Experiences with constructed wetland systems in Korea

In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands＇ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.     

自然状态与加热改性的黄铁矿处理含铬(VI)废水的实验研究

最近几年,人们对一些天然矿物在处理重金属污染物过程中所表现出的高效性、经济性和安全性倍加青睐,并逐渐发展成环境矿物材料研究的方向［１,２］。国外对某些矿物吸附机理也有较系统的评述,有关含铬矿物与有机物的作用也有报道［１,３］。１　实验部分（１）试样来源：黄铁矿取自硫铁矿矿山,经鉴定与粉碎,淘洗,烘干,筛分,磁选后获得。（２）含铬（ＶＩ）废水：用分析纯重铬酸钾（Ｋ２Ｃｒ２Ｏ７）和蒸馏水配制。（３）实验仪器：反应体系的酸度用ＰＨＳ３Ｃ型酸度计测定,反应平衡时的吸光度用ＵＶ１６０Ａ分光光度计测定,…     

膨润土对阳离子染色废水的脱色实验研究

阳离子染料是纺织印染工业中重要的染色原料之一,它对晴纶织品着色具有特殊的效果。着色后的染色废水呈酸性(pH=4～4.5),具色度大(平均为500倍左右,黑、大红等深色废水色度更高)、悬浮物小等特点。资料表明,对阳离子废水采用生化、物化或化学凝聚法处理都难以达到较理想的脱色效果。膨膨土有对阳离子交换量高的特点,在阳离子黑色(604~#)染料自配废水中,加入膨润土吸附染化料的显色剂中的色基盐,生成难溶或溶解度小的物质沉淀,达到对废水的脱色目的。 1.材料与方法 (1)采集贵州、浙江两地产膨润土为试验材料,粉碎至100目以下,各以250、500、1000mg称重分包待用。(2)配制浓度为2％的PAC溶液和1‰的PAM溶     

即时合成Zn-Mg-Al层状双氢氧化物处理含Zn2+废水实验研究

在模拟含Zn2 废水中加入Mg2 和Al3 ,以NaOH为沉淀剂,研究金属盐水解即时合成层状双氢氧化物(LDH)去除Zn2 的可行性。详细探讨了体系终点pH值、配料中Mg2 /Zn2 摩尔比值及反应温度和时间对Zn2 去除率的影响,结合X射线衍射分析(XRD)探讨了Zn2 去除机理,并与化学沉淀法进行了比较。结果表明,实验条件下只有pH值显著影响Zn2 去除率(p<0.05),在9.0~11.0范围内去除效果最佳,达99%以上。通过XRD分析结合即时合成法特点,废水中Zn2 主要是在晶体生成阶段以Zn-Mg-Al三元LDH化合物形式被去除的。与化学沉淀法相比,即时合成法效果更好,适用pH值范围更广,用来处理含Zn2 废水更具优势。     

含氟废水的粉煤灰处理实验研究

进行了影响粉煤灰处理含氟废水的各种条件实验，（pH、水灰比、氟浓度、振荡平衡时间），结果表明最佳处理条件是pH值为2．5、水灰比为小于20、氟浓度小于500mg/l、振荡平衡时间大于2．5h，并研究了粉煤灰处理含氟废水的机理，给出了其吸附等温式。     

Experimental Study on Treatment of High-concentrated Sulfur Wastewater by Process of Depositing Natrojarosite and Its Environmental Significance

High-concentrated sulfur wastewater with sodium and COD （chemical oxygen demand） up to 26000 mg/L from a chemical plant, Jiangsu Province of China has been treated by deposition of natrojarosite in lab. The results indicated that the COD of the wastewater was decreased sharply from 26000 mg/L to 1001 mg/L, with removal rate of COD up to 96% by twice precipitations of natrojarosite and twice oxidation of H202. The treated sulfur wastewater reached the requirement of subsequent biochemical treatment to water quality. The optimal operational parameters should be controlled on pH value between 2.50 and 3.20 and 50 g FeCly6H2O solid added in per liter wastewater. The study provided an experimental basis for pretreatment of high-concentrated sulfur wastewater and proposed a new mineralogical method on treatment of other wastewaters. Depositing process of jarosite and its analogs should be able to be used to treat wastewater from mine and other industries to remove S, Fe and other toxic and harmful elements, such as As, Cr, Hg, Pb, etc. in the water.     

羟基磷灰石吸附水溶液中Cd^2＋的影响因素的研究

对羟基磷灰石(Hap)固定水溶性Cd2+的影响因素进行了较为系统的实验研究.实验表明去除率与Cd2+初始浓度呈负相关,在Cd2+初始浓度<10 mg/L时,与作用时间、pH值、Hap用量呈正相关,温度对去除率的影响较小.通过正交实验确定了最佳吸附条件Hap用量为5 g/L,pH值为6,作用时间5 min.     

钽铌钨锡多金属矿分离加工废水处理工艺研究

研究了采用石灰中和＋化学絮凝沉淀、有机复合脱氮剂分质处理钽铌钨锡多金属矿分离加工产生的酸性和碱性废水,氟化物、氨氮去除率可达到99.9%以上,重金属离子去除率可达到99%以上,氨回收率可达到98%以上。该处理工艺可实现废水资源化,回收的稀氨水可返回生产工艺再利用,具有良好的环境效益和经济效益。     

天然褐铁矿处理含Hg（Ⅱ）废水的实验研究

利用水合金属氧化物和氢氧化物矿物表面重金属离子发生吸附作用的原理，进行了天然褐铁矿处理含Hg(Ⅱ)废水的实验。结果表明：试样用量、粒径、废水浓度、pH值、离子强度、反应时间、振荡器转速等因素对Hg(Ⅱ)的吸附率有一定的影响，其中pH值的影响最大；Hg(Ⅱ)在天然褐铁矿上的吸附等温曲线不同于Langmuir和Fre-undlich等温线，而为台阶型，符合分级离子／配位子交换等温曲线。     

天然锰钾矿处理印染废水实验研究

利用天然锰钾矿处理印染废水，讨论了介质pH值、样品用量、样品粒径、反应时间、光照和同存电解质等实验条件对活性艳红X—3B印染废水脱色速率的影响。处理了工业中常用的10种活性染料印染废水和华丰印染厂实际废水，大部分染料的脱色率达到了95％，处理后的华丰印染厂的CODcr和色度都达到了纺织染整工业废水排放一级标准，且天然锰钾矿可以被重复使用。锰的溶解情况研究结果表明，加入染料后，溶液中Mn(Ⅱ)的浓度大大提高，表明染料能将Mn(Ⅳ)还原为可溶的Mn(Ⅱ)，即染料与锰钾矿颗粒物界面发生了氧化还原反应，使染料的发色基团破坏而导致脱色。