彗星 onsider那句“人工濕地。” 雖然不是一對矛盾的條款，這兩個詞構成了一個不太可能的組合。 建設意味著項目製造和建造的人類。 那麼，有建設與濕地，自然區域所形成的複雜的運作地質，生物和水文？
即使是單詞“濕地”本身傳達混合的含義。 濕地意味著一個領域，既不是完全的土地也沒有水，有特色的陸地和水生系統。 在談到濕地中，“不倫不類”可能被引用 - 或者，把有關的短語，一個變化可能正好是杜撰，“魚，家禽及哺乳動物，”來形容各種各樣的野生動物吸引到結合地面的水生濕地環境。
連接技術與自然過程，人工濕地的確有廣泛和多樣的影響。 一個日益重要的水的話題，人工濕地吸引了許多關注和重視，從人員到環保廢水處理，在亞利桑那州和世界各地。
什麼是構築 濕地？
總之，人工濕地是一種水處理設施。 複製過程中發生的自然濕地，人工濕地是複雜的，集成系統中，水，植物，動物，微生物和環境 - 陽光，土壤，空氣 - 互動，以改善水質。
在某種程度上，什麼是人製造的是人為的 - 而什麼是由自然被說成是自然 - 人工濕地是人工濕地。 鑑於地質，水文和生物創造自然濕地，人工濕地是導致人類技能和技術。 人類的設計，建造和運營人工濕地處理廢水。
然而，人工濕地是指作為純粹人為的，人為的或設計不完全準確，輕視他們最顯著的特點。 通過利用，甚至企圖以優化的物理，化學和生物過程的自然濕地生態系統，人工濕地也都在不同程度上，自然的環境。
如果適當建造，維修和操作，人工濕地能有效去除多種污染物與市政和工業廢水和雨水。 這種系統特別有效地去除污染物如BOD，懸浮物，氮，磷，碳氫化合物，甚至金屬。 它們被用來處理城市污水，工業和商業廢水，農田徑流，雨水徑流，動物廢棄物，礦山酸性排水和垃圾填埋場滲濾液。
雖然主要目的的人工濕地是將各種廢水，通常服務設施以及其他用途。 研究會進行，研究和評估的運作過程中的濕地。 濕地還可以作為野生動物的網站，以吸引各種動物提供棲息地。 此外，濕地可以是一個吸引公眾歡迎遊客，探索其對環境和教育的可能性。
人工濕地越來越多地被用在亞利桑那州處理廢水。 1990年，亞利桑那州只有四個人工濕地處理城市污水。 今天，26市和現場人工濕地運作的狀態，至少有24人要么等待批准或正在建設中。
人工濕地在亞利桑那州的變化很大的規模和功能，服務城市，企業和個人家園。 在金曼人工濕地設施有量3000000加侖每一天。 人工濕地在處理污水雅各湖酒店從難民營地，洗衣房和出租小屋和它的體積約 2000加侖的一天。 人工濕地在尤馬 -梅薩灌區汽車維修場處理車輛“洗架”徑流，具有體積小於 200加侖的一天。
優勢，人工濕地的好處
人工濕地提供各種好處。 這擴大了他們在不同的利益訴求，工程師和那些參與了運作的污水處理設施，環保和有關人士與休閒。 不像有些水的問題，其中一個組的優勢，缺點是另一個有效運作的人工濕地可提供廣泛的利益範圍的利益。
特雷斯里奧斯的人工濕地示範項目以外的鳳凰演示一些人工濕地的優勢。 該設施是檢驗成效的濕地處理污水的鳳凰第91大道污水處理廠。 開始於 1995年，特雷斯里奧斯是第一步在發展更廣闊的人工濕地設施。
鳳凰水務署轄下的特雷斯里奧斯項目，代表了多城市分區域運營集團。 SCROG包括援引格倫代爾，梅薩，鳳凰城，斯科茨代爾和天普。 其他項目參與者包括美國墾務局，環境保護局和工程公司的CH2M希爾和格里利和漢森。
鳳凰官員特雷斯里奧斯開發項目的一部分戰略滿足預期更嚴厲的聯邦水質標準的污水處理設施。 預計該升級的第91號工廠將耗資巨大，官員尋求更便宜的選擇。
不依靠混凝土和鋼筋，人工濕地通常可以少建造費用比其他治療方案。 里奧斯的特雷斯試點工程造價 350萬美元興建。 相對於 6.25億美元官員估計將需要升級的第91號工廠，預計成本擴大特雷斯里奧斯人工濕地試點項目進入全面的污水處理設施 8000萬美元。
人工濕地處理技術和方法的承諾進一步的優勢。 研究是展示效果自然進程的治療廢水。 此外，隨著技術含量低的方法到位，沒有新的或複雜的技術工具，將是必要的。 植物和微生物的活性劑的過程中。
人工濕地的另一個優點是，操作和維護成本可能會低於傳統的處理廠。 更少的能源和物資需要和人工濕地設施可以通過定期組織現場勞動，而不是連續的，全職的關注。 在特雷斯里奧斯兩名全職員工的操作和維護該設施。
最近轉換為人工濕地，全鎮的杰羅姆選擇這個過程通過機械處理廠處理的廢水。 維修的機械處理廠是成本約 1000美元每月，而成本保持濕地有望成為“很少或沒有。” 建設預計今年夏天開始。
其他種類的利益也產生。 通過複製的自然過程發生在濕地生態系統，特雷斯里奧斯是絕不僅僅是一個高效的污水處理設施。 特雷斯里奧斯已成為在一定程度上真實的東西，一個正常運作的濕地，一個站點與現有的水和緊急植被吸引不同的野生動物。 環境景點有一個重要特點，許多人工濕地。
遊客在特雷斯里奧斯來看看它的緩慢移動的水蜿蜒團塊之間的植被和查看各種野生動物。 四十五種不同的鳥類品種過往亦曾在該地區以及爬行動物，魚類和其他動物，包括海狸殖民地。 通常被視為“附帶利益”，對很多人來說這樣的環境特點是主要景點的人工濕地。
特雷斯里奧斯等人工濕地都在增加濕地內的狀態。 在亞利桑那州和其他地區的美國，天然濕地已取得的地位的一種瀕危物種。 普遍認為，一旦土地價值不大，少用，濕地被認為是邊緣和消耗。 因此，少數亞利桑那州的原始濕地保持不變。
天然濕地
領悟人工濕地處理工藝，運作的自然濕地必須被理解。 天然濕地不同地稱為沼澤，沼澤，沼澤，沼澤，濕草甸，泥坑，或在美國西南部，cienegas和蒂納哈斯。 這些條款的濕地定義不一定都是一樣的。 植物類型，水和地理條件各不相同，形成不同類型的濕地。
