁移能力的顺序是:CrHgCdNiZnCuAs≈Pb。研究结果将在污泥的农业利用中为污泥中重金属危害的评估提供科学依据。     

贵州省典型城市污水处理厂污泥养分与重金属含量调查

分别采集贵州省8个典型地级城市污水处理厂冬季和夏季的脱水污泥样品,进行室内分析测试,研究其养分和重金属特性。结果表明,贵州省主要地级城市脱水污泥pH为6.5-7.4,盐分含量为0.4-0.9。城市污泥中有机质、全量N、P高于一般农家肥,但全K量较低。污泥中全量重金属Cu、Pb、Ni、Cr、Hg和As均远低于国家农用标准,但一个处理厂污泥Cd、Zn超标,另有一处理厂污泥Cd超标,有3个处理厂污泥存在Zn超标现象。形态分析表明,Cd在多数污泥中化学形态主要是以生物有效态的形式存在,而Zn主要以稳定的化学形态存在,说明Cd存在环境风险,而Zn相对安全,表明贵州地区脱水污泥多数可安全农用,冬季和夏季脱水污泥的养分和重金属浓度没有显著差异。     

蚯蚓对土壤中重金属的富集作用研究

通过向供试土壤中添加CuSO4、ZnSO4、Pb（Ac）2、HgCl2以模拟受污土壤,研究接种于其中的微小双胸蚯蚓对重金属的富集作用。以不加重金属盐类为对照,分别研究了不同培养时间和不同重金属浓度对富集量的影响。结果表明,蚯蚓对各种重金属的富集量随着培养时间的增加而变化,且对不同重金属最大富集量的出现时间也不相同。在第2周时蚯蚓对Cu、Pb富集量达到最大,而对Zn的富集量在第4周时达到最大。与Cu、Zn、Pb的富集量相比,蚯蚓对Hg没有明显的富集作用,且对Hg的最大富集量时间不明显。在其耐受浓度范围内,蚯蚓对重金属的富集量随着重金属浓度的增加而增加,且蚯蚓对重金属的吸收顺序为：Zn〉Cu〉Pb〉Hg,说明了微小双胸蚯蚓对Cu、Zn、Pb、Hg4种元素有一定的忍耐和富集能力,但其对重金属的忍耐和富集能力是有选择性的,说明不同重金属表现出的毒性是不一样的。研究结果初步推断,影响蚯蚓对重金属富集作用的主要原因可能是体内酶的作用,不同重金属可以从多方面干扰了动物机体内的生理生化功能。     

污泥堆肥对盐碱土土壤环境和作物生长的影响

以城市污水处理厂污泥堆肥为研究对象,采用盆栽试验方法研究不同用量(0%,5%,10%,20%)污泥堆肥施入盐碱土后,对玉米、大豆生长情况及土壤环境的影响。结果表明,施用污泥堆肥可降低盐碱土pH值和总盐含量,提高土壤养分及酶活,增加土壤微生物量碳、微生物量氮,同时施用污泥堆肥土壤重金属Zn、Cu含量增加,当施用量为20%时,土壤Zn含量超标。另外,玉米和大豆在污泥堆肥施用比例分别为10%和5%时长势最佳,且作物籽粒中重金属含量在国家食品卫生标准范围内。     

城市土壤重金属有机酸淋溶特征与动力学机制

以典型工业城陕西省铜川市土壤为研究对象,采用BCR(欧共体标准物质局)连续形态分级法和Hakanson潜在风险指数法分别研究了人类活动性元素Pb,Cu,Cr,Zn的形态分布特征、环境迁移与生态风险;利用振荡浸提动力学试验(25℃平衡振荡24h)探讨了人工合成低氨基多羧酸(APCAs)乙二胺四乙酸(EDTA)、二乙烯三胺五乙酸(DTPA)和低分子有机酸(LMWOAs)抗坏血酸(Vc)对重金属Pb,Cu,Cr,Zn的淋溶解吸特征与动力学机制。结果表明,铜川市工业区土壤重金属污染程度严重,总体潜在生态风险程度较强;重金属Zn和Cu的环境迁移趋势较大。淋溶动力学试验表明,不同类型有机酸对土壤Pb,Cr,Cu和Zn的淋溶解吸具有相似的动力学过程,但淋溶速率和解吸量随有机酸的不同各异。重金属Pb,Cr,Cu和Zn各形态量之和与有机酸EDTA和DTPA淋溶解吸量呈指数关系,而与低分子有机酸Vc淋溶解吸量成线性关系。从而进一步表明低分子有机酸Vc与氨基多羧酸类有机酸EDTA和DTPA对土壤重金属Pb,Cr,Cu,Zn淋溶解吸机制不同。     

