According to incomplete statistics, Guangzhou produces about 18,000 tons of garbage per day, with an average annual increase of about 7%. Guangzhou's goal is to achieve a 100% harmless treatment rate for household waste and a 50% resource utilization rate by 2015, and to achieve zero growth in daily household waste output by 2015, using 2010 as the baseline. To achieve these established goals, Guangzhou's waste treatment pressure is even greater than Beijing's. Guangzhou's main measures are to actively promote the resource utilization and incineration of household waste, and to achieve zero landfill of raw garbage by 2020.

It is reported that, like the problems encountered by Beijing and Guangzhou, many cities in China now face the "garbage siege" dilemma. Cities need to develop, and the inevitable consequence is the rapid growth of household waste. How can the "garbage siege" be broken?

Incineration Is the General Trend; Cement Kilns Emerge as a New Force

Cement kilns have relatively obvious advantages in disposing of solid waste and hazardous materials. For example, the temperature is higher, and materials remain in the high-temperature zone for about one hour, which can effectively avoid the formation of dioxins; an incinerator is a purely combustion environment, whereas the alkaline environment of a cement kiln is more conducive to decomposing many toxic and harmful substances; the oxygen control during cement kiln calcination is very strict, which helps reduce harmful substances in waste, such as reducing highly toxic hexavalent chromium ions to stable trivalent chromium.

As early as 10 years ago, Huaxin Cement began studying the development history of the cement industry in developed countries and exploring the feasibility of using cement kilns for collaborative waste disposal. Drawing on advanced foreign experience, it successfully developed waste pretreatment and cement kiln collaborative disposal technologies with independent intellectual property rights, and has built and operated the Wuxue household waste pretreatment plant, Huangshi municipal sludge pretreatment plant, Yichang municipal sludge pretreatment plant, Zigui waterborne floating debris pretreatment plant, Wuxue contaminated soil treatment plant, and Wuxue high-risk waste treatment platform.

The cement kiln collaborative household waste disposal technology has advantages such as a small footprint, no secondary pollution, and comprehensive utilization of waste resources. It is undoubtedly another encouraging attempt to break the garbage siege and realize the dream of "Beautiful China."

Emphasize Sorting and Pretreatment; Strengthen Quality Monitoring

Experts say that the issue people worry about most, the secondary air pollution caused by dioxins produced after waste incineration, can be greatly reduced by removing plastics and other chemical products before incineration and excluding food residues and other products that cannot be recycled and will not cause substantial environmental harm, thereby greatly reducing toxic gas emissions from incineration.

Japan is a country that does waste sorting relatively well. In fact, after the 1970s, Japan promoted small-scale waste incineration on a large scale nationwide, which led to serious exceedances of dioxin levels in the atmosphere. After learning its painful lesson, it began to change its approach. The number of waste incineration plants in Japan once accounted for 70% of the world's total, and 60% of municipal solid waste was treated by incineration. In the 1990s, dioxin levels in Japan's atmosphere were actually 10 times those of other industrialized countries. Having learned its bitter lesson, Japan moved the focus of waste treatment upstream, made waste reduction a priority, and strengthened emission controls. First, it promulgated the Special Measures Law on Dioxins, and dioxin emission limits were substantially raised. It then successively promulgated a series of laws related to waste reduction, starting from individuals and households, reducing waste at the source, and implementing waste sorting.

Huaxin Cement's ecological household waste treatment technology attaches great importance to waste sorting, waste pretreatment, and secondary pollution control technologies. The entire technical process plan includes waste pretreatment, waste gas purification, wastewater treatment, secondary fuel treatment, and inorganic residue treatment, and will control secondary pollution through technical means. It is reported that the household waste ecological treatment project to be built in Zhuhai will process 1,000 tons of garbage per day. First, waste sorting will be carried out at the waste pretreatment plant. Recyclable materials will be recycled; non-recyclable materials, after crushing, drying, and other processes, will become fuel and raw materials for the cement plant and be transported to the cement plant in Jiangmen, where they will be completely and cleanly treated in high-temperature incineration in a 1,500°C cement kiln. No pollution will be generated in Zhuhai.

It is understood that over the years, Huaxin Cement has gained much successful experience in waste treatment. In January 2010, Huaxin signed a household waste disposal cooperation agreement with the Wuxue Municipal People's Government and invested in the construction of a household waste pretreatment plant with a daily disposal capacity of 350 tons. As China's first waste disposal production line using pretreatment and cement kiln collaborative treatment technology, this model has been widely recognized by industry professionals for being the first of its kind in China and for its advanced technical advantages. Since it was put into operation in June 2011, by the end of 2012 it had disposed of more than 100,000 tons of household waste. It has received more than 600 visits and research tours from national ministries and commissions, provincial departments and municipal bureaus, and industry experts, becoming an external demonstration window for the company's environmental protection business.

To prove that cement kilns can safely and environmentally treat household waste collaboratively, Huaxin Cement regularly commissions qualified third-party institutions to conduct dioxin/furan emission tests at the main chimney of cement kilns that collaboratively treat hazardous waste. The test reports are submitted to environmental protection authorities at all levels and to customers.

Strengthen Policy Support; Realize the Beautiful Dream

In April 2011, led by the Ministry of Housing and Urban-Rural Development and coordinated with more than a dozen ministries and commissions including the Ministry of Environmental Protection and the National Development and Reform Commission, the Opinions on Further Strengthening Urban Household Waste Treatment Work was issued and approved by the State Council for distribution and implementation. For the first time, it clearly set out a national timetable for harmless treatment of urban household waste and proposed national targets for harmless treatment of urban household waste, namely that by 2015, the harmless treatment rate of urban household waste nationwide should reach more than 80%, and all household waste in municipalities directly under the central government, provincial capitals, and cities specifically designated in the state plan should be treated harmlessly. By 2030, urban household waste nationwide should basically achieve harmless treatment, and sorted collection and disposal of household waste should be fully implemented. Urban household waste treatment facilities and services should extend to small towns and villages, and urban and rural household waste treatment should approach the average level of developed countries.　

Heavy tasks and tight timelines are the difficulties before us. Using cement kiln collaborative disposal technology for urban household waste can both use waste as raw material and fuel to reduce resource consumption and fully leverage the advantages of the high-temperature combustion environment of the alkaline fine dense solid phase in cement rotary kilns to thoroughly dispose of harmful substances, truly achieving the diversified target requirements of "harmless, resource-based, and intensive" waste treatment. At the same time, it conforms to the national economic development requirements of adjusting structure, transforming the growth model, and ensuring growth, and guides China's cement industry onto a path of green, environmentally friendly, and sustainable development. Promoting cement kiln collaborative urban household waste disposal technology in cities where conditions permit is undoubtedly a feasible policy that benefits the country and the people and helps realize the Beautiful Chinese Dream.

In practice, cement enterprises also need to pay attention to waste moisture treatment, control of various interfering components, wastewater treatment, fly ash control, and other aspects to ensure cement production quality and waste treatment quality and to minimize environmental impact. At the government level, corresponding policies and supporting conditions should be formulated.

Relevant departments should vigorously encourage cement enterprises to actively use cement kilns for collaborative disposal of urban household waste, so as to promote the continuous improvement and widespread implementation of cement kiln collaborative urban household waste disposal technology.