濕地之間的過渡地區水和土地。 1977年清潔水法修正案提供了廣闊的濕地定義：“術語”濕地“是指那些地區被淹沒或飽和地表或地下水的頻率和持續時間足夠的支持，並在正常情況下做支撐，其普及率植被的典型改編為生活在飽和土壤條件。“
濕地是天然的插座。 發生在低窪地區，濕地得到徑流水和溢出從河流和溪流。 對此，各種濕地生物進化過程的機制或在地質時間來治療流入。 這些機制的陷阱沉積物和分解廣泛的污染物進入元素的化合物。
濕地有一種天然的，與生俱來的能力，處理廢水。 水緩緩移動，通過濕地，為淺流，飽和基板或兩者兼而有之。 慢速流動和淺水水域造成沉積物定居。 緩慢流動也採取行動，延長接觸時間的水和表面之間的濕地內。
有機和無機材料在濕地形成一個複雜的質量。 這種大規模發生一起煤氣 /水交匯處，促進社會的各種不同的微生物，分解或變換各種各樣的物質。
密集生長的維管束植物適應飽和的條件往往蓬勃發展，濕地和促進其處理能力。 隨著減緩水流，植被造成微環境，並提供實習場所的微生物群落。 此外，模具廠早在秋季和積累的垃圾。 這將創建更多的物質和交流場所，以及提供一個源的碳，氮和磷的微生物燃料 流程。
運作的 人工濕地
上述非常簡要介紹了適應自然的過程中使用人工濕地。 人工濕地項目可能在不同的操作和治療目標，但都依賴於這個自然過程。 在特雷斯描述污水處理里奧斯 - 雖然它可能與發生在其他什麼人工濕地 - 將有助於解釋適應自然的過程中使用的人造濕地。
特雷斯里奧斯的試點項目，既是經營設施，也是一個測試實驗室。 正在處理的污水和各種配置的自然過程中被測試，在努力尋找最合適的設計，施工和運營標準，以備後用一個全面的濕地。
人工濕地的一部分的一種治療火車，一個階段的治療過程。 在特雷斯里奧斯濕地，廢水處理是先在第91大街到輔助設備的先進水平。 這種廢水具有較少的營養成分，是更高的質量比二級處理的廢水。 特雷斯里奧斯必須得到高質量的廢水由於其野生動物的棲息地。 人工濕地有能力處理廢水的質量要低得多，包括初級處理過的廢水。 基層處理後的廢水處理一般僅限於物理分離。 過濾去除浮動材料，固體沉澱。 進入濕地污水處理與主很可能會限制對人類和大多數動物。
特雷斯里奧斯的濕地由三幅覆蓋 14畝。 坐落在河岸/山地面積上北岸的鹽河，六畝海菲爾德網站是由兩個獨立的細胞。 無論是在經營的串聯或並聯，細胞排列，以確定人工濕地效益的廢水拋光和最佳電池配置最佳的水質。
座落在鹽河排水繞道，4.5畝的卵石網站由兩個平行的盆地。 一是內襯植被表土，以方便建立和減少水的滲透。 另一種是單衣，複製條件時定位一個全尺寸的濕地在沙子和卵石的河底。 建立濕地的可行性在這樣的土壤條件和能力的濕地反彈後，洪水正在測試在這個網站。
特雷斯里奧斯採用三相濕地系統，污水正從沼澤到深池再回到沼澤，同時通過緊急和開放水域。 污水先流入新興領域的淺沼澤初始治療。 不等深度從 0.5至1.5英尺，淺領域包括香蒲，蘆葦和bulrushes。提供最佳的水鳥棲息地，bulrushes均勻種植在緊急沼澤地區。
（生物學家推測，豐富的植被在特雷斯里奧斯可能吸引梆子鐵路，瀕臨滅絕的物種，這可能造成一個有趣的監管形勢，如何將存在一個瀕危物種的人工濕地影響其管理？）
水然後收集在更深，開放式水池，從 3至4.5英尺深。 通過將水由淺到深的水才流回淺水，廢水變成混音。 這確保了水會接觸更多的表面，無論是在底部的游泳池或部分淹沒的植被。 從而出現更多的治療。 此外，深潭減緩水流在進入下一個流動的路徑，這將確保更多的治療時間。
深池是一個重要的棲息地面積的野禽，包括嵌套島嶼。 有一次沉水植物生長在特雷斯里奧斯深潭，但他們吃了一個物種的羅非魚，非原生魚，即鑽進了水池。 魚為食的鳥類，如藍鯡魚，鯡魚和白鷺夜柄邊緣的深池求魚。
從深池的廢水再進入第二沼澤。 這裡 bulrushes過濾和處理廢棄產品添加水禽生產和藻類在深水池。處理後的水再流入一般幹鹽河床。
會發生什麼濕地處理後的廢水，是一個重要問題。 審議其最終的使用有助於確定質量的廢水排放到濕地和濕地的類型治療過程中使用。
大自然提供了模式不僅對治療過程中，也為物理設計的特雷斯里奧斯。 形狀的細胞被設計為重複的自然濕地。 避免直邊，細胞有不規則邊界提供微棲息地吸引水生和半aquative生物。
覆蓋三個畝，第三特雷斯里奧斯網站由12個小型研究細胞。 設在一個廢棄的污泥乾燥盆地，這些細胞有密切監測，以測試各方面的治療過程。 例如，其中的主要研究目標是確定什麼樣的影響越來越深的數量區對水質。
以下是案例研究各種亞利桑那人工濕地。 他們不僅包括說明各類業務，而且還找出各種問題與人工濕地。
針尾鴨湖/紅發沼澤
顯示低人工濕地在亞利桑那州東北部是第一個在國家和一個民族的第一個。 因此，該設施是吸引了國家的重視和人工濕地中經常提到的文獻。
隨著它的歷史意義，顯示低設施一般提供了許多人期望的濕地。 坐落在一個有吸引力的自然景觀，濕地具有豐富的野生動物，用流動的水慢慢蜿蜒通過團塊植被。 植被島嶼主機築巢水禽和濕地吸引各種野生動物。 建立野生動物棲息地的核心是要設計和運行濕地。
顯示低設施實際上是一個複雜的由幾個濕地。 針尾鴨湖，率先建成，開始接受1979年城市污水。 該網站是位於國家森林服務土地。 兩個政府機構，美國林業局和亞利桑那遊戲和魚，聯手與城市建設的濕地，建立夥伴關係一直延續至今。 自加入其他團體，包括奧杜邦協會。
要創建針尾鴨湖，污水被抽成灘或自然抑鬱。 水控制結構和兩個堤防建成的凹陷內，以及美國林業局的島嶼修建14套料，以提高水禽繁殖。 這些島嶼是保護野生鳥類築巢的動物，如臭鼬和郊狼。 幾種植物種子的品種，島嶼然後分別用稻草覆蓋，以保持水分和保護海島免受侵蝕。