堆肥对重金属污染土壤上茼蒿品质和产量的影响

为了解堆肥施人重金属Cu、Cd污染土壤后对蔬菜品质和产量的影响,利用盆栽试验研究了不同堆肥用量下茼蒿品质、产量和重金属含量的变化。结果表明,随着堆肥用量的增加,茼蒿产量、粗蛋白、VC、P和K含量先显著增加后降低,而茼蒿可溶性糖含量呈先显著降低后增加的趋势。堆肥量的增加显著降低茼蒿中Cu含量,比对照最多降低35．5％。茼蒿地上部Cd、根部Cu和Cd含量呈先显著降低又上升的趋势。茼蒿地上部Cd含量在堆肥用量为20g·kg^-1时达最低,根部Cu、Cd含量与对照相比最多分别降低20．1％和39．5％。对于污染地区的茼蒿种植,试验堆肥的适量施用是切实可行的。     

污泥中重金属的环境活性及生态风险评估

研究了湖南省长沙市、株洲市和常德市10个污水处理厂剩余污泥中As,Cd,Cu,Ni,Pb,Zn的含量和形态特征,并利用潜在生态危害指数法对污泥农用过程中重金属的生态风险进行了综合评价。结果表明,城市污泥中富含有机质及N,P,K等养分,然而,污泥表现为以Cd为主的多金属污染,不能直接农用。污泥中Cd含量为1.43～260mg/kg,以可还原态为主,占全量比例高于28.9%;As,Pb的可还原态,Ni,Zn的酸可溶态和可还原态,Cu可还原态和氧化态所占比例较高,表明污泥中重金属的潜在环境活性较高。风险指数评价结果表明,污泥中Cd和As是潜在的强生态风险元素;以工业废水处理为主的污水处理厂污泥重金属单因子生态风险相对较高,且综合潜在生态风险严重。     

Effects of Wastewater Irrigation on Physicochemical Properties of Soil and Availability of Heavy Metals in Soil and Vegetables

The present study investigated the impact of irrigation with wastewater on nutritional property and heavy‐metal concentrations in the soil and consequent accumulation in vegetables at sites having long‐term uses of wastewater for irrigation. Samples of irrigation water, soil, and root and shoot parts of palak plants were analyzed to determine the concentration of heavy metals. Wastewater irrigation led to increases in the total and phytoavailable heavy‐metal concentrations in the soil at all the sites. Heavy‐metal concentrations in soil under wastewater irrigation were negatively and positively correlated with soil hydrogen potential (pH) and organic carbon (OC), respectively. The enrichment factor and metal pollution index were higher at wastewater‐irrigated sites as compared to the clean water–irrigated ones. The study concludes that wastewater irrigation modified the physicochemical properties of the soil, leading to more availability of heavy metals in the soil and consequently to the plant.     

不同施肥处理对番茄产量品质及土壤有效态重金属含量的影响

以露地番茄（Solanum lycopersicom L.）为试材,进行了施用有机肥、无机肥及有机无机肥配施对番茄产量、品质和土壤有效态重金属含量的影响研究。结果表明,在施氮量相同条件下,有机肥与无机肥配施番茄产量增幅较大,以6∶4养分配施比例产量最高,总产量比对照提高了15.6%。施用无机肥番茄果实可溶性糖含量和可滴定酸含量较高,维生素C含量以施用有机肥处理的最高;番茄果实的营养品质和口感以施用有机肥处理的最佳。番茄果实中可溶性糖、酸和维生素C含量的变化规律与肥料施用无相关性,可能是受番茄产量高低的影响。施用有机肥番茄果实硝酸盐含量明显低于施用无机肥和有机无机肥配施处理,亚硝酸盐含量则以施用无机肥和低有机肥配施量处理的含量较低。施肥有明显降低番茄果实Hg含量的作用,但却提高了Pb和As含量,对Cu、Zn和Cd含量的影响较小;施用有机肥可显著降低番茄果实Cr含量。施肥提高了土壤有效态Zn和Cd含量,降低了土壤有效态Pb含量,对土壤有效态Cr和As含量的影响较小;施用有机肥使土壤有效态Cu含量显著降低,而使土壤有效态Hg的含量提高;施用无机肥可提高土壤有效态Cu的含量。不同施肥处理番茄果实重金属含量变化与土壤有效态重金属含量变化不一致的主要原因,可能是由于施肥改变了番茄的生物产量,从而产生对植株吸收重金属元素的生物稀释作用造成。各试验处理番茄果实硝酸盐和亚硝酸盐及重金属含量均远低于国家蔬菜或食品中污染物限量标准,说明合理施用有机肥、无机肥和有机无机肥配施不会造成番茄果实硝酸盐、亚硝酸盐以及重金属污染。     