最初的47畝的湖面收到200000加侖廢水每天，這一數額已增至50萬加侖的市政二級出水。 1986年，顯示低複雜擴大到包括其他濕地，包括沼澤紅發和電話湖，形成一個複雜的由幾個湖泊和沼澤。 現在複雜的9個單元組成，涵蓋約 200畝，可處理1420000加侖廢水每天服務人口13500。 經處理後的水不排出的濕地，但仍然蒸發和創造的棲息地。
供應污水處理設施的潟湖濕地使用曝氣，穩定塘和加氯室。 該污水再進入濕地處理系統，包括拋光池塘，湖泊，渠道暢通，河岸地區和濕地。 管理濕地涉及控制水量，質量和交貨，與水位也仔細監管。水可以改行，讓一些池塘乾涸，植被管理和維護。
建立有力的植被覆蓋是必要的處理廢水，吸引野生動物。 香蒲，水草，穗莎草急於建立和各種自然濕地。 成功的種植包括hardstem，softstem和鹼 bulrushes和申格pondweed。 擊劍保持國內牲畜放牧在該地區。
運營商的濕地衡量成功的設施部分由野生動物的數量吸引到該地區。 一個 16週的調查顯示在1991年確定的125種鳥類利用濕地。 十大瀕臨滅絕的鳥類分類為，威脅或敏感的濕地被發現。 該地區還吸引了落基山麋鹿，騾鹿， 叉角羚，黑熊，狼，浣熊和各種兩棲動物。
針尾鴨湖是向公眾開放，吸引了人類的遊客，從死刑犯，外的狀態，甚至國外。 其公共使用計劃包括為殘疾人鋪平跟踪訪問和觀景盲目，可以容納 50名學生。 本地學生使用的設施作為戶外教室，了解回收利用，濕地生態和野生動物。
環境特點質疑
在許多思想和人工濕地環境或野生動物的景點一起去。 這是因為人工濕地項目，一般抓住了媒體關注的是那些有趣的環境特徵。 並非所有的人工濕地，然而，對環境的設施。 和其他人想要做的是被發現的一些問題如何生物學家誰仔細環境特點是工作到濕地項目。
城市的金曼有一個專為人工濕地污水處理，無環保景點。 該設施的設計，主要用於水處理是明顯的，從它的設計。 濕地包括兩列火車，每三個單元格。 每個單元約半英里長，150英尺寬。 一列火車有25畝的濕地面積和可以治療約一百萬加侖的一天。 金曼的人工濕地是最大的市人工濕地在亞利桑那州。
金曼市的官員決定對濕地環境景點由於關心的法律責任。 這些功能將吸引公眾的注意，官員不希望城市負責遊客。 此外，市政府官員擔心，人工濕地與野生動物的棲息地可能會吸引獵人。 以最少的人員在該設施，沒有人會提供給警方的區域。
（官員在第91大街工廠在鳳凰城有問題，與獵人拍攝到的濕地，也是一個爆炸裝置被扔進一池魚殺死一個數字。）
人工濕地的金曼，但是，仍然吸引野生動物。 黑色鳥，導軌，麻雀和雷恩斯使用該設施，與候鳥和岸鳥還將訪問。 周圍的圍欄設施並沒有出鹿和麋鹿。 而稀缺的水在沙漠確保了水體，即使沒有任何內置的環境吸引力，還是會吸引各種野生動物。
另外一些生物學家擔心，人工濕地環境的改進計劃沒有得到妥善的吸引力，他們的野生動物，有時誇大了。 馬蒂 Jakle，生物學家和鳥類觀察者感興趣的河岸地區，提出這樣的問題在信亞利桑那州的環境質量。
他指出，大多數圖片的人工濕地表現得非常均勻緻密納入緊急水生植物，通常香蒲或蘆葦。 這些植物物種的棲息地很少或結構的多樣性。 因此，他的問題是什麼類型的環境正在發生的增強，以及是否人工濕地，其實，提供高品質的棲息地。
他指出，人工濕地常常吸引常見品種，如美國黑鴨，歌曲麻雀，畫眉和redwinged和問題是否創造這些物種繁殖棲息地，應是當務之急。 相反，他認為人工濕地的設計應以吸引野生動物棲息地需要改善。
他認為，環保事業將是最好的棲息地類型的服務，如果確定了早在濕地規劃的過程。 各種生境類型，然後可以考慮，例如，棲息地為新熱帶移民（鶯，唐納雀，捕蠅器等），敏感品種（梆子和黑色鐵軌，雪白鷺，豹蛙等）;或常見的品種為教育目的（大藍鷺，美國黑鴨，黑頸高蹺等）。
其他生物學家說，比開放水域範圍內的植被人工濕地需要慎重考慮。 理想的比例應為約 50/50創造最好的野生動物棲息地。 並非所有的人工濕地維持這個比例。 此外，一些生物學家說，設計人員的人工濕地應種植樹木附近河岸地區的濕地是不同的。 否則，濕地是斷章取義。 三葉楊和柳樹應該種植面積創造了河岸附近的濕地。
斯威特沃特濕地，一個社區項目
由於它可以提供環境，娛樂和教育效益，一個人工濕地項目可以吸引公眾的關注和參與，程度遠遠超過了，例如，傳統的污水處理廠。 事實上，一個精心構造的濕地，創造性地管理項目可以成為一個社區項目，與人心甘情願地貢獻其規劃，設計，甚至它的建設和運營。 圖森水的斯威特沃特濕地是這樣的社區外展項目。
在什麼可能似乎是一個不祥的開始，圖森的斯威特沃特濕地工程起源於響應提起訴訟由亞利桑那州環境質量部。 起訴書指控的城市是違反了國家飲用水的監測和報告要求。 圖森隨後通過談判解決，致力於城市，除其他外，設計和建造一個實驗性濕地/充電設施，與相關的野生動物棲息地和教育設施。
圖森市水務官員要求市長和理事會批准通知和公眾參與城市規劃的濕地/充電項目。 批准1994年10月，該計劃呼籲建立一個特設公民濕地/充值諮詢委員會，成員由市長任命和理事會。 服務作為一種社會情緒的傳聲筒，該委員會參與規劃和設計項目。
項目參與進一步擴大，與各聯邦，州和地方機構以及非政府組織協助委員會，市的工作人員和顧問團隊在設計設施。 在這些努力都加入美國魚類和野生生物服務，亞利桑那遊戲魚部，城市公園和休閒部門，亞利桑那大學，亞利桑那州的鄉土植物學會，亞利桑那州索諾蘭沙漠博物館，圖森奧杜邦學會和圖森的環境資源中心教育。
十大委員會會議和三次信息公開房屋被1994年12月舉行的1995年9月上旬。 該委員會提出了各種設施的設計建議。 例如，該委員會建議，一個兩個濕地池塘在不公開的訪問，從而保持它專門為野生動物。有限的停車設施的另一項建議，以控制參觀人數。
要建立與當地教育機構的橋樑，一個濕地/充電教育推廣計劃正式成立。 鬥獸場學區的REACH計劃和鎮中學的高級媒體製作類成為直接參與。 REACH學生花一學期的學習有關濕地和他們建議採取各種教育內容包括在設施的設計。 學生們還設計了官方標誌的項目。 他們提出了他們的建議，市長和理事會 1995年5月期間，研究會。
鎮中學學生製作的紀錄片描繪了三個視頻公眾參與過程和活動的REACH學生。 他們的紀錄片已在當地學校和播出證明市長和理事會。 這在複雜和廣泛的公眾參與運動吸引了全國的關注，並擔任藍圖努力為公眾參與在其他城市。
中央對這次公開活動，事實上，它的原因，是濕地本身的設施，以進一步處理廢水的補給和重用。 濕地的甜水是成為第一階段的擴張城市的水回收設施。
The city's reclaimed water treatment plant's filters are periodically cleaned by backwashing. The backwash water then is recycled through the county's treatment plant for reprocessing, at an annual cost of about $100,000. 而不是被 reprocessed by the plant, the backwash water now is to be treated in the Sweetwater Wetlands.
The backwash water first will be conveyed to settling ponds to separate suspended solids, before entering the polishing basins or the wetland ponds. After physical separation occurs in the settling ponds, microbiological transformations take place in the wetland ponds. The backwash water will be treated to meet or exceed secondary standards. Sweetwater Wetlands will have 1.2 acres of settling basins, two wetland ponds totalling 17 acres with a volume of 300 acre-feet and six acres of recharge basins. About 300 acre-feet of backwash water will be treated annually for recharge.
Estimated total construction cost is about $1.7 million, with about $600,000 earmarked for public-use amenities. The facility design was finalized in late 1995. Construction is expected to be completed in early autumn 1997.
Other Wetland Benefits
Some type of water resource management innovation has occurred when Sweetwater, a constructed wetland wastewater treatment facility, can become a community or civic project, with citizens willingly contributing time and effort, from offering design suggestions to creating logos and planting trees. The project obviously is serving a broader purpose than just wastewater treatment.
Along with whatever public relations benefits it promotes, citizen involvement, very apparent at Sweetwater but encouraged in other such projects as well, is helping to change attitudes about the use of technology and about wastewater as a water resource. Such attitude changes may be another notable achievement of constructed wetlands.
Some environmentalists and other people at times have been wary of technology, especially when used to adapt natural processes to serve human needs. They fear its careless use can be destructive to the natural world. And admittedly human interference in the natural world has occasionally caused damage. For example, the dams that form lakes often harm and even destroy riparian ecosystems.