沈哈高速公路两侧土壤重金属污染特征及评价

为探讨高速公路对农田土壤重金属污染的影响,对沈哈高速公路两侧农田60个土壤样品Ph、Cu、Zn、Cd分布状况进行了分析。结果表明,高速公路两侧在距路肩0—320m范围内,Cu、Pb和Zn全量和有效态含量总体上呈现随距离增加而降低的趋势,Cd的变化规律不明显。高速公路两侧的土壤已不同程度出现重金属富集现象,其中Pb属轻度污染且主要集中在东侧距路肩20m处,Cd属重度污染。受研究地点主导风向的影响,高速公路东侧农田土壤的Ph含量明显高于西侧。高速公路旁土壤重金属以Ph、Cd污染为主,污染物主要来源于汽车尾气。     

腐殖酸与活性污泥对污染土壤联合修复研究

采用正交试验的方法,研究了表面活性剂溶出和微生物降解联合作用对重金属铜、锌、铅和多环芳烃菲、萘、芘人工老化污染土壤的修复效率。选择腐殖酸为表面活性剂,强化微生物对有机污染物的降解性能,将高效降解菌的降解能力有效地发挥出来;用驯化的活性污泥为土壤生物修复剂,强化腐殖酸对重金属的洗提作用,旨在降低重金属和多环芳烃在土壤中的污染作用,提高修复效率。结果表明,接种2.0%活性污泥,温度为35℃,pH值为6.5,腐殖酸加入量为5mg/g的土壤为最佳修复条件,在此条件下菲、萘、芘的总修复率分别为73.4%,80.5%和68.2%;重金属离子Cu2+,Zn2+,Pb3+的总修复率分别为75.5%,64.2%和71.7%。添加腐殖酸和驯化活性污泥可明显提高土壤中重金属和多环芳烃的修复效率,表明化学溶出与生物降解同时作用于复合污染土壤具有较好的协同作用。     

Application of Organic Wastes in a Soil Polluted with Different Rates of Cr-Pb: Effects on Soil Biological Properties

An experiment was performed to determine the effects of adding municipal solid waste (MSW) and poultry manure (PM) to a soil polluted with chromium (Cr), lead (Pb), and Cr + Pb on the biological parameters of the soil. Soil was mixed with two solutions of Cr(NO₃)₃ and/or Pb(NO₃)₂ to give three concentrations (0, 100, and 250 mg Cr kg^?1 soil and 0, 100, and 250 mg Pb kg^?1 soil) and treated with MSW or PM. When the soil was contaminated with the metals without combining, the greatest adenosine triphosphate (ATP), urease, and phosphatase inhibition percentages occurred for 250 mg Pb kg^?1 soil. When the heavy metals were mixed, the inhibition of the biochemical parameters increased. The application of MSW and PM decreased the inhibition of the biochemical parameters and microbial population in the polluted soils. The inhibition percentage was greater for the soil amended with MSW than with PM, possibly due to the high humic acid concentration.     

苏南某冶炼厂周边农田土壤重金属分布及风险评价

选择江苏南部冶炼厂周边污染的水稻田,采集耕层0～15cm的土壤,分析土壤中重金属Cd、Pb、Hg、As、Zn、Cu的污染程度及其空间变异特征。结果表明,土壤Cd、Pb、Cu、Zn、Hg的全量随着距污染源距离的增加而减少,呈现由东北向西南扩散的趋势,As则是由西北向东南扩散。6种重金属中Cd、Hg的污染范围相对较大,Zn的污染范围最小。DTPA浸提的6种重金属有效态含量都是距污染源距离越远而越少。采用内梅罗综合污染指数法对土壤中的重金属进行风险评价,土壤重金属的综合污染指数为39.27,污染程度已超过5级,为重度污染,其中Cd、Hg污染最为严重,含量范围分别为3.98～44.58mg·kg-1、0.36～2.01mg·kg-1,As为中度污染,Pb、Cu、Zn则为轻度污染,说明研究区域农产品安全生产存在很大的风险。