Unlike dams, however, constructed wetlands demonstrate that human projects can work in harmony with natural processes, to the advantage of both humans and the natural world. This experience can help define a suitable environmental role for technology. To some, technology may then seem less threatening.
Also, using wastewater to create wetlands helps redeem wastewater from its status as a befouled residue of civilized life or, in other words, water waste. It enables even wastewater to share, to some extent, the image of water as a basic and elementary resource, with the potential to support life, satisfy human needs, and even be a source of beauty. The role of water in our lives, especially our civilized lives, thus is better understood and appreciated.
Domestic Wetlands
Constructed wetlands range broadly in size, from the very large scale municipal systems to smaller systems for individual, single-family residences. Many homeowners likely find the idea of a constructed wetland appealing. To have one's very own personal wetland certainly is an attractive thought. Also, and more significantly, constructed wetlands, by providing water for outside use, help conserve water.
A constructed wetland, however, is an option for only very few home-owners. Homeowners living in urban areas usually are required to connect to a sewer system, and people in outlying areas generally use septic tanks and leach fields. Only if conditions are unsuitable for a septic tank and leachfield can a homeowner adopt an alternative means of on-site disposal.
For example, a septic system is not suitable if the building site has ten feet or less of soil to bedrock. Nor is it suitable if the site has tight or impacted soil that percolates at less than one inch per hour in a water percolation test or has a high water table. Since such conditions preclude the use of a conventional soil absorption system, homeowners in such situations could consider wastewater treatment alternatives.
A constructed wetland is such an alternative, although it is often referred to as an "non-conventional" option. Its dubious status is due to its relatively recent use in Arizona, despite their long-time use in other states. As a result, some officials believe that constructed wetlands for domestic use have not been adequately tested in this state.
Most constructed wetlands to treat domestic wastewater are subsurface systems. Wastewater then is not exposed on the surface of the yard or property, to raise odor, insect, public health or safety concerns.
In a constructed wetland system for domestic use, wastewater first flows to a septic tank which acts as a primary treatment system. Here solids are settled. From the septic tank, the effluent flows through a perforated inlet or distribution pipe buried in rock or gravel into vegetated submerged beds. Plants typical of subsurface flow wetlands are bulrushes and cattails; ornamentals such as canna lily, pickerelweed and arrowhead also are effective in treatment.
Subsurface wetland flow systems work on the principle that aquatic plants transfer oxygen from above-surface leaves to sub-surface roots. Aerobic bacteria attach to the roots, and anaerobic bacteria attach to the rocks. The effluent flowing through the wetland is treated by the action of the bacteria attached to the plant roots and rocks.
After treatment the water is released. Disposal options include reusing the treated water on turf. Another option is to install a drip system to irrigate the landscape in the yard. These options involve subsurface disposal systems with no human contact with the treated water. Other uses include evaporating the water in a pond or watering livestock.
Not all domestic constructed wetlands are subsurface systems. Some interesting projects are underway to treat domestic wastewater for use in designed and landscaped ponds. Several households, at least four or five, would pool wastewater for use in a common wetland. Some land-scapers and designers are promoting this use of constructed wetlands to create pocket parks in cul-de-sacs and other places having a cluster of houses and a common area.
Not many Arizona homeowners have on-site wetlands to treat their wastewater. First of all, not many of them live in areas with conditions to justify installing a constructed wetland. Also strict regulations presently discourage householders from building wetlands. However, constructed wetlands for domestic use may increase in Arizona in the future. As the state continues to grow, construction is occurring in areas with unsuitable conditions for septic tanks and leachfields. People settling in such areas might decide to install wetlands.
Wetland Research at the Rovey Dairy
The University of Arizona, USDA's Natural Resources Conservation Service and the Rovey Dairy in Glendale are working together on a constructed wetland project to treat the dairy's wastewater. The project serves three purposes, to equip an operating dairy with an improved wastewater treatment system, to enable the dairy industry and the regulatory community to evaluate an innovative treatment option and to provide researchers an opportunity to study the system. An ADWR augmentation grant funds the project, with ADEQ providing funds for water quality work.
Because of its size and complex operations, Rovey Dairy is an appropriate facility to host the project. Dairy farms are becoming large operations, both in Arizona and nationally. With 1,750 cows, the Rovey Dairy can be considered "high average." (The average Arizona dairy herd size is about 1000 cows.) Research results gained here will be applicable to similar operations.
Between 50,000 and 60,000 gallons of dairy wastewater is expected to enter the system each day. Recycling this water could represent a significant savings to the dairy. Uses of the treated wastewater, however, will depend upon its quality when it leaves the wetlands.
The project, by studying what is occurring within and under the wetland ponds, will enable researchers to better understand the workings of the treatment process and the variables affecting it. University of Arizona researchers are involved in the project from the departments of Soil, Water and Environmental Science, Agricultural and Bio-systems Engineering and Animal Sciences and the Office of Arid Land Studies
From the dairy, the wastewater, containing both solids and liquids, first goes to a solid separator. About 50 percent of the solids are separated out before the water flows to parallel anaerobic and aerobic ponds. The water then is routed to the constructed wetland ponds or cells for further treatment, to approximately secondary water quality standards.
The Rovey Dairy wetland system consists of eight ponds or cells, each 200 ft. by 40 ft., and arranged in two rows of four parallel cells. The tanks are alternately lined with either plastic or clay. Each pair of ponds contains a specific aquatic plant specie, either cattail, one of two types of bulrush, or giant reed.
Researchers can direct the waste-water to a single cell or a combination of cells to test water treatment effectiveness. Since there are two sets of wetland cells, one lined with clay and the other with plastic, and each set of cells is made up of four separate cells, each with different species of plant, an operator can direct the wastewater through varied treatment paths.
Research possibilities become even more numerous since waste-water, after passing through a particular treatment process (eg, a clay-lined pond with cattails), then can be mixed with water that passed through a different treatment process (eg, plastic-lined pond with bulrushes) and be tested or even treated with yet another treatment process (eg, clay-lined pond with reeds) before testing.
Along with determining the quality of water in the ponds, the researchers also are studying infiltration characteristics of the plastic or clay linings. Neutron probe access tubes are installed beneath the ponds, with three tubes under each row of four parallel ponds. The probes are in a horizontal pattern and transverse to the length of the pond. This allows water seepage to be determined along the length of the ponds, at different points in the treatment process.
When saturation or near-saturation points are detected beneath the wetlands, suction samplers will extract water samples to determine water quality. Researchers then will be able to better evaluate its suitability as incidental recharge. They also will determine where in the flow of the water maximum treatment is occurring and what residuals are coming out. Researchers also are interested whether the linings will self-seal as the interstitial pore spaces of the soils become clogged with organic material and microbial mass. This subsurface study is one of the more innovative components of the project.
濕地處理乳品廢水有幾個用於乳製品操作取決於其質量。 根據規定非飲用的水不能接觸到牛奶，擠奶過程，擠奶設備，擠奶廳或內部。 處理過的水，但是，可以用來清洗奶牛外的客廳或循環沖洗廢物。
另一種可能性是處理後的水補給。 這將需要處理的水，至少二級水質標準。 項目計劃現在請獲取一個試點充電許可證，允許經營一個小規模的充電設施。 使用處理後的水進行勾兌與灌溉水是另一種可能的選擇。
項目成果預計將適用於乳品業務在各個領域的西南。 研究人員還希望其他行業旁邊奶製品會從項目中受益，例如，食品加工業，它使用大量的水。 另外一個成功的濕地為一本日記操作會工作，為養豬業。
研究人員還認為這種模式可以成為亞利桑那州的濕地灌溉。 水用於灌溉現在返回系統中重用，與回流經常大量ladened各種成分，包括化學品的肥料。 水質可以得到明顯的改善，如果灌溉水治療之前，在濕地系統中重複使用。
與其他人工濕地，該 Rovey操作將作為教育設施。 它的目標受眾感興趣的人組成的廢水處理工藝 - 大學畢業的學生，顧問，業內人士等。
通過涉及範圍廣泛的利益 - 大學，政府和私營部門 - Rovey乳業項目是一個合作企業行使。 不同的利益是相互受益的合作。
構築生態系統 研究
皮馬縣的污水管理處表現出早期意識的重要性和潛在的人工濕地技術出資時，評估報告在80年代初。然後，它建立了建造生態系統研究基金（CERF）於 1989年，提供了研究和業務支持。
設計和建造作為試點規模的研究和示範設施，中央應急基金提供的研究人員來自亞利桑那大學的辦公室旱地的研究，以及各部門的土壤，水和環境科學，水文學及水資源，化學與環境工程，土木工程工程一個網站，以評估成效的人工濕地在乾旱氣候。
該工廠位於毗鄰皮馬縣的羅傑道污水處理廠和包括六個平行襯塑水道。 五水道測量 200英尺長，30英尺寬五英尺深，與第六稍大，更深。
實驗時首先關注中央應急基金主要採用浮動水生植物系統（FAP）。 這些系統依賴於浮動，而不是根植物處理廢水污染物在人工濕地。 冬季生存的能力和治療效果的水風信子和浮萍，兩個自由浮動的水草，進行了比較。 研究發現，浮萍更霜寬容，但水風信子更有效地處理廢水。
目前的研究是在中央應急基金的影響都比較飲用水和污水對各種本土和當地現有的植物，包括灌木和樹木。 污水似乎不影響原生植被，相反，它似乎刺激其生長。 研究人員還正在研究可能集中在一些濕地植物的材料去除廢水;是否為例，重金屬可能會最終在植物根部的葉子。
Recent CERF research is looking at pathogens in constructed wetlands. Researchers are monitoring indicator organisms such as total and fecal coliforms, viruses and pathogens such as giardia and cryptosporidium. The research is focusing on two questions. How do pathogens enter the system? Possibly wildlife attracted to many constructed wetlands is the source. CERF researchers also seek to answer the question: How effectively do constructed wetlands remove the pathogens from the wastewater?
CERF research also is concerned with increasing the list of plants for use in constructed wetlands. Constructed wetlands generally rely on a few "workhorse" species: bulrush, cattail and reeds. By collecting additional data, CERF researchers are studying the effectiveness of other types of plants such as cottonwoods and willows. CERF, in fact, has taken the lead in adapting trees to a constructed wetland system. The intent is to establish a more complex vegetative community at a constructed wetland site.
Because of its many research and teaching activities, CERF has been a model for much constructed wetland activity in Arizona. Many designers of constructed wetland facilities and engineers have visited CERF to learn about constructed wetland operations in an arid region.
(Tours of the CERF can be arranged by calling 520-293-2103.)
Constructed Wetlands in Arid Lands
Constructed wetlands offer special arid land benefits. In such areas, where an ethic of careful water use prevails, constructed wetlands, along with varied other water strategies, provide the means to more fully conserve and reuse water.
For example, the Sahuarita School District calculated water reuse benefits to be derived from a full-scale constructed wetland. During the school year, from September through May, the district produces a daily average of 51,000 gallons of wastewater. The wetlands could treat this wastewater to provide 21 acre-feet of treated water. With approximately 15 acres of turf to irrigate, using about 50 acre-feet of water per year, a full-scale wetland would supply about 40 percent of the district's turf water demand. Other rural school districts could similarly benefit from a constructed wetland.
Many large resorts in Arizona produce from 20,000 to 60,000 gallons of wastewater per day. Such resorts might achieve considerable water savings by reusing wastewater treated by a constructed wetlands to water vegetation and golf courses. The Flagstaff Arboretum's constructed wetland treats from 250 to 1,200 gallons per day depending upon the season. The water is used to irrigate vegetation. Producing a vastly greater amount of wastewater, resorts' water savings would be significant.
Not only do they help conserve water, but constructed wetlands allow "double-dipping." The same body of water, at the same time, is used for two different purposes, wastewater treatment and environmental enhancement. Another example of a double dipping is aquaculture using irrigation water in canals to grow fish. These examples may not represent water conservation per se. They are, however, arrangements to make a supply of water go further and as a result are a wise use of water. Using water wisely is a guiding principle for life in arid lands.
Constructed wetlands also serve arid lands in other ways. In wetter regions of the United States, a constructed wetland might be one body of water among many. In contrast, a constructed wetland in Arizona might be the single patch of blue in an otherwise arid landscape. Constructed wetlands therefore attract more attention in arid regions, with their water resource potential likely to be more fully explored and developed.
Developing Wetland 條例
With the increased use of constructed wetlands, government agencies are concerned with devising appropriate regulations, to protect public health and safety without unduly burdening constructed wetland designers and operators. To contribute to this effort, projects are underway to identify, at the state and federal levels, impediments or barriers to wetland construction.
At the state level, the process began when the Arizona Department of Environmental Quality published in 1995 the Arizona Guidance Manual for Constructed Wetlands for Water Quality Improvement. Funded by the US Environmental Protection Agency, the publication consolidated technical and design issues and described case studies of constructed wetlands projects in arid lands. ADEQ uses the manual when reviewing constructed wetland permit applications. The manual also provides engineers and scientists with information about the treatment potential of constructed wetlands.
ADEQ officials organized a workshop to discuss the use of the manual and to identify issues that inhibit wetland construction in Arizona. A Total Quality Improvement team was formed made up of ADEQ staff and others with constructed wetlands experience and expertise to address the concerns. TQI's mission statement was to recommend solutions to regulatory and technical issues related to constructed wetlands.
ADEQ believes the regulatory framework is in place, but some fine tuning is in order to accommodate constructed wetland situations. Part of the problem is that constructed wetlands basically are categorized as wastewater treatment facilities. As a result, both conventional and nonconventional treatment facilities fall under the same set of regulations. ADEQ recognizes the need for regulations that acknowledge some of the unique conditions of constructed wetlands.
For example, a regulatory issue addressed by the committee had to do with monitoring constructed wetlands. Exceedences that show up may be the result of natural processes occurring within the wetland system and may take weeks, even months to correct; whereas, such conditions in a conventional plant could be corrected in a matter of days, maybe hours.
A similar inquiry is taking place at the federal level. Funding from EPA's Environmental Technology Initiative Program is supporting a team of regulators and affected parties to identify, describe, and provide recommendations to resolve constructed wetlands policy and permitting issues at the federal level. Work on the report is in progress. For information about the project contact Bob Bashtian of EPA at 202-260-7378.
Prompted in part by issues arising at the 91st Avenue Wastewater Treatment Plant, the federal effort has an Arizona connection, although the scope of the report is national. Also some common ground is covered between the state and national committees since they share several members. As a result, some cross-fertilization resulted. Other than that, however, the two efforts are separate and distinct.
結論
The use of constructed wetlands to treat wastewater is relatively new. The impressive results achieved thus far have prompted great expectations about the technology and what it can achieve. Yet, as promising as the early work is, it is still early work, representing initial efforts to apply natural wetland processes to the varied and complex wastewater treatment needs arising from human activities.
In response to early enthusiasm, some researchers caution that constructed wetlands will not solve all water treatment problems. They point out that the full water quality possibilities--and limitations--of constructed wetlands are not fully known. Some express concern that the promotion of constructed wetlands may be outrunning the available knowledge and technology. More work needs to be done.
For example, researchers are studying plants for the remediation of radioactive contamination. Yet, much more research will be needed to determine whether plants can be used for this task and to what extent. Also the ability of plants to remove certain chemicals from wastewater still is being studied. Even whether wetland plants should be harvested needs further examination.
The available constructed wetlands information and knowledge is extensive compared to even five years ago, and the database is growing. As more projects are planned and further research conducted, the treatment possibilities of constructed wetlands will be better understood.
The writer thanks all the people and organizations contributing information to this newsletter, especially the following: Eric Ellman, Environmental Compliance International, Ltd. ; Tom Besett,John Carollo Engineers ; Bob Freitas, Martin Karpiscak, University of Arizona ; Marty Jakle, US Fish & Wildlife Service ; Paul Kinshella, City of Phoenix ; Bob Knight, CH2M Hill ; Peter Livingston, WestLand Resources ; Diane Losch, Marvin Murray, Joseph Smith, US Bureau of Reclamation ; Ralph Marra, Tucson Water ; Kris Randall, Arizona Department of Environmental Quality ; Roland Wass, 91st Ave. Wastewater Treatment Plant . The ideas and opinions expressed in the newsletter do not necessarily reflect the views of any of the above people or organizations